N-acetylgalactosaminyltransferase 7 (Galnt7)

Glycopeptide transferase involved with O-linked oligosaccharide biosynthesis, which catalyzes the transfer of an N-acetyl-D-galactosamine residue to an already glycosylated peptide. Compared to other proteins of the family, it does not act as a peptide transferase that transfers GalNAc on serine or threonine residue on the protein receptor, but rather 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. .