Polypeptide N-acetylgalactosaminyltransferase

In enzymology, a polypeptide N-acetylgalactosaminyltransferase is an enzyme that catalyzes the chemical reaction


 * UDP-N-acetyl-D-galactosamine + polypeptide $$\rightleftharpoons$$ UDP + N-acetyl-D-galactosaminyl-polypeptide

Thus, the two substrates of this enzyme are UDP-N-acetyl-D-galactosamine and polypeptide, whereas its two products are UDP and N-acetyl-D-galactosaminyl-polypeptide.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyl-transferase. Other names in common use include protein-UDP acetylgalactosaminyltransferase, UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase, UDP-N-acetylgalactosamine:kappa-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-alpha-D-galactosamine:polypeptide, N-acetylgalactosaminyltransferase, UDP-N-acetylgalactosamine-glycoprotein, N-acetylgalactosaminyltransferase, UDP-N-acetylgalactosamine-protein N-acetylgalactosaminyltransferase, UDP-N-acetylgalactosamine:polypeptide, N-acetylgalactosaminyltransferase, and UDP-N-acetylgalactosamine:protein N-acetylgalactosaminyl transferase. This enzyme participates in o-glycan biosynthesis and glycan structures - biosynthesis 1. It has 2 cofactors: manganese, and Calcium.

Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes, , , , and.