RNase Y, a novel endoribonuclease, initiates riboswitch turnover in Bacillus subtilis.
In contrast to Escherichia coli, initiation of mRNA decay in Gram-positive organisms is poorly understood. We studied the fate of the highly structured RNAs generated by premature transcription termination of S-adenosylmethionine (SAM)-dependent riboswitches in Bacillus subtilis. An essential protein of earlier unknown function, YmdA, was identified as a novel endoribonuclease (now called RNase Y) that was capable of preferential cleaving in vitro of the 5' monophosphorylated yitJ riboswitch upstream of the SAM-binding aptamer domain. Antiterminated full-length yitJ mRNA was not a substrate for RNase Y in vivo and in vitro, transcripts capable of forming the antiterminator were only cleaved in the presence of SAM. Turnover of 10 other SAM-dependent riboswitches was also initiated by RNase Y. Depletion of this ribonuclease increased the half-life of bulk mRNA more than two-fold. This indicates that RNase Y might be not only important for riboswitch RNA turnover but also as a key player in the initiation of mRNA decay in B. subtilis. About 40% of the sequenced eubacterial species have an RNase Y orthologue.
Institut de Biologie Physico-Chimique, CNRS UPR9073, affiliated with Université de Paris 7-Denis-Diderot, Paris, France.
Karen
K
Shahbabian
Ailar
A
Jamalli
Léna
L
Zig
Harald
H
Putzer
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001483:Base Sequence; D004722:Endoribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005095:Exoribonucleases / Q000378:metabolism / Q000502:physiology; D008954:Models, Biological; D005810:Multigene Family / Q000235:genetics; D009690:Nucleic Acid Conformation; D030781:Organisms, Genetically Modified; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D020871:RNA Stability / Q000235:genetics*; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D004722:Endoribonucleases; D005095:Exoribonucleases; C080868:ribonuclease R