title: Evidence for a common molecular origin of the capsule gene loci in gram-negative bacteria expressing group II capsular polysaccharides.
abstract: Capsular polysaccharides of Gram-negative bacteria contribute to a large extent to the pathogenicity of these organisms. We show here that the molecular organization of the capsule gene loci in different serogroups of Neisseria meningitidis is similar to that of Haemophilus influenzae and Escherichia coli. A common molecular origin of the mechanisms of encapsulation is indicated by strong homology of the genes involved in transport of the capsular polysaccharides to the cell surface in all these organisms. The proteins involved in capsular polysaccharide transport fit the characteristics of ABC (ATP-binding cassette) transporters. Furthermore, by sequence comparison of the sialytransferases of N. meningitidis B and E. coli K1, the capsule of which is composed of alpha 2,8-linked polyneuraminic acid, a significant degree of homology was observed, indicating that the capsular polysaccharide type itself has the same evolutionary origin in these two pathogens.
authors.affiliation: Institut für Medizinische Hochschule Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Frosch
authors.forename: U
authors.initials: U
authors.lastname: Edwards
authors.forename: K
authors.initials: K
authors.lastname: Bousset
authors.forename: B
authors.initials: B
authors.lastname: Krausse
authors.forename: C
authors.initials: C
authors.lastname: Weisgerber
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial; D016667:Bacterial Capsules; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006193:Haemophilus influenzae / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis / Q000235:genetics* / Q000378:metabolism; D009876:Operon; D010802:Phylogeny; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D012799:Sialyltransferases / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity
chemical_list: D018528:ATP-Binding Cassette Transporters; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C068021:MalK protein, Bacteria; C489398:MalK protein, E coli; D008565:Membrane Proteins; D011135:Polysaccharides, Bacterial; D011993:Recombinant Fusion Proteins; C036962:capsular polysaccharide K1; D012799:Sialyltransferases