FunctionThis protein is the basis of the ABO blood group system. The histo-blood group ABO involves three carbohydrate antigens: A, B, and H. A, B, and AB individuals express a glycosyltransferase activity that converts the H antigen to the A antigen (by addition of UDP-GalNAc) or to the B antigen (by addition of UDP-Gal), whereas O individuals lack such activity.
PathwayProtein modification; protein glycosylation.
Sequence similaritiesBelongs to the glycosyltransferase 6 family.
DomainThe conserved DXD motif is involved in cofactor binding. The manganese ion interacts with the beta-phosphate group of UDP and may also have a role in catalysis.
Post-translational modificationsThe soluble form derives from the membrane form by proteolytic processing.
Cellular localizationGolgi apparatus > Golgi stack membrane. Secreted. Membrane-bound form in trans cisternae of Golgi. Secreted into the body fluid.