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Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes
Transfer RNAs (tRNAs) link the genetic code in the form of messenger RNA (mRNA) to protein sequence. Translocation of tRNAs through the ribosome from aminoacyl (A) site to peptidyl (P) site and from P site to exit site is catalyzed in eukaryotes by the translocase elongation factor 2 (EF-2) and in p...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Elsevier Ltd.
2010
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340587/ https://www.ncbi.nlm.nih.gov/pubmed/20159470 http://dx.doi.org/10.1016/j.str.2009.12.007 |
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author | Flanagan, John F. Namy, Olivier Brierley, Ian Gilbert, Robert J.C. |
author_facet | Flanagan, John F. Namy, Olivier Brierley, Ian Gilbert, Robert J.C. |
author_sort | Flanagan, John F. |
collection | PubMed |
description | Transfer RNAs (tRNAs) link the genetic code in the form of messenger RNA (mRNA) to protein sequence. Translocation of tRNAs through the ribosome from aminoacyl (A) site to peptidyl (P) site and from P site to exit site is catalyzed in eukaryotes by the translocase elongation factor 2 (EF-2) and in prokaryotes by its homolog EF-G. During tRNA movement one or more “hybrid” states (A/P) is occupied, but molecular details of them and of the translocation process are limited. Here we show by cryo-electron microscopy that a population of mammalian ribosomes stalled at an mRNA pseudoknot structure contains structurally distorted tRNAs in two different A/P hybrid states. In one (A/P′), the tRNA is in contact with the translocase EF-2, which induces it. In the other (A/P″), the translocase is absent. The existence of these alternative A/P intermediate states has relevance to our understanding of the mechanics and kinetics of translocation. |
format | Online Article Text |
id | pubmed-4340587 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | Elsevier Ltd. |
record_format | MEDLINE/PubMed |
spelling | pubmed-43405872015-02-25 Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes Flanagan, John F. Namy, Olivier Brierley, Ian Gilbert, Robert J.C. Structure Article Transfer RNAs (tRNAs) link the genetic code in the form of messenger RNA (mRNA) to protein sequence. Translocation of tRNAs through the ribosome from aminoacyl (A) site to peptidyl (P) site and from P site to exit site is catalyzed in eukaryotes by the translocase elongation factor 2 (EF-2) and in prokaryotes by its homolog EF-G. During tRNA movement one or more “hybrid” states (A/P) is occupied, but molecular details of them and of the translocation process are limited. Here we show by cryo-electron microscopy that a population of mammalian ribosomes stalled at an mRNA pseudoknot structure contains structurally distorted tRNAs in two different A/P hybrid states. In one (A/P′), the tRNA is in contact with the translocase EF-2, which induces it. In the other (A/P″), the translocase is absent. The existence of these alternative A/P intermediate states has relevance to our understanding of the mechanics and kinetics of translocation. Elsevier Ltd. 2010-02-10 2010-02-09 /pmc/articles/PMC4340587/ /pubmed/20159470 http://dx.doi.org/10.1016/j.str.2009.12.007 Text en Copyright © 2010 Elsevier Ltd. All rights reserved. Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active. |
spellingShingle | Article Flanagan, John F. Namy, Olivier Brierley, Ian Gilbert, Robert J.C. Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title | Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title_full | Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title_fullStr | Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title_full_unstemmed | Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title_short | Direct Observation of Distinct A/P Hybrid-State tRNAs in Translocating Ribosomes |
title_sort | direct observation of distinct a/p hybrid-state trnas in translocating ribosomes |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340587/ https://www.ncbi.nlm.nih.gov/pubmed/20159470 http://dx.doi.org/10.1016/j.str.2009.12.007 |
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