Reaction: (1) UDP-N-acetyl-α-D-galactosamine + [protein]-L-serine = UDP + [protein]-3-O-(N-acetyl-α-D-galactosaminyl)-L-serine
(2) UDP-N-acetyl-α-D-galactosamine + [protein]-L-threonine = UDP + [protein]-3-O--(N-acetyl-α-D-galactosaminyl)-L-threonine
Other name(s): protein-UDP acetylgalactosaminyltransferase; UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase; UDP-N-acetylgalactosamine:κ-casein polypeptide N-acetylgalactosaminyltransferase; uridine diphosphoacetylgalactosamine-glycoprotein acetylgalactosaminyltransferase; glycoprotein acetylgalactosaminyltransferase; polypeptide-N-acetylgalactosamine transferase; UDP-acetylgalactosamine-glycoprotein acetylgalactosaminyltransferase; UDP-acetylgalactosamine:peptide-N-galactosaminyltransferase; UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase; UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine-glycoprotein N-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine-protein N-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine:protein N-acetylgalactosaminyl transferase; ppGalNAc-T; polypeptide GalNAc-transferase
Systematic name: UDP-N-α-acetyl-D-galactosamine:[protein]-3-O-N--acetyl-α-D-galactosaminyl transferase (configuration-retaining)
Comments: Requires both Mn2+ and Ca2+. The glycosyl residue is transferred to threonine or serine hydroxy groups on the polypeptide core of submaxillary mucin, κ-casein, apofetuin and some other acceptors of high molecular mass.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9075-15-4
References:
1. Sugiura, M., Kawasaki, T. and Yamashina, I. Purification and characterization of UDP-GalNAc:polypeptide N-acetylgalactosamine transferase from an ascites hepatoma, AH 66. J. Biol. Chem. 257 (1982) 9501-9507. [PMID: 6809738]
2. Takeuchi, M., Yoshikawa, M., Sasaki, R. and Chiba, H. Purification and characterization of UDP-N-acetylgalactosamine-κ-casein polypeptide N-acetylgalactosaminyltransferase from mammary-gland of lactating cow. Agric. Biol. Chem. 49 (1985) 1059-1069.