title: General N-and O-Linked Glycosylation of Lipoproteins in Mycoplasmas and Role of Exogenous Oligosaccharide.
abstract: The lack of a cell wall, flagella, fimbria, and other extracellular appendages and the possession of only a single membrane render the mycoplasmas structurally simplistic and ideal model organisms for the study of glycoconjugates. Most species have genomes of about 800 kb and code for few proteins predicted to have a role in glycobiology. The murine pathogens Mycoplasma arthritidis and Mycoplasma pulmonis have only a single gene annotated as coding for a glycosyltransferase but synthesize glycolipid, polysaccharide and glycoproteins. Previously, it was shown that M. arthritidis glycosylated surface lipoproteins through O-linkage. In the current study, O-linked glycoproteins were similarly found in M. pulmonis and both species of mycoplasma were found to also possess N-linked glycans at residues of asparagine and glutamine. Protein glycosylation occurred at numerous sites on surface-exposed lipoproteins with no apparent amino acid sequence specificity. The lipoproteins of Mycoplasma pneumoniae also are glycosylated. Glycosylation was dependent on the glycosidic linkages from host oligosaccharides. As far as we are aware, N-linked glycoproteins have not been previously described in Gram-positive bacteria, the organisms to which the mycoplasmas are phylogenetically related. The findings indicate that the mycoplasma cell surface is heavily glycosylated with implications for the modulation of mycoplasma-host interactions.
authors.affiliation: Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: James M
authors.initials: JM
authors.lastname: Daubenspeck
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: David S
authors.initials: DS
authors.lastname: Jordan
authors.affiliation: Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Warren
authors.initials: W
authors.lastname: Simmons
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Renfrow
authors.affiliation: Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.|Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Kevin
authors.initials: K
authors.lastname: Dybvig
mesh_terms: D000595:Amino Acid Sequence; D001216:Asparagine / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D002473:Cell Wall / Q000737:chemistry; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D004187:Disaccharides / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005973:Glutamine / Q000737:chemistry; D006023:Glycoproteins / Q000737:chemistry; D006031:Glycosylation; D006094:Gram-Positive Bacteria / Q000737:chemistry; D006601:Hexoses / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009177:Mycoplasma pneumoniae / Q000737:chemistry*; D045803:Mycoplasma pulmonis / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D010802:Phylogeny; D011485:Protein Binding; D053719:Tandem Mass Spectrometry
chemical_list: D001426:Bacterial Proteins; D004187:Disaccharides; D006023:Glycoproteins; D006601:Hexoses; D008074:Lipoproteins; D009844:Oligosaccharides; D005973:Glutamine; D001216:Asparagine