title: Cell-surface-associated polypeptides CshA and CshB of high molecular mass are colonization determinants in the oral bacterium Streptococcus gordonii.
abstract: The human oral bacterium Streptococcus gordonii expresses, on the cell surface, two antigenically related high-molecular-mass polypeptides denoted CshA and CshB, encoded by genes at separate chromosomal loci. The precursor form of CshA is composed of four distinct segments: (i) a 41-amino-acid residue leader peptide, (ii) N-terminal 42-878 residues, (iii) residues 879-2417 comprising 13 repeat blocks of 101 amino acid residues and three shorter blocks, and (iv) a C-terminal anchor domain similar to those present in some other Gram-positive bacterial cell-wall polypeptides. Insertional mutations within cshA reduced both cell-surface hydrophobicity and ability to adhere to oral Actinomyces naeslundii. Insertional mutations in cshB had less effect on hydrophobicity and coadherence. However, expression of both polypeptides was found to be necessary for streptococci to colonize the murine oral cavity.
authors.affiliation: Department of Oral Biology and Oral Pathology, University of Otago, Dunedin, New Zealand.
authors.forename: R
authors.initials: R
authors.lastname: McNab
authors.forename: H F
authors.initials: HF
authors.lastname: Jenkinson
authors.forename: D M
authors.initials: DM
authors.lastname: Loach
authors.forename: G W
authors.initials: GW
authors.lastname: Tannock
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D009055:Mouth / Q000382:microbiology; D016254:Mutagenesis, Insertional; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013291:Streptococcus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C079041:CshA protein, Streptococcus gordonii; D004269:DNA, Bacterial; D008565:Membrane Proteins; D011498:Protein Precursors