This Article Full Text (PDF) Other Versions of this Article: JB.00966-07v1 189/20/7195    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fontaine, L. Articles by Hols, P. Search for Related Content PubMed PubMed Citation Articles by Fontaine, L. Articles by Hols, P.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.00966-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Quorum-Sensing regulation of the production of Blp bacteriocins in Streptococcus thermophilus

Unité de Génétique, Institut des Sciences de la Vie, Université catholique de Louvain, Place Croix du Sud 5, B-1348 Louvain-la-Neuve, Belgium, Institut National de la Recherche Agronomique (INRA), Unité de Génétique Microbienne, Unité de Biochimie Bactérienne, Domaine de Vilvert, 78350 Jouy-en-Josas, France, and Laboratoire de Microbiologie et de Biochimie Appliquées (LMBA), UMR 5248 CBMN, CNRS-Université de Bordeaux 1-ENITAB, F-33170 Gradignan, France

^* To whom correspondence should be addressed. Email: hols{at}gene.ucl.ac.be.

	Abstract

The blp gene cluster identified in the genome sequences of S. thermophilus LMG18311, CNRZ1066, and LMD-9 (Stblp) displays all the characteristics of a Class II bacteriocin locus. In the present study, we showed that the Stblp locus is only fully functional in strain LMD-9 and regulates the production of antimicrobial peptides that inhibit strains LMG18311 and CNRZ1066. The Stblp cluster of LMD-9 contains 23 genes that are transcriptionally organized in six operons: StblpABC (peptide transporter genes and pheromone gene), StblpRH (two-component regulatory system genes), StblpD-orf1, StblpU-orf3 and StblpE-F (bacteriocin precursors and immunity genes), and StblpG-X (unknown function). All the operons, except the regulatory unit StblpRH, were shown to be co-regulated at the transcriptional level by a quorum-sensing mechanism involving the mature pheromone StBlpC*, which was extracellularly detected as two active forms (30 and 19 aa). These operons are differentially transcribed depending on growth phase and pheromone concentration. They all contain a motif with two imperfect direct repeats in their mapped promoter regions that could serve as binding sites of the response regulator StBlpR. By constructing deletion mutants, the Stblp locus of strain LMD-9 was shown to encode all the essential functions associated with bacteriocin production, quorum-sensing regulation, and immunity.

This article has been cited by other articles:

• Fontaine, L., Hols, P. (2008). The Inhibitory Spectrum of Thermophilin 9 from Streptococcus thermophilus LMD-9 Depends on the Production of Multiple Peptides and the Activity of BlpGSt, a Thiol-Disulfide Oxidase. Appl. Environ. Microbiol. 74: 1102-1110 [Abstract] [Full Text]