title: Lipoprotein receptors in oral streptococci.
abstract: Streptococcus gordonii produces cell-surface lipopolypeptides that have been implicated in the determination of cell adherence and aggregation properties. SarA lipopolypeptide produced by S. gordonii is highly similar to the oligopeptide-binding protein AmiA in Streptococcus pneumoniae and to the OppA and SpoOKA oligopeptide-binding proteins in Bacillus subtilis. Insertional mutagenesis was used to inactivate the genes encoding SarA (76kDa) lipoprotein and a related 78-kDa lipoprotein denoted SarG. SarA- mutants were defective in serum-induced aggregation, competence, growth on complex nitrogen sources, and ability to colonize the oral cavity. Conversely, SarG- mutants were unaltered in the above properties, but were deficient in growth on simple nitrogen sources. It is proposed that SarA plays a central role in environmental sensing of extracellular factors by streptococci leading to modulation of cell-surface composition and growth responses of cells.
authors.affiliation: Department of Oral Biology and Oral Pathology, University of Otago, Dunedin, New Zealand.
authors.forename: H F
authors.initials: HF
authors.lastname: Jenkinson
authors.forename: R
authors.initials: R
authors.lastname: McNab
authors.forename: D M
authors.initials: DM
authors.lastname: Loach
authors.forename: G W
authors.initials: GW
authors.lastname: Tannock
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002874:Chromosome Mapping; D005798:Genes, Bacterial; D006801:Humans; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D009055:Mouth / Q000382:microbiology; D016296:Mutagenesis; D010641:Phenotype; D018110:Receptors, Lipoprotein / Q000235:genetics / Q000378:metabolism*; D012463:Saliva / Q000382:microbiology; D013291:Streptococcus / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D008074:Lipoproteins; D018110:Receptors, Lipoprotein; C088021:SarA protein, bacterial; D015534:Trans-Activators