title: Diversity in the protein N-glycosylation pathways within the Campylobacter genus.
abstract: The foodborne bacterial pathogen, Campylobacter jejuni, possesses an N-linked protein glycosylation (pgl) pathway involved in adding conserved heptasaccharides to asparagine-containing motifs of >60 proteins, and releasing the same glycan into its periplasm as free oligosaccharides. In this study, comparative genomics of all 30 fully sequenced Campylobacter taxa revealed conserved pgl gene clusters in all but one species. Structural, phylogenetic and immunological studies showed that the N-glycosylation systems can be divided into two major groups. Group I includes all thermotolerant taxa, capable of growth at the higher body temperatures of birds, and produce the C. jejuni-like glycans. Within group I, the niche-adapted C. lari subgroup contain the smallest genomes among the epsilonproteobacteria, and are unable to glucosylate their pgl pathway glycans potentially reminiscent of the glucosyltransferase regression observed in the O-glycosylation system of Neisseria species. The nonthermotolerant Campylobacters, which inhabit a variety of hosts and niches, comprise group II and produce an unexpected diversity of N-glycan structures varying in length and composition. This includes the human gut commensal, C. hominis, which produces at least four different N-glycan structures, akin to the surface carbohydrate diversity observed in the well-studied commensal, Bacteroides. Both group I and II glycans are immunogenic and cell surface exposed, making these structures attractive targets for vaccine design and diagnostics.
authors.affiliation: Alberta Glycomics Centre and Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
authors.forename: Harald
authors.initials: H
authors.lastname: Nothaft
authors.forename: Nichollas E
authors.initials: NE
authors.lastname: Scott
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Hu
authors.forename: Bernadette
authors.initials: B
authors.lastname: Beadle
authors.forename: Christopher
authors.initials: C
authors.lastname: Fodor
authors.forename: William G
authors.initials: WG
authors.lastname: Miller
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Cordwell
authors.forename: Christine M
authors.initials: CM
authors.lastname: Szymanski
mesh_terms: D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002167:Campylobacter / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006020:Glycopeptides / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000276:immunology; D010802:Phylogeny; D011134:Polysaccharides / Q000276:immunology; D015203:Reproducibility of Results
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D006020:Glycopeptides; D007106:Immune Sera; D009844:Oligosaccharides; D011134:Polysaccharides