Mutation of waaC, encoding heptosyltransferase I in Campylobacter jejuni 81-176, affects the structure of both lipooligosaccharide and capsular carbohydrate.
Autor(es): Kanipes Margaret I.; Papp-Szabo Erzsebet; Guerry Patricia; Monteiro Mario A.
Resumo: Campylobacter jejuni 81-176 lipooligosaccharide (LOS) is composed of two covalently linked domains: lipid A, a hydrophobic anchor, and a nonrepeating core oligosaccharide, consisting of an inner and outer core region. We report the isolation and characterization of the deepest rough C. jejuni 81-176 mutant by insertional mutagenesis into the waaC gene, encoding heptosyltransferase I that catalyzes the transfer of the first L-glycero-D-manno-heptose residue to 3-deoxy-D-manno-octulosonic residue (Kdo)-lipid A. Tricine gel electrophoresis, followed by silver staining, showed that site-specific mutation in the waaC gene resulted in the expression of a severely truncated LOS compared to wild-type strain 81-176. Gas-liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy showed that the waaC LOS species lacked all sugars distal to Kdo-lipid A. Parallel structural studies of the capsular polysaccharides of the wild-type strain 81-176 and waaC mutant revealed loss of the 3-O-methyl group in the waaC mutant. Complementation of the C. jejuni mutant by insertion of the wild-type C. jejuni waaC gene into a chromosomal locus resulted in LOS and capsular structures identical to those expressed in the parent strain. We also report here the presence of O-methyl phosphoramidate in wild-type strain 81-176 capsular polysaccharide.
Imprenta: Journal of Bacteriology, v. 188, n. 9, p. 3273-3279, 2006
Identificador do objeto digital: 10.1128/JB.188.9.3273-3279.2006
Descritores: Guillain-Barre Syndrome - Biosynthesis ; Guillain-Barre Syndrome - DNA ; Guillain-Barre Syndrome - Molecular Structure ; Guillain-Barre Syndrome - Pathogenesis
Data de publicação: 2006
