Crystal structure of the retaining galactosyltransferase LgtC from Neisseria meningitidis in complex with donor and acceptor sugar analogs.

摘要: Many bacterial pathogens express lipooligosaccharides that mimic human cell surface glycoconjugates, enabling them to attach host receptors and evade the immune response. In Neisseria meningitidis, galactosyltransferase LgtC catalyzes a key step in biosynthesis of lipooligosaccharide structure by transferring alpha-d-galactose from UDP-galactose terminal lactose. The product retains configuration donor sugar glycosidic bond; is thus retaining glycosyltranferase. We report 2 A crystal structures complex with manganese UDP 2-deoxy-2-fluoro-galactose (a analog) presence absence acceptor analog 4'-deoxylactose. structures, together results site-directed mutagenesis kinetic analysis, give valuable insights into unique catalytic mechanism and, as first glycosyltransferase both sugars, provide starting point for inhibitor design.