O60513 · B4GT4_HUMAN
- ProteinBeta-1,4-galactosyltransferase 4
- GeneB4GALT4
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids344 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Galactose (Gal) transferase involved in the synthesis of terminal N-acetyllactosamine (LacNac) unit present on glycan chains of glycoproteins and glycosphingolipids (PubMed:12511560, PubMed:17690104, PubMed:32827291, PubMed:9792633).
Catalyzes the transfer of Gal residue via a beta1->4 linkage from UDP-Gal to the non-reducing terminal N-acetyl glucosamine 6-O-sulfate (6-O-sulfoGlcNAc) in the linearly growing chain of both N- and O-linked keratan sulfate proteoglycans. Cooperates with B3GNT7 N-acetyl glucosamine transferase and CHST6 and CHST1 sulfotransferases to construct and elongate mono- and disulfated disaccharide units [->3Galbeta1->4(6-sulfoGlcNAcbeta)1->] and [->3(6-sulfoGalbeta)1->4(6-sulfoGlcNAcbeta)1->] within keratan sulfate polymer (PubMed:17690104).
Transfers Gal residue via a beta1->4 linkage to terminal 6-O-sulfoGlcNAc within the LacNac unit of core 2 O-glycans forming 6-sulfo-sialyl-Lewis X (sLex). May contribute to the generation of sLex epitope on mucin-type glycoproteins that serve as ligands for SELL/L-selectin, a major regulator of leukocyte migration (PubMed:12511560).
In the biosynthesis pathway of neolacto-series glycosphingolipids, transfers Gal residue via a beta1->4 linkage to terminal GlcNAc of a lactotriaosylceramide (Lc3Cer) acceptor to form a neolactotetraosylceramide (PubMed:9792633).
Catalyzes the transfer of Gal residue via a beta1->4 linkage from UDP-Gal to the non-reducing terminal N-acetyl glucosamine 6-O-sulfate (6-O-sulfoGlcNAc) in the linearly growing chain of both N- and O-linked keratan sulfate proteoglycans. Cooperates with B3GNT7 N-acetyl glucosamine transferase and CHST6 and CHST1 sulfotransferases to construct and elongate mono- and disulfated disaccharide units [->3Galbeta1->4(6-sulfoGlcNAcbeta)1->] and [->3(6-sulfoGalbeta)1->4(6-sulfoGlcNAcbeta)1->] within keratan sulfate polymer (PubMed:17690104).
Transfers Gal residue via a beta1->4 linkage to terminal 6-O-sulfoGlcNAc within the LacNac unit of core 2 O-glycans forming 6-sulfo-sialyl-Lewis X (sLex). May contribute to the generation of sLex epitope on mucin-type glycoproteins that serve as ligands for SELL/L-selectin, a major regulator of leukocyte migration (PubMed:12511560).
In the biosynthesis pathway of neolacto-series glycosphingolipids, transfers Gal residue via a beta1->4 linkage to terminal GlcNAc of a lactotriaosylceramide (Lc3Cer) acceptor to form a neolactotetraosylceramide (PubMed:9792633).
Catalytic activity
- N-acetyl-D-glucosamine + UDP-alpha-D-galactose = beta-D-galactosyl-(1->4)-N-acetyl-D-glucosamine + H+ + UDPThis reaction proceeds in the forward direction.
- 3-O-{beta-D-galactosyl-(1->3)-[6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] + UDP-alpha-D-galactose = 3-O-{beta-D-galactosyl-(1->3)-[beta-D-galactosyl-(1->4)-6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-seryl-[protein] + H+ + UDPThis reaction proceeds in the forward direction.
- 3-O-{beta-D-galactosyl-(1->3)-[6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + UDP-alpha-D-galactose = 3-O-{beta-D-galactosyl-(1->3)-[beta-D-galactosyl-(1->4)-6-O-sulfo-N-acetyl-beta-D-glucosaminyl-(1->6)]-N-acetyl-alpha-D-galactosaminyl}-L-threonyl-[protein] + H+ + UDPThis reaction proceeds in the forward direction.
Cofactor
Activity regulation
Up-regulated by LALBA.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.031 mM | UDP-Gal | |||||
238 μM | GlcNAc-B-S-pNP | |||||
0.43 mM | SO3->6GlcNAc (6SGN) | |||||
330 mM | GlcNAc | |||||
0.11 mM | SO3 ->6GlcNAcbeta1->2Manalpha1->3(Manalpha1->6)Manbeta1->4GlcNAcbeta1->4( Fucalpha1->6)GlcNAc (6S-biGP) | |||||
7.7 mM | GlcNAcbeta1->2Manalpha1->3(Manalpha1->6)Manbeta1->4GlcNAcbeta1->4(Fuc alpha1->6)GlcNAc (biGP) | |||||
0.091 mM | SO3->6GlcNAcbeta1->6(Galbeta1->3)GalNAcalpha1-O-pNP (6S-core2-O-pNP) | |||||
0.5 mM | GlcNAcbeta1->6(Galbeta1->3)GalNAcalpha1-O-pNP (core2-O-pNP) | |||||
0.38 mM | SO3->6GlcNAcbeta1->3Galbeta1->4(SO3->6)GlcNAc (agL2L2) | |||||
0.63 mM | SO3->6GlcNAcbeta1->3(SO3->6)Galbeta1->4(SO3->6)GlcNAc (agL2L4) |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
3.6 nmol/min/mg | toward SO3->6GlcNAc (6SGN) | ||||
1.5 nmol/min/mg | toward GlcNAc | ||||
3.2 nmol/min/mg | toward 6GlcNAcbeta1->2Manalpha1->3(Manalpha1->6)Manbeta1->4GlcNAcbeta1->4(Fu calpha1->6)GlcNAc (6S-biGP) | ||||
0.42 nmol/min/mg | toward GlcNAcbeta1->2Manalpha1->3(Manalpha1->6)Manbeta1->4GlcNAcbeta1->4(Fuc alpha1->6)GlcNAc (biGP) | ||||
4.8 nmol/min/mg | toward SO3->6GlcNAcbeta1->6(Galbeta1->3)GalNAcalpha1-O-pNP (6S-core2-O-pNP) | ||||
1.2 nmol/min/mg | toward GlcNAcbeta1->6(Galbeta1->3)GalNAcalpha1-O-pNP (core2-O-pNP) | ||||
7.8 nmol/min/mg | toward SO3->6GlcNAcbeta1->3Galbeta1->4(SO3->6)GlcNAc (agL2L2) | ||||
7.8 nmol/min/mg | toward SO3->6GlcNAcbeta1->3(SO3->6)Galbeta1->4(SO3->6)GlcNAc (agL2L4) |
Pathway
Protein modification; protein glycosylation.
Glycolipid biosynthesis.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 129-133 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: PHRNR | ||||||
Binding site | 168-170 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: FNR | ||||||
Binding site | 195-196 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: VD | ||||||
Binding site | 196 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 224 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 256 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: W | ||||||
Binding site | 258-261 | N-acetyl-D-glucosamine (UniProtKB | ChEBI) | ||||
Sequence: GEDD | ||||||
Binding site | 289 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 289-291 | UDP-alpha-D-galactose (UniProtKB | ChEBI) | ||||
Sequence: HTR | ||||||
Binding site | 301 | N-acetyl-D-glucosamine (UniProtKB | ChEBI) | ||||
Sequence: R |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Cellular Component | Golgi apparatus | |
Cellular Component | Golgi membrane | |
Cellular Component | membrane | |
Molecular Function | galactosyltransferase activity | |
Molecular Function | metal ion binding | |
Molecular Function | N-acetyllactosamine synthase activity | |
Molecular Function | UDP-galactosyltransferase activity | |
Biological Process | carbohydrate metabolic process | |
Biological Process | glycosylation | |
Biological Process | keratan sulfate biosynthetic process | |
Biological Process | lactosylceramide biosynthetic process | |
Biological Process | membrane lipid metabolic process | |
Biological Process | protein glycosylation |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Chemistry
Names & Taxonomy
Protein names
- Recommended nameBeta-1,4-galactosyltransferase 4
- EC number
- Short namesBeta-1,4-GalTase 4; Beta4Gal-T4; b4Gal-T4
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionO60513
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Golgi apparatus membrane ; Single-pass type II membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-12 | Cytoplasmic | ||||
Sequence: MGFNLTFHLSYK | ||||||
Transmembrane | 13-38 | Helical; Signal-anchor for type II membrane protein | ||||
Sequence: FRLLLLLTLCLTVVGWATSNYFVGAI | ||||||
Topological domain | 39-344 | Lumenal | ||||
Sequence: QEIPKAKEFMANFHKTLILGKGKTLTNEASTKKVELDNCPSVSPYLRGQSKLIFKPDLTLEEVQAENPKVSRGRYRPQECKALQRVAILVPHRNREKHLMYLLEHLHPFLQRQQLDYGIYVIHQAEGKKFNRAKLLNVGYLEALKEENWDCFIFHDVDLVPENDFNLYKCEEHPKHLVVGRNSTGYRLRYSGYFGGVTALSREQFFKVNGFSNNYWGWGGEDDDLRLRVELQRMKISRPLPEVGKYTMVFHTRDKGNEVNAERMKLLHQVSRVWRTDGLSSCSYKLVSVEHNPLYINITVDFWFGA |
Keywords
- Cellular component
Disease & Variants
Features
Showing features for mutagenesis, natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 6 | Has no impact on N-glycosylation. | ||||
Sequence: T → A | ||||||
Natural variant | VAR_022697 | 116 | in dbSNP:rs3764779 | |||
Sequence: Q → E | ||||||
Mutagenesis | 222 | Has no impact on localization to the Golgi apparatus. Decreases N-glycosylation. Impairs the catalytic activity. Impairs keratan sulfate biosynthesis; when associated with A-337. | ||||
Sequence: T → A | ||||||
Mutagenesis | 337 | Impairs localization to the Golgi apparatus. Abolishes N-glycosylation. Impairs the interaction with SLC35A/UGT1. Impairs the catalytic activity. Impairs keratan sulfate biosynthesis; when associated with A-222. | ||||
Sequence: T → A |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 368 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for chain, disulfide bond, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000080542 | 1-344 | Beta-1,4-galactosyltransferase 4 | |||
Sequence: MGFNLTFHLSYKFRLLLLLTLCLTVVGWATSNYFVGAIQEIPKAKEFMANFHKTLILGKGKTLTNEASTKKVELDNCPSVSPYLRGQSKLIFKPDLTLEEVQAENPKVSRGRYRPQECKALQRVAILVPHRNREKHLMYLLEHLHPFLQRQQLDYGIYVIHQAEGKKFNRAKLLNVGYLEALKEENWDCFIFHDVDLVPENDFNLYKCEEHPKHLVVGRNSTGYRLRYSGYFGGVTALSREQFFKVNGFSNNYWGWGGEDDDLRLRVELQRMKISRPLPEVGKYTMVFHTRDKGNEVNAERMKLLHQVSRVWRTDGLSSCSYKLVSVEHNPLYINITVDFWFGA | ||||||
Disulfide bond | 77↔118 | |||||
Sequence: CPSVSPYLRGQSKLIFKPDLTLEEVQAENPKVSRGRYRPQEC | ||||||
Disulfide bond | 189↔208 | |||||
Sequence: CFIFHDVDLVPENDFNLYKC | ||||||
Glycosylation | 220 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 335 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N |
Post-translational modification
N-glycosylated.
Keywords
- PTM
Proteomic databases
PTM databases
Structure
Sequence
- Sequence statusComplete
- Length344
- Mass (Da)40,041
- Last updated1998-08-01 v1
- Checksum6B7742676FE8A58B
Computationally mapped potential isoform sequences
There are 9 potential isoforms mapped to this entry
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 182 | in Ref. 4; AAG50147 | ||||
Sequence: L → R |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AF038662 EMBL· GenBank· DDBJ | AAC39735.1 EMBL· GenBank· DDBJ | mRNA | ||
AF022367 EMBL· GenBank· DDBJ | AAC72493.1 EMBL· GenBank· DDBJ | mRNA | ||
AB024436 EMBL· GenBank· DDBJ | BAA75821.1 EMBL· GenBank· DDBJ | mRNA | ||
AF020920 EMBL· GenBank· DDBJ | AAG50147.1 EMBL· GenBank· DDBJ | mRNA | ||
AY359008 EMBL· GenBank· DDBJ | AAQ89367.1 EMBL· GenBank· DDBJ | mRNA | ||
CR749555 EMBL· GenBank· DDBJ | CAH18352.1 EMBL· GenBank· DDBJ | mRNA | ||
BC004523 EMBL· GenBank· DDBJ | AAH04523.1 EMBL· GenBank· DDBJ | mRNA | ||
BC062618 EMBL· GenBank· DDBJ | AAH62618.1 EMBL· GenBank· DDBJ | mRNA |