lipopolysaccharide heptosyltransferase and similar proteins. Lipopolysaccharide heptosyltransferase (2.4.99.B6) is involved in the biosynthesis of lipooligosaccharide (LOS). Lipopolysaccharide (LPS) is a major component of the outer membrane of gram-negative bacteria. LPS heptosyltransferase transfers heptose molecules from ADP-heptose to 3-deoxy-D-manno-octulosonic acid (KDO), a part of the inner core component of LPS. This family also contains lipopolysaccharide 1,2-N-acetylglucosaminetransferase EC 2.4.1.56 and 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.
Glycosyltransferase family 9 (heptosyltransferase). Members of this family belong to glycosyltransferase family 9. Lipopolysaccharide is a major component of the outer leaflet of the outer membrane in Gram-negative bacteria. It is composed of three domains; lipid A, Core oligosaccharide and the O-antigen. All of these enzymes transfer heptose to the lipopolysaccharide core.
Alpha 1,6-fucosyltransferase similar to Bradyrhizobium NodZ. Bradyrhizobium NodZ is an alpha 1,6-fucosyltransferase involved in the biosynthesis of the nodulation factor, a lipo-chitooligosaccharide formed by three-to-six beta-1,4-linked N-acetyl-d-glucosamine (GlcNAc) residues and a fatty acid acyl group attached to the nitrogen atom at the non-reducing end. NodZ transfers L-fucose from the GDP-beta-L-fucose donor to the reducing residue of the chitin oligosaccharide backbone, before the attachment of a fatty acid group. O-fucosyltransferase-like proteins are GDP-fucose dependent enzymes with similarities to the family 1 glycosyltransferases (GT1). They are soluble ER proteins that may be proteolytically cleaved from a membrane-associated preprotein, and are involved in the O-fucosylation of protein substrates, the core fucosylation of growth factor receptors, and other processes.