This enzyme is the enzyme that synthesizes A antigen, which is the blood group carbohydrate antigen, encoded by the ABO gene. Its enzyme activity is a1,3-N-acetylgalactosaminyltransferase activity that transfers GalNAc from the donor UDP-GalNAc to the galactose residue of the non-reducing terminal of the acceptor (H type carbohydrate antigen) by an a1-3 bond.
A blood type
Histo-Blood group antigen
This page does not indicate all of the enzymatic reaction, and expression of "A(ABO)".