Identification of small RNAs expressed in Caulobacter crescentus in response to DNA damage

RNA-based regulation of gene expression is substantially contributing to the ability of bacteria to rapidly adapt to changing environmental conditions. This study employs RNAseq to define the transcriptome of Caulobacter in response to treatment with the DNA-crosslinking agent mitomycin C. We identify a small, regulatory RNA ChvR synthesized under the control of the conserved ChvIG two-component system which represses production of a TonB-dependent receptor, ChvT, in Caulobacter crescentus. ChvR significantly reduces ChvT expression under different physiological conditions, including the response to DNA damage and growth in minimal medium. Full regulation requires the formation of two distinct base-pairs between the sRNA and its cognate mRNA target, and occurs independent of the ubiquitous RNA chaperone, Hfq. Overall design: Global analysis of gene expression in wild-type Caulobacter crescentus in response to the DNA-damaging agent mitomycin C