title: Identification of a D-glycero-D-manno-heptosyltransferase gene from Helicobacter pylori.
abstract: We have identified a Helicobacter pylori d-glycero-d-manno-heptosyltransferase gene, HP0479, which is involved in the biosynthesis of the outer core region of H. pylori lipopolysaccharide (LPS). Insertional inactivation of HP0479 resulted in formation of a truncated LPS molecule lacking an alpha-1,6-glucan-, dd-heptose-containing outer core region and O-chain polysaccharide. Detailed structural analysis of purified LPS from HP0479 mutants of strains SS1, 26695, O:3, and PJ1 by a combination of chemical and mass spectrometric methods showed that HP0479 likely encodes alpha-1,2-d-glycero-d-manno-heptosyltransferase, which adds a d-glycero-d-manno-heptose residue (DDHepII) to a distal dd-heptose of the core oligosaccharide backbone of H. pylori LPS. When the wild-type HP0479 gene was reintegrated into the chromosome of strain 26695 by using an "antibiotic cassette swapping" method, the complete LPS structure was restored. Introduction of the HP0479 mutation into the H. pylori mouse-colonizing Sydney (SS1) strain and the clinical isolate PJ1, which expresses dd-heptoglycan, resulted in the loss of colonization in a mouse model. This indicates that H. pylori expressing a deeply truncated LPS is unable to successfully colonize the murine stomach and provides evidence for a critical role of the outer core region of H. pylori LPS in colonization.
authors: Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada.
authors: Koji
authors: K
authors: Hiratsuka
authors: Susan M
authors: SM
authors: Logan
authors: J Wayne
authors: JW
authors: Conlan
authors: Vandana
authors: V
authors: Chandan
authors: Annie
authors: A
authors: Aubry
authors: Natalia
authors: N
authors: Smirnova
authors: Heather
authors: H
authors: Ulrichsen
authors: Kenneth H N
authors: KH
authors: Chan
authors: Douglas W
authors: DW
authors: Griffith
authors: Blair A
authors: BA
authors: Harrison
authors: Jianjun
authors: J
authors: Li
authors: Eleonora
authors: E
authors: Altman
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D008070:Lipopolysaccharides / Q000096:biosynthesis / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D017385:Sequence Homology; D013270:Stomach / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D008070:Lipopolysaccharides; D016695:Glycosyltransferases; C086735:heptosyltransferase