Sensing of 5' monophosphate by Escherichia coli RNase G can significantly enhance association with RNA and stimulate the decay of functional mRNA transcripts in vivo.
The RNase E/G family of endoribonucleases has a central role in RNA degradation and processing. Previous work has shown that their cleavage of substrates in vitro can be stimulated by the presence of a 5' monophosphate group. It has not however, established the importance of this activation for any natural RNA processing or decay pathway in vivo. Here we provide for Escherichia coli RNase G the first evidence that the sensing of a 5' monophosphate is required in vivo for the normal rapid decay of functional mRNAs; moreover, we show in vitro that, in contrast to a previous study, the presence of a 5' monophosphate can enhance the affinity of RNase G binding to RNA. The implications of these results along with our finding that the maturation of 16S rRNA is unaffected in cells containing an RNase G mutant impaired in 5' end sensing are discussed with regard to current models of RNA processing and decay and the molecular mechanism that underlies RNA cleavage by the RNase E/G family.
Jourdan
Stefanie S
SS
Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, England, UK.
McDowall
Kenneth J
KJ
D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D016880:Anisotropy; D004722:Endoribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010710:Phosphates / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D010710:Phosphates; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012336:RNA, Ribosomal, 16S; D000426:Alcohol Dehydrogenase; C068383:adhE protein, E coli; D000445:Aldehyde Oxidoreductases; D004722:Endoribonucleases; C081905:rng protein, E coli; C022537:ribonuclease E