title: A new quorum-sensing system (TprA/PhrA) for Streptococcus pneumoniae D39 that regulates a lantibiotic biosynthesis gene cluster.
abstract: The Phr peptides of the Bacillus species mediate quorum sensing, but their identification and function in other species of bacteria have not been determined. We have identified a Phr peptide quorum-sensing system (TprA/PhrA) that controls the expression of a lantibiotic gene cluster in the Gram-positive human pathogen, Streptococcus pneumoniae. Lantibiotics are highly modified peptides that are part of the bacteriocin family of antimicrobial peptides. We have characterized the basic mechanism for a Phr-peptide signaling system in S. pneumoniae and found that it induces the expression of the lantibiotic genes when pneumococcal cells are at high density in the presence of galactose, a main sugar of the human nasopharynx, a highly competitive microbial environment. Activity of the Phr peptide system is not seen when pneumococcal cells are grown with glucose, the preferred carbon source and the most prevalent sugar encountered by S. pneumoniae during invasive disease. Thus, the lantibiotic genes are expressed under the control of both cell density signals via the Phr peptide system and nutritional signals from the carbon source present, suggesting that quorum sensing and the lantibiotic machinery may help pneumococcal cells compete for space and resources during colonization of the nasopharynx.
authors: Department of Microbiology, Immunology and Molecular Genetics, University of California, 609 Charles E. Young Dr. East, 1602 Molecular Science Building, Los Angeles, California, 90095, USA.
authors: Sharon E
authors: SE
authors: Hoover
authors: Department of Microbiology, Immunology and Molecular Genetics, University of California, 609 Charles E. Young Dr. East, 1602 Molecular Science Building, Los Angeles, California, 90095, USA.
authors: Amilcar J
authors: AJ
authors: Perez
authors: Department of Biology, Indiana University Bloomington, Jordan Hall, 1001 East Third Street, Bloomington, Indiana, 47405, USA.
authors: Ho-Ching T
authors: HC
authors: Tsui
authors: Department of Biology, Indiana University Bloomington, Jordan Hall, 1001 East Third Street, Bloomington, Indiana, 47405, USA.
authors: Dhriti
authors: D
authors: Sinha
authors: Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Avenue, Bloomington, Indiana, 47405, USA.
authors: David L
authors: DL
authors: Smiley
authors: Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Avenue, Bloomington, Indiana, 47405, USA.
authors: Richard D
authors: RD
authors: DiMarchi
authors: Department of Biology, Indiana University Bloomington, Jordan Hall, 1001 East Third Street, Bloomington, Indiana, 47405, USA.
authors: Malcolm E
authors: ME
authors: Winkler
authors: Department of Microbiology, Immunology and Molecular Genetics, University of California, 609 Charles E. Young Dr. East, 1602 Molecular Science Building, Los Angeles, California, 90095, USA.
authors: Beth A
authors: BA
authors: Lazazzera
mesh_terms: D001407:Bacillus / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005810:Multigene Family; D053038:Quorum Sensing / Q000235:genetics / Q000502:physiology*; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins