title: The core and O-polysaccharide structure of the Caulobacter crescentus lipopolysaccharide.
abstract: Here we describe the analysis of the structure of the lipopolysaccharide (LPS) from Caulobacter crescentus strain JS1025, a derivative of C. crescentus CB15 NA1000 with an engineered amber mutation in rsaA, leading to the loss of the protein S-layer and gene CCNA_00471 encoding a putative GDP-L-fucose synthase. LPS was isolated using an aqueous membrane disruption method. Polysaccharide and core oligosaccharide were produced by mild acid hydrolysis and analyzed by nuclear magnetic resonance spectroscopy and chemical methods. Spectra revealed the presence of two polysaccharides, one of them, a rhamnan, could be removed using periodate oxidation. Another polymer, built from 4-amino-4-deoxy-D-rhamnose (perosamine), mannose, and 3-O-methyl-glucose, should be the O-chain of the LPS according to genetic data. The attribution of the rhamnan as a part of LPS or a separate polymer was not possible.
authors.affiliation: Department of Microbiology and Immunology, 2350 Health Sciences Mall, Life Sciences Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Electronic address: Mikedave@mail.ubc.ca.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Jones
authors.affiliation: National Research Council of Canada, 100 Sussex Drive, Building Sussex, Room 3079, Ottawa, Ontario K1A 0R6, Canada. Electronic address: Evguenii.Vinogradov@nrc-cnrc.gc.ca.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.affiliation: Department of Microbiology and Immunology, 2350 Health Sciences Mall, Life Sciences Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Electronic address: Nomellin@mail.ubc.ca.
authors.forename: John F
authors.initials: JF
authors.lastname: Nomellini
authors.affiliation: Department of Microbiology and Immunology, 2350 Health Sciences Mall, Life Sciences Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Electronic address: Jsmit@mail.ubc.ca.
authors.forename: John
authors.initials: J
authors.lastname: Smit
mesh_terms: D002240:Carbohydrate Sequence; D016935:Caulobacter crescentus / Q000737:chemistry* / Q000166:cytology; D003837:Deoxy Sugars / Q000737:chemistry; D005110:Extracellular Space / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000737:chemistry; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry*
chemical_list: D003837:Deoxy Sugars; D008351:Mannans; D019081:O Antigens; C065836:rhamnan
keywords: Extracellular polysaccharides; Lipopolysaccharides; Nuclear magnetic resonance