undecaprenyldiphospho-muramoylpentapeptide beta-N-acetylglucosaminyltransferase. MurG (EC 2.4.1.227) is an N-acetylglucosaminyltransferase, the last enzyme involved in the intracellular phase of peptidoglycan biosynthesis. It transfers N-acetyl-D-glucosamine (GlcNAc) from UDP-GlcNAc to the C4 hydroxyl of a lipid-linked N-acetylmuramoyl pentapeptide (NAM). The resulting disaccharide is then transported across the cell membrane, where it is polymerized into NAG-NAM cell-wall repeat structure. MurG belongs to the GT-B structural superfamily of glycoslytransferases, which have characteristic N- and C-terminal domains, each containing a typical Rossmann fold. The two domains have high structural homology despite minimal sequence homology. The large cleft that separates the two domains includes the catalytic center and permits a high degree of flexibility.
amylovoran biosynthesis glycosyltransferase AmsD and similar proteins. This family is most closely related to the GT4 family of glycosyltransferases. AmSD in Erwinia amylovora has been shown to be involved in the biosynthesis of amylovoran, the acidic exopolysaccharide acting as a virulence factor. This enzyme may be responsible for the formation of galactose alpha-1,6 linkages in amylovoran.