title: Mutation of waaC, encoding heptosyltransferase I in Campylobacter jejuni 81-176, affects the structure of both lipooligosaccharide and capsular carbohydrate.
abstract: 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.
authors.affiliation: Department of Chemistry, North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411, USA.
authors.forename: Margaret I
authors.initials: MI
authors.lastname: Kanipes
authors.forename: Erzsebet
authors.initials: E
authors.lastname: Papp-Szabo
authors.forename: Patricia
authors.initials: P
authors.lastname: Guerry
authors.forename: Mario A
authors.initials: MA
authors.lastname: Monteiro
mesh_terms: D016667:Bacterial Capsules / Q000737:chemistry* / Q000378:metabolism; D016123:Campylobacter jejuni / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry*; D004269:DNA, Bacterial; D015180:Electrophoresis, Gel, Two-Dimensional; D005419:Flavonoids; D005759:Gastroenteritis / Q000209:etiology; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism*; D020275:Guillain-Barre Syndrome / Q000209:etiology; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D014774:Virulence
chemical_list: D002241:Carbohydrates; D004269:DNA, Bacterial; D005419:Flavonoids; D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides; C017769:tricin; D016695:Glycosyltransferases; C086735:heptosyltransferase