Affiliation:
1. Canadian Bacterial Diseases Network, Department of Microbiology, University of Guelph, Guelph, Ontario, Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada
Abstract
The structures of the lipopolysaccharide O-antigens from Klebsiella serotypes 02(2a,2f,2g), O2(2a,2e) and O2(2a,2e,2h) have been determined. These O-polysaccharides are part of a family of related structures, which share a D-galactan I backbone. D-galactan I has the repeating unit structure: [→3)-β-D-Gal f-(1→3)-α-D-Gal p-(1→]. The O-polysaccharide of serotype O2(2a,2f,2g) differs from other known O-polysaccharides in Klebsiella spp. Each of the main-chain Gal p residues in the 02(2a,2f,2g) O-polysaccharide is substituted with an α-(1→4)-linked D-Gal p residue, to form a trisaccharide repeating unit. The LPS O-polysaccharides of serotypes O2(2a,2e) and O2(2a,2e,2h) both contain α-(1→2)-linked D-Galp substituents on the main-chain Galp residues, and resemble serotype O9. The only difference between the 09, O2(2a,2e), and O2(2a,2e,2h) carbohydrate structures involves the stoichiometry of addition of side chain α-D-Gal p residues. However, the polymers from serotypes O2(2a,2e), O2(2a,2e,2h) and 09 are all modified by O-acetylation and these modifications may contribute to altered antigenic factors. The structures reported here resolve ambiguities between previous chemical and serological analyses of 02 antigens. Genetic analyses showed that enzymes involved in the addition of α-D-Gal p residues are encoded by genes outside the rfbO9 (O-antigen biosynthesis) region and this provides an explanation for occasional non-stoichiometric addition of side chain α-D-Galp residues.
Subject
Infectious Diseases,Cell Biology,Molecular Biology,Immunology,Microbiology
Cited by
33 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献