Expanding control in bacteria: interplay between small RNAs and transcriptional regulators to control gene expression

Small regulatory RNAs (sRNAs) are now considered as major post-transcriptional regulators of gene expression in bacteria. Their importance is related to their variety in probably all bacterial species as well as to the extreme diversity of physiological functions of their target genes. An increasing amount of data point to an intimate connection between sRNAs and transcriptional regulatory networks to control multiple functions as important as motility or group behavior. The resulting mixed circuits unravel novel regulatory links and their properties are just starting to be characterized.