Insights into sRNA Genes Regulated by Two-Component Systems in the Bacillus cereus Group

Two-component systems (TCSs) and small regulatory RNAs (sRNAs) form dense regulatory networks in bacteria. To expand the known repertoire of TCS regulons in the Bacillus cereus group, we employed an in silico strategy to identify sRNA genes that might be regulated by response regulators (RRs) of TCS. Using the whole genomes of 21 fully sequenced strains of the B. cereus group, we identified 12 different types of novel sRNA genes. Using transcriptome data from B. thuringiensis CT- 43, we confirmed the independent transcription of both the sRNA_bc4 gene and the sRNA_bc6 gene. Furthermore, the sRNA_bc6 and sRNA_bc12 genes were demonstrated to exist exclusively in the B. cereus group and thus have the potential to act as molecular markers. Finally, we modified the recognition motifs of PhoP and YclJ in the B. cereus group. These results significantly contribute to our understanding of TCS regulons in bacteria.