B3galt2 is beta-1,3-galactosyltransferase that transfers galactose from UDP-galactose to substrates with a terminal beta-N-acetylglucosamine (beta-GlcNAc) residue. B3galt2 can also utilize substrates with a terminal galactose residue, albeit with lower efficiency. B3galt2 is involved in the biosynthesis of the carbohydrate moieties of glycolipids and glycoproteins.