This entry represents the Glycosyltransferase 99 family N-terminal domain, which is found in a new family of glycosyltransferases (GTs) assigned as family GT99 in the CAZy database. The GT99 family includes a prototype beta-Kdo GT from WbbB, a modula ...
This entry represents the Glycosyltransferase 99 family N-terminal domain, which is found in a new family of glycosyltransferases (GTs) assigned as family GT99 in the CAZy database. The GT99 family includes a prototype beta-Kdo GT from WbbB, a modular protein participating in lipopolysaccharide (LPS) O-antigen synthesis in Raoultella terrigena. Kdo (3-deoxy-D-manno-oct-2-ulosonic acid) is an eight-carbon sugar mostly found in Gram-negative bacteria, where it is involved in attaching surface polysaccharides to their lipid anchors. Alpha-Kdo provides a bridge between lipid A and the core oligosaccharide in all bacterial LPSs, while an oligosaccharide of beta-Kdo residues links group 2 capsular polysaccharides to (lyso)phosphatidylglycerol. beta-Kdo is also found in a small number of other bacterial polysaccharides. The structure and function of the prototypical cytidine monophosphate-Kdo-dependent alpha-Kdo glycosyltransferase from LPS assembly is well characterized. The WbbB2-401 protein structure is built around two alpha/beta domains with recognizable Rossmann-fold topology, broadly meeting the criteria of conforming to a GT-B fold.
