The Vibrio harveyi master quorum-sensing regulator, LuxR, a TetR-type protein is both an activator and a repressor: DNA recognition and binding specificity at target promoters.

TitleThe Vibrio harveyi master quorum-sensing regulator, LuxR, a TetR-type protein is both an activator and a repressor: DNA recognition and binding specificity at target promoters.
Publication TypeJournal Article
Year of Publication2008
AuthorsPompeani, AJ, Irgon, JJ, Berger, MF, Bulyk, ML, Wingreen, NS, Bassler, BL
JournalMol Microbiol
Volume70
Issue1
Pagination76-88
Date Published2008 Oct
ISSN1365-2958
KeywordsBacterial Proteins, Binding Sites, DNA, Bacterial, Fluorescence Polarization, Gene Expression Regulation, Bacterial, Genes, Bacterial, Mutagenesis, Site-Directed, Promoter Regions, Genetic, Protein Array Analysis, Quorum Sensing, Regulon, Repressor Proteins, Sequence Analysis, DNA, Substrate Specificity, Trans-Activators, Vibrio
Abstract

<p>Quorum sensing is the process of cell-to-cell communication by which bacteria communicate via secreted signal molecules called autoinducers. As cell population density increases, the accumulation of autoinducers leads to co-ordinated changes in gene expression across the bacterial community. The marine bacterium, Vibrio harveyi, uses three autoinducers to achieve intra-species, intra-genera and inter-species cell-cell communication. The detection of these autoinducers ultimately leads to the production of LuxR, the quorum-sensing master regulator that controls expression of the genes in the quorum-sensing regulon. LuxR is a member of the TetR protein superfamily; however, unlike other TetR repressors that typically repress their own gene expression and that of an adjacent operon, LuxR is capable of activating and repressing a large number of genes. Here, we used protein binding microarrays and a two-layered bioinformatics approach to show that LuxR binds a 21 bp consensus operator with dyad symmetry. In vitro and in vivo analyses of two promoters directly regulated by LuxR allowed us to identify those bases that are critical for LuxR binding. Together, the in silico and biochemical results enabled us to scan the genome and identify novel targets of LuxR in V. harveyi and thus expand the understanding of the quorum-sensing regulon.</p>

DOI10.1111/j.1365-2958.2008.06389.x
Alternate JournalMol. Microbiol.
PubMed ID18681939
PubMed Central IDPMC2628434
Grant ListR01 AI 05442 / AI / NIAID NIH HHS / United States
R01 AI054442 / AI / NIAID NIH HHS / United States
R01 G 065859-05 / / PHS HHS / United States
R01 GM065859 / GM / NIGMS NIH HHS / United States
R01 GM065859-06 / GM / NIGMS NIH HHS / United States
R01 HG003988 / HG / NHGRI NIH HHS / United States
/ / Howard Hughes Medical Institute / United States