conserved hypothetical protein. This model represents nearly the full length of MJ1255 from Methanococcus jannaschii and of an unpublished protein from Vibrio cholerae, as well as the C-terminal half of a protein from Methanobacterium thermoautotrophicum. A small region (~50 amino acids) within the domain appears related to a family of sugar transferases. [Hypothetical proteins, Conserved]

Glycosyl transferase family 1.

UDP:flavonoid glycosyltransferase YjiC, YdhE family [Carbohydrate transport and metabolism].

UDP-glycosyltransferases and similar proteins. This family includes the Gtfs, a group of homologous glycosyltransferases involved in the final stages of the biosynthesis of antibiotics vancomycin and related chloroeremomycin. Gtfs transfer sugar moieties from an activated NDP-sugar donor to the oxidatively cross-linked heptapeptide core of vancomycin group antibiotics. The core structure is important for the bioactivity of the antibiotics.

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.