Cleavage of poly(A) tails on the 3′-end of RNA by ribonuclease E of Escherichia coli
| Autor: | A von Gabain, Mark R. Tock, M. H. Mallen, Vladimir R. Kaberdin, Andrew P. Walsh, Kenneth J. McDowall |
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| Předmět: |
Base Sequence
RNase P Exosome complex Ribonuclease E Molecular Sequence Data Oligonucleotides RNA Biology Non-coding RNA medicine.disease_cause Article Kinetics Biochemistry Endoribonucleases Escherichia coli Genetics medicine Nucleic Acid Conformation Directionality RNA Messenger Phosphorylation Degradosome Poly A 3' Untranslated Regions |
| Zdroj: | Scopus-Elsevier |
| Popis: | RNase E initiates the decay of Escherichia coli RNAs by cutting them internally near their 5′-end and is a component of the RNA degradosome complex, which also contains the 3′-exonuclease PNPase. Recently, RNase E has been shown to be able to remove poly(A) tails by what has been described as an exonucleolytic process that can be blocked by the presence of a phosphate group on the 3′-end of the RNA. We show here, however, that poly(A) tail removal by RNase E is in fact an endonucleolytic process that is regulated by the phosphorylation status at the 5′- but not the 3′-end of RNA. The rate of poly(A) tail removal by RNase E was found to be 30-fold greater when the 5′-terminus of RNA substrates was converted from a triphosphate to monophosphate group. This finding prompted us to re-analyse the contributions of the ribonucleolytic activities within the degradosome to 3′ attack since previous studies had only used substrates that had a triphosphate group on their 5′-end. Our results indicate that RNase E associated with the degradosome may contribute to the removal of poly(A) tails from 5′-monophosphorylated RNAs, but this is only likely to be significant should their attack by PNPase be blocked. |
| Databáze: | OpenAIRE |
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