More than 140 bacterial small non-coding RNAs (sRNAs) have been discovered in Escherichia coli and other bacteria, most of them pathogenic. The sRNA genes are typically encoded in intergenic regions and range from 50 to 500 nucleotides long. Evidences accumulated over the last years point out that sRNAs act as major regulators of adaptive responses at the post-transcriptional level. The mechanisms by which sRNAs modulate the expression of its targets often involve the interaction with their mRNA targets, mediated by the Hfq protein a RNA chaperone. The RNA chaperone Hfq, has been...