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Conserved domains on  [gi|123847331|sp|Q3LZX1|]
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RecName: Full=Spike glycoprotein; Short=S glycoprotein; AltName: Full=E2; AltName: Full=Peplomer protein; Contains: RecName: Full=Spike protein S1; Contains: RecName: Full=Spike protein S2; Contains: RecName: Full=Spike protein S2'; Flags: Precursor

Protein Classification

Graphical summary

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List of domain hits

Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
516-1177 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


:

Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1410.13  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTDSVRDPQTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 595
Cdd:cd22378     1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  596 AIRADQLTPAWRVYSTGVNVFQTQAGCLIGAEHVNASYECDIPIGAGICASYHTASVLRSTGQKSIVAYTMSLGAENSIA 675
Cdd:cd22378    81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVSLLRSTSQKSIVAYTMSLGAENSIA 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  676 YANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVK 755
Cdd:cd22378   161 YSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVFAQVK 240
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  756 QMYKTPAIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLT 835
Cdd:cd22378   241 QMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLPPLLT 320
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  836 DEMVAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALG 915
Cdd:cd22378   321 DEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTSTALG 400
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  916 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 995
Cdd:cd22378   401 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 480
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  996 TKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 1075
Cdd:cd22378   481 TKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 560
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1076 RNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 1155
Cdd:cd22378   561 RNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 640
                         650       660
                  ....*....|....*....|..
gi 123847331 1156 NEVAKNLNESLIDLQELGKYEQ 1177
Cdd:cd22378   641 NEVAKNLNESLIDLQELGKYEQ 662
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
17-295 0e+00

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


:

Pssm-ID: 394950  Cd Length: 280  Bit Score: 545.39  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   17 EGCGIISRKPQPKMAQVSSSRRGVYYNDDIFRSDVLHLTQDYFLPFDSNLTQYFSLNVDSDRYTYFDNPILDFGDGVYFA 96
Cdd:cd21624     1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALGERKYYFDNPVLPFGDGVYFA 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   97 ATEKSNVIRGWIFGSSFDNTTQSAVIVNNSTHIIIRVCNFNLCKEPMYTVSR-GTQQNAWVYQSAFNCTYDRVEKSFQLD 175
Cdd:cd21624    81 ATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKpGTQTNSWIYSNAFNCTYEYVSQSFQLD 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  176 TTPKTGNFKDLREYVFKNRDGFLSVYQTYTAVNLPRGLPTGFSVLKPILKLPFGINITSYRVVMAMFSQTTSNFLPESAA 255
Cdd:cd21624   161 VSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQSNWTAGNAA 240
                         250       260       270       280
                  ....*....|....*....|....*....|....*....|
gi 123847331  256 YYVGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCTIK 295
Cdd:cd21624   241 YYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
SARS-CoV-like_Spike_S1_RBD cd21477
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
310-514 1.40e-147

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein and similar proteins; This subfamily contains the receptor-binding domain of the S1 subunit of coronavirus (CoV) spike (S) proteins from highly pathogenic human virus, severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), SARS coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV), and other SARS-like coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2 and SARS-CoV use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV, SARS-CoV-2, and most CoVs.


:

Pssm-ID: 394824  Cd Length: 205  Bit Score: 442.72  E-value: 1.40e-147
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  310 RVSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 389
Cdd:cd21477     1 RVSPTTEVVRFPNITNLCPFDKVFNATRFPSVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  390 TFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTGNYYYRSHRKTKLKPFERDLSSDDGNGVYTLSTYD 469
Cdd:cd21477    81 TFLIRGSEVRQVAPGQTGVIADYNYKLPDDFTGCVIAWNTAKQDNGNYYYRSHRKSKLKPFERDLSSDENSGVRTLSTYD 160
                         170       180       190       200
                  ....*....|....*....|....*....|....*....|....*
gi 123847331  470 FNPNVPVAYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 514
Cdd:cd21477   161 FNPTVPVGYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 205
CoV_S2_C pfam19214
Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich ...
1202-1241 2.30e-05

Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich intravirion region found at the C-terminus of coronavirus spike proteins (S). These cysteine residues are targets for palmitoylation, necessary for efficiently S incorporation into virions and S-mediated membrane fusions.


:

Pssm-ID: 465998  Cd Length: 42  Bit Score: 42.79  E-value: 2.30e-05
                           10        20        30        40
                   ....*....|....*....|....*....|....*....|..
gi 123847331  1202 LLCCMTSCCSCLKGaCSCGSCC-KFDE-DDSEPVLKGVKLHY 1241
Cdd:pfam19214    1 FCCCCTGCCGCCFG-CSCGGCCdSYDKrDDVYPAEVVEKVHV 41
 
Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
516-1177 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1410.13  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTDSVRDPQTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 595
Cdd:cd22378     1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  596 AIRADQLTPAWRVYSTGVNVFQTQAGCLIGAEHVNASYECDIPIGAGICASYHTASVLRSTGQKSIVAYTMSLGAENSIA 675
Cdd:cd22378    81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVSLLRSTSQKSIVAYTMSLGAENSIA 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  676 YANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVK 755
Cdd:cd22378   161 YSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVFAQVK 240
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  756 QMYKTPAIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLT 835
Cdd:cd22378   241 QMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLPPLLT 320
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  836 DEMVAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALG 915
Cdd:cd22378   321 DEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTSTALG 400
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  916 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 995
Cdd:cd22378   401 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 480
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  996 TKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 1075
Cdd:cd22378   481 TKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 560
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1076 RNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 1155
Cdd:cd22378   561 RNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 640
                         650       660
                  ....*....|....*....|..
gi 123847331 1156 NEVAKNLNESLIDLQELGKYEQ 1177
Cdd:cd22378   641 NEVAKNLNESLIDLQELGKYEQ 662
CoV_S2 pfam01601
Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic ...
679-1180 0e+00

Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic 'corona' after which the group is named. The Spike glycoprotein is translated as a large polypeptide that is subsequently cleaved to S1 pfam01600 and S2,. The S2 subunit normally contains multiple key components, including one or more fusion peptides (FP), a second proteolytic site (S2') and two conserved heptad repeats (HRs), driving membrane penetration and virus-cell fusion. The HRs can trimerize into a coiled-coil structure built of three HR1-HR2 helical hairpins presenting as a canonical six-helix bundle and drag the virus envelope and the host cell bilayer into close proximity, preparing for fusion to occur.


Pssm-ID: 460263  Cd Length: 502  Bit Score: 664.35  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   679 NSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVKQMY 758
Cdd:pfam01601    1 GNISIPTNFTISVQTEYIQTTSPKVSVDCAQYVCNGNERCLQLLVQYGSFCSTIEQALQGSARLEDVEVLSMLSISNRAL 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   759 KTPAIKDFGG-FNFSQILPDPskPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLTDE 837
Cdd:pfam01601   81 TLATISNFGSdFNFSSFLPCL--NSGRSAIEDLLFDKVVTSGLGTVDAYKKCTKGTSIADLVCAQYYNGIMVLPGVVDAE 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   838 MVAAYTAALVSGTATAGWTFGAGAalqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALGKL 917
Cdd:pfam01601  159 KMAMYTASLTGGMAFGGLTGAAAA---IPFALAVQARLNYLGLQTDVLQENQKILANAFNNAVGNITDGFTTTASALSKI 235
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   918 QDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATK 997
Cdd:pfam01601  236 QDVVNANAQALNQLTQQLSNNFGAISSSIQDIYSRLDQLEADAQVDRLINGRLAALNAFVTQQLTKASEVKASRQLAQQK 315
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   998 MSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGK-AYFPREGVFVSNGTS-WFITQ 1075
Cdd:pfam01601  316 VNECVKSQSSRYGFCGNGTHLFSLPQAAPNGIMFLHTVLVPTEYITVKATPGLCVNGTtGYAPRDGQFVLNNTSnWYITP 395
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  1076 RNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLgDISGINASVVNIQKEI--- 1152
Cdd:pfam01601  396 RNMYQPRPITGSDFVQISSCDVNFVNITNTKLPPLIPDYVDFNKELEDIYKNLNSTLPDL-DLDIFNATILNLTDEIkdl 474
                          490       500
                   ....*....|....*....|....*...
gi 123847331  1153 DRLNEVAKNLNESLIDLQELGKYEQYIK 1180
Cdd:pfam01601  475 ERLQELIDNLNQTLVDLEWLNRYETYIK 502
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
17-295 0e+00

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394950  Cd Length: 280  Bit Score: 545.39  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   17 EGCGIISRKPQPKMAQVSSSRRGVYYNDDIFRSDVLHLTQDYFLPFDSNLTQYFSLNVDSDRYTYFDNPILDFGDGVYFA 96
Cdd:cd21624     1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALGERKYYFDNPVLPFGDGVYFA 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   97 ATEKSNVIRGWIFGSSFDNTTQSAVIVNNSTHIIIRVCNFNLCKEPMYTVSR-GTQQNAWVYQSAFNCTYDRVEKSFQLD 175
Cdd:cd21624    81 ATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKpGTQTNSWIYSNAFNCTYEYVSQSFQLD 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  176 TTPKTGNFKDLREYVFKNRDGFLSVYQTYTAVNLPRGLPTGFSVLKPILKLPFGINITSYRVVMAMFSQTTSNFLPESAA 255
Cdd:cd21624   161 VSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQSNWTAGNAA 240
                         250       260       270       280
                  ....*....|....*....|....*....|....*....|
gi 123847331  256 YYVGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCTIK 295
Cdd:cd21624   241 YYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
SARS-CoV-like_Spike_S1_RBD cd21477
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
310-514 1.40e-147

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein and similar proteins; This subfamily contains the receptor-binding domain of the S1 subunit of coronavirus (CoV) spike (S) proteins from highly pathogenic human virus, severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), SARS coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV), and other SARS-like coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2 and SARS-CoV use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV, SARS-CoV-2, and most CoVs.


Pssm-ID: 394824  Cd Length: 205  Bit Score: 442.72  E-value: 1.40e-147
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  310 RVSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 389
Cdd:cd21477     1 RVSPTTEVVRFPNITNLCPFDKVFNATRFPSVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  390 TFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTGNYYYRSHRKTKLKPFERDLSSDDGNGVYTLSTYD 469
Cdd:cd21477    81 TFLIRGSEVRQVAPGQTGVIADYNYKLPDDFTGCVIAWNTAKQDNGNYYYRSHRKSKLKPFERDLSSDENSGVRTLSTYD 160
                         170       180       190       200
                  ....*....|....*....|....*....|....*....|....*
gi 123847331  470 FNPNVPVAYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 514
Cdd:cd21477   161 FNPTVPVGYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 205
bCoV_S1_N pfam16451
Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal ...
34-325 2.73e-85

Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal domain of the betacoronavirus-like trimeric spike glycoprotein. The distal S1 subunit of the coronavirus spike protein is responsible for receptor binding. S1 contains two domains; an N-terminal galectin-like domain (NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Either the S1 NTD or S1 RBD, or occasionally both, are involved in binding to host receptors. S1 NTD is located on the side of the spike trimer and mainly recognizes sugar receptors. For many betacoronaviruses (b-CoVs), for example mouse hepatitis virus (MHV), the RBD is located in the NTD. The structure of the MHV S1 NTD showed the same fold as human galectins (galactose-binding lectin), however it does not bind any sugar; instead, it binds to the carcinoembryonic antigen cell-adhesion molecule CEACAM1) through protein-protein interactions. All three CEACAM21a-binding sites in MHV spikes can be fully occupied by CEACAM1a. It has been shown that CEACAM1a binding to the MHV spike weakens the interactions between S1 and S2 and facilitates the proteolysis of the spike protein and dissociation of S1. The homologous bovine CoV (BCov) S1 NTD also possesses a galectin fold but binds to sialic acid-containing moieties on host cell membranes, as does the NTD of three other group A b-Covs, namely human CoV (HCoV) OC43, avian b-CoV, and infectious bronchitis virus (IBV). Despite the S1 NTD of human respiratory b-CoV HKU1 being highly homologous to the NTDs of MHV and bovine CoV, it does not bind to either sugar or human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and the RBD is found instead in the S1 RBD domain.


Pssm-ID: 465119  Cd Length: 296  Bit Score: 279.68  E-value: 2.73e-85
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331    34 SSSRRGVYY-NDDIFrSDVLHLTQDYFLPFDSNLTQYFSLNVDSDRYTYFDNPILDFGDGVYFAATEKSNVIRG------ 106
Cdd:pfam16451    2 VSKADGTYYlPDRVY-SNTTTLRQGLFPKQGDNVTNYVYSPAHHCGKRNFSTPFLPFGDGIFVHIGNASNATGGriisep 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   107 --WIFGSSFDNTTQSAVIVNNS--THIIIRVCNFNLCKEPMYTVSRG----TQQNAWVYQ-SAFNCTYDRVEkSFQLDTt 177
Cdd:pfam16451   81 paFVFGSTFGNTSHTLIIAPDScqTNLTILVCNFTLCANPVTACRWGagnyNANNSLVYFkNAINCTFNRTY-NITFDT- 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   178 pktgnfkDLREYVFKNRDGFLSVYQTYTavnlPRGLPTGFSVLKPILKLPFGINITSYRVVMAMFSqTTSNFLPESAAYY 257
Cdd:pfam16451  159 -------SLIYFGFKQQDGGFHIYYSYW----LPDLDSGPPTLFPFATLPLGINITYFQVIPSSIR-STQNCRRANAAYY 226
                          250       260       270       280       290       300
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 123847331   258 VGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCTIKNFNVDKGIYQTSNFRVSPTQEV-IRFPNITN 325
Cdd:pfam16451  227 VAPLKPSTFLLDFDVNGYITNAVDCSFDPLSELKCSTGSFEPDTGVYSTSSYRAQPVGSVyVRQPNVTC 295
bCoV_S1_RBD pfam09408
Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor ...
339-499 9.62e-39

Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor binding domain (S1 RBD) of the betacoronavirus spike glycoprotein. The spike glycoprotein is arranged in trimers on the surface of the viral membrane and is essential for viral entry. The spike protein is translated as a large polypeptide that is subsequently cleaved to the distal S1, responsible for receptor binding, and the membrane-anchored S2 responsible for membrane fusion. The coronavirus (SARS-CoV) S1 subunit is composed of two distinct domains: an N-terminal domain (S1 NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Each of these domains have been implicated in binding to host receptors. However, most coronaviruses are not known to utilize both the S1 NTD and S1 RBD for viral entry. SARS-CoV makes use of its S1 RBD to bind to the human angiotensin-converting enzyme 2 (ACE2) as its host receptor.


Pssm-ID: 462789  Cd Length: 156  Bit Score: 141.87  E-value: 9.62e-39
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   339 PNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADTFLIRSSEVRQVAPGETGVIADYNYKLPD 418
Cdd:pfam09408    1 PSPANWERKTFSNCNFDFSVLLSLLQVSSFKCYGVSPSKLADMCYGSVTIDYFAIPETHKSNLQPGSPGAISKYNYKLPD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   419 DFTGCVIAWNTAKHD----TGNYYYRSHRKTKLKPFERDLSSddgngvyTLSTYDFNPNVPVAYQAtrVVVLSFELLNAP 494
Cdd:pfam09408   81 DFYGCVLAFNVNANTnyafADNYPYRYIKPGQYQPCNSFVST-------VPNSPDGHYCTPSSFNG--VVVITLKPATGS 151

                   ....*
gi 123847331   495 ATVCG 499
Cdd:pfam09408  152 NLVCP 156
CoV_S2_C pfam19214
Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich ...
1202-1241 2.30e-05

Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich intravirion region found at the C-terminus of coronavirus spike proteins (S). These cysteine residues are targets for palmitoylation, necessary for efficiently S incorporation into virions and S-mediated membrane fusions.


Pssm-ID: 465998  Cd Length: 42  Bit Score: 42.79  E-value: 2.30e-05
                           10        20        30        40
                   ....*....|....*....|....*....|....*....|..
gi 123847331  1202 LLCCMTSCCSCLKGaCSCGSCC-KFDE-DDSEPVLKGVKLHY 1241
Cdd:pfam19214    1 FCCCCTGCCGCCFG-CSCGGCCdSYDKrDDVYPAEVVEKVHV 41
 
Name Accession Description Interval E-value
SARS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22378
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
516-1177 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from SARS-CoV-2 (COVID-19) and related betacoronaviruses in the B lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the sarbecovirus subgenus (B lineage), including highly pathogenic human CoVs such as Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS-CoV-2 (also known as a 2019 novel coronavirus or 2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related coronaviruses. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411965 [Multi-domain]  Cd Length: 662  Bit Score: 1410.13  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTDSVRDPQTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 595
Cdd:cd22378     1 FNGLTGTGVLTPSSKRFQPFQQFGRDVSDFTDSVRDPKTLEILDISPCSFGGVSVITPGTNASSEVAVLYQDVNCTDVPT 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  596 AIRADQLTPAWRVYSTGVNVFQTQAGCLIGAEHVNASYECDIPIGAGICASYHTASVLRSTGQKSIVAYTMSLGAENSIA 675
Cdd:cd22378    81 AIHADQLTPAWRVYSTGSNVFQTQAGCLIGAEHVNTSYECDIPIGAGICASYHTVSLLRSTSQKSIVAYTMSLGAENSIA 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  676 YANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVK 755
Cdd:cd22378   161 YSNNSIAIPTNFSISVTTEVMPVSMAKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALSGIAVEQDKNTQEVFAQVK 240
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  756 QMYKTPAIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLT 835
Cdd:cd22378   241 QMYKTPTIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDINARDLICAQKFNGLTVLPPLLT 320
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  836 DEMVAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALG 915
Cdd:cd22378   321 DEMIAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKQIANQFNKAISQIQESLTTTSTALG 400
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  916 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 995
Cdd:cd22378   401 KLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAA 480
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  996 TKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 1075
Cdd:cd22378   481 TKMSECVLGQSKRVDFCGKGYHLMSFPQAAPHGVVFLHVTYVPSQERNFTTAPAICHEGKAYFPREGVFVSNGTSWFITQ 560
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1076 RNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 1155
Cdd:cd22378   561 RNFYSPQIITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRL 640
                         650       660
                  ....*....|....*....|..
gi 123847331 1156 NEVAKNLNESLIDLQELGKYEQ 1177
Cdd:cd22378   641 NEVAKNLNESLIDLQELGKYEQ 662
betaCoV_Spike_SD1-2_S1-S2_S2 cd22370
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
516-1172 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses; This family contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses, including three highly pathogenic human coronaviruses (CoVs), Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411957 [Multi-domain]  Cd Length: 667  Bit Score: 1052.46  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTDSVRDPQTLEILDISPCSFGGVSVITPGTNaSSEVAVLYQDVNCTDVPT 595
Cdd:cd22370     1 LYGYTGTGVLTETNATFLPFQNFGYDSNGNLIAFKDPQTNTIYTILPCVSGPVSVITPGNN-TNEVAVLYNGLNCSEVPS 79
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  596 AIRADQLTPAWRVYSTGVNVFQTQAGCLIGAE-HVNASYECDIPIGAGICASYHTASVL--RSTGQKSIVAYTMSLGAEN 672
Cdd:cd22370    80 AISAVSLTPWWRVYSSTSNYFDTPVGCLLGAVnSSNNSYECDLPLGAGLCASYTTQSVLrsRSVASRSIRLTTMSFFAEN 159
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  673 ----SIAYANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQ 748
Cdd:cd22370   160 svdvEVAYSNFSIQIPTNFTIAVTEEFIPTTMPKVTVDCAQYVCGDSSECSNLLLQYGTFCDNINRALTGVALLQDKNQL 239
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  749 EVFAQVKQMYKTPA-IKDFGGFNFSQILPDPS---KPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKF 824
Cdd:cd22370   240 EVFASVKQIVKTPApLKDFGGFNFSSLLPCLGsngGSSARSAIEDLLFNKVTLADVGFMKQYDDCTGGSAARDLICAQSF 319
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  825 NGLTVLPPLLTDEMVAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQ 904
Cdd:cd22370   320 NGLKVLPPLLTDEMIAAYTSALLGGTATSGWTFGASSAAQIPFAMQMAYRFNGIGVTQQVLVENQKLIANKFNQALGSIQ 399
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  905 ESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRA 984
Cdd:cd22370   400 TGFTATNSALAKLQDVVNQNAQALNTLVKQLSNNFGAISSSLNDILSRLDKLEADVQIDRLINGRLQVLQTYVTQQLIRA 479
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  985 AEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFPREGVF 1064
Cdd:cd22370   480 SEIRASAQLAAQKMSECVKGQSKRVDFCGNGTHLMSFPQSAPNGVVFLHVTYKPTSYKNVTTAPAICHNGKAYFPKEGVF 559
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1065 VSNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINAS 1144
Cdd:cd22370   560 VKNNNSWMFTGRNFYEPEIITTDNTFYSGSCDVNFTYVNNTVYNPLQPELDDFKAELDKFFKNHTSPDPNLGDLSGINAS 639
                         650       660
                  ....*....|....*....|....*...
gi 123847331 1145 VVNIQKEIDRLNEVAKNLNESLIDLQEL 1172
Cdd:cd22370   640 FVDLQKEMDTLQEVVKQLNESLIDLKEL 667
CoV_Spike_S1-S2_S2 cd21698
S1/S2 cleavage region and the S2 fusion subunit of coronavirus spike (S) proteins; This model ...
640-1172 0e+00

S1/S2 cleavage region and the S2 fusion subunit of coronavirus spike (S) proteins; This model represents the S1/S2 cleavage region and the S2 subunit of the spike (S) glycoprotein from coronavirus (CoVs), including three highly pathogenic human CoVs, Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect S1 and S2. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV, and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP), and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. Notably, SARS-CoV-2 has a functional polybasic (furin) cleavage site through the insertion of PRRAR*SV (* indicates the cleavage site) at the S1/S2 interface, which is absent in SARS-CoV and other SARS-related CoVs. The S1/S2 cleavage region and the S2 fusion subunit play an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411955 [Multi-domain]  Cd Length: 523  Bit Score: 732.30  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  640 GAGICASYhtasvlrstgqkSIVAYTMSLGAENS---IAYANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSL 716
Cdd:cd21698     1 YGGICICY------------DGAIYTVSTGQEESpsiVAISTENIAIPSNFTLSVTTEYLQVTMTKVSVDCTTYVCGGSP 68
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  717 ECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVKQMYKTPAIKDFGGFNFSQILPDPSKPTKRSFIEDLLFNKVT 796
Cdd:cd21698    69 RCKNLLLQYGSACDTIEQALRGIAVLEDSEVSNMFSTSKQALKLAIIKSFGGFNFSQILPTPSRPSGRSAIEDLLFTKVV 148
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  797 LADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGwtfgAGAALQIPFAMQMAYRFN 876
Cdd:cd21698   149 TAGLGTVDQYKNCTKGIAIADLACAQYYNGIMVLPPVADAEKMAMYTGSLTAGMVFGG----ITAAAAIPFSLAMQARLN 224
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  877 GIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKV 956
Cdd:cd21698   225 YVGLQQNVLLENQKLLANSFNKAIGNISDAFSSTSSALQKIQDVVNQQAQALNTLTSQLSNNFGAISSSIQDIYQRLDKL 304
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  957 EAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTY 1036
Cdd:cd21698   305 EADVQVDRLITGRLAALNAFVTQQLIKAAEVRQSRRLAQQKINECVKSQSSRYGFCGNGTHLFSIPQSAPSGIVFLHTVL 384
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1037 VPSQEKNFTTAPAICHEGKAYFPRE--GVFVSNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTV-YDPLQPE 1113
Cdd:cd21698   385 VPTSYKNVTAYPGICVDGKAGSPLEgpLVFIQNNNHWFVTPRNMYEPRIITTADFVQITSCDANVTIVNNTVnLDPVIPD 464
                         490       500       510       520       530       540
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 123847331 1114 LDSFKEELDKYF---KNHTSPDVDLGdisGINASVVNIQKEIDRLNEVAKNLNESLIDLQEL 1172
Cdd:cd21698   465 YVDVNEELDDYIqnlPNHTLPDLDLS---GYNATILNISSEIDRLNEVAKNLNQSVVELQEY 523
CoV_S2 pfam01601
Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic ...
679-1180 0e+00

Coronavirus spike glycoprotein S2; The coronavirus spike glycoprotein forms the characteriztic 'corona' after which the group is named. The Spike glycoprotein is translated as a large polypeptide that is subsequently cleaved to S1 pfam01600 and S2,. The S2 subunit normally contains multiple key components, including one or more fusion peptides (FP), a second proteolytic site (S2') and two conserved heptad repeats (HRs), driving membrane penetration and virus-cell fusion. The HRs can trimerize into a coiled-coil structure built of three HR1-HR2 helical hairpins presenting as a canonical six-helix bundle and drag the virus envelope and the host cell bilayer into close proximity, preparing for fusion to occur.


Pssm-ID: 460263  Cd Length: 502  Bit Score: 664.35  E-value: 0e+00
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   679 NSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVKQMY 758
Cdd:pfam01601    1 GNISIPTNFTISVQTEYIQTTSPKVSVDCAQYVCNGNERCLQLLVQYGSFCSTIEQALQGSARLEDVEVLSMLSISNRAL 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   759 KTPAIKDFGG-FNFSQILPDPskPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARDLICAQKFNGLTVLPPLLTDE 837
Cdd:pfam01601   81 TLATISNFGSdFNFSSFLPCL--NSGRSAIEDLLFDKVVTSGLGTVDAYKKCTKGTSIADLVCAQYYNGIMVLPGVVDAE 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   838 MVAAYTAALVSGTATAGWTFGAGAalqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALGKL 917
Cdd:pfam01601  159 KMAMYTASLTGGMAFGGLTGAAAA---IPFALAVQARLNYLGLQTDVLQENQKILANAFNNAVGNITDGFTTTASALSKI 235
                          250       260       270       280       290       300       310       320
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   918 QDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATK 997
Cdd:pfam01601  236 QDVVNANAQALNQLTQQLSNNFGAISSSIQDIYSRLDQLEADAQVDRLINGRLAALNAFVTQQLTKASEVKASRQLAQQK 315
                          330       340       350       360       370       380       390       400
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   998 MSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGK-AYFPREGVFVSNGTS-WFITQ 1075
Cdd:pfam01601  316 VNECVKSQSSRYGFCGNGTHLFSLPQAAPNGIMFLHTVLVPTEYITVKATPGLCVNGTtGYAPRDGQFVLNNTSnWYITP 395
                          410       420       430       440       450       460       470       480
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  1076 RNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLgDISGINASVVNIQKEI--- 1152
Cdd:pfam01601  396 RNMYQPRPITGSDFVQISSCDVNFVNITNTKLPPLIPDYVDFNKELEDIYKNLNSTLPDL-DLDIFNATILNLTDEIkdl 474
                          490       500
                   ....*....|....*....|....*...
gi 123847331  1153 DRLNEVAKNLNESLIDLQELGKYEQYIK 1180
Cdd:pfam01601  475 ERLQELIDNLNQTLVDLEWLNRYETYIK 502
bat-HKU9-CoV-like_Spike_SD1-2_S1-S2_S2 cd22381
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
516-1235 0e+00

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Rousettus bat coronavirus HKU9 and related betacoronaviruses in the D lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the nobecovirus subgenus (D lineage), including Rousettus bat coronavirus HKU9 (Ro-BatCoV HKU9). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411968 [Multi-domain]  Cd Length: 731  Bit Score: 619.46  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTDSVRDPQTleILDISPCSFGGVSVitpGTNASSEVAVLYQDVNCTDVPT 595
Cdd:cd22381     1 LYGYTGTGVLSTSNLTIPDSKVFSASSTGDIIAVSVNGT--VYSISPCVSVPISV---GYDPGFERALLFNGLSCSERAR 75
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  596 AIrADQLTPAWR--VYSTGVNVFQTQAGCLIGAEHVNASY--ECDIPIGAGICASYHTASVLRSTGQK--SIVAYTMSLG 669
Cdd:cd22381    76 AV-SEPASDYWRasVSDGANNTFDTPSGCVYNVINRTTITvnQCSMPLGNSLCLVNNTTAVSARGSLSllSLVTYDPLYD 154
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  670 AENSIAYANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQE 749
Cdd:cd22381   155 SSVTPLTPVYWVSIPTNFTLAATTEYIQTTAPKINIDCAKYLCGDSSRCLTVLLQYGTFCDDVNKALARVSTILDASLVS 234
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  750 VFAQVKQMYKTPAIKDFGG-FNFSQIL----PDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCL-----GDVsaRDLI 819
Cdd:cd22381   235 LVSELTSDVVRSENLAFDGdYNFTGLMgclgSNCNSKSYRSALSDLLYNKVKVADPGFMQSYQKCIdsqwgGNI--RDLI 312
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  820 CAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSA 899
Cdd:cd22381   313 CTQTFNGISVLPPIVSPGMQALYTSLLVGAVASSGYTFGITSVGVIPFATQLQFRLNGLGVTTQVLVENQKLIANSFNKA 392
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  900 IGKIQESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQ 979
Cdd:cd22381   393 LVSIQKGFDATNQALSKMQTVINQHAQQLQTLVQQLGNSFGAISSSINEIFSRLDGLEANAEVDRLINGRMVVLNTYVTQ 472
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  980 QLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFP 1059
Cdd:cd22381   473 LLIQASEVRAQAALAKQKISECVKAQSLRNDFCGNGTHVLSIPQLAPNGVLFIHYSYQPTAYALVQTAAGLCFNGTGYAP 552
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1060 REGVFV--SNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGD 1137
Cdd:cd22381   553 RGGLFVlpNNSNLWHFTKMNFYNPVNISYSNTQVLTSCSVNYTTVNYTVLNPSEPSDFNFQEEFDKWYKNQSSQFNNTFN 632
                         650       660       670       680       690       700       710       720
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1138 ISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYVWLGFIAGLIAIVMVTILLCCMTSCCSCLKGAC 1217
Cdd:cd22381   633 PSDFNFSTVDVNEQLATLTDVVKQLNESFIDLKKLNVYEQTIKWPWYVWLAMIAGLVGLALAVVMLLCMTNCCSCFKGMC 712
                         730
                  ....*....|....*...
gi 123847331 1218 SCGSCCKFDEDDSEPVLK 1235
Cdd:cd22381   713 SCKQCQYDEVEDVYPAVR 730
SARS-CoV-like_Spike_S1_NTD cd21624
N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory ...
17-295 0e+00

N-terminal domain of the S1 subunit of the Spike (S) protein from Severe acute respiratory syndrome coronavirus and related betacoronaviruses in the B lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the sarbecovirus subgenera (B lineage), including the highly pathogenic human coronavirus (CoV), Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2 and SARS-CoV, use the C-domain to bind their receptors. The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394950  Cd Length: 280  Bit Score: 545.39  E-value: 0e+00
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   17 EGCGIISRKPQPKMAQVSSSRRGVYYNDDIFRSDVLHLTQDYFLPFDSNLTQYFSLNVDSDRYTYFDNPILDFGDGVYFA 96
Cdd:cd21624     1 EGCTTFSDKTAPNMTQYSSSRRGVYYPDDIFRSDVLVLTQDYFLPFNSNVTWYHSLNALGERKYYFDNPVLPFGDGVYFA 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   97 ATEKSNVIRGWIFGSSFDNTTQSAVIVNNSTHIIIRVCNFNLCKEPMYTVSR-GTQQNAWVYQSAFNCTYDRVEKSFQLD 175
Cdd:cd21624    81 ATEKSNVVRGWIFGSTFDNTSQSAIIVNNGTHIIIRVCNFQLCKNPMFAVSKpGTQTNSWIYSNAFNCTYEYVSQSFQLD 160
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  176 TTPKTGNFKDLREYVFKNRDGFLSVYQTYTAVNLPRGLPTGFSVLKPILKLPFGINITSYRVVMAMFSQTTSNFLPESAA 255
Cdd:cd21624   161 VSEKNGNFKHLREFVFKNVDGFLKVYHGYQPINVVRGLPSGFSVLKPIFKLPLGINITNFRVVLTMFSPAQSNWTAGNAA 240
                         250       260       270       280
                  ....*....|....*....|....*....|....*....|
gi 123847331  256 YYVGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCTIK 295
Cdd:cd21624   241 YYVGYLKPTTFMLKFDENGTITDAVDCSQDPLAELKCTLK 280
MERS-CoV-like_Spike_SD1-2_S1-S2_S2 cd22379
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
560-1180 3.58e-166

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Middle East respiratory syndrome coronavirus and related betacoronaviruses in the C lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the merbecovirus subgenus (C lineage), including Middle East respiratory syndrome coronavirus (MERS-CoV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411966 [Multi-domain]  Cd Length: 682  Bit Score: 510.11  E-value: 3.58e-166
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  560 ISPCSFGGVSVITpgTNASSEVAVLYQDVNCTDVPT-AIRADQLTPAWRVYSTGVNVFQTQAGCLIGAehVNASY---EC 635
Cdd:cd22379    44 VRPCVSVPVSVIY--DKSTNTHATLFGSVACEHISTmMSQFSRSTQSMLRRRSTNGPLQTAVGCVIGL--VNTSLtveDC 119
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  636 DIPIGAGICASYHTASVLRSTGQKSIVAYTMSLGAENSIAYANNS---IAIPTNFSISVTTEVMPVSMAKTAVDCTMYIC 712
Cdd:cd22379   120 KLPLGQSLCAVPPTLTPRSVSSVPGEQLASINFNHPLQVDQLNSSgfkVSIPTNFSFGVTQEYIQTTIQKVTVDCKQYVC 199
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  713 GDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVKQMYKTPAIKDFGG-FNFSqILPDPSKPT----KRSFI 787
Cdd:cd22379   200 NGFEKCEQLLREYGQFCSKINQALHGANLRQDDSVRNLFASIKTSQSQPLIAGLGGdFNLT-LLEPPSISTgsrsYRSAI 278
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  788 EDLLFNKVTLADAGFMKQYGDCL--GDVSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTFGAGAALQI 865
Cdd:cd22379   279 EDLLFDKVTIADPGYMQGYDECMkqGPPSARDLICAQYVAGYKVLPPLYDVNMEAAYTSSLLGSIAGAGWTAGLSSFAAI 358
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  866 PFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSV 945
Cdd:cd22379   359 PFAQSIFYRLNGVGITQQVLSENQKLIANKFNQALGAMQTGFTTTNLAFQKVQDAVNANAQALSKLASELSNTFGAISSS 438
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  946 LNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSA 1025
Cdd:cd22379   439 IGDILKRLDVLEQEAQIDRLINGRLTSLNAFVAQQLVRSETAARSAQLAKDKVNECVKSQSKRNGFCGQGTHIVSFVINA 518
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1026 PHGVVFLHVTYVPSQEKNFTTAPAICHEG---KAYFPREGVFVSNGT-----SWFITQRNFYSPQLITTDNT-FVSGncD 1096
Cdd:cd22379   519 PNGLYFFHVGYVPTNHVNVTAAYGLCDSAnptNCIAPVNGYFIKNNTtrivdEWSYTGSSFYAPEPITSANTrYVSP--D 596
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1097 VVIGIINNTVYDPL---QPELDsFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELG 1173
Cdd:cd22379   597 VTFQNLSNNLPPPLlsnSTDID-FKDELEEFFKNVSSQIPNFGSISQINTTLLDLSDEMLSLQQVVKALNESYIDLKELG 675

                  ....*..
gi 123847331 1174 KYEQYIK 1180
Cdd:cd22379   676 NYTYYQK 682
HKU1-CoV-like_Spike_SD1-2_S1-S2_S2 cd22380
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
518-1172 5.57e-148

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from human HKU1 and OC43 coronaviruses and related betacoronaviruses in the A lineage; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from betacoronaviruses in the embecovirus subgenus (A lineage), including highly pathogenic human coronaviruses (CoVs), HKU1 and OC43 CoVs, as well as murine hepatitis virus (MHV). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of MHV is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411967 [Multi-domain]  Cd Length: 663  Bit Score: 461.55  E-value: 5.57e-148
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  518 GLKGTGVLTS-SSKRFQSFQQFGRDTSDFTDSVRDPQTLEILDISPCSFGGVSVITpgTNASSEVAVLYQDVNCTDVPTA 596
Cdd:cd22380     3 GITGQGIFKEvNADYYNSWQNLLYDSNGNLYGFRDYLTNKTYMIRSCYSGRVSAAF--HANASEPALLYRNLKCSYVFNN 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  597 IRADQLTPawrvystgVNVFQTQAGCLIGAEHVNASY--ECDIPIGAGICASYHTASVLR---STGQK--SIVAYTMSLg 669
Cdd:cd22380    81 TISREEQP--------LNYFDSYLGCVVNADNSTSSAvqTCDLRMGSGYCVDYSTSRRSRrsiSTGYRftTFEPFTVNL- 151
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  670 AENSIAYANN--SIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNT 747
Cdd:cd22380   152 VNDSVEPVGGlyEIQIPTNFTIGNHEEFIQTSSPKVTIDCAAFVCGDYAACRQQLVEYGSFCDNINAILNEVNELLDTTQ 231
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  748 QEVFAQVKQ------MYKTPAIKDFGGFNFSQIL----PDPSKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDVSARD 817
Cdd:cd22380   232 LQVANSLMQgvtlssRLKDGINFNVDDINFSPVLgclgSDCNAASSRSAIEDLLFDKVKLSDVGFVEAYNNCTGGAEIRD 311
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  818 LICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTFGAGaalqIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFN 897
Cdd:cd22380   312 LLCVQSFNGIKVLPPVLSENQISGYTTAATAASLFPPWSAAAG----VPFSLNVQYRINGLGVTMDVLSQNQKLIANAFN 387
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  898 SAIGKIQESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYV 977
Cdd:cd22380   388 NALGAIQEGFDATNSALAKIQSVVNANAEALNNLLQQLSNRFGAISASLQEILSRLDALEAQAQIDRLINGRLTALNAYV 467
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  978 TQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEG-KA 1056
Cdd:cd22380   468 SQQLSDSTLVKFSAAQAIEKVNECVKSQSPRINFCGNGNHILSLVQNAPYGLYFIHFSYVPTSFVTAKVSPGLCIAGdRG 547
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1057 YFPREGVFVSNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVIG-----IINNTVydplqPELDSFKEELDKYFKNHTSP 1131
Cdd:cd22380   548 IAPKSGYFVNVNNEWMFTGSGYYYPEPITDKNVVVMSSCAVNYTkapdvMLNTSI-----PNLPDFKEELDQWFKNQTSV 622
                         650       660       670       680
                  ....*....|....*....|....*....|....*....|.
gi 123847331 1132 DVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQEL 1172
Cdd:cd22380   623 APDLSLDEYINVTFLDLQDEMNRIQEAIKVLNESYINLKEI 663
SARS-CoV-like_Spike_S1_RBD cd21477
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
310-514 1.40e-147

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein and similar proteins; This subfamily contains the receptor-binding domain of the S1 subunit of coronavirus (CoV) spike (S) proteins from highly pathogenic human virus, severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), SARS coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV), and other SARS-like coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2 and SARS-CoV use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV, SARS-CoV-2, and most CoVs.


Pssm-ID: 394824  Cd Length: 205  Bit Score: 442.72  E-value: 1.40e-147
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  310 RVSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 389
Cdd:cd21477     1 RVSPTTEVVRFPNITNLCPFDKVFNATRFPSVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  390 TFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTGNYYYRSHRKTKLKPFERDLSSDDGNGVYTLSTYD 469
Cdd:cd21477    81 TFLIRGSEVRQVAPGQTGVIADYNYKLPDDFTGCVIAWNTAKQDNGNYYYRSHRKSKLKPFERDLSSDENSGVRTLSTYD 160
                         170       180       190       200
                  ....*....|....*....|....*....|....*....|....*
gi 123847331  470 FNPNVPVAYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 514
Cdd:cd21477   161 FNPTVPVGYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 205
alphaCoV-HKU2-like_Spike_SD1-2_S1-S2_S2 cd22371
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the CoV ...
516-1223 7.85e-145

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the CoV spike (S) glycoprotein from Rhinolophus bat coronavirus HKU2 and related alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Wencheng shrew coronavirus (WESV), Lucheng Rn rat coronavirus (LRNV), and two bat viruses (Rhinolophus bat coronavirus HKU2 and BtRf-AlphaCoV/YN2012). Members of this group form a distinct cluster that is separated from the other alphacoronaviruses. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411958 [Multi-domain]  Cd Length: 686  Bit Score: 454.25  E-value: 7.85e-145
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  516 FNGLKGTGVLTSSSKRFQSFQqfgrDTSDFTDSVRDPQTLEIL-DISPCSFGGVSVITpgtNASSEVAVLYQDVNC--TD 592
Cdd:cd22371     1 IDGVTFQGILYETNFTFDSFY----NLLYKGSMVKYVRILGVVyEVEPCNEFSYSVLK---NNSSSYGTLYSGADCnqID 73
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  593 VPTAIRADQLTpawrvysTGVNvfqTQAGCLIGAEHVN-ASYECDIPIGAGICASYHTAS--VLRSTGQKSIVAYTMSLG 669
Cdd:cd22371    74 TKTFRFKARSH-------TGTN---TSLGCLFNASYTNdTYTTCLNPLGNGFCADVNVTSpvVGNIGIQKHDTDYVRPIL 143
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  670 AENSIAyannsiaIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQE 749
Cdd:cd22371   144 TEQFIE-------LPLDHQLVVKEQFLQTSMPKFDVDCERYICDVSKACRELLFKYGGFCSKITADIKGSSILLDSQILG 216
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  750 VFAQVKQMYKTPAIkDFGGFNFSQILPdpsKPTKRSFIEDLLFNKVTLADAGFMKQYGDCLGDvSARDLICAQKFNGLTV 829
Cdd:cd22371   217 LYKTIAVDFSSPDV-DFGDFNFSMFMS---EKNGRSFIEDLLFDKIVTTGPGFYQDYYDCKKM-NLQDLTCAQYYNGIMV 291
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  830 LPPLLTDEMVAAYTAAlVSGTATAGwTFGaGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQESLSS 909
Cdd:cd22371   292 IPPIMDDETIGMYGGI-VAASMTAG-LFG-GQAGMVTWNTAMAGRLNALGVTQDALVEDVNKLANGFNNLTQSVSKLAKT 368
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  910 TASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRA 989
Cdd:cd22371   369 TSQALSAIQAVVNQNAAQVEQLVQGLSENFGAISNNFEVIAERLEKLEADQQMDRLINGRMNVLQNFVTNYKLKISELKS 448
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  990 SANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYFP----REGVFV 1065
Cdd:cd22371   449 TQRLVQSLINECVYAQSLRNGFCGDGLHVMSLMQNAPDGIMFFHYTLKPNNTIIVKTTPGLCLSNEVCIKpidaKFGVLV 528
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1066 S-NGTSWFITQRNFYSPQLITTDNTfVSGNCDVVIGIINNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISgINAS 1144
Cdd:cd22371   529 SaNDSYWHFTPRNIYNPENITNSNI-IAVSGGANYTTVNNTIDIIEPPQNPPIDEEFRELYKNVTLELEQLKNIT-FDMS 606
                         650       660       670       680       690       700       710       720
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1145 VVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYVWLGFIAGLIAIVMVTILLCCMTSCCSCLkGAC--SCGSC 1222
Cdd:cd22371   607 KLNLTYEIDRLNEIAENVSKLHVTVSEFNKYVQYVKWPWYVWLAIFLVLILFSFLMLWCCCATGCCGCC-GCCgaACNSC 685

                  .
gi 123847331 1223 C 1223
Cdd:cd22371   686 C 686
gammaCoV_Spike_SD1-2_S1-S2_S2 cd22372
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
509-1172 1.90e-142

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from avian infectious bronchitis coronavirus (IBV) and related gammacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from gammacoronaviruses, including avian infectious bronchitis virus, and Beluga whale coronavirus SW1 (whale-CoV SW1). The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411959 [Multi-domain]  Cd Length: 661  Bit Score: 447.13  E-value: 1.90e-142
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  509 NQCVNFNFNGLKGTGVLTssskrfqsfqqfgrdtsDFTDSVRDPQTLE-----ILDISpcsfGGVSVItpgtNASSEVAV 583
Cdd:cd22372     7 NKCVDYNIYGRVGQGFIT-----------------NVTDSAADYNYLAdgglaILDTS----GAIDIF----VVQGEYGL 61
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  584 LYQDVN-CTDVPTairadQLtpawrVYSTGVNVfqtqaGCLI-----GAEHVNASYECDIPIGAGICASYHTASV----L 653
Cdd:cd22372    62 NYYKVNpCEDVNQ-----QF-----VVSGGNLV-----GILTsrnetGSQLLENQFYIKLTNGTRRRRRSISENVtscpY 126
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  654 RSTGQKSI-----VAYTMSLGAENSIAYANN---SIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQY 725
Cdd:cd22372   127 VSYGKFCIkpdgsISTIVPQELETFVAPLLNvteNVLIPNSFNLTVTDEYIQTRMDKVQINCLQYVCGNSLECRKLFQQY 206
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  726 GSFCTQLNRALTGIAIEQDKNTQEVFAQVKQM-YKTPAIKDF--GGFNFSQILPDPSKPTKRSFIEDLLFNKVTLADAGF 802
Cdd:cd22372   207 GPVCDNILSIVNSVNQKEDMELLSFYSSTKPGgFNTPVFNNVstGGFNISLLLPPPSSPQGRSFIEDLLFTKVETVGLPT 286
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  803 MKQYGDCLGD--VSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTfGAGAalqIPFAMQMAYRFNGIGV 880
Cdd:cd22372   287 DDAYKKCTAGplGFLKDLVCAQEYNGLLVLPPIITAEMQTMYTGSLVASMAFGGIT-AAGA---IPFATQIQARINHLGI 362
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  881 TQNVLYENQKLIANQFNSAIGKIQESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEV 960
Cdd:cd22372   363 TQSLLLKNQEKIAASFNKAIGHMQEGFRSTSLALQQIQDVVNKQSAILTETMASLNKNFGAISSVIQDIYQQLDAIQADA 442
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  961 QIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQ 1040
Cdd:cd22372   443 QVDRLITGRLSSLSVLASAKQAEYYKVSQQRELATQKINECVKSQSNRYGFCGNGRHVLTIPQNAPNGIVFIHFTYTPES 522
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1041 EKNFTTAPAICHEGK-----AYFPR--EGVFVS-NGTsWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPL-Q 1111
Cdd:cd22372   523 FVNVTAIVGFCVNPAngsqyAIVPAngRGIFIQvNGT-YYITARDMYMPRDITAGDIVTLTSCQANYVSVNKTVITTFvD 601
                         650       660       670       680       690       700
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 123847331 1112 PELDSFKEELDKYFkNHTSPdvDLGDISGINASVV--NIQKEIDRLNEVAKNLNESLIDLQEL 1172
Cdd:cd22372   602 NDDFDFDDELSKWW-NETKH--ELPDFDQFNYTIPilNISNEIDRIQEVIQGLNDSLIDLETL 661
delta-PiCoV-like_Spike_SD1-2_S1-S2_S2 cd22374
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
509-1222 1.96e-119

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Pigeon coronavirus UAE-HKU29, and related avian deltacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Pigeon coronavirus UAE-HKU29, and related avian deltacoronaviruses including Falcon coronavirus UAE-HKU27, Magpie-robin coronavirus HKU18, Sparrow coronavirus HKU17, and Night heron coronavirus HKU19. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the (C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411961 [Multi-domain]  Cd Length: 739  Bit Score: 388.09  E-value: 1.96e-119
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  509 NQCVNFNFNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTdSVRDPQTLEILDISPCSFggvsvitpgtnaSSEVAVLYQDV 588
Cdd:cd22374    26 DVCTKYNIYGKTGTGIIRLTNQSYIAGLYYTSPSGDLL-AFKNVTTQTVYSVTPCRL------------SSQVAVYNGSI 92
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  589 NCTDVPTAiradQLTPAWRVYSTGVNVFQtqagcligaEHVNASYECDIPI----GAGICASyhtasvlrstGQKSIVAY 664
Cdd:cd22374    93 IAAFTSTE----NFTIADFTYSRATPMFY---------YHSIGNDTCETPVitfgSIGVCPG----------GGLHFVDP 149
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  665 TMSlGAENSIAYANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQD 744
Cdd:cd22374   150 TSN-EFTNVVPISTQNISIPKNFTVSIQTEYIQIEQQPVTVDCRQYVCNGNPRCLQLLMQYTSACSTIEQALSLNARLEA 228
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  745 KNTQEVFAQVKQMYKTPAIKDFG----GFNFSQILPdpSKPTKRSFIEDLLFNKVTLADAGFMKQ-YGDCLGDVSARDLI 819
Cdd:cd22374   229 ASIQTMLTYSPETLKLANITNFQsddvNYNLTNILP--KKYQGRSAIEDLLFDKVVTNGLGTVDQdYKACTNGVSIADLV 306
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  820 CAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSA 899
Cdd:cd22374   307 CAQYYNGIMVLPGVADPEKMAQYTASLTGGMVFGGLT----SAAAIPFSLAVQSRLNYVALQTDVLQQNQQILADSFNNA 382
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  900 IGKI-------QESLSST-------ASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRL 965
Cdd:cd22374   383 MGNItlafkevSEGLSQVsgaittvANALTKIQTVVNSQGQALATLTEQLANNFQAISASIADIYNRLNQLEADAQVDRL 462
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  966 ITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFT 1045
Cdd:cd22374   463 ITGRLAALNAFVTQTLSKLAEVRQARQLALDKINECVKSQSSRYGFCGNGTHLFSIVNAAPYGFVFFHTVLLPTQYATVQ 542
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1046 TAPAICHEGKA---YFPREGVFVSNGTsWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPE---LDSFKE 1119
Cdd:cd22374   543 AYSGICQNGRAlalKDPSLALFRGTDK-YLVTPRNMYQPRTAAQADFVYIESCTVTYLNLTDTTIDAVIPDyvdVNKTVE 621
                         650       660       670       680       690       700       710       720
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1120 ELDKYFKNHTSPDVDLG-----------DISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIKWPWYVWLG 1188
Cdd:cd22374   622 DILNNLPNYTKPDLDIGrynntilnlttEINDLNGRAENLSQIVENLEEYIKKINATLVDLEWLNRVETYIKWPWWVWLL 701
                         730       740       750
                  ....*....|....*....|....*....|....*...
gi 123847331 1189 FIAGLIAIV--MVTILLCcmTSCCsclkGAC--SCGSC 1222
Cdd:cd22374   702 IALAITAFVciLVTIFLC--TGCC----GGCfgCCGGC 733
alphaCoV_Spike_SD1-2_S1-S2_S2 cd22369
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
505-1172 5.44e-118

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) protein from alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses including human coronaviruses (HCoVs), HCoV-NL63, and HCoV-229E, and porcine coronaviruses, transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV), among others. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP), and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1 the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411956 [Multi-domain]  Cd Length: 666  Bit Score: 382.02  E-value: 5.44e-118
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  505 ELVKNQCVNFNFNGLKGTGVLTSSSKRFQS---FQQFGRDTSDFTDSVrdpqTLEILDISPCSFggvsvitpgtnaSSEV 581
Cdd:cd22369     4 VVHLNVCTDYTIYGITGRGIIRKSNSTYIAglyYTSNSGQLLGFKNST----TGEVFSVTPCQL------------SSQV 67
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  582 AVlYQDvNCTDVPTAIRADQLTpawRVYSTGVNVFQTqagcligaeHVNASYECDIPI----GAGICASYHTASVLRSTG 657
Cdd:cd22369    68 AV-VSD-NIVGVMSATNNVSLG---FNNTIETPSFYY---------HSNGAENCTEPVltygSIGVCADGSITEVTPRSV 133
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  658 QKSIVAytmslgaenSIAYANnsIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALT 737
Cdd:cd22369   134 SPEPVS---------PIITGN--ISIPSNFTVSVQVEYLQMYLKPVSVDCSTYVCNGNPRCLQLLTQYASACRTIEEALQ 202
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  738 GIA-IEQDKNTQEVFAQVKQMYKTPAIKDFGGFNFSQILPdpSKPTKRSFIEDLLFNKVTLADAGFMKQ-YGDCLGD--V 813
Cdd:cd22369   203 LSArLESVEVNSMITVSEEALRLANISTFFDDYNLSAVLP--AGVGGRSAIEDLLFDKVVTSGLGTVDEdYKACTKGlgI 280
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  814 SARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGwtFGAGAAlqIPFAMQMAYRFNGIGVTQNVLYENQKLIA 893
Cdd:cd22369   281 AAADVACAQYYNGIMVLPGVVDAEKMALYTASLTGGMVLGG--FTAAAA--IPFSLAVQSRLNYVALQTDVLQRNQQILA 356
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  894 NQFNSAIGKI--------------QESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAE 959
Cdd:cd22369   357 NSFNSAMGNItvafsevndaiqqtSDAINTVAQALNKVQNVVNEQGQALSQLTKQLASNFQAISSSIEDIYNRLDGLAAD 436
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  960 VQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPS 1039
Cdd:cd22369   437 AQVDRLITGRLAALNAFVTQTLTKYTEVRASRQLAQQKINECVKSQSSRYGFCGNGTHLFSIVNAAPDGIMFLHTVLLPT 516
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1040 QEKNFTTAPAICHEGKAYFPREGV---FVSNGTSWFITQRNFYSPQLITTDNtFVS-GNCDVV-IGIINNTVYDPLQPEL 1114
Cdd:cd22369   517 EYVTVAAWAGLCVDGKAYVLRDDVvltLFKLNDKYYVTPRDMFEPRVPVSSD-FVQiSNCNVTyVNITSDELPEVIPDYI 595
                         650       660       670       680       690       700       710
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 123847331 1115 DSFK--EELDKYFKNHTSPDVDLgDIsgINASVVNIQKEID--------------RLNEVAKNLNESLIDLQEL 1172
Cdd:cd22369   596 DVNKtlEEFLANLPNYTLPDLPL-DI--FNATYLNLTGEIAdlenksesllnttvELQELIDNINNTLVDLEWL 666
TGEV-like_Spike_SD1-2_S1-S2_S2 cd22377
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
506-1222 2.46e-117

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from transmissible gastroenteritis virus and related alphacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine transmissible gastroenteritis virus (TGEV), canine coronavirus (CCoV), and feline coronavirus (FCoV). They display greater than 96% sequence identity and have been grouped in the same species, alphacoronavirus 1, within the Alphacoronavirus genus. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411964 [Multi-domain]  Cd Length: 751  Bit Score: 382.96  E-value: 2.46e-117
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  506 LVKNQCVNFNFNGLKGTGVLTSSSKRFQS---FQQFGRDTSDFTDSVrdpqTLEILDISPCSFGGVSVITPGtnassEVA 582
Cdd:cd22377     5 LVKDECTDYNIYGFQGTGIIRNTTSRLVAglyYTSISGDLLAFKNST----TGEIFTVVPCDLTAQAAVIND-----EIV 75
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  583 VLYQDVNCTDVPTAIRADQLTPAWRVYSTGVNVFQTQAGCLIGAEHVNASYECDIPI---GAGICasyhtasvlrSTGQK 659
Cdd:cd22377    76 GAITSVNQTDLFEFVNHTQSRRSRRSTLGLVHTYTMPQFYYITKWNNDTSTNCTSVItysSFAIC----------NTGEI 145
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  660 SIVAYTMSLGAENSIAY----ANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRA 735
Cdd:cd22377   146 KYVNVTHVEIVDDSIGVikpiSTGNITIPKNFTVAVQAEYIQIQVKPVVVDCAKYVCNGNRHCLKLLTQYTSACQTIENA 225
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  736 L-TGIAIE----------QDKNTQevFAQVKQMYKT-PAIKDFGGFNF---SQILPdpSKPTKRSFIEDLLFNKVTLADA 800
Cdd:cd22377   226 LnLGARLEslmlndmitvSDRSLE--LATVEKFNSTvLGGEKLGGFYFdglKDLLP--PRIGKRSAIEDLLFNKVVTSGL 301
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  801 GFMKQ-YGDCLGDVSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTAtagwtFGA-GAALQIPFAMQMAYRFNGI 878
Cdd:cd22377   302 GTVDDdYKKCSAGTDVADLVCAQYYNGIMVLPGVVDDNKMAMYTASLIGGMA-----LGSiTSAVAVPFAMQVQARLNYV 376
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  879 GVTQNVLYENQKLIANQFNSAIGKI--------------QESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISS 944
Cdd:cd22377   377 ALQTDVLQENQKILANAFNNAIGNItlalgkvsnaitttSDGFNTMASALTKIQSVVNQQGEALSQLTSQLQKNFQAISS 456
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  945 VLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQS 1024
Cdd:cd22377   457 SIAEIYNRLEKVEADAQVDRLITGRLAALNAYVSQTLTQYAEVKASRQLAMEKVNECVKSQSDRYGFCGNGTHLFSLVNS 536
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1025 APHGVVFLHVTYVPSQEKNFTTAPAIC-HEGKAYFPRE---GVFVSNGTsWFITQRNFYSPQLITTDNTFVSGNCDVVig 1100
Cdd:cd22377   537 APDGLLFFHTVLLPTEWEEVTAWSGICvNDTYAYVLKDfltSIFSYNGT-YMVTPRNMFQPRKPQMSDFVQITSCEVT-- 613
                         650       660       670       680       690       700       710       720
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1101 iINNTVYDPLQPEL-------DSFKEELDKYFKNHTSPDVDLGdISGINASVVNIQKEIDRLNEVA-------------- 1159
Cdd:cd22377   614 -FLNTTYTTFQEIVidyidinKTIADMLEQYNPNYTVPELDLQ-LEIFNQTKLNLTAEIDQLEQRAdnltniahelqqyi 691
                         730       740       750       760       770       780
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 123847331 1160 KNLNESLIDLQELGKYEQYIKWPWYVWLgfIAGLIAIVMVTILL--CCMTSCCSClkgaCSC-GSC 1222
Cdd:cd22377   692 DNLNKTLVDLEWLNRIETYVKWPWYVWL--LIGLVVVFCIPLLLfcCLSTGCCGC----FGClGSC 751
delta-PDCoV-like_Spike_SD1-2_S1-S2_S2 cd22373
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
509-1179 6.32e-108

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine coronavirus HKU15, avian coronaviruses, and related deltacoronaviruses; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from porcine coronavirus PDCoV, and several avian coronaviruses such as quail deltacoronavirus (QdCoV) UAE-HKU30, white-eye coronavirus HKU16, common moorhen coronavirus HKU21, thrush CoV HKU12, and munia CoV HKU13, all from the Buldecovirus subgenus of deltacoronaviruses. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HCoV-KU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Ro-BatCoV HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411960 [Multi-domain]  Cd Length: 648  Bit Score: 354.14  E-value: 6.32e-108
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  509 NQCVNFNFNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTdSVRDPQTLEILDISPCSfggvsvitpgtnASSEVAVlyqdV 588
Cdd:cd22373     1 DVCTDYTIYGVSGTGIIKPSDLQLHNGIAFTSPTGELY-AFKNITTGKTYQVLPCE------------TPSQLIV----I 63
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  589 NCTDVpTAIRADQLTpawrvystgVNVFQTQAGCLIGAEHVNA-SYECDIPIgagicASYHTASVLrSTGqkSIVAYTMS 667
Cdd:cd22373    64 NNTIV-GAITSSNST---------ENGFTTTIVTPTFYYSTNAtSFNCTKPV-----LSYGPISVC-SDG--AIVGTSTL 125
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  668 LGAENSI-AYANNSIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKN 746
Cdd:cd22373   126 QDTRPSIvSLYDGEVEIPSAFTLSVQTEYLQVQAEQVVVDCPQYVCNGNSRCLQLLAQYTSACSNIESALHSSAQLDSRE 205
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  747 TQEVFAQVKQMYKTPAIKDF-GGFNFSQILPDpsKPTKRSFIEDLLFNKVTLADAGFMKQ-YGDCLGDVSARDLICAQKF 824
Cdd:cd22373   206 ITNMFQTSTQSLELANITNFkGDYNFTSILTT--KIGGRSAIEDLLFNKVVTNGLGTVDQdYKSCSKDMAIADLVCSQYY 283
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  825 NGLTVLPPLLTDEMVAAYTAALVSGTATAGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKI- 903
Cdd:cd22373   284 NGIMVLPGVVDAEKMAMYTGSLTGAMVFGGLT----AAAAIPFSTAVQARLNYVALQTNVLQENQKILAESFNQAVGNIs 359
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  904 -------------QESLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRL 970
Cdd:cd22373   360 lalssvndaiqqtSEALNTVANAINKIQTVVNQQGEALSHLTAQLSNNFQAISTSIQDIYNRLDEVEANQQVDRLITGRL 439
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  971 QSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAI 1050
Cdd:cd22373   440 AALNAYVTQLLNQMSQIRQSRLLAQQKINECVKSQSSRYGFCGNGTHLFSITQAAPNGIFFMHAVLVPTKFTRVNASAGI 519
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1051 CHEGKAYFPREG--VFVSNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVigiINNTVYDPLQ---PELDSFKEELDKYF 1125
Cdd:cd22373   520 CVDNTKGYSLQPqlILYQFNNSWRVTPRNMYEPRLPRQADFIPLTDCSVT---FYNTTAADLPniiPDYVDVNQTVSDII 596
                         650       660       670       680       690
                  ....*....|....*....|....*....|....*....|....*....|....
gi 123847331 1126 KNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQelgkyeQYI 1179
Cdd:cd22373   597 DNLPTPTPPQLDVDIYNNTILNLTQEINDLQERSKNLSQIADRLQ------QYI 644
PDEV-like_Spike_SD1-2_S1-2_S2 cd22376
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
628-1176 1.66e-100

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from Porcine epidemic diarrhea virus and related alphacoronavirus; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses, including porcine epidemic diarrhea virus (PEDV), Scotophilus bat coronavirus, and swine enteric coronavirus, among others. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1 the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411963 [Multi-domain]  Cd Length: 673  Bit Score: 334.80  E-value: 1.66e-100
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  628 HVNASYECDIPI----GAGICASYHTASVLRSTGQKSIVAytMSLGaensiayannSIAIPTNFSISVTTEVMPVSMAKT 703
Cdd:cd22376    98 HSNDGSNCTEPVlvysNIGVCKSGSIGYVPSQSGQPKIAP--MVTG----------NISIPTNFTMSIRTEYLQLYNTPV 165
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  704 AVDCTMYICGDSLECSNLLLQYGSFCTQLNRALTGIAIEQDKNTQEVFAQVKQMYKTPAIKDF--GGFNFSQILPdpSKP 781
Cdd:cd22376   166 SVDCAMYVCNGNSRCKQLLTQYTSACKTIESALQLSARLESVEVNSMLTISEEALQLATISSFngGGYNFTNVLG--ASV 243
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  782 TKRSFIEDLLFNKVTLADAGFMKQ-YGDCLGDVSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTfgAG 860
Cdd:cd22376   244 QKRSFIEDLLFNKVVTNGLGTVDEdYKRCSNGLSVADLVCAQYYSGVMVLPGVVDAEKLHMYSASLIGGMVLGGIT--AA 321
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  861 AALqiPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQES--------------LSSTASALGKLQDVVNQNAQ 926
Cdd:cd22376   322 AAL--PFSYAVQARLNYVALQTDVLQRNQQLLAESFNSAIGNITSAfesvkeaisqtsqgLNTVAHALTKVQDVVNSQGA 399
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  927 ALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQS 1006
Cdd:cd22376   400 ALNQLTVQLQHNFQAISSSIDDIYSRLDQLSADAQVDRLITGRLSALNAFVAQTLTKYTEVQASRKLAQQKVNECVKSQS 479
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1007 KRVDFCG-KGYHLMSFPQSAPHGVVFLHVTYVPSQEKNFTTAPAICHEGKAYF-PREGVFVSNG-------TSWFITQRN 1077
Cdd:cd22376   480 QRYGFCGgDGEHIFSLVQAAPQGLLFLHTVLVPGDFVNVTAIAGLCVDDEIALtLREPGVLFTHevltytaTEYFVSPRK 559
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1078 FYSPQLITTDNTFVSGNCDVV-IGIINNTVYDPLQPELDSFK--EELDKYFKNHTSPDVDLgDIsgINASVVNIQKEI-- 1152
Cdd:cd22376   560 MFEPRKPTVSDFVQIESCVVTyVNLTSDQLPDVIPDYIDVNKtlDEILASLPNRTGPSLPL-DV--FNATYLNLTGEIad 636
                         570       580       590
                  ....*....|....*....|....*....|....*.
gi 123847331 1153 ------------DRLNEVAKNLNESLIDLQELGKYE 1176
Cdd:cd22376   637 leqrseslrnttEELRSLIYNINNTLVDLEWLNRVE 672
HCoV-NL63-229E-like_Spike_SD1-2_S1-S2_S2 cd22375
SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) ...
504-1180 3.95e-97

SD-1 and SD-2 subdomains, the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoproteins from HCoV-NL63, HCoV-229E, and related alphacoronavirus; This group contains the SD-1 and SD-2 subdomains of the S1 subunit C-terminal domain (C-domain), the S1/S2 cleavage region, and the S2 fusion subunit of the spike (S) glycoprotein from alphacoronaviruses, including human coronaviruses (HCoVs), HCoV-NL63 and HCoV-229E. The CoV S protein is an envelope glycoprotein that plays a very important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains the coronavirus fusion machinery and is primarily alpha-helical. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-domain. The S1 C-domain also contains two subdomains (SD-1 and SD-2), which connect the S1 and S2 subunits. Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. The S2 subunit comprises the fusion peptide (FP), a second proteolytic site (S2'), followed by an internal fusion peptide (IFP) and two heptad-repeat domains (HR1 and HR2) preceding the transmembrane domain (TM). After binding of the S1 subunit RBD on the virion to its receptor on the target cell, the HR1 and HR2 domains interact with each other to form a six-helix bundle (6-HB) fusion core, bringing viral and cellular membranes into close proximity for fusion and infection. In order to catalyze the membrane fusion reaction, CoV S needs to be primed through cleavage at the S1/S2 and S2' sites. In the case of human-infecting coronaviruses such as SARS-CoV-2, HCoV-OC43, MERS-CoV, and HKU1, the spike protein contains an insertion of (R/K)-(2X)n-(R/K) (furin cleavage motif) at the S1/S2 site, which is absent in SARS-CoV and other SARS-related coronaviruses, as well as Rousettus bat coronavirus HKU9. The region modeled in this cd (SD-1 and SD-2, the S1/S2 cleavage region, and the S2 fusion subunit) plays an essential role in viral entry by initiating fusion of the viral and cellular membranes.


Pssm-ID: 411962 [Multi-domain]  Cd Length: 677  Bit Score: 325.32  E-value: 3.95e-97
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  504 TELVKNQCVNFNFNGLKGTGVLTSSSKRFQSFQQFGRDTSDFTdSVRDPQTLEILDISPCsfggvsvitpgtNASSEVAV 583
Cdd:cd22375     3 SNVVLNNCTKYNIYDYSGTGVIRSSNDSFIGGITYTSNSGNLL-GFKDVSTGTIYSITPC------------NPPDQVVV 69
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  584 LYQDVnctdvPTAIRADQLTpawrvySTGV-NVFQTQAGCLIGaehvNASYECDIPI----GAGICASYHTASVL-RSTG 657
Cdd:cd22375    70 YQQAI-----VGAMLSENET------RYGLsNVVELPNFYYAS----NGTYNCTDAVltysNFGICADGSIIPVRpRNVS 134
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  658 QKSIVAytmslgaensIAYANnsIAIPTNFSISVTTEVMPVSMAKTAVDCTMYICGDSLECSNLLLQYGSFCTQLNRALT 737
Cdd:cd22375   135 DNGVSA----------IVTAN--LSIPSNWTTSVQVEYLQITSTPIVVDCSTYVCNGNPRCVELLKQYTSACKTIEDALR 202
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  738 GIAIEQDKNTQEVFAQVKQMYKTPAIKDFGGFNFSQILP----DPSKPTKRSFIEDLLFNKVTLADAGFMK-QYGDCLGD 812
Cdd:cd22375   203 LSARLESADVSSMLTFDSNAFTLANVSSFGDYNLSSVLPqlptSGSRIAGRSAIEDLLFSKVVTSGLGTVDaDYKSCTKG 282
                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  813 VSARDLICAQKFNGLTVLPPLLTDEMVAAYTAALVSGTATAGWTfgagAALQIPFAMQMAYRFNGIGVTQNVLYENQKLI 892
Cdd:cd22375   283 LSIADLACAQYYNGIMVLPGVADAERMAMYTGSLIGGMALGGLT----SAAAIPFSLALQARLNYVALQTDVLQENQKIL 358
                         410       420       430       440       450       460       470       480
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  893 ANQFNSAIGKIQESLSST--------------ASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEA 958
Cdd:cd22375   359 AASFNKAMTNIVDAFTGVndaitqtsqaiqtvATALNKIQDVVNQQGNALNHLTSQLRQNFQAISSSIQAIYDRLDTIQA 438
                         490       500       510       520       530       540       550       560
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  959 EVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVP 1038
Cdd:cd22375   439 DQQVDRLITGRLAALNAFVSQTLTKYTEVRASRQLAQQKVNECVKSQSNRYGFCGNGTHIFSIVNAAPEGLVFLHTVLLP 518
                         570       580       590       600       610       620       630       640
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331 1039 SQEKNFTTAPAICHEGKAYFPREG---VFVSNGTSWFITQRNFYSPQLITTDNTFVSGNCDVVIGIINNTVYDPLQPE-L 1114
Cdd:cd22375   519 TQYKDVEAWSGLCVDGVNGYVLRQpnlALYKDGGVFRITSRVMFEPRIPTMADFVQIENCNVTFVNISRSELQTIVPEyV 598
                         650       660       670       680       690       700       710
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 123847331 1115 DSFK--EELDKYFKNHTSPDVDL-----------GDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQYIK 1180
Cdd:cd22375   599 DVNKtlQELIEKLPNYTVPDLDLdqynqtilnltSEISTLENKSAELNYTVQKLQTLIDNINSTLVDLKWLNRVETYIK 677
SARS-CoV-2_Spike_S1_RBD cd21480
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 ...
310-514 4.24e-97

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome coronavirus 2 Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from highly pathogenic human virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV). The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While RBD of mouse hepatitis virus (MHV) is located at the NTD, most of other CoVs, including SARS-CoV-2 use the C-domain to bind their receptors. Recent studies found that the receptor-binding domain (RBD) of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV-2 and most CoVs.


Pssm-ID: 394827  Cd Length: 223  Bit Score: 308.95  E-value: 4.24e-97
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  310 RVSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 389
Cdd:cd21480     1 RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYAD 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  390 TFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTG-----NYYYRSHRKTKLKPFERDLSSD------- 457
Cdd:cd21480    81 SFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKvggnyNYLYRLFRKSNLKPFERDISTEiyqagst 160
                         170       180       190       200       210       220
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 123847331  458 DGNGV------YTLSTYDFNPNVPVAYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 514
Cdd:cd21480   161 PCNGVegfncyFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNF 223
SARS-CoV_Spike_S1_RBD cd21481
receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related ...
310-514 9.70e-92

receptor-binding domain of the S1 subunit of severe acute respiratory syndrome-related coronavirus Spike (S) protein; This group contains the receptor-binding domain of the S1 subunit of the spike (S) protein from severe acute respiratory syndrome-related coronavirus (SARS-CoV) and similar coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV use the C-domain to bind their receptors. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for SARS-CoV and most CoVs.


Pssm-ID: 394828  Cd Length: 222  Bit Score: 294.29  E-value: 9.70e-92
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  310 RVSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYAD 389
Cdd:cd21481     1 RVVPSGDVVRFPNITNLCPFGEVFNATKFPSVYAWERKKISNCVADYSVLYNSTFFSTFKCYGVSATKLNDLCFSNVYAD 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  390 TFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHD---TG--NYYYRSHRKTKLKPFERDLS----SDDG- 459
Cdd:cd21481    81 SFVVKGDDVRQIAPGQTGVIADYNYKLPDDFMGCVLAWNTRNIDatsTGnyNYKYRYLRHGKLRPFERDISnvpfSPDGk 160
                         170       180       190       200       210       220
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 123847331  460 -------NGVYTLSTYDFNPNVPVAYQATRVVVLSFELLNAPATVCGPKLSTELVKNQCVNF 514
Cdd:cd21481   161 pctppalNCYWPLNDYGFYTTTGIGYQPYRVVVLSFELLNAPATVCGPKLSTDLIKNQCVNF 222
bCoV_S1_N pfam16451
Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal ...
34-325 2.73e-85

Betacoronavirus-like spike glycoprotein S1, N-terminal; This entry represents the N-terminal domain of the betacoronavirus-like trimeric spike glycoprotein. The distal S1 subunit of the coronavirus spike protein is responsible for receptor binding. S1 contains two domains; an N-terminal galectin-like domain (NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Either the S1 NTD or S1 RBD, or occasionally both, are involved in binding to host receptors. S1 NTD is located on the side of the spike trimer and mainly recognizes sugar receptors. For many betacoronaviruses (b-CoVs), for example mouse hepatitis virus (MHV), the RBD is located in the NTD. The structure of the MHV S1 NTD showed the same fold as human galectins (galactose-binding lectin), however it does not bind any sugar; instead, it binds to the carcinoembryonic antigen cell-adhesion molecule CEACAM1) through protein-protein interactions. All three CEACAM21a-binding sites in MHV spikes can be fully occupied by CEACAM1a. It has been shown that CEACAM1a binding to the MHV spike weakens the interactions between S1 and S2 and facilitates the proteolysis of the spike protein and dissociation of S1. The homologous bovine CoV (BCov) S1 NTD also possesses a galectin fold but binds to sialic acid-containing moieties on host cell membranes, as does the NTD of three other group A b-Covs, namely human CoV (HCoV) OC43, avian b-CoV, and infectious bronchitis virus (IBV). Despite the S1 NTD of human respiratory b-CoV HKU1 being highly homologous to the NTDs of MHV and bovine CoV, it does not bind to either sugar or human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and the RBD is found instead in the S1 RBD domain.


Pssm-ID: 465119  Cd Length: 296  Bit Score: 279.68  E-value: 2.73e-85
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331    34 SSSRRGVYY-NDDIFrSDVLHLTQDYFLPFDSNLTQYFSLNVDSDRYTYFDNPILDFGDGVYFAATEKSNVIRG------ 106
Cdd:pfam16451    2 VSKADGTYYlPDRVY-SNTTTLRQGLFPKQGDNVTNYVYSPAHHCGKRNFSTPFLPFGDGIFVHIGNASNATGGriisep 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   107 --WIFGSSFDNTTQSAVIVNNS--THIIIRVCNFNLCKEPMYTVSRG----TQQNAWVYQ-SAFNCTYDRVEkSFQLDTt 177
Cdd:pfam16451   81 paFVFGSTFGNTSHTLIIAPDScqTNLTILVCNFTLCANPVTACRWGagnyNANNSLVYFkNAINCTFNRTY-NITFDT- 158
                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   178 pktgnfkDLREYVFKNRDGFLSVYQTYTavnlPRGLPTGFSVLKPILKLPFGINITSYRVVMAMFSqTTSNFLPESAAYY 257
Cdd:pfam16451  159 -------SLIYFGFKQQDGGFHIYYSYW----LPDLDSGPPTLFPFATLPLGINITYFQVIPSSIR-STQNCRRANAAYY 226
                          250       260       270       280       290       300
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 123847331   258 VGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCTIKNFNVDKGIYQTSNFRVSPTQEV-IRFPNITN 325
Cdd:pfam16451  227 VAPLKPSTFLLDFDVNGYITNAVDCSFDPLSELKCSTGSFEPDTGVYSTSSYRAQPVGSVyVRQPNVTC 295
CoV_Spike_S1_RBD cd21470
receptor-binding domain of the S1 subunit of coronavirus spike (S) proteins; This family ...
311-499 2.09e-57

receptor-binding domain of the S1 subunit of coronavirus spike (S) proteins; This family contains the receptor-binding domain (RBD) of the S1 subunit of coronavirus (CoV) spike (S) proteins from three highly pathogenic human coronaviruses (CoVs), including Middle East respiratory syndrome coronavirus (MERS-CoV), Severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), and SARS coronavirus 2 (SARS-CoV-2), also known as a 2019 novel coronavirus (2019-nCoV), as well as S proteins from related coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV use the C-domain to bind their receptors. MHV uses mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a) as the receptor, and the receptors for SARS-CoV and MERS-CoV are human angiotensin-converting enzyme 2 (ACE2) and human dipeptidyl peptidase 4 (DPP4), respectively. Recent studies found that the RBD of SARS-CoV-2 S protein binds strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. Moreover, SARS-CoV-2 RBD exhibited significantly higher binding affinity to the ACE2 receptor than SARS-CoV RBD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394823  Cd Length: 171  Bit Score: 195.78  E-value: 2.09e-57
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  311 VSPTQEVIRFPNITNRCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADT 390
Cdd:cd21470     1 VKPSGSVVRRPNNTPLCDFSEWLNATSVPSVYNWERKVFSNCNFNLSKLLSLFSVDSFTCNGISPAKIAGLCFSSITVDK 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  391 FLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTG-----NYYYRSHrktklkpferdlssddgngVYTL 465
Cdd:cd21470    81 FAIPLSRKSDLQPGSAGFIQDYNYKIDFDNTSCQLAYNLPANNATitknhDYVYIQK-------------------FLGW 141
                         170       180       190
                  ....*....|....*....|....*....|....
gi 123847331  466 STYDFNPNvpvaYQATRVVVLSFELLNAPATVCG 499
Cdd:cd21470   142 STDGCTSG----DQCQIFFNISFQYGNASGTVCS 171
CoV_Spike_S1_NTD cd21527
N-terminal domain of the S1 subunit of coronavirus Spike (S) proteins; This family contains ...
34-292 2.75e-51

N-terminal domain of the S1 subunit of coronavirus Spike (S) proteins; This family contains the N-terminal domain (NTD) of the S1 subunit of coronavirus (CoV) Spike (S) proteins from all four (A-D) lineages of betacoronaviruses, including three highly pathogenic human CoVs (HCoV) such as Middle East respiratory syndrome (MERS)-related CoV, Severe acute respiratory syndrome (SARS) CoV, and SARS-CoV-2, also known as a 2019 novel coronavirus (2019-nCoV) or COVID-19 virus. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2, SARS-CoV and MERS-CoV, use the C-domain to bind their receptors. However, some CoVs from the A lineage, such as mouse hepatitis virus (MHV) uses the NTD to bind its receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a). Bovine CoV and HCoV-OC43, also from the A lineage, recognize a sugar moiety, 5-N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2), on cell-surface glycoproteins or glycolipids; this binding is also through the S1 NTD. The S1 NTD has also been the target for neutralizing antibodies, including human antibody CDC2-A2, and murine antibodies G2 and 5F9, which target MERS-CoV NTD. In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394949  Cd Length: 268  Bit Score: 181.91  E-value: 2.75e-51
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   34 SSSRRGVYYNDDIFRSDVLHLTQDYFLPFDSNLTQY-FSLNVDSDRYTYFDNPILDFGDGVYFAATEK--------SNVI 104
Cdd:cd21527     9 VSKGLGTYYPDDRVYSNTTLLLQGLFPYDGSNFTNYaLKGSHALGTLWFYPPFVSPFNNGIFVKVKNTknstsatiYSEY 88
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  105 RGWIFGSSFDNTTQSAVIVNNSTH--IIIRVCNFNLCKEP-MYTVSR--GTQQN-AWVYQS-AFNCTYdrvEKSFQLDtt 177
Cdd:cd21527    89 PAIVFGSTFGNTSYTVVIQPDNGGtlLEASACQYEMCEYNaTICVPKtdGSDGNySWHIDSnAFNCTF---EYNFTYN-- 163
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  178 pktgNFKDLREYVFKNRDGFLSVYQTYTavnlprgLPTGFSVLKPILKLPFGINITSYRVVMAMFSQTTSNFLPESAAYY 257
Cdd:cd21527   164 ----VNADLLYFGFYQEDGTLYAYYSDY-------VDLYGGPLKFLFSLPLGDNLTNYYVIPLTCRSIQSSDRKFAAAYY 232
                         250       260       270
                  ....*....|....*....|....*....|....*
gi 123847331  258 VGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKC 292
Cdd:cd21527   233 VTYLTPRTFLLNFDENGVITNAVDCSSNFLSELKC 267
bCoV_S1_RBD pfam09408
Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor ...
339-499 9.62e-39

Betacoronavirus spike glycoprotein S1, receptor binding; This entry represents the receptor binding domain (S1 RBD) of the betacoronavirus spike glycoprotein. The spike glycoprotein is arranged in trimers on the surface of the viral membrane and is essential for viral entry. The spike protein is translated as a large polypeptide that is subsequently cleaved to the distal S1, responsible for receptor binding, and the membrane-anchored S2 responsible for membrane fusion. The coronavirus (SARS-CoV) S1 subunit is composed of two distinct domains: an N-terminal domain (S1 NTD) and a receptor-binding domain (S1 RBD) also referred to as the S1 CTD or domain B. Each of these domains have been implicated in binding to host receptors. However, most coronaviruses are not known to utilize both the S1 NTD and S1 RBD for viral entry. SARS-CoV makes use of its S1 RBD to bind to the human angiotensin-converting enzyme 2 (ACE2) as its host receptor.


Pssm-ID: 462789  Cd Length: 156  Bit Score: 141.87  E-value: 9.62e-39
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   339 PNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADTFLIRSSEVRQVAPGETGVIADYNYKLPD 418
Cdd:pfam09408    1 PSPANWERKTFSNCNFDFSVLLSLLQVSSFKCYGVSPSKLADMCYGSVTIDYFAIPETHKSNLQPGSPGAISKYNYKLPD 80
                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   419 DFTGCVIAWNTAKHD----TGNYYYRSHRKTKLKPFERDLSSddgngvyTLSTYDFNPNVPVAYQAtrVVVLSFELLNAP 494
Cdd:pfam09408   81 DFYGCVLAFNVNANTnyafADNYPYRYIKPGQYQPCNSFVST-------VPNSPDGHYCTPSSFNG--VVVITLKPATGS 151

                   ....*
gi 123847331   495 ATVCG 499
Cdd:pfam09408  152 NLVCP 156
bat_HKU4-like_Spike_S1_RBD cd21487
receptor-binding domain of the S1 subunit of the Spike (S) protein from Tylonycteris bat ...
311-415 5.60e-10

receptor-binding domain of the S1 subunit of the Spike (S) protein from Tylonycteris bat coronavirus HKU4 and similar proteins; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from Tylonycteris bat coronavirus HKU4 and other Middle East Respiratory Syndrome (MERS)-related coronaviruses. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including human MERS-CoV that is phylogenetically closely related to bat CoV HKU4 use the C-domain to bind their receptors. HKU4 is able to bind the MERS-CoV receptor, human dipeptidyl peptidase 4 (DPP4), also called CD26. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs including MERS-CoV, and most likely, bat CoV HKU4.


Pssm-ID: 394834  Cd Length: 219  Bit Score: 60.76  E-value: 5.60e-10
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  311 VSPTQEVIRFPNITnRCPFDKVFNATRfPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADT 390
Cdd:cd21487     1 ASATGTFIEQPNAT-ECDFSPMLTGVA-PQVYNFKRLVFSNCNYNLTKLLSLFAVDEFSCNGISPDAIARGCYSTLTVDY 78
                          90       100
                  ....*....|....*....|....*
gi 123847331  391 FLIRSSEVRQVAPGETGVIADYNYK 415
Cdd:cd21487    79 FAYPLSMKSYIRPGSAGNIPLYNYK 103
HKU1-like_CoV_Spike_S1_RBD cd21478
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1 ...
307-423 1.22e-08

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1 and related coronaviruses; This family contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, human coronavirus OC43 (HCoV-OC43), mouse hepatitis virus (MHV), porcine hemagglutinating encephalomyelitis virus (HEV), and other related coronaviruses. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease. HCoV-OC43 is of zoonotic origin and is endemic in the human population, causing mild respiratory tract infections and possible severe complications or fatalities in young children, the elderly, and immunocompromised individuals. MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract. Porcine HEV is associated with acute outbreaks of wasting and encephalitis in nursing piglets from pig farms. These viruses are related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBDs of MHV and HCoV-OC43 are located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394825  Cd Length: 223  Bit Score: 56.70  E-value: 1.22e-08
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  307 SNFRVSPTQEVIR-FPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTS 385
Cdd:cd21478     1 TGYTVQPIADVYRrIPNLPD-CDIEEWLNAPTVPSPLNWERKTFSNCNFNMSSLLSLVQADSFSCNNIDASKIYGMCFGS 79
                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 123847331  386 VYADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGC 423
Cdd:cd21478    80 ITIDKFAIPNSRKVDLQLGSSGYLQSFNYRIDTAATSC 117
HCoV-OC43-like_Spike_S1_RBD cd21485
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus OC43 ...
309-428 1.64e-08

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus OC43 and related proteins; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from several betacoronaviruses including human coronavirus OC43 (HCoV-OC43) and bovine respiratory coronavirus (BCoV), among others. HCoV-OC43 is of zoonotic origin and is endemic in the human population, causing mild respiratory tract infections and possible severe complications or fatalities in young children, the elderly, and immunocompromised individuals. These viruses are related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. It has been reported that HCoV-OC43 uses 9-O-acetyl-sialic acid (9-O-Ac-Sia) as a receptor, which is terminally linked to oligosaccharides decorating glycoproteins and gangliosides at the host cell surface. HCoV-OC43 appears to bind 9-O-Ac-Sia at the NTD. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394832  Cd Length: 312  Bit Score: 57.71  E-value: 1.64e-08
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  309 FRVSPTQEVIR-FPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVY 387
Cdd:cd21485     3 YTVQPIADVYRrIPNLPD-CNIEAWLNDKSVPSPLNWERKTFSNCNFNMSSLMSFIQADSFTCNNIDAAKIYGMCFSSIT 81
                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 123847331  388 ADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWN 428
Cdd:cd21485    82 IDKFAIPNGRKVDLQLGNLGYLQSFNYRIDTTATSCQLYYN 122
HKU1_N1_CoV_Spike_S1_RBD cd21483
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, ...
307-428 6.96e-08

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, isolate N1; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, isolate N1. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease, and is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs, and most likely, for HKU1.


Pssm-ID: 394830  Cd Length: 306  Bit Score: 55.89  E-value: 6.96e-08
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  307 SNFRVSPTQEV-IRFPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTS 385
Cdd:cd21483     1 SGFTVKPVATVhRRIPDLPD-CDIDKWLNNFNVPSPLNWERKIFSNCNFNLSTLLRLVHTDSFSCNNFDESKIYGSCFKS 79
                          90       100       110       120
                  ....*....|....*....|....*....|....*....|...
gi 123847331  386 VYADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWN 428
Cdd:cd21483    80 IVLDKFAIPNSRRSDLQLGSSGFLQSSNYKIDTTSSSCQLYYS 122
HKU1_N5-like_CoV_Spike_S1_RBD cd21482
receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, ...
307-428 1.22e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from human coronavirus HKU1, isolate N5 and isolate N2; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from human coronavirus (CoV) HKU1, isolates N5 and N2. HKU1 is a human betacoronavirus that causes mild yet prevalent respiratory disease, and is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. Although a protein receptor has not yet been identified for HKU1, antibodies against the C-domain, but not those against the NTD, blocked HKU1 infection of cells, suggesting that the S1 C-domain is the primary HKU1 receptor-binding site. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs, and most likely, for HKU1.


Pssm-ID: 394829  Cd Length: 304  Bit Score: 55.07  E-value: 1.22e-07
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  307 SNFRVSPTQEVIR-FPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTS 385
Cdd:cd21482     1 SGFTVKPVATVYRrIPNLPD-CDIDNWLNNVSVPSPLNWERRIFSNCNFNLSTLLRLVHVDSFSCNNLDKSKIFGSCFNS 79
                          90       100       110       120
                  ....*....|....*....|....*....|....*....|...
gi 123847331  386 VYADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWN 428
Cdd:cd21482    80 ITVDKFAIPNRRRDDLQLGSSGFLQSSNYKIDISSSSCQLYYS 122
MERS-like_CoV_Spike_S1_RBD cd21479
receptor-binding domain of the S1 subunit of the Spike (S) protein from Middle East ...
311-415 1.38e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from Middle East respiratory syndrome coronavirus; This family contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from the human coronavirus that causes Middle East Respiratory Syndrome (MERS-CoV) and related coronaviruses from animals. MERS-CoV causes severe pulmonary disease in humans. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including MERS-CoV use the C-domain to bind their receptors. MERS-CoV use human dipeptidyl peptidase 4 (DPP4), also called CD26, as its receptor. It binds DPP4 through the RBD of its S1 subunit and then fuses viral and host membranes through its S2 subunit. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs including MERS-CoV.


Pssm-ID: 394826  Cd Length: 216  Bit Score: 53.55  E-value: 1.38e-07
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  311 VSPTQEVIRFPNITNrCPFDKVFNATRfPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADT 390
Cdd:cd21479     1 AKPRGTFIEQAEGVE-CDFSPLLKGTP-PQVYNFKRLVFTNCNYNLTKLLSLFQVDEFSCHQISPSALATGCYSSLTVDY 78
                          90       100
                  ....*....|....*....|....*
gi 123847331  391 FLIRSSEVRQVAPGETGVIADYNYK 415
Cdd:cd21479    79 FAYPLSMKSYLQPGSAGPIVQFNYK 103
HEV_Spike_S1_RBD cd21508
receptor-binding domain of the S1 subunit of the Spike (S) protein from porcine ...
307-439 2.82e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from porcine hemagglutinating encephalomyelitis virus; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from porcine hemagglutinating encephalomyelitis virus (HEV), which is associated with acute outbreaks of wasting and encephalitis in nursing piglets from pig farms. Porcine HEV is related to the zoonotic SARS and MERS betacoronaviruses, which have high fatality rates and pandemic potential. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs use the C-domain to bind their receptors. The protein receptor for porcine HEV has not yet been identified. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394835  Cd Length: 298  Bit Score: 53.59  E-value: 2.82e-07
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  307 SNFRVSPTQEVIR-FPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTS 385
Cdd:cd21508     1 NGYTVQPVATVYRrIPDLPN-CDIEAWLNSKTVSSPLNWERKIFSNCNFNMGRLMSFIQADSFGCNNIDASRLYGMCFGS 79
                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....
gi 123847331  386 VYADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHDTGNYYY 439
Cdd:cd21508    80 ITIDKFAIPNSRKVDLQVGKSGYLQSFNYKIDTAVSSCQLYYSLPAANVSVTHY 133
MHV-like_Spike_S1_RBD cd21484
receptor-binding domain of the S1 subunit of the Spike (S) protein from mouse hepatitis virus ...
307-433 4.04e-07

receptor-binding domain of the S1 subunit of the Spike (S) protein from mouse hepatitis virus and other rodent coronaviruses; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from mouse hepatitis virus (MHV) and other rodent coronaviruses. MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). MHV uses mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a) as the receptor; the RBD of MHV is located at the NTD. Most CoVs, such as SARS-CoV and MERS-CoV, use the C-domain to bind their receptors. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs.


Pssm-ID: 394831  Cd Length: 264  Bit Score: 52.96  E-value: 4.04e-07
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  307 SNFRVSPTQEVIR-FPNITNrCPFDKVFNATRFPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTS 385
Cdd:cd21484     1 SGYTVQPVGVVYRrVPNLPD-CKIEEWLTAKSVPSPLNWERKTFQNCNFNLSSLLRYVQAESLSCNNIDASKVYGMCFGS 79
                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 123847331  386 VYADTFLIRSSEVRQVAPGETGVIADYNYKLPDDFTGCVIAWNTAKHD 433
Cdd:cd21484    80 ISIDKFAIPNSRRVDLQLGNSGFLQSFNYKIDTRATSCQLYYSLAQNN 127
MHV-like_Spike_S1_NTD cd21625
N-terminal domain of the S1 subunit of the Spike (S) protein from murine hepatitis virus and ...
67-292 1.64e-06

N-terminal domain of the S1 subunit of the Spike (S) protein from murine hepatitis virus and related betacoronaviruses in the A lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the embecovirus subgenera (A lineage), including murine hepatitis virus (MHV), human coronavirus (HCoV) HKU1 and OC43, and bovine CoV (BCoV). MHV is the most common viral pathogen in contemporary laboratory mouse colonies manifesting as a primary infection in the upper respiratory tract, while HCoV-HKU1 causes mild yet prevalent respiratory disease in humans. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While most CoVs, including SARS-CoV and MERS-CoV use the C-domain to bind their receptors, several CoVs in the A lineage use the NTD to bind their receptors. MHV binds its protein receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a), through its S1 NTD. BCoV and HCoV-OC43 recognize a sugar moiety, 5-N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2), on cell-surface glycoproteins or glycolipids; this binding is also through the S1 NTD. In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394951  Cd Length: 284  Bit Score: 51.24  E-value: 1.64e-06
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   67 TQYFSLNvdsdrytYFDNPIL-DFGDGVyFAATEKSNVIR---------GWIFGSSFDNTTQSAVI-------VNNSTHI 129
Cdd:cd21625    68 TLLLSTL-------WFKPPFLsEFNNGI-FAKVKNTKVSKngvmysefpTIVIGSTFVNTSYTVVVqphtgnsDNKLQGI 139
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  130 I-IRVCNFNLCKEPmYTVSRGTQQNAwvyqsafnctydRVEkSFQLDTTPKTGNFKdlREYVFK-NRDG-FLSVYQ---T 203
Cdd:cd21625   140 LeISVCQYTMCEYP-NTICKPNLGNQ------------RIE-LWHTDTGVPSCLYK--RNFTYDvNADWlYFHFYQeggT 203
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  204 YTAVNLPRGLPTGFsvlkpILKLPFGINITSYRVVmamfsQTTSNFLPESAAYYVGNLKYSTFMLRFNENGTITDAVDCS 283
Cdd:cd21625   204 FYAYYADTGSVTTF-----LFSVYLGTVLSHYYVM-----PLTCNSTALTLEYWVTPLTKRQYLLAFNQDGVITNAVDCA 273

                  ....*....
gi 123847331  284 QNPLAELKC 292
Cdd:cd21625   274 SDFMSEIKC 282
CoV_S2_C pfam19214
Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich ...
1202-1241 2.30e-05

Coronavirus spike glycoprotein S2, intravirion; This entry represents the cysteine rich intravirion region found at the C-terminus of coronavirus spike proteins (S). These cysteine residues are targets for palmitoylation, necessary for efficiently S incorporation into virions and S-mediated membrane fusions.


Pssm-ID: 465998  Cd Length: 42  Bit Score: 42.79  E-value: 2.30e-05
                           10        20        30        40
                   ....*....|....*....|....*....|....*....|..
gi 123847331  1202 LLCCMTSCCSCLKGaCSCGSCC-KFDE-DDSEPVLKGVKLHY 1241
Cdd:pfam19214    1 FCCCCTGCCGCCFG-CSCGGCCdSYDKrDDVYPAEVVEKVHV 41
human_MERS-CoV_Spike_S1_RBD cd21486
receptor-binding domain of the S1 subunit of the Spike (S) protein from human Middle East ...
327-425 8.58e-05

receptor-binding domain of the S1 subunit of the Spike (S) protein from human Middle East respiratory syndrome coronavirus; This group contains the receptor-binding domain (RBD) of the S1 subunit of the spike (S) protein from the human coronavirus that causes Middle East Respiratory Syndrome (MERS-CoV). MERS-CoV causes severe pulmonary disease in humans. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). While the RBD of mouse hepatitis virus (MHV) is located at the NTD, most CoVs, including MERS-CoV use the C-domain to bind their receptors. MERS-CoV use human dipeptidyl peptidase 4 (DPP4), also called CD26, as its receptor. It binds DPP4 through the RBD of its S1 subunit and then fuses viral and host membranes through its S2 subunit. Due to the key role of the S protein RBD in viral attachment, it is the major target for antibody-mediated neutralization. This model corresponds to the S1 subunit C-domain that serves as the RBD for most CoVs including MERS-CoV.


Pssm-ID: 394833  Cd Length: 219  Bit Score: 45.12  E-value: 8.58e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  327 CPFDKVFNATRfPNVYAWERTKISDCVADYTVLYNSTSFSTFKCYGVSPSKLIDLCFTSVYADTFLIRSSEVRQVAPGET 406
Cdd:cd21486    16 CDFSPLLSGTP-PQVYNFKRLVFTNCNYNLTKLLSLFSVNDFTCSQISPAAIASNCYSSLILDYFSYPLSMKSDLSVSSA 94
                          90
                  ....*....|....*....
gi 123847331  407 GVIADYNYKLPDDFTGCVI 425
Cdd:cd21486    95 GPISQFNYKQSFSNPTCLI 113
batCoV-HKU9-like_Spike_S1_NTD cd21627
N-terminal domain of the S1 subunit of the Spike (S) protein from Rousettus bat coronavirus ...
77-292 1.02e-04

N-terminal domain of the S1 subunit of the Spike (S) protein from Rousettus bat coronavirus HKU9 and related betacoronaviruses in the D lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the nobecovirus subgenera (D lineage), including Rousettus bat coronavirus HKU9 and related bat CoVs. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including SARS-CoV-2, SARS-CoV, and MERS-CoV use the C-domain to bind their receptors. However, CoV such as mouse hepatitis virus (MHV) uses the NTD to bind its receptor, mouse carcinoembryonic antigen related cell adhesion molecule 1a (mCEACAM1a). The S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394953  Cd Length: 289  Bit Score: 45.80  E-value: 1.02e-04
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331   77 DRYTYFDNPILDFGDGVY-----FAATEKSNVIRGWIFGSSFDNTTQ-----------------SAVIVNNSTHIIIRVC 134
Cdd:cd21627    53 GKPGIYNTTILPVGDGLFvhtymYRQQDSSNTYCQEPFGVAFGNTFEqdriaiviiapgnlgswPAVSKRTTTNVHILVC 132
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  135 -NFNLCKEPMYtvsrgtqqNAW------VYQSAFNC--TYDRVEKSFqlDTTPKTGNFKdlreYVFKNRDGFLSVYQTYT 205
Cdd:cd21627   133 sNATLCANPAF--------NRWgpagsiYASDAFVChgNSCFVNNTF--IIPINTSRIN----LAFRFKDGNLLLYHSAW 198
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 123847331  206 AVNLPRGLPTGFSvLKPILKLPFGINITSyrvvmAMFSQTTSNFLPESA---------AYYVGNLKYSTFMLRFNENGTI 276
Cdd:cd21627   199 LPTSGLNLSGDYP-LHYYMSVPVGFNLPN-----AQFFQSVVRPNTEPAdgacaafqnNLYIAPLSKRELLVSYDDNGSP 272
                         250
                  ....*....|....*.
gi 123847331  277 TDAVDCSQNPLAELKC 292
Cdd:cd21627   273 VNVADCSADAGSELYC 288
MERS-CoV-like_Spike_S1_NTD cd21626
N-terminal domain of the S1 subunit of the Spike (S) protein from Middle East respiratory ...
254-293 5.84e-04

N-terminal domain of the S1 subunit of the Spike (S) protein from Middle East respiratory syndrome-related coronavirus and related betacoronaviruses in the C lineage; This subfamily contains the N-terminal domain (NTD) of the S1 subunit of the Spike (S) proteins from betacoronaviruses in the merbecovirus subgenera (C lineage), including the highly pathogenic human coronavirus (CoV), Middle East respiratory syndrome (MERS)-related CoV, and related bat CoVs. The CoV S protein is an envelope glycoprotein that plays the most important role in viral attachment, fusion, and entry into host cells, and serves as a major target for the development of neutralizing antibodies, inhibitors of viral entry, and vaccines. It is synthesized as a precursor protein that is cleaved into an N-terminal S1 subunit (~700 amino acids) and a C-terminal S2 subunit (~600 amino acids) that mediates attachment and membrane fusion, respectively. Three S1/S2 heterodimers assemble to form a trimer spike protruding from the viral envelope. The S1 subunit contains a receptor-binding domain (RBD), while the S2 subunit contains a hydrophobic fusion peptide and two heptad repeat regions. S1 contains two structurally independent domains, the N-terminal domain (NTD) and the C-terminal domain (C-domain). Depending on the virus, either the NTD or the C-domain can serve as the receptor-binding domain (RBD). Most CoVs, including MERS-CoV, use the C-domain to bind their receptors. Despite using the C-domain as its receptor, neutralizing antibodies targeting MERS-CoV S1-NTD have been reported, including human antibody CDC2-A2, murine antibodies G2 and 5F9, and macaque antibodies FIB-H1 and JC57-13. G2 has been shown to strongly disrupt the attachment of MERS-CoV S to its receptor, dipeptidyl peptidase-4 (DPP4). In addition, the S1 NTD contributes to the Spike trimer interface.


Pssm-ID: 394952  Cd Length: 328  Bit Score: 43.49  E-value: 5.84e-04
                          10        20        30        40
                  ....*....|....*....|....*....|....*....|
gi 123847331  254 AAYYVGNLKYSTFMLRFNENGTITDAVDCSQNPLAELKCT 293
Cdd:cd21626   289 AAFYIYKLHPLTYLLDFDVDGYIRRAIDCGYDDLSQLQCS 328
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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