title: Topological analysis of a putative virB8 homologue essential for the cag type IV secretion system in Helicobacter pylori.
abstract: The type IV secretion system encoded by the cag pathogenicity island of Helicobacter pylori is recognized as a major virulence determinant, governing the translocation of the CagA protein to eukaryotic cells. Despite the presence of 18 genes within the cag pathogenicity island which are essential for this process, several homologues encoding basic functions of a type IV secretion apparatus, such as a virB8 homologue, are still missing. We show here the presence of conserved VirB8 motifs in the cag-encoded apparatus protein HP530 and demonstrate that this protein adopts in E. coli a transmembrane topology similar to VirB8 and its homologues. Thus, we propose that HP530 is a type IV secretion component homologous to VirB8.
authors.affiliation: Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Buhrdorf
authors.forename: Cornelia
authors.initials: C
authors.lastname: Förster
authors.forename: Rainer
authors.initials: R
authors.lastname: Haas
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fischer
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D004926:Escherichia coli / Q000235:genetics; D016480:Helicobacter pylori / Q000378:metabolism* / Q000472:pathogenicity; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014169:Transformation, Bacterial; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D008565:Membrane Proteins; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori