Fig. 10: Fate of the RNAs cleaved by RNase Y in S. pyogenes.

RNase Y processing occurs preferentially after a G. The two processing products generated from the same molecule were never detected together. Subsequently to RNase Y activity, three different events are conceivable. a Both generated RNA fragments are degraded by exoRNases and/or endoRNases; hence, this activity would be undetectable in our experimental setting. b The RNA fragments upstream of the RNase Y processing position were detected (i.e., 3′ ends), but not the downstream products (i.e., 5′ ends). Among the 130 RNAs detected, we demonstrated that 52% of the RNA products were trimmed by 3′-to-5′ exoRNases (mainly PNPase and/or YhaM). The remaining 48% were targeted either by several 3′-to-5′ exoRNases or by unidentified RNases. c The RNAs downstream of the RNase Y processing position were detected (i.e., 5′ ends), but not the upstream products (i.e., 3′ ends). Since 87.4% of the detected 5′ ends were mapped after G, we deduced that these RNAs were not further trimmed. The remaining 12.6% of the detected 5′ ends were not located after a G; therefore, we hypothesized that these ends were likely targeted by the 5′-to-3′ exoRNase J1.