The signaling peptide PapR is required for the activity of the quorum-sensor PlcRa in .

The transcriptional regulator PlcR, its cognate cell-cell signaling heptapeptide PapR, and the oligopeptide permease OppABCDF, required for PapR import, form a quorum-sensing system that controls the expression of virulence factors in and species. In strain ATCC 14579, the transcriptional regulator PlcRa activates the expression of gene, which encodes an AbrB-like transcriptional regulator involved in cysteine biosynthesis. PlcRa is a structural homolog of PlcR: in particular, its C-terminal TPR peptide-binding domain could be similarly arranged as in PlcR.

The CodY-dependent clhAB2 operon is involved in cell shape, chaining and autolysis in Bacillus cereus ATCC 14579.

The Gram-positive pathogen Bacillus cereus is able to grow in chains of rod-shaped cells, but the regulation of chaining remains largely unknown. Here, we observe that glucose-grown cells of B. cereus ATCC 14579 form longer chains than those grown in the absence of glucose during the late exponential and transition growth phases, and identify that the clhAB2 operon is required for this chain lengthening phenotype.

PlcRa, a new quorum-sensing regulator from Bacillus cereus, plays a role in oxidative stress responses and cysteine metabolism in stationary phase.

We characterized a new quorum-sensing regulator, PlcRa, which is present in various members of the B. cereus group and identified a signaling heptapeptide for PlcRa activity: PapRa(7). We demonstrated that PlcRa is a 3D structural paralog of PlcR using sequence analysis and homology modeling.