Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Bacillus subtilis rpsO gene specifies a small (388-nucleotide), monocistronic mRNA that encodes ribosomal protein S15. We showed earlier that rpsO mRNA decay intermediates accumulated to a high level in a strain lacking polynucleotide phosphorylase. Here, we used inducibly expressed derivatives of rpsO, encoding smaller RNAs that had the complex 5' region deleted, to study aspects of mRNA processing in B. subtilis. An IPTG (isopropyl-beta-d-thiogalactopyranoside)-inducible rpsO transcript that contained lac sequences at the 5' end, called lac-rpsO RNA, was shown to undergo processing to result in an RNA that was 24 nucleotides shorter than full length. Such processing was dependent on the presence of an accessible 5' terminus; a lac-rpsO RNA that contained a strong stem-loop at the 5' end was not processed and was extremely stable. Interestingly, this stability depended also on ribosome binding to a nearby Shine-Dalgarno sequence but was independent of downstream translation. Either RNase J1 or RNase J2 was capable of processing lac-rpsO RNA, demonstrating for the first time a particular in vivo processing event that could be catalyzed by both enzymes. Decay intermediates were detected in the pnpA strain only for a lac-rpsO RNA that was untranslated. Analysis of processing of an untranslated lac-rpsO RNA in the pnpA strain shortly after induction of transcription suggested that endonuclease cleavage at 3'-proximal sites was an early step in turnover of mRNA.
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PMID:Processing and stability of inducibly expressed rpsO mRNA derivatives in Bacillus subtilis. 1963 85

rpsO mRNA, a small monocistronic mRNA that encodes ribosomal protein S15, was used to study aspects of mRNA decay initiation in Bacillus subtilis. Decay of rpsO mRNA in a panel of 3'-to-5' exoribonuclease mutants was analyzed using a 5'-proximal oligonucleotide probe and a series of oligonucleotide probes that were complementary to overlapping sequences starting at the 3' end. The results provided strong evidence that endonuclease cleavage in the body of the message, rather than degradation from the native 3' end, is the rate-determining step for mRNA decay. Subsequent to endonuclease cleavage, the upstream products were degraded by polynucleotide phosphorylase (PNPase), and the downstream products were degraded by the 5' exonuclease activity of RNase J1. The rpsO mRNA half-life was unchanged in a strain that had decreased RNase J1 activity and no RNase J2 activity, but it was 2.3-fold higher in a strain with decreased activity of RNase Y, a recently discovered RNase of B. subtilis encoded by the ymdA gene. Accumulation of full-length rpsO mRNA and its decay intermediates was analyzed using a construct in which the rpsO transcription unit was under control of a bacitracin-inducible promoter. The results were consistent with RNase Y-mediated initiation of decay. This is the first report of a specific mRNA whose stability is determined by RNase Y.
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PMID:Initiation of decay of Bacillus subtilis rpsO mRNA by endoribonuclease RNase Y. 2041 91