PMID: identifiant
de la référence Pubmed : |
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 (16611927)  |
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| titre : |
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Small protein B interacts with the large and the small subunits of a stalled ribosome during trans-translation. |
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| auteur(s) : |
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Marc Hallier1, Jessie Desreac1, Brice Felden ( ) 1 |
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| laboratoire : |
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| résumé : |
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During trans-translation, stalled bacterial ribosomes are rescued by small protein B (SmpB) and by transfer-messenger RNA (tmRNA). Stalled ribosomes switch translation from the defective messages to a short internal reading frame on tmRNA that tags the nascent peptide chain for degradation and recycles the ribosomes. We present evidences that SmpB binds the large and small ribosomal subunits in vivo and in vitro. The binding between SmpB and the ribosomal subunits is very tight, with a dissociation constant of 1.7 x 10(-10) M, similar to its K(D) for the 70S ribosome or for tmRNA. tmRNA displaces SmpB from its 50S binding but not from the 30S. In vivo, SmpB is detected on the 50S when trans-translation is impaired by lacking tmRNA or a functional SmpB. SmpB contacts the large subunit transiently and early during the trans-translational process. The affinity of SmpB for the two ribosomal subunits is modulated by tmRNA in the course of trans-translation. It is the first example of two copies of the same protein interacting with two different functional sites of the ribosomes. |
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| domaine : |
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Sciences du Vivant/Biochimie, Biologie Moléculaire
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langue du texte
intégral : |
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Anglais |
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| ISSN : |
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0305-1048 |
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| type de publication : |
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Articles dans des revues avec comité de lecture |
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| DOI : |
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10.1093/nar/gkl097 |
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| journal : |
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| Audience : |
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internationale |
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| date de publication : |
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2006 |
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date de publication
électronique : |
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12/04/2006 |
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| volume : |
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34 |
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| numéro : |
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6 |
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| page, identifiant, ... : |
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1935-43 |
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| Descripteur(s) MeSH : |
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Binding Sites – Binding – Competitive – Escherichia coli Proteins – Mutation – Protein Biosynthesis – RNA – Bacterial – RNA-Binding Proteins – Ribosomes – Binding Sites |
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| contrat, financement : |
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This work was supported by the "Région Bretagne" (Programme d'accueil d'équipes en émergence) to Brice Felden. Funding to pay the Open Access publication charges for this article was provided by Region Bretagne |
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