New insights into small RNA-dependent translational regulation in prokaryotes

Bacterial small RNAs (sRNAs) typically repress translation of target mRNAs by pairing directly to the ribosome-binding site (RBS) and competing with initiating ribosomes, an event that is often followed by rapid mRNA decay. In recent years, however, many examples of translation-repressing sRNAs pairing outside the RBS have been described. In this review, we focus on newly characterized mechanisms that explain how a sRNA can modulate translation by binding outside of the RBS and discuss new insights into the events following translation repression. These new mechanisms broaden current perspectives of sRNA pairing sites on mRNA targets and demonstrate how the interplay between sRNAs, mRNA structures, and protein partners can contribute to post-transcriptional regulation.