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Conserved domains on  [gi|633256133|dbj|BAO78384|]
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cytochrome oxidase subunit I, partial (mitochondrion) [Zapornia fusca]

Protein Classification

heme-copper oxidase family protein( domain architecture ID 14)

heme-copper oxidase family protein may catalyze the transfer of electrons from an electron donor onto molecular oxygen

Graphical summary

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List of domain hits

 Name Accession Description Interval E-value
Heme_Cu_Oxidase_I super family cl00275
Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in ...
 1-220 5.58e-160

Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in the respiratory chains of prokaryotes and mitochondria which catalyze the reduction of O2 and simultaneously pump protons across the membrane. The superfamily is diverse in terms of electron donors, subunit composition, and heme types. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. It has been proposed that Archaea acquired heme-copper oxidases through gene transfer from Gram-positive bacteria. Membership in the superfamily is defined by subunit I, which contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons to the binuclear center. Only subunit I is common to the entire superfamily. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from the electron donor on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I of cytochrome c oxidase (CcO) and ubiquinol oxidase. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electron transfer occurs in two segments: from the electron donor to the low-spin heme, and from the low-spin heme to the binuclear center. The first segment can be a multi-step process and varies among the different families, while the second segment, a direct transfer, is consistent throughout the superfamily.


The actual alignment was detected with superfamily member MTH00116:

Pssm-ID: 469701  Cd Length: 515  Bit Score: 452.24  E-value: 5.58e-160
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00116  22 FGAWAGMVGTALSLLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00116 102 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTCINMKPPAMSQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00116 182 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
 
Name Accession Description Interval E-value
COX1 MTH00116
cytochrome c oxidase subunit I; Provisional
 1-220 5.58e-160

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177177  Cd Length: 515  Bit Score: 452.24  E-value: 5.58e-160
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00116  22 FGAWAGMVGTALSLLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00116 102 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTCINMKPPAMSQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00116 182 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
Cyt_c_Oxidase_I cd01663
Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the ...
 1-220 6.94e-133

Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the respiratory chains of eukaryotes and most bacteria, is a multi-chain transmembrane protein located in the inner membrane of mitochondria and the cell membrane of prokaryotes. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. Only subunits I and II are essential for function, but subunit III, which is also conserved, may play a role in assembly or oxygen delivery to the active site. Subunits I, II, and III of mammalian CcO are encoded within the mitochondrial genome and the remaining 10 subunits are encoded within the nuclear genome. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme (heme a3) and a copper ion (CuB). It also contains a low-spin heme (heme a), believed to participate in the transfer of electrons to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from cytochrome c on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are transferred from cytochrome c (the electron donor) to heme a via the CuA binuclear site in subunit II, and directly from heme a to the binuclear center.


Pssm-ID: 238833  Cd Length: 488  Bit Score: 382.22  E-value: 6.94e-133
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:cd01663   13 FGLWSGLVGTSLSLLIRLELSQPGSQLGNDQLYNVIVTAHALIMIFFMVMPALIGGFGNWLVPLMIGAPDMAFPRLNNLS 92

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:cd01663   93 FWLLPPSLLLLLLSALVEGGAGTGWTVYPPLSSILAHSGPSVDLAIFSLHLAGISSILGAINFITTIFNMRAPGMTLEKM 172

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:cd01663  173 PLFVWSVLITAFLLLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQHLFWFFGHP 232
CtaD_CoxA TIGR02891
cytochrome c oxidase, subunit I; This large family represents subunit I's (CtaD, CoxA, CaaA) ...
 5-220 7.70e-75

cytochrome c oxidase, subunit I; This large family represents subunit I's (CtaD, CoxA, CaaA) of cytochrome c oxidases of bacterial origin. Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits I-III form the functional core of the enzyme complex. Subunit I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit II and heme a of subunit I to the bimetallic center formed by heme a3 and copper B. This cytochrome c oxidase shows proton pump activity across the membrane in addition to the electron transfer. In the bacilli an apparent split (paralogism) has created a sister clade (TIGR02882) encoding subunits (QoxA) of the aa3-type quinone oxidase complex which reacts directly with quinones, bypassing the interaction with soluble cytochrome c. This model attempts to exclude these sequences, placing them between the trusted and noise cutoffs. These families, as well as archaeal and eukaryotic cytochrome c subunit I's are included within the superfamily model, pfam00115. [Energy metabolism, Electron transport]


Pssm-ID: 213748  Cd Length: 499  Bit Score: 234.04  E-value: 7.70e-75
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133    5 AGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMiGGFGNWLVPLMIGAPDMAFPRMNNMSFWLL 84
Cdd:TIGR02891  20 FFLVGGVLALLMRAQLATPGNTFMDAETYNQLFTMHGTIMIFLFAIPIL-AGFGNYLLPLMIGARDMAFPRLNAFSYWLY 98

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   85 PPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFV 164
Cdd:TIGR02891  99 LFGGLLLLASFFTGGAPDTGWTMYPPLSSTSGSPGVGVDLWLLGLHLLGISSILGAVNFIVTILNMRAPGMTLMRMPLFV 178

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 633256133  165 WSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:TIGR02891 179 WGILVTSILILLAFPVLIAALILLLLDRLFGTHFFDPARGGDPLLWQHLFWFFGHP 234
CyoB COG0843
Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];
5-220 2.54e-72

Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];


Pssm-ID: 440605  Cd Length: 535  Bit Score: 228.47  E-value: 2.54e-72
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   5 AGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLL 84
Cdd:COG0843   29 FLLIGGLLALLMRLQLAGPGLGLLSPETYNQLFTMHGTIMIFFFATP-FLAGFGNYLVPLQIGARDMAFPRLNALSFWLY 107

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  85 PPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFV 164
Cdd:COG0843  108 LFGGLLLLISLFVGGAADVGWTFYPPLSGLEASPGVGVDLWLLGLALFGVGSILGGVNFIVTILKMRAPGMTLMRMPLFT 187

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 633256133 165 WSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:COG0843  188 WAALVTSILILLAFPVLAAALLLLLLDRSLGTHFFDPAGGGDPLLWQHLFWFFGHP 243
COX1 pfam00115
Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key ...
 1-220 4.56e-46

Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key enzyme in aerobic metabolism. Proton pumping haem-copper oxidases represent the terminal, energy-transfer enzymes of respiratory chains in prokaryotes and eukaryotes. The CuB-haem a3 (or haem o) binuclear centre, associated with the largest subunit I of cytochrome c and ubiquinol oxidases (E.C:1.10.3.11), is directly involved in the coupling between dioxygen reduction and proton pumping. Some terminal oxidases generate a transmembrane proton gradient across the plasma membrane (prokaryotes) or the mitochondrial inner membrane (eukaryotes). The enzyme complex consists of 3-4 subunits (prokaryotes) up to 13 polypeptides (mammals) of which only the catalytic subunit (equivalent to mammalian subunit I (COXI) is found in all haem-copper respiratory oxidases. The presence of a bimetallic centre (formed by a high-spin haem and copper B) as well as a low-spin haem, both ligated to six conserved histidine residues near the outer side of four transmembrane spans within CO I is common to all family members.


Pssm-ID: 459678  Cd Length: 432  Bit Score: 157.73  E-value: 4.56e-46
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133    1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:pfam00115   9 TALVWFLVGGLLGLLIRLQLAFPGLNFLSPLTYNQLRTLHGNLMIFWFATP-FLFGFGNYLVPLMIGARDMAFPRLNALS 87

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   81 FWLLPPSFLLLLASStveAGAGTGWTVYPPLAGnlahagasVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQyQT 160
Cdd:pfam00115  88 FWLVVLGAVLLLASF---GGATTGWTEYPPLVG--------VDLWYIGLLLAGVSSLLGAINFIVTILKRRAPGMTL-RM 155

                         170       180       190       200       210       220
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNttffdpAGGGDPILYQHLFWFFGHP 220
Cdd:pfam00115 156 PLFVWAILATAILILLAFPVLAAALLLLLLDRSLG------AGGGDPLLDQHLFWWFGHP 209
 
Name Accession Description Interval E-value
COX1 MTH00116
cytochrome c oxidase subunit I; Provisional
 1-220 5.58e-160

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177177  Cd Length: 515  Bit Score: 452.24  E-value: 5.58e-160
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00116  22 FGAWAGMVGTALSLLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00116 102 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTCINMKPPAMSQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00116 182 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
COX1 MTH00103
cytochrome c oxidase subunit I; Validated
 1-220 1.67e-146

cytochrome c oxidase subunit I; Validated


Pssm-ID: 177165  Cd Length: 513  Bit Score: 417.75  E-value: 1.67e-146
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00103  22 FGAWAGMVGTALSLLIRAELGQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00103 102 FWLLPPSFLLLLASSMVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAMSQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00103 182 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
COX1 MTH00153
cytochrome c oxidase subunit I; Provisional
 1-220 1.74e-144

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177210  Cd Length: 511  Bit Score: 412.72  E-value: 1.74e-144
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00153  20 FGAWSGMVGTSLSLLIRAELGQPGSLIGDDQIYNVIVTAHAFIMIFFMVMPIMIGGFGNWLVPLMLGAPDMAFPRMNNMS 99

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00153 100 FWLLPPSLTLLLSSSMVESGAGTGWTVYPPLSSNIAHSGASVDLAIFSLHLAGISSILGAINFITTIINMRSKGMTLDRM 179

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00153 180 PLFVWSVLITAILLLLSLPVLAGAITMLLTDRNLNTSFFDPAGGGDPILYQHLFWFFGHP 239
COX1 MTH00167
cytochrome c oxidase subunit I; Provisional
 1-220 2.71e-135

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177222  Cd Length: 512  Bit Score: 389.42  E-value: 2.71e-135
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00167  22 FGAWAGMVGTALSLLIRAELSQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00167 102 FWLLPPSLLLLLASSGVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGSINFITTIINMKPPGITQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00167 182 PLFVWSILVTTILLLLSLPVLAAAITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
Cyt_c_Oxidase_I cd01663
Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the ...
 1-220 6.94e-133

Cytochrome C oxidase subunit I. Cytochrome c oxidase (CcO), the terminal oxidase in the respiratory chains of eukaryotes and most bacteria, is a multi-chain transmembrane protein located in the inner membrane of mitochondria and the cell membrane of prokaryotes. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. Only subunits I and II are essential for function, but subunit III, which is also conserved, may play a role in assembly or oxygen delivery to the active site. Subunits I, II, and III of mammalian CcO are encoded within the mitochondrial genome and the remaining 10 subunits are encoded within the nuclear genome. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme (heme a3) and a copper ion (CuB). It also contains a low-spin heme (heme a), believed to participate in the transfer of electrons to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from cytochrome c on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are transferred from cytochrome c (the electron donor) to heme a via the CuA binuclear site in subunit II, and directly from heme a to the binuclear center.


Pssm-ID: 238833  Cd Length: 488  Bit Score: 382.22  E-value: 6.94e-133
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:cd01663   13 FGLWSGLVGTSLSLLIRLELSQPGSQLGNDQLYNVIVTAHALIMIFFMVMPALIGGFGNWLVPLMIGAPDMAFPRLNNLS 92

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:cd01663   93 FWLLPPSLLLLLLSALVEGGAGTGWTVYPPLSSILAHSGPSVDLAIFSLHLAGISSILGAINFITTIFNMRAPGMTLEKM 172

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:cd01663  173 PLFVWSVLITAFLLLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQHLFWFFGHP 232
COX1 MTH00077
cytochrome c oxidase subunit I; Provisional
 1-220 1.03e-128

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214419  Cd Length: 514  Bit Score: 372.74  E-value: 1.03e-128
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00077  22 FGAWAGMVGTALSLLIRAELSQPGTLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00077 102 FWLLPPSFLLLLASSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTSINMKPPSMSQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00077 182 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPVLYQHLFWFFGHP 241
COX1 MTH00183
cytochrome c oxidase subunit I; Provisional
 1-220 7.20e-128

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177234  Cd Length: 516  Bit Score: 370.41  E-value: 7.20e-128
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00183  22 FGAWAGMVGTALSLLIRAELSQPGALLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00183 102 FWLLPPSFLLLLASSGVEAGAGTGWTVYPPLAGNLAHAGASVDLTIFSLHLAGVSSILGAINFITTIINMKPPAISQYQT 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00183 182 PLFVWAVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 241
COX1 MTH00142
cytochrome c oxidase subunit I; Provisional
 1-220 3.47e-125

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214431  Cd Length: 511  Bit Score: 363.66  E-value: 3.47e-125
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00142  20 FGAWAGMVGTGLSLLIRAELGQPGSLLGDDQLYNVIVTAHAFVMIFFMVMPVMIGGFGNWLVPLMLGAPDMAFPRMNNMS 99

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00142 100 FWLLPPALLLLLSSAAVESGAGTGWTVYPPLSSNLAHSGGSVDLAIFSLHLAGVSSILGAINFITTVINMRAGGMKFERV 179

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00142 180 PLFVWSVKITAILLLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQHLFWFFGHP 239
COX1 MTH00223
cytochrome c oxidase subunit I; Provisional
 1-220 2.58e-123

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177260  Cd Length: 512  Bit Score: 358.91  E-value: 2.58e-123
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00223  19 FGMWSGLVGTSLSLLIRAELGQPGALLGDDQLYNVIVTAHAFVMIFFLVMPMMIGGFGNWLVPLMLGAPDMAFPRLNNMS 98

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00223  99 FWLLPPSLYLLLSSSAVESGVGTGWTVYPPLSSNLAHAGPSVDLAIFSLHLAGVSSILGAINFITTIINMRSPGMQLERL 178

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00223 179 PLFVWSVKVTAFLLLLSLPVLAGAITMLLTDRNFNTSFFDPAGGGDPILYQHLFWFFGHP 238
COX1 MTH00037
cytochrome c oxidase subunit I; Provisional
 1-220 2.31e-112

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177112  Cd Length: 517  Bit Score: 331.02  E-value: 2.31e-112
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00037  22 FGAWAGMVGTAMSVIIRTELAQPGSLLQDDQIYNVIVTAHALVMIFFMVMPIMIGGFGNWLIPLMIGAPDMAFPRMNNMS 101

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00037 102 FWLIPPSFLLLLASAGVESGAGTGWTIYPPLSSNIAHAGGSVDLAIFSLHLAGASSILASINFITTIINMRTPGMTFDRL 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00037 182 PLFVWSVFITAFLLLLSLPVLAGAITMLLTDRNINTTFFDPAGGGDPILFQHLFWFFGHP 241
COX1 MTH00007
cytochrome c oxidase subunit I; Validated
 1-220 2.38e-109

cytochrome c oxidase subunit I; Validated


Pssm-ID: 133649  Cd Length: 511  Bit Score: 323.01  E-value: 2.38e-109
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00007  19 LGVWGGLLGTSMSLLIRIELGQPGAFLGSDQLYNTIVTAHAFLMIFFLVMPVFIGGFGNWLVPLMLGAPDMAFPRLNNMS 98

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00007  99 FWLLPPALILLVSSAAVEKGVGTGWTVYPPLASNLAHAGPSVDLAIFSLHLAGVSSILGAINFITTVINMRWKGLRLERI 178

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00007 179 PLFVWAVVITVVLLLLSLPVLAGAITMLLTDRNLNTSFFDPAGGGDPILYQHLFWFFGHP 238
COX1 MTH00182
cytochrome c oxidase subunit I; Provisional
 1-220 1.31e-103

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 214451  Cd Length: 525  Bit Score: 309.06  E-value: 1.31e-103
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00182  24 FGAGAGMIGTAFSMLIRLELSAPGAMLGDDHLYNVIVTAHAFIMIFFLVMPVMIGGFGNWLVPLYIGAPDMAFPRLNNIS 103

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00182 104 FWLLPPALILLLGSAFVEQGAGTGWTVYPPLSSIQAHSGGAVDMAIFSLHLAGVSSILGAINFITTIFNMRAPGVTFNRL 183

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00182 184 PLFVWSILITAFLLLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILFQHLFWFFGHP 243
COX1 MTH00184
cytochrome c oxidase subunit I; Provisional
 1-220 2.83e-103

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177235  Cd Length: 519  Bit Score: 307.91  E-value: 2.83e-103
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00184  24 FGAFAGMIGTAFSMLIRLELSAPGSMLGDDHLYNVIVTAHAFVMIFFLVMPVMIGGFGNWFVPLYIGAPDMAFPRLNNIS 103

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00184 104 FWLLPPALTLLLGSAFVEQGAGTGWTVYPPLSSIQAHSGGSVDMAIFSLHLAGISSILGAMNFITTIFNMRAPGITMDRM 183

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00184 184 PLFVWSILVTTFLLLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILYQHLFWFFGHP 243
COX1 MTH00079
cytochrome c oxidase subunit I; Provisional
 1-220 1.05e-97

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177148  Cd Length: 508  Bit Score: 293.13  E-value: 1.05e-97
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00079  23 FGLWSGMVGTSLSLIIRLELSKPGLLLGNGQLYNSVITAHAILMIFFMVMPSMIGGFGNWMLPLMLGAPDMSFPRLNNLS 102

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAgNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00079 103 FWLLPTSLFLILDSCFVDMGPGTSWTVYPPLS-TLGHPGSSVDLAIFSLHCAGISSILGGINFMVTTKNLRSSSISLEHM 181

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00079 182 SLFVWTVFVTVFLLVLSLPVLAGAITMLLTDRNLNTSFFDPSTGGNPLLYQHLFWFFGHP 241
COX1 MTH00026
cytochrome c oxidase subunit I; Provisional
 1-220 3.43e-94

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 164599  Cd Length: 534  Bit Score: 284.98  E-value: 3.43e-94
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00026  23 FGALSGAIGTAFSMLIRLELSSPGSMLGDDHLYNVIVTAHAFVMIFFLVMPTMIGGFGNWFVPLMIGAPDMAFPRLNNIS 102

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:MTH00026 103 FWLLPPALFLLLGSSLVEQGAGTGWTVYPPLASIQAHSGGSVDMAIFSLHLAGLSSILGAMNFITTVMNMRTPGMTMSRI 182

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00026 183 PLFVWSVFITAILLLLSLPVLAGAITMLLTDRNFNTTFFDPAGGGDPILYQHLFWFFGHP 242
Heme_Cu_Oxidase_I cd00919
Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in ...
 1-220 3.59e-83

Heme-copper oxidase subunit I. Heme-copper oxidases are transmembrane protein complexes in the respiratory chains of prokaryotes and mitochondria which catalyze the reduction of O2 and simultaneously pump protons across the membrane. The superfamily is diverse in terms of electron donors, subunit composition, and heme types. The number of subunits varies from three to five in bacteria and up to 13 in mammalian mitochondria. It has been proposed that Archaea acquired heme-copper oxidases through gene transfer from Gram-positive bacteria. Membership in the superfamily is defined by subunit I, which contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons to the binuclear center. Only subunit I is common to the entire superfamily. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from the electron donor on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I of cytochrome c oxidase (CcO) and ubiquinol oxidase. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electron transfer occurs in two segments: from the electron donor to the low-spin heme, and from the low-spin heme to the binuclear center. The first segment can be a multi-step process and varies among the different families, while the second segment, a direct transfer, is consistent throughout the superfamily.


Pssm-ID: 238461  Cd Length: 463  Bit Score: 254.76  E-value: 3.59e-83
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPlMIGAPDMAFPRMNNMS 80
Cdd:cd00919   11 FAFVALLLGGLLALLIRLELATPGSLFLDPQLYNQLVTAHGVIMIFFFVMPAIFGGFGNLLPP-LIGARDLAFPRLNNLS 89

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQT 160
Cdd:cd00919   90 FWLFPPGLLLLLSSVLVGGGAGTGWTFYPPLSTLSYSSGVGVDLAILGLHLAGVSSILGAINFITTILNMRAPGMTLDKM 169

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:cd00919  170 PLFVWSVLVTAILLLLALPVLAAALVMLLLDRNFGTSFFDPAGGGDPVLYQHLFWFFGHP 229
CtaD_CoxA TIGR02891
cytochrome c oxidase, subunit I; This large family represents subunit I's (CtaD, CoxA, CaaA) ...
 5-220 7.70e-75

cytochrome c oxidase, subunit I; This large family represents subunit I's (CtaD, CoxA, CaaA) of cytochrome c oxidases of bacterial origin. Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits I-III form the functional core of the enzyme complex. Subunit I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit II and heme a of subunit I to the bimetallic center formed by heme a3 and copper B. This cytochrome c oxidase shows proton pump activity across the membrane in addition to the electron transfer. In the bacilli an apparent split (paralogism) has created a sister clade (TIGR02882) encoding subunits (QoxA) of the aa3-type quinone oxidase complex which reacts directly with quinones, bypassing the interaction with soluble cytochrome c. This model attempts to exclude these sequences, placing them between the trusted and noise cutoffs. These families, as well as archaeal and eukaryotic cytochrome c subunit I's are included within the superfamily model, pfam00115. [Energy metabolism, Electron transport]


Pssm-ID: 213748  Cd Length: 499  Bit Score: 234.04  E-value: 7.70e-75
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133    5 AGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMiGGFGNWLVPLMIGAPDMAFPRMNNMSFWLL 84
Cdd:TIGR02891  20 FFLVGGVLALLMRAQLATPGNTFMDAETYNQLFTMHGTIMIFLFAIPIL-AGFGNYLLPLMIGARDMAFPRLNAFSYWLY 98

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   85 PPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFV 164
Cdd:TIGR02891  99 LFGGLLLLASFFTGGAPDTGWTMYPPLSSTSGSPGVGVDLWLLGLHLLGISSILGAVNFIVTILNMRAPGMTLMRMPLFV 178

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 633256133  165 WSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:TIGR02891 179 WGILVTSILILLAFPVLIAALILLLLDRLFGTHFFDPARGGDPLLWQHLFWFFGHP 234
CyoB COG0843
Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];
5-220 2.54e-72

Heme/copper-type cytochrome/quinol oxidase, subunit 1 [Energy production and conversion];


Pssm-ID: 440605  Cd Length: 535  Bit Score: 228.47  E-value: 2.54e-72
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   5 AGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLVPLMIGAPDMAFPRMNNMSFWLL 84
Cdd:COG0843   29 FLLIGGLLALLMRLQLAGPGLGLLSPETYNQLFTMHGTIMIFFFATP-FLAGFGNYLVPLQIGARDMAFPRLNALSFWLY 107

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  85 PPSFLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFV 164
Cdd:COG0843  108 LFGGLLLLISLFVGGAADVGWTFYPPLSGLEASPGVGVDLWLLGLALFGVGSILGGVNFIVTILKMRAPGMTLMRMPLFT 187

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 633256133 165 WSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:COG0843  188 WAALVTSILILLAFPVLAAALLLLLLDRSLGTHFFDPAGGGDPLLWQHLFWFFGHP 243
COX1 MTH00048
cytochrome c oxidase subunit I; Provisional
 1-220 8.72e-67

cytochrome c oxidase subunit I; Provisional


Pssm-ID: 177123  Cd Length: 511  Bit Score: 213.77  E-value: 8.72e-67
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:MTH00048  23 LGVWSGFVGLSLSLLIRLNFLDPYYNVISLDVYNFLITNHGIIMIFFFLMPVLIGGFGNYLLPLLLGLSDLNLPRLNALS 102

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  81 FWLLPPSFLLLLASstVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSqYQT 160
Cdd:MTH00048 103 AWLLVPSIVFLLLS--MCLGAGVGWTFYPPLSSSLFSSSWGVDFLMFSLHLAGVSSLFGSINFICTIYSAFMTNVF-SRT 179

                        170       180       190       200       210       220
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:MTH00048 180 SIILWSYLFTSILLLLSLPVLAAAITMLLFDRNFGSAFFDPLGGGDPVLFQHMFWFFGHP 239
Ubiquinol_Oxidase_I cd01662
Ubiquinol oxidase subunit I. Ubiquinol oxidase, the terminal oxidase in the respiratory ...
 8-220 4.10e-61

Ubiquinol oxidase subunit I. Ubiquinol oxidase, the terminal oxidase in the respiratory chains of aerobic bacteria, is a multi-chain transmembrane protein located in the cell membrane. It catalyzes the reduction of O2 and simultaneously pumps protons across the membrane. The number of subunits in ubiquinol oxidase varies from two to five. Subunit I contains a heme-copper binuclear center (the active site where O2 is reduced to water) formed by a high-spin heme and a copper ion. It also contains a low-spin heme, believed to participate in the transfer of electrons from ubiquinol to the binuclear center. For every reduction of an O2 molecule, eight protons are taken from the inside aqueous compartment and four electrons are taken from ubiquinol on the opposite side of the membrane. The four electrons and four of the protons are used in the reduction of O2; the four remaining protons are pumped across the membrane. This charge separation of four charges contributes to the electrochemical gradient used for ATP synthesis. Two proton channels, the D-pathway and K-pathway, leading to the binuclear center have been identified in subunit I. It is generally believed that the channels contain water molecules that act as 'proton wires' to transfer the protons. A well-defined pathway for the transfer of pumped protons beyond the binuclear center has not been identified. Electrons are believed to be transferred directly from ubiquinol (the electron donor) to the low-spin heme, and directly from the low-spin heme to the binuclear center.


Pssm-ID: 238832  Cd Length: 501  Bit Score: 198.57  E-value: 4.10e-61
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   8 IGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGgFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPS 87
Cdd:cd01662   24 RGGVDALLMRTQLALPGNDFLSPEHYNQIFTMHGTIMIFLFAMPLVFG-LMNYLVPLQIGARDVAFPRLNALSFWLFLFG 102

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  88 FLLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFVWSV 167
Cdd:cd01662  103 GLLLNASLLIGGFPDAGWFAYPPLSGLEYSPGVGVDYWILGLQFSGIGTLLGAINFIVTILKMRAPGMTLMRMPIFTWTT 182

                        170       180       190       200       210
                 ....*....|....*....|....*....|....*....|....*....|...
gi 633256133 168 LITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:cd01662  183 LVTSILILFAFPVLTAALALLELDRYFGTHFFTNALGGNPMLWQHLFWIFGHP 235
COX1 pfam00115
Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key ...
 1-220 4.56e-46

Cytochrome C and Quinol oxidase polypeptide I; Cytochrome c oxidase (E.C:7.1.1.9) is a key enzyme in aerobic metabolism. Proton pumping haem-copper oxidases represent the terminal, energy-transfer enzymes of respiratory chains in prokaryotes and eukaryotes. The CuB-haem a3 (or haem o) binuclear centre, associated with the largest subunit I of cytochrome c and ubiquinol oxidases (E.C:1.10.3.11), is directly involved in the coupling between dioxygen reduction and proton pumping. Some terminal oxidases generate a transmembrane proton gradient across the plasma membrane (prokaryotes) or the mitochondrial inner membrane (eukaryotes). The enzyme complex consists of 3-4 subunits (prokaryotes) up to 13 polypeptides (mammals) of which only the catalytic subunit (equivalent to mammalian subunit I (COXI) is found in all haem-copper respiratory oxidases. The presence of a bimetallic centre (formed by a high-spin haem and copper B) as well as a low-spin haem, both ligated to six conserved histidine residues near the outer side of four transmembrane spans within CO I is common to all family members.


Pssm-ID: 459678  Cd Length: 432  Bit Score: 157.73  E-value: 4.56e-46
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133    1 FGAWAGMIGTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPiMIGGFGNWLVPLMIGAPDMAFPRMNNMS 80
Cdd:pfam00115   9 TALVWFLVGGLLGLLIRLQLAFPGLNFLSPLTYNQLRTLHGNLMIFWFATP-FLFGFGNYLVPLMIGARDMAFPRLNALS 87

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   81 FWLLPPSFLLLLASStveAGAGTGWTVYPPLAGnlahagasVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQyQT 160
Cdd:pfam00115  88 FWLVVLGAVLLLASF---GGATTGWTEYPPLVG--------VDLWYIGLLLAGVSSLLGAINFIVTILKRRAPGMTL-RM 155

                         170       180       190       200       210       220
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  161 PLFVWSVLITAVLLLLSLPVLAAGITMLLTDRNLNttffdpAGGGDPILYQHLFWFFGHP 220
Cdd:pfam00115 156 PLFVWAILATAILILLAFPVLAAALLLLLLDRSLG------AGGGDPLLDQHLFWWFGHP 209
QoxB TIGR02882
cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type ...
 9-220 5.12e-39

cytochrome aa3 quinol oxidase, subunit I; This family (QoxB) encodes subunit I of the aa3-type quinone oxidase, one of several bacterial terminal oxidases. This complex couples oxidation of reduced quinones with the reduction of molecular oxygen to water and the pumping of protons to form a proton gradient utilized for ATP production. aa3-type oxidases contain two heme a cofactors as well as copper atoms in the active site. [Energy metabolism, Electron transport]


Pssm-ID: 131928  Cd Length: 643  Bit Score: 141.92  E-value: 5.12e-39
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133    9 GTALSLLIRAELGQPGSLLGDDQIYNVIVTAHAFVMIFFMVMPIMIGgFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSF 88
Cdd:TIGR02882  68 GGIDALLMRAQLTVPDNKFLDAQHYNEIFTTHGVIMIIFMAMPFIIG-LMNIVVPLQIGARDVAFPVLNALSFWLFFAGA 146

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133   89 LLLLASSTVEAGAGTGWTVYPPLAGNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFVWSVL 168
Cdd:TIGR02882 147 MLFNISFVIGGSPDAGWTNYAPLAGPEFSPGVGVNYYLIALQISGIGTLMTGINFFVTILKMRAPGMKLMQMPMFTWTTL 226

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|..
gi 633256133  169 ITAVLLLLSLPVLAAGITMLLTDRNLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:TIGR02882 227 ITTLIIIFAFPVLTVALALMTTDRIFDTAFFTVAHGGMPMLWANLFWIWGHP 278
PRK15017 PRK15017
cytochrome o ubiquinol oxidase subunit I; Provisional
 33-220 7.48e-37

cytochrome o ubiquinol oxidase subunit I; Provisional


Pssm-ID: 184978  Cd Length: 663  Bit Score: 135.83  E-value: 7.48e-37
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133  33 YNVIVTAHAFVMIFFMVMPIMIGgFGNWLVPLMIGAPDMAFPRMNNMSFWLLPPSFLLLLASSTVEAGAGTGWTVYPPLA 112
Cdd:PRK15017  99 YDQIFTAHGVIMIFFVAMPFVIG-LMNLVVPLQIGARDVAFPFLNNLSFWFTVVGVILVNVSLGVGEFAQTGWLAYPPLS 177

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 633256133 113 GNLAHAGASVDLAIFSLHLAGVSSILGAINFITTAINMKPPALSQYQTPLFVWSVLITAVLLLLSLPVLAAGITMLLTDR 192
Cdd:PRK15017 178 GIEYSPGVGVDYWIWSLQLSGIGTTLTGINFFVTILKMRAPGMTMFKMPVFTWASLCANVLIIASFPILTVTVALLTLDR 257

                        170       180
                 ....*....|....*....|....*...
gi 633256133 193 NLNTTFFDPAGGGDPILYQHLFWFFGHP 220
Cdd:PRK15017 258 YLGTHFFTNDMGGNMMMYINLIWAWGHP 285
 
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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