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Specificity and polymorphism of the PlcR-PapR quorum-sensing system in the Bacillus cereus group.

ABSTRACT: The expression of extracellular virulence factors in various species of the Bacillus cereus group is controlled by the plcR and papR genes, which encode a transcriptional regulator and a cell-cell signaling peptide, respectively. A processed form of PapR, presumably a pentapeptide, specifically interacts with PlcR to facilitate its binding to its DNA targets. This activating mechanism is strain specific, with this specificity being determined by the first residue of the pentapeptide. We carried out in vivo complementation assays and compared the PlcR-PapR sequences of 29 strains from the B. cereus group. Our findings suggested that the fifth amino acid of the pentapeptide is also involved in the specificity of activation. We identified four classes of PlcR-PapR pairs, defining four distinct pherotypes in the B. cereus group. We used these findings to look at the evolution of the PlcR-PapR quorum-sensing system with regard to the phylogeny of the species forming the B. cereus group.

SUBMITTER: Slamti L

PROVIDER: S-EPMC545710 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature

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Specificity and polymorphism of the PlcR-PapR quorum-sensing system in the Bacillus cereus group.

Slamti Leyla L Lereclus Didier D

Journal of bacteriology 20050201 3

The expression of extracellular virulence factors in various species of the Bacillus cereus group is controlled by the plcR and papR genes, which encode a transcriptional regulator and a cell-cell signaling peptide, respectively. A processed form of PapR, presumably a pentapeptide, specifically interacts with PlcR to facilitate its binding to its DNA targets. This activating mechanism is strain specific, with this specificity being determined by the first residue of the pentapeptide. We carried ...[more]

PMID: 15659693

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PapR peptide maturation: role of the NprB protease in Bacillus cereus 569 PlcR/PapR global gene regulation.

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Structural basis for the activation mechanism of the PlcR virulence regulator by the quorum-sensing signal peptide PapR.

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The YvfTU two-component system is involved in plcR expression in Bacillus cereus.

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Distinct mutations in PlcR explain why some strains of the Bacillus cereus group are nonhemolytic.

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| S-EPMC415780 | biostudies-literature

Molecular basis for group-specific activation of the virulence regulator PlcR by PapR heptapeptides.

Project description:The transcriptional regulator PlcR and its cognate cell-cell signalling peptide PapR form a quorum-sensing system that controls the expression of extra-cellular virulence factors in various species of the Bacillus cereus group. PlcR and PapR alleles are clustered into four groups defining four pherotypes. However, the molecular basis for group specificity remains elusive, largely because the biologically relevant PapR form is not known. Here, we show that the in vivo active form of PapR is the C-terminal heptapeptide of the precursor, and not the pentapeptide, as previously suggested. Combining genetic complementation, anisotropy assays and structural analysis we provide a detailed functional and structural explanation for the group specificity of the PlcR-PapR quorum-sensing system. We further show that the C-terminal helix of the PlcR regulatory domain, specifically the 278 residue, in conjunction with the N-terminal residues of the PapR heptapeptide determines this system specificity. Variability in the specificity-encoding regions of plcR and papR genes suggests that selection and evolution of quorum-sensing systems play a major role in adaptation and ecology of Bacilli.

| S-EPMC2441798 | biostudies-literature

A cell-cell signaling peptide activates the PlcR virulence regulon in bacteria of the Bacillus cereus group.

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| S-EPMC126190 | biostudies-literature

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