Small stable RNA maturation and turnover in B acillus subtilis

Summary Stable RNA maturation is a key process in the generation of functional RNAs , and failure to correctly process these RNAs can lead to their elimination through quality control mechanisms. Studies of the maturation pathways of ribosomal RNA and transfer RNA in B acillus subtilis showed they were radically different from E scherichia coli and led to the identification of new B . subtilis ‐specific enzymes. We noticed that, despite their important roles in translation, a number of B . subtilis small stable RNAs still did not have characterised maturation pathways, notably the tmRNA , involved in ribosome rescue, and the RNase P RNA , involved in tRNA maturation. Here, we show that tmRNA is matured by RNase P and RNase Z at its 5′ and 3′ extremities, respectively, whereas the RNase P RNA is matured on its 3′ side by RNase Y . Recent evidence that several RNases are not essential in B . subtilis prompted us to revisit maturation of the scRNA , a component of the signal recognition particle involved in co‐translational insertion of specific proteins into the membrane. We show that RNase Y is also involved in 3′ processing of scRNA . Lastly, we identified some of the enzymes involved in the turnover of these three stable RNAs .