first ricin B-type lectin domain, beta-trefoil fold, found in Viscum album B chain of beta-galactoside-specific lectins and similar proteins; This subfamily includes Viscum album beta-galactoside-specific lectins 1-4 (also known as mistletoe lectins or MLs), which inhibit growth of the human tumor cell line Molt4. They contain A and B chains. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 266 CSASEPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 345
Cdd:cd23485   1 CSASEPTVRIVGRNGMTVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 80

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....
gi 47716663 346 VREATIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 399
Cdd:cd23485  81 VREATIWQIWGNGTIINPRSNLVLAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 134

Ribosome inactivating protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    13 TGEEYFRFITLLRDYV-SSGSFSNEIPLLRQSGGGVEAARFVLVELTNEGGDSITAAIDVTNLYVVAYQAG-SQSYFLSG 90
Cdd:pfam00161   2 TADSYRDFIEDLRKALaSGDHVSHGIPVLPPQVPPRQPARWVHVVLVNTGTSSLTLALRVDNLYLVGFRNRnGYWYEFSD 81

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    91 PGTHLFTGTTRSSLPFNGSYPDLEQYAG-HRKQIPLGIDQLIQSVTAL-RFPGNTRTQ---ARSILILIQMISEAARFNP 165
Cdd:pfam00161  82 GSIYAALITGSTTLPFGGSYSLLENGGGaNLENVPLGRQQLEEAVSALaRYPPGGAPTadlARALAVLIQMVCEAARFRY 161

                         170       180
                  ....*....|....*....|....*....
gi 47716663   166 ILWRARQYINSGASFLPDVYMLELETSWG 194
Cdd:pfam00161 162 IERTVAAGWDEGLGVSPTGTMVKLENNWG 190

first ricin B-type lectin domain, beta-trefoil fold, found in Viscum album B chain of beta-galactoside-specific lectins and similar proteins; This subfamily includes Viscum album beta-galactoside-specific lectins 1-4 (also known as mistletoe lectins or MLs), which inhibit growth of the human tumor cell line Molt4. They contain A and B chains. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 266 CSASEPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 345
Cdd:cd23485   1 CSASEPTVRIVGRNGMTVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 80

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....
gi 47716663 346 VREATIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 399
Cdd:cd23485  81 VREATIWQIWGNGTIINPRSNLVLAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 134

Ribosome inactivating protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    13 TGEEYFRFITLLRDYV-SSGSFSNEIPLLRQSGGGVEAARFVLVELTNEGGDSITAAIDVTNLYVVAYQAG-SQSYFLSG 90
Cdd:pfam00161   2 TADSYRDFIEDLRKALaSGDHVSHGIPVLPPQVPPRQPARWVHVVLVNTGTSSLTLALRVDNLYLVGFRNRnGYWYEFSD 81

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    91 PGTHLFTGTTRSSLPFNGSYPDLEQYAG-HRKQIPLGIDQLIQSVTAL-RFPGNTRTQ---ARSILILIQMISEAARFNP 165
Cdd:pfam00161  82 GSIYAALITGSTTLPFGGSYSLLENGGGaNLENVPLGRQQLEEAVSALaRYPPGGAPTadlARALAVLIQMVCEAARFRY 161

                         170       180
                  ....*....|....*....|....*....
gi 47716663   166 ILWRARQYINSGASFLPDVYMLELETSWG 194
Cdd:pfam00161 162 IERTVAAGWDEGLGVSPTGTMVKLENNWG 190

Ricin-type beta-trefoil; Carbohydrate-binding domain formed from presumed gene triplication.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    405 TIYGFNDLCMESNGGS--VWVETCVSQQ-NDRWALYGDGSIRPeQNQDQCLTSGRDSVAGINIVSCSGGSSGQRWVFTNE 481
Cdd:smart00458   1 IISGNTGKCLDVNGNKnpVGLFDCHGTGgNQLWKLTSDGAIRI-KDTDLCLTANGNTGSTVTLYSCDGTNDNQYWEVNKD 79

                           90       100       110
                   ....*....|....*....|....*....|....*....
gi 47716663    482 GAILNLKNGLAMDVAN-PGLGQIIIYPATGKPNQMWLPV 519
Cdd:smart00458  80 GTIRNPDSGKCLDVKDgNTGTKVILWTCSGNPNQKWIFE 118

Ricin-type beta-trefoil lectin domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663   272 TVRIVGRN-GMNVDVRDDDfHDGNQIQLWPSKSNNDpNQLWTIKRDGTIRSNGS--CLTTYGYTAGVYVMIFDCNTAVrE 348
Cdd:pfam00652   2 TGRIRNRAsGKCLDVPGGS-SAGGPVGLYPCHGSNG-NQLWTLTGDGTIRSVASdlCLDVGSTADGAKVVLWPCHPGN-G 78

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 47716663   349 ATIWQIWGNGT-IINPRSNLALAASSGIKGTT-LTVQT-LDYTLGQGW 393
Cdd:pfam00652  79 NQRWRYDEDGTqIRNPQSGKCLDVSGAGTSNGkVILWTcDSGNPNQQW 126

first ricin B-type lectin domain, beta-trefoil fold, found in Viscum album B chain of beta-galactoside-specific lectins and similar proteins; This subfamily includes Viscum album beta-galactoside-specific lectins 1-4 (also known as mistletoe lectins or MLs), which inhibit growth of the human tumor cell line Molt4. They contain A and B chains. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 266 CSASEPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 345
Cdd:cd23485   1 CSASEPTVRIVGRNGMTVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 80

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....
gi 47716663 346 VREATIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 399
Cdd:cd23485  81 VREATIWQIWGNGTIINPRSNLVLAASSGIKGTTLTVQTLDYTLGQGWLAGNDT 134

first ricin B-type lectin domain, beta-trefoil fold, found in type II ribosome-inactivating proteins (RIPs); Type II ribosome-inactivating proteins (RIPs) inhibit translation in eukaryotes by irreversibly inactivating the 28S rRNA and preventing the binding of elongation factor II to the ribosome. They consist of a catalytic A-chain which has rRNA N-glycosidase activity and a lectin B-chain containing two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The lectin chain facilitates the internalization of the catalytic chain on binding to the cell surface. The two chains are connected by a disulfide bridge. This model corresponds to the first ricin B-type lectin domain. Members of this subfamily includes Ricinus communis ricin, bitter gourd (Momordica charantia) seed lectin (BGSL), snake gourd (Trichosanthes anguina) seed lectin (SGSL), Sambucus ebulus ebulin I, Sambucus nigra nigrin b (also known as agglutinin V or SNAV), SNAI (also known as agglutinin I), SNAI' and SNAIf, Abrus precatorius abrin (ABR) and agglutinin-I (AAG), and Viscum album beta-galactoside-specific lectins 1-4 (also known as mistletoe lectins or MLs).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 271 PTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNnDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTAVREAT 350
Cdd:cd23443   1 PTVRIVGRDGLCVDVKDGYYSDGNPVILWPCKSQ-DANQLWTFKRDGTIRSNGKCLTTNGYSPGSYVVIYDCSTAVAEAT 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....
gi 47716663 351 IWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWL 394
Cdd:cd23443  80 KWEVSDDGTIINPASGLVLTADSGTSGTTLTVETNIYASSQGWR 123

first ricin B-type lectin domain, beta-trefoil fold, found in Abrus precatorius abrin, agglutinin-I and similar proteins; This subfamily includes Abrus precatorius abrin (ABR) and agglutinin-I (AAG), which share a high degree of sequence similarity and belong to the type II ribosome-inactivating protein (RIP) family. Type II RIPs inhibit protein synthesis in eukaryotic cells and can also induce apoptosis. They are two-polypeptide proteins with a toxic A chain and a lectin-like B chain linked by a disulfide bond. The A chain of abrin and agglutinin-I is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. Agglutinin-I is less toxic than abrin. The B chain is a galactose-specific lectin that facilitates the binding to the cell membrane that precedes endocytosis. The B-chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 265 TCSAS-EPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCN 343
Cdd:cd23484   3 ICSSRyEPTVRIGGRDGMCVDVYDNGYHNGNRIIMWKCKDRLEENQLWTLKSDKTIRSNGKCLTTYGYAPGNYVMIYDCT 82

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*
gi 47716663 344 TAVREATIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGND 398
Cdd:cd23484  83 SAVAEATYWEIWDNGTIINPKSALVLSAESSSMGGTLTVQTNEYLMRQGWRTGNN 137

first ricin B-type lectin domain, beta-trefoil fold, found in Cinnamomum camphora type II ribosome-inactivating protein (RIP) cinnamomin and similar proteins; RIPs are a group of ribotoxins that inhibit mammalian protein biosynthesis by irreversible inactivation of their 60S ribosomal subunit. Type II RIPs in plant cells comprise part of the plant's defense system towards animals. Cinnamomin is a type II RIP isolated from Cinnamomum camphora seeds. It shows inhibitory effects on cultured carcinoma cells and on the larvae of bollworm and mosquito. There are three cinnamomin isoforms (I, II, III). They are composed of two polypeptide chains (A- and B-chain) linked by a disulfide bond. The A-chain displays specific activity as an RNA N-glycosidase that blocks protein synthesis, whereas the B-chain is responsible for the binding to galactose-terminated receptors on cell membranes. The B-chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 270 EPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTAVREA 349
Cdd:cd23486   1 EPTVRISGRNGLCVDVRDGKYNNGNPIQLWPCKQNSDVNQLWTLRRDGTIRSNGKCLTTNGYSAGDYVMIYDCRTPVTAA 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 47716663 350 TIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGND 398
Cdd:cd23486  81 SIWQFWANGTIINPQSALVLSAESGNPRTTLTVQADIYASRQGWLAGNN 129

first ricin B-type lectin domain, beta-trefoil fold, found in Sambucus ebulus ebulin I and similar proteins; The family includes Sambucus ebulus ebulin I and Sambucus nigra nigrin b (also known as agglutinin V or SNAV), SNAI (also known as agglutinin I), SNAI' and SNAIf. Ebulin l is a type II ribosome-inactivating protein (RIP) isolated from the leaves of Sambucus ebulus. It is a disulfide-linked heterodimer composed of a toxic A chain and a galactoside-specific lectin B chain. It is considered a nontoxic type II RIP due to a reduced cytotoxicity on whole cells and animals as compared with other toxic type II RIP like ricins. Ebulin l binds an A-chain substrate analogue, pteroic acid. It binds bind galactose and lactose in subdomain 1alpha in a similar manner to that of ricin. In contrast, it binds only the monosaccharide galactose, and not the disaccharide lactose in subdomain 2gamma. SNAV is a non-toxic GalNAc-specific type II RIP which strongly inhibits mammalian protein synthesis but does not affect plant nor bacterial protein synthesis. SNAI is a Neu5Ac(alpha2-6)Gal/GalNAc-specific agglutinin. It also acts as a type II RIP that strongly inhibits mammalian but not plant ribosomes. SNAI' is another NeuAc(alpha2,6)Gal/GalNAc binding type II RIP from elderberry (Sambucus nigra) bark. It is a minor bark protein which closely resembles the major Neu5Ac(alpha2,6)Gal/GalNAc binding type II RIP, SNAI, with respect to its carbohydrate-binding specificity and ribosome-inactivating activity but has a different molecular structure due to a single cysteine residue present in the B chain of SNAI but absent from SNAI'. SNAIf is a fruit-specific SNAI. It functions as a fetuin-binding fruit lectin. Like Ebulin l, SNAV, SNAI, SNAI' and SNAIf consist of a sugar-binding B chain linked via a disulfide bond to the catalytically active A chain. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain. It may also be responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 270 EPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSksNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTAVREA 349
Cdd:cd23483   1 EFTRRISGRDGLCVDVRNGYDTDGTPVQLWPC--GTQRNQQWTFDTDGTIRSMGKCMTANGLNSGSYVMIYNCSTAAPEA 78

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*....
gi 47716663 350 TIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGWLAGND 398
Cdd:cd23483  79 TKWVVSIDGTITNPSSGLVLTAPRAASGTTLLLENNIHAASQGWTVGND 127

second ricin B-type lectin domain, beta-trefoil fold, found in Ricinus communis ricin, agglutinin and similar proteins; This subfamily includes ricin and agglutinin (RCA), toxic lectins from Ricinus communis. Ricin is highly toxic to animal cells, and to a lesser extent to plant cells. As a prototype AB toxin, ricin is composed of two polypeptide chains (A- and B-chain) linked by a disulfide bond. Ricin A chain acts as an RNA N-glycosidase that removes a specific adenine residue from an exposed loop of the 28S rRNA (A4324 in mammals), leading to rRNA breakage. Ricin B chain functions as a lectin that mediates cell binding via different oligosaccharide residues on the cell surface, including N-acetylglucosamine and galactose residues found on glycolipids and glycoproteins. It is also responsible for cell agglutination. Agglutinin shows high sequence similarity with ricin. It is only a weak toxin but a strong hemagglutinin. By contrast, ricin is a potent toxin but a weak hemagglutinin. Like ricin, agglutinin consists of a sugar-binding B chain linked via a disulfide bond to the catalytically active A chain. The B-chain of ricin and agglutinin contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the second ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 401 PREVTIYGFNDLCMESNGGSVWVETCVSQQNDR-WALYGDGSIRPEQNQDQCLTSG---RDSVagINIVSCSGGSSGQRW 476
Cdd:cd23487   1 PFVTTIVGLYGLCLQANSGKVWIEDCSSEKAEQqWALYADGSIRPQQNRDNCLTSDaniKETV--VKILSCGPASSGQRW 78

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*
gi 47716663 477 VFTNEGAILNLKNGLAMDV--ANPGLGQIIIYPATGKPNQMWLPV 519
Cdd:cd23487  79 MFKNDGTILNLYNGLVLDVraSDPSLKQIILHPFHGDLNQIWLPL 123

second ricin B-type lectin domain, beta-trefoil fold, found in Sambucus ebulus ebulin I and similar proteins; This subfamily includes Sambucus ebulus ebulin I and Sambucus nigra nigrin b (also known as agglutinin V or SNAV), SNAI (also known as agglutinin I), SNAI' and SNAIf. Ebulin l is a type II ribosome-inactivating protein (RIP) isolated from the leaves of Sambucus ebulus. It is a disulfide-linked heterodimer composed of a toxic A chain and a galactoside-specific lectin B chain. It is considered a nontoxic type II RIP due to a reduced cytotoxicity on whole cells and animals as compared with other toxic type II RIP like ricin. Ebulin l binds an A-chain substrate analogue, pteroic acid. It binds bind galactose and lactose in subdomain 1alpha in a similar manner to that of ricin. In contrast, it binds only the monosaccharide galactose, and not the disaccharide lactose in subdomain 2gamma. SNAV is a non-toxic GalNAc-specific type II RIP which strongly inhibits mammalian protein synthesis but does not affect plant nor bacterial protein synthesis. SNAI is Neu5Ac(alpha2-6)Gal/GalNAc specific agglutinin. It also acts as a type II RIP that strongly inhibits mammalian but not plant ribosomes. SNAI' is another NeuAc(alpha2,6)Gal/GalNAc binding type II RIP from elderberry (Sambucus nigra) bark. It is a minor bark protein which closely resembles the major Neu5Ac(alpha2,6)Gal/GalNAc binding type II RIP, SNAI, with respect to its carbohydrate-binding specificity and ribosome-inactivating activity but has a different molecular structure due to a single cysteine residue present in the B chain of SNAI but absent from SNAI'. SNAIf is fruit specific SNAI. It functions as fetuin-binding fruit lectin. Like Ebulin l, SNAV, SNAI, SNAI' and SNAIf consist of a sugar-binding B chain linked via a disulfide bond to the catalytically active A chain. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain. It may also be responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The model corresponds to the second ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 401 PREVTIYGFNDLCMESNGGS--VWVETCV-SQQNDRWALYGDGSIRPEQNQDQCLTS-GRDSVAGINIVSCSGGSSgQRW 476
Cdd:cd23490   1 PIVTFIVGYKEMCLQANGENngVWMEDCVvTSVQQQWALYGDGTIRVNSDRSLCVTSnGYNSKDLIIILKCQGLPN-QRW 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|...
gi 47716663 477 VFTNEGAILNLKNGLAMDVA--NPGLGQIIIYPATGKPNQMWL 517
Cdd:cd23490  80 VFNTDGTIVNPNSKLVMDVKqsDVSLREIILFPPTGNPNQQWI 122

first ricin B-type lectin domain, beta-trefoil fold, found in snake gourd (Trichosanthes anguina) seed lectin (SGSL) and similar proteins; Type II ribosome-inactivating proteins (RIPs) inhibit translation in eukaryotes by irreversibly inactivating the 28S rRNA and preventing the binding of elongation factor II to the ribosome. SGSL is a non-toxic three-chain type II RIP consisting of Aalpha, Abeta and B chains with Abeta and B being disulfide-linked. The Aalpha and Abeta chains constitute the rRNA glycosidase domain and the B chain contains two ricin B-type carbohydrate-binding lectin domains. SGSL may have no glycosidase activity due to small changes in both the nucleotide binding and carbohydrate binding capabilities. It binds galactose and derivatives with a preference for the beta-anomeric forms. It also binds prophyrins. SGSL has hemagglutinating activity towards rabbit and human erythrocytes. The ricin B-type lectin domain shows a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 266 CSASEPTVRIVGRNGMNVDVRDDDFHDGNQIQLWPSksNNDPNQLWTIKRDGTIRSNGSCLTTYGYTAGVYVMIFDCNTA 345
Cdd:cd23482   3 CLVETRTTRISGRDALCVDVAGALTSDGSRLILYPC--GQQVNQKWTFHSDGTVRSLGKCLATNNSKFGNLVVIYDCSKL 80

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|...
gi 47716663 346 VREATIWQIWGNGTIINPR-SNLALAASSGIKGTTLTVQTLDYTLGQGWLAGN 397
Cdd:cd23482  81 AAEDISWDVSVGGTIMNPNyEDLALTSNKATRSTNLTMEVNTYSASQGWRVGN 133

second ricin B-type lectin domain, beta-trefoil fold, found in bitter gourd (Momordica charantia) seed lectin (BGSL) and similar proteins; Type II ribosome-inactivating proteins (RIPs) inhibit translation in eukaryotes by irreversibly inactivating the 28S rRNA and preventing the binding of elongation factor II to the ribosome. BGSL is a non-toxic four-chain type II RIPs resulting from covalent association through a disulfide bridge between two identical copies of a two-chain unit. The two-chain unit consists of a catalytic A-chain and a lectin B-chain. The catalytic A-chain cannot firmly bind adenine due to the substitution of an aromatic residue involved in ensuring the proper orientation of the base in toxic RIPs, by a glycyl residue. BGSL is a galactose-specific lectin containing two ricin B-type lectin domains in B-chain. The ricin B-type lectin domain shows beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The model corresponds to the second ricin B-type lectin domain. In BGSL, sugar does not bind at the 2gamma site. Its 1alpha site binds sugar, which is similar to that in snake gourd (Trichosanthes anguina) seed lectin (SGSL).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 401 PREVTIYGFNDLCMES--NGGSVWVETCVSQQNDR-WALYGDGSIRPEQNQDQCLTSGRDSVAGINIVSCSGGSSGQRWV 477
Cdd:cd23488   1 PIVTTIIGLRHMCLEAtdNDTNVWLESCVKNKTKQyWALYSDDTIRVNNNRNLCVSSSTDSSSKLIVIRRCDGSINQRWV 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|..
gi 47716663 478 FTNEGAILNLKNGLAMDVANPG--LGQIIIYPATGKPN-QMW 516
Cdd:cd23488  81 FTPQGTISNPGYEAVMDVAQNDvyLKKIVLSSATDKGNgQQW 122

Ricin-type beta-trefoil; Carbohydrate-binding domain formed from presumed gene triplication.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663    274 RIVGRNGMNVDVRDDDfhdgNQIQLWPSKSNNdPNQLWTIKRDGTIRSNGS--CLTTYGYTaGVYVMIFDCNTAvREATI 351
Cdd:smart00458   1 IISGNTGKCLDVNGNK----NPVGLFDCHGTG-GNQLWKLTSDGAIRIKDTdlCLTANGNT-GSTVTLYSCDGT-NDNQY 73

                           90       100       110       120
                   ....*....|....*....|....*....|....*....|..
gi 47716663    352 WQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLDYTLGQGW 393
Cdd:smart00458  74 WEVNKDGTIRNPDSGKCLDVKDGNTGTKVILWTCSGNPNQKW 115

Ricin-type beta-trefoil lectin domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663   272 TVRIVGRN-GMNVDVRDDDfHDGNQIQLWPSKSNNDpNQLWTIKRDGTIRSNGS--CLTTYGYTAGVYVMIFDCNTAVrE 348
Cdd:pfam00652   2 TGRIRNRAsGKCLDVPGGS-SAGGPVGLYPCHGSNG-NQLWTLTGDGTIRSVASdlCLDVGSTADGAKVVLWPCHPGN-G 78

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 47716663   349 ATIWQIWGNGT-IINPRSNLALAASSGIKGTT-LTVQT-LDYTLGQGW 393
Cdd:pfam00652  79 NQRWRYDEDGTqIRNPQSGKCLDVSGAGTSNGkVILWTcDSGNPNQQW 126

ricin B-type lectin domain, beta-trefoil fold, found in Shewanella algae sphingolipid ceramide N-deacylase (SCDase) and similar proteins; SCDase (EC 3.5.1.69) is an enzyme which hydrolyzes the N-acyl linkage between fatty acid and sphingosine in ceramide of various glycosphingolipids and sphingomyelin. Shewanella algae SCDase contains two ricin B-type lectin domains at its C-terminus. The ricin B-type lectin domain shows a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain may harbor a sugar-binding pocket.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 408 GFNDLCM-----ESNGGSVWVETCVSQQNDRWALYGDGSIRPEQNQDQCLTSGRDSVAGINIV--SCSgGSSGQRWVFtN 480
Cdd:cd23456   8 QASGLCLdvsggATNGANVVVYDCNNSNSQKWYYDATGRLHSKANPGKCLDAGGENSNGANVVlwACN-DSANQRWDF-D 85

                        90       100       110
                ....*....|....*....|....*....|....*..
gi 47716663 481 EGAILNLKN-GLAMDVANPGLGQIIIYPATGKPNQMW 516
Cdd:cd23456  86 GNFIRSRNNtNLALDAYGSQGSNVGLWQFHGGANQQW 122

ricin B-type lectin domain, beta-trefoil fold; The ricin B-type lectin domain is a carbohydrate-binding domain formed from presumed gene triplication. It shows a beta-trefoil fold characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The ricin B-type lectin domain was originally found in Ricin, which is a legume lectin from the seeds of the castor bean plant, Ricinus communis. It is also found in many carbohydrate-recognition proteins like plant and bacterial AB-toxins, glycosidases, or proteases, which serve diverse functions such as inhibitory toxicity, enzymatic activity, and signal transduction. The ricin B-type lectin domain can be present in one or more copies and has been shown in some instances to bind simple sugars, such as galactose or lactose. The most characteristic, though not completely conserved, sequence feature is the presence of a Q-W pattern. Consequently, the ricin B-type lectin domain has also been referred as the (QxW)3 domain and the three homologous regions as the QxW repeats. A disulfide bond is also conserved in some QxW repeats.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 410 NDLCME------SNGGSVWVETCVSQQNDRWALY----GDGSIRPeQNQDQCLT-SGRDSVAGINIV--SCSGGSSgQRW 476
Cdd:cd00161  10 SGKCLDvaggstANGAPVQQWTCNGGANQQWTLTpvgdGYYTIRN-VASGKCLDvAGGSTANGANVQqwTCNGGDN-QQW 87

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*..
gi 47716663 477 VFTNEGA----ILNLKNGLAMDVANPGL---GQIIIYPATGKPNQMW 516
Cdd:cd00161  88 RLEPVGDgyyrIVNKHSGKCLDVSGGSTangANVQQWTCNGGANQQW 134

ricin B-type lectin domain, beta-trefoil fold, found in Streptomyces olivaceoviridis endo-1,4-beta-xylanase and similar proteins; The family includes Streptomyces olivaceoviridis endo-1,4-beta-xylanase (XLN, EC 3.2.1.8), Streptomyces avermitilis beta-L-arabinopyranosidase (EC 3.2.1.185), and Streptomyces coelicolor extracellular exo-alpha-L-arabinofuranosidase (ABF, EC 3.2.1.55). XLN, also called xylanase, or 1,4-beta-D-xylan xylanohydrolase, belongs to the glycosyl hydrolase 10 (cellulase F) family. It contributes to hydrolyze hemicellulose, the major component of plant cell walls. XLN contains a (beta/alpha)8-barrel as a catalytic domain, a family 13 carbohydrate binding module (CBM13) as a xylan binding domain (XBD) and a Gly/Pro-rich linker between them. Beta-L-arabinopyranosidase belongs to the glycosyl hydrolase 27 (GH27) family. It has a GH27 catalytic domain, an antiparallel beta-domain containing Greek key motifs, another antiparallel beta-domain forming a jellyroll structure, and a CBM13 module. ScAraf62A, also called ABF, or arabinosidase, or arabinoxylan arabinofuranohydrolase, belongs to the glycosyl hydrolase 62 (GH62) family. It is involved in the degradation of xylan and is a key enzyme in the complete degradation of the plant cell wall. It has a specific arabinofuranose-debranching activity on xylan from gramineae. It acts synergistically with xylanases and binds specifically to xylan. ScAraf62A comprises a CBM13 module at its N-terminus and a catalytic domain at its C-terminus. This model corresponds to the CBM13 module, which is a ricin B-type lectin domain with a beta-trefoil fold, characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain may contain a potential sugar-binding pocket.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 270 EPTVRIVG-RNGMNVDVRDDDFHDGNQIQLWPskSNNDPNQLWTIKRDGTIRSNGS-CLTTYG--YTAGVYVMIFDCNTA 345
Cdd:cd23418   3 AGGGQIRGyGSGRCLDVPGGSTTNGTRLILWD--CHGGANQQFTFTSAGELRVGGDkCLDAAGggTTNGTPVVIWPCNGG 80

                        90       100
                ....*....|....*....|....
gi 47716663 346 vrEATIWQIWGNGTIINPRSNLAL 369
Cdd:cd23418  81 --ANQKWRFNSDGTIRNVNSGLCL 102

ricin B-type lectin domain, beta-trefoil fold, found in glucan endo-1,3-beta-glucosidase and similar proteins; Glucan endo-1,3-beta-glucosidase (EC 3.2.1.39), also called (1->3)-beta-glucan endohydrolase, or (1->3)-beta-glucanase, or laminarinase, belongs to the glycosyl hydrolase 64 (GH64) family. It catalyzes hydrolysis of (1->3)-beta-D-glucosidic linkages in (1->3)-beta-D-glucans. It has been implicated in the defense against fungal pathogens. Glucan endo-1,3-beta-glucosidase contains a C-terminal ricin B-type lectin domain with a beta-trefoil fold, characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain bears a potential sugar binding site.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 416 SNGGSVWVETCVSQQNDRWALYGDGSIRpeqNQDQCLT-SGRDSVAGINIV--SCsGGSSGQRWVFTNEGAILNLKNGLA 492
Cdd:cd23451  22 ADGNPVQIYTCNGTAAQKWTLGTDGTLR---VLGKCLDvSGGGTANGTLVQlwDC-NGTGAQKWVPRADGTLYNPQSGKC 97

                        90       100
                ....*....|....*....|....*..
gi 47716663 493 MDVANPGL---GQIIIYPATGKPNQMW 516
Cdd:cd23451  98 LDAPGGSTtdgTQLQLYTCNGTAAQQW 124

ricin B-type lectin domain, beta-trefoil fold, found in Lumbricus terrestris 29-kDa galactose-binding lectin (EW29) and similar proteins; EW29 is a galactose-binding lectin from the earthworm Lumbricus terrestris. It contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The second ricin B-type lectin domain may harbor two sugar-binding pockets in subdomains alpha and gamma. EW29 uses these two sugar-binding sites for its function as a single domain-type hemagglutinin.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 275 IVGR-NGMNVDVRDDDFHDGNQIQLWPSKSNNDPNQLWTI-KRDGTIRS--NGSCLTTYGYtAGVYVMIFDCNTAVREat 350
Cdd:cd23449   5 IKSKlNGKVLDVEGANAKPGAKVIMWEKKGGAEDNQLWYEdEVTGTIRSklNDFCLDASGD-KGLILNPYDPSNPKQQ-- 81

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*..
gi 47716663 351 iWQIwGNGTIINpRSN----LALAASSGIKGTTLTVQTLDYTLGQGW 393
Cdd:cd23449  82 -WKI-SGNKIQN-RSNpdnvLDIKGGSKDDGARLCAWEYNGGPNQLW 125

ricin B-type lectin domain, beta-trefoil fold, found in alpha-galactosidase A (AglA) and similar proteins; AglA (EC 3.2.1.22), also called melibiase A, hydrolyzes a variety of simple alpha-D-galactosides as well as more complex molecules such as oligosaccharides and polysaccharides. It belongs to the glycosyl hydrolase 27 (GH27) family. AglA contains an N-terminal GH27 catalytic domain, an alpha galactosidase C-terminal beta sandwich domain in the middle region, and a carbohydrate-binding domain at the C-terminus. The carbohydrate-binding domain is also known as a ricin B-type lectin domain with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain may contain a potential sugar-binding pocket.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 406 IYGFNDL-CMESNGGSVWVETCVSQQNDRWALYGDGSIRPEQNQDQCLTSGRDSVAginiVSCSGGSSGQRWVFTNEGAI 484
Cdd:cd23425   7 IFNTASGnCLTADAAEVKFQTCDGSDSQIWQVRKSGILRNLSNTGQCLTADGANVS----LSPCDTSTSQNWSYEISGNL 82

                ....*....
gi 47716663 485 LNLKNGLAM 493
Cdd:cd23425  83 VNKKTGLCL 91

ricin B-type lectin domain, beta-trefoil fold, found in Rarobacter faecitabidus serine protease I (RPI) and similar proteins; RPI, also called serine protease 1, is a major serine protease exhibiting lytic activity toward living yeast cells. It has a lectin-like affinity for mannose. Mannoproteins may be the native substrate for RPI. RPI contains a C-terminal ricin B-type lectin domain with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain bears a potential sugar binding site.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 404 VTIYGFNDLCME------SNGGSVWVETCVSQQNDRWALYGDGSIRpeqNQDQCLT---SGRDSVAGINIVSCSGgSSGQ 474
Cdd:cd23452   4 TPIIGLANKCIDvpnsstTDGAPLQLWDCNGTNAQKWTFASDGTLR---ALGKCLDvawGGTDNGTAVQLWTCSG-NPAQ 79

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*
gi 47716663 475 RWVFTNEGAILNLKNGLAMDVANPGLGQ---IIIYPATGKPNQMW 516
Cdd:cd23452  80 QFVLSGAGDLVNPQANKCVDVSGGNSGNgtrLQLWECSGNANQKW 124

ricin B-type lectin domain, beta-trefoil fold, found in Drosophila melanogaster polypeptide N-acetylgalactosaminyltransferase 1 (Pgant1) and similar proteins; Pgant1, also called pp-GaNTase 1, protein-UDP acetylgalactosaminyltransferase 1, or UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 1, functions as a GalNAc transferase (EC 2.4.1.41) that catalyzes the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor. Pgant1 can both act as a peptide transferase that transfers GalNAc onto unmodified peptide substrates, and as a glycopeptide transferase that requires the prior addition of a GalNAc on a peptide before adding additional GalNAc moieties. It prefers the monoglycosylated Muc5AC-3 as a substrate. Members of this subfamily contain a ricin B-type lectin domain at the C-terminus. The ricin B-type lectin domain shows a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. Each subdomain bears a potential sugar binding site.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 307 PNQLWTIKRDGTIRSNGSCLTTYGyTAGVYVMIFDCNTAVREATIWQIWGNGTIINPRSNLALAASSGIKGTTLTVQTLD 386
Cdd:cd23459  43 SNQLFSLSKKGELRREESCADVQG-TEESKVILITCHGLEKFNQKWKHTKGGQIVHLASGKCLDAEGLKSGDDVTLAKCD 121

                ....*..
gi 47716663 387 YTLGQGW 393
Cdd:cd23459 122 GSLSQKW 128

first ricin B-type lectin domain, beta-trefoil fold, found in Sambucus ebulus ebulin I and similar proteins; The family includes Sambucus ebulus ebulin I and Sambucus nigra nigrin b (also known as agglutinin V or SNAV), SNAI (also known as agglutinin I), SNAI' and SNAIf. Ebulin l is a type II ribosome-inactivating protein (RIP) isolated from the leaves of Sambucus ebulus. It is a disulfide-linked heterodimer composed of a toxic A chain and a galactoside-specific lectin B chain. It is considered a nontoxic type II RIP due to a reduced cytotoxicity on whole cells and animals as compared with other toxic type II RIP like ricins. Ebulin l binds an A-chain substrate analogue, pteroic acid. It binds bind galactose and lactose in subdomain 1alpha in a similar manner to that of ricin. In contrast, it binds only the monosaccharide galactose, and not the disaccharide lactose in subdomain 2gamma. SNAV is a non-toxic GalNAc-specific type II RIP which strongly inhibits mammalian protein synthesis but does not affect plant nor bacterial protein synthesis. SNAI is a Neu5Ac(alpha2-6)Gal/GalNAc-specific agglutinin. It also acts as a type II RIP that strongly inhibits mammalian but not plant ribosomes. SNAI' is another NeuAc(alpha2,6)Gal/GalNAc binding type II RIP from elderberry (Sambucus nigra) bark. It is a minor bark protein which closely resembles the major Neu5Ac(alpha2,6)Gal/GalNAc binding type II RIP, SNAI, with respect to its carbohydrate-binding specificity and ribosome-inactivating activity but has a different molecular structure due to a single cysteine residue present in the B chain of SNAI but absent from SNAI'. SNAIf is a fruit-specific SNAI. It functions as a fetuin-binding fruit lectin. Like Ebulin l, SNAV, SNAI, SNAI' and SNAIf consist of a sugar-binding B chain linked via a disulfide bond to the catalytically active A chain. The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain. It may also be responsible for cell agglutination (lectin activity). The B chain contains two ricin B-type lectin domains with a beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. This model corresponds to the first ricin B-type lectin domain.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 47716663 406 IYGFNDLCME------SNGGSVWVETCVSQQNDRWALYGDGSIRpeqNQDQCLT-SGRDSVAGINIVSCSGGSSGQ-RWV 477
Cdd:cd23483   6 ISGRDGLCVDvrngydTDGTPVQLWPCGTQRNQQWTFDTDGTIR---SMGKCMTaNGLNSGSYVMIYNCSTAAPEAtKWV 82

                        90
                ....*....|....*.
gi 47716663 478 FTNEGAILNLKNGLAM 493
Cdd:cd23483  83 VSIDGTITNPSSGLVL 98

ricin B-type lectin domain, beta-trefoil fold, found in the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3)-like subfamily; The GALNT3-like subfamily includes GALNT3, GALNT4, GALNT6 and GALNT12. They act as GalNAc transferases (EC 2.4.1.41) that catalyze the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor. GALNT3 has activity toward HIV envelope glycoprotein gp120, EA2, Muc2 and Muc5. It probably glycosylates fibronectin in vivo as well as FGF23. It plays a central role in phosphate homeostasis. GALNT4 shows highest activity towards Muc7, EA2 and Muc2, with a lower activity compared to GALNT2. It glycosylates 'Thr-57' of SELPLG. GALNT6 may participate in the synthesis of oncofetal fibronectin. It has activity toward Muc1a, Muc2, EA2 and fibronectin peptides. GALNT12 has activity toward non-glycosylated peptides such as Muc5AC, Muc1a and EA2, and no detectable activity with non-glycosylated Muc2 and Muc7. It displays enzymatic activity toward the Gal-NAc-Muc5AC glycopeptide, but no detectable activity to mono-GalNAc-glycosylated Muc1a, Muc2, Muc7 and EA2. It may play an important role in the initial step of mucin-type oligosaccharide biosynthesis in digestive organs. Members of this family comprise a glycosyltransferase region and a ricin B-type lectin domain. The glycosyltransferase region contains two conserved domains, domain A (also called GT1 motif) and domain B (also called Gal/GalNAc-T motif). This model corresponds to the ricin B-type lectin domain with a beta-trefoil fold, which are characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry. The ricin B-type lectin domain binds to GalNAc and contributes to the glycopeptide specificity.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 47716663 411 DLCME-SNGGSVWVETCVSQQNDR-----WALYGDGSIRPEQNqDQCLTSGRDSVAginIVSCSGGSSGQRWVFT 479
Cdd:cd23435  58 ELCLHaSGSDEVILQHCTSKGKDVppeqkWLFTQDGTIRNPAS-GLCLHASGYKVL---LRTCNPSDDSQKWTFI 128