GALNT7
Domain
There are two conserved domains in the glycosyltransferase region: the N-terminal domain (domain A, also called GT1 motif), which is probably involved in manganese coordination and substrate binding and the C-terminal domain (domain B, also called Gal/GalNAc-T motif), which is probably involved in catalytic reaction and UDP-Gal binding.
The ricin B-type lectin domain binds to GalNAc and contributes to the glycopeptide specificity.
Function
Glycopeptide transferase involved in O-linked oligosaccharide biosynthesis, which catalyzes the transfer of an N-acetyl-D-galactosamine residue to an already glycosylated peptide. In contrast to other proteins of the family, it does not act as a peptide transferase that transfers GalNAc onto serine or threonine residue on the protein receptor, but instead requires the prior addition of a GalNAc on a peptide before adding additional GalNAc moieties. Some peptide transferase activity is however not excluded, considering that its appropriate peptide substrate may remain unidentified.
Pathway
Protein modification; protein glycosylation.
Sequence Similarities
Belongs to the glycosyltransferase 2 family. GalNAc-T subfamily.
Tissue Specificity
Widely expressed. Expressed in uterus, retina, kidney, small intestine, omentum, stomach and CNS.
Cellular localization
- Golgi apparatus membrane
- Single-pass type II membrane protein
Alternative names
N-acetylgalactosaminyltransferase 7, Polypeptide GalNAc transferase 7, Protein-UDP acetylgalactosaminyltransferase 7, UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 7, GalNAc-T7, pp-GaNTase 7, GALNT7