title: Involvement of PhoP-PhoS homologs in Enterococcus faecalis virulence.
abstract: Eleven PhoP-PhoS homolog pairs were identified by searching the Enterococcus faecalis V583 genome sequence database at The Institute for Genomic Research with the Bacillus subtilis PhoP-PhoS sequences. Each pair appears to be a potential two-component system composed of a response regulator and a sensor kinase. Seven of the homologs were disrupted in E. faecalis strain OG1RF. TX10293, a mutant disrupted in one of these genes (etaR, the first gene of the gene pair designated etaRS), showed delayed killing and a higher 50% lethal dose in a mouse peritonitis model. The predicted EtaR protein sequence showed greatest similarity to LisR of Listeria monocytogenes (77%) and CsrR of Streptococcus pyogenes (70%); EtaS is 53% similar to LisK and 54% similar to CsrS. When grown in vitro, the TX10293 mutant was more sensitive to low pH (pH 3.4) and more resistant to high temperature (55 degrees C) than wild-type OG1RF. In conclusion, many potential two-component systems are identified for E. faecalis, one of which, EtaRS, was shown to be involved in stress response and virulence.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Houston Medical School, Houston, Texas 77030, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Teng
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Kavindra V
authors.initials: KV
authors.lastname: Singh
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Murray
authors.forename: George M
authors.initials: GM
authors.lastname: Weinstock
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D013293:Enterococcus faecalis / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D005798:Genes, Bacterial; D005809:Genes, Regulator; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000737:chemistry; D013696:Temperature; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C061064:PhoP protein, Bacteria; D011494:Protein Kinases; C432144:CsrS protein, bacteria