Yeast translation elongation factor eEF3 promotes late stages of tRNA translocation
| Autor: | Bertrand Beckert, Namit Ranjan, Daniel N. Wilson, Agnieszka A. Pochopien, Colin Chih Chien Wu, Rachel Green, Sandra Blanchet, Marina V. Rodnina |
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| Rok vydání: | 2020 |
| Předmět: |
Saccharomyces cerevisiae Proteins
E‐site tRNA E-site Chromosomal translocation Saccharomyces cerevisiae Biology EEF2 Ribosome General Biochemistry Genetics and Molecular Biology Translocation Genetic Article 03 medical and health sciences ABC ATPase 0302 clinical medicine RNA Transfer RNA Messenger Molecular Biology cryo‐EM 030304 developmental biology 0303 health sciences General Immunology and Microbiology General Neuroscience Cryoelectron Microscopy Articles Protein Biosynthesis & Quality Control Peptide Elongation Factors L1 stalk TRNA binding Cell biology Elongation factor A-site Protein Biosynthesis Transfer RNA eEF3 Ribosomes 030217 neurology & neurosurgery |
| Zdroj: | The EMBO Journal EMBO Journal |
| ISSN: | 1460-2075 |
| Popis: | In addition to the conserved translation elongation factors eEF1A and eEF2, fungi require a third essential elongation factor, eEF3. While eEF3 has been implicated in tRNA binding and release at the ribosomal A and E sites, its exact mechanism of action is unclear. Here, we show that eEF3 acts at the mRNA–tRNA translocation step by promoting the dissociation of the tRNA from the E site, but independent of aminoacyl‐tRNA recruitment to the A site. Depletion of eEF3 in vivo leads to a general slowdown in translation elongation due to accumulation of ribosomes with an occupied A site. Cryo‐EM analysis of native eEF3‐ribosome complexes shows that eEF3 facilitates late steps of translocation by favoring non‐rotated ribosomal states, as well as by opening the L1 stalk to release the E‐site tRNA. Additionally, our analysis provides structural insights into novel translation elongation states, enabling presentation of a revised yeast translation elongation cycle. A combination of rapid kinetics, ribosome profiling, and cryo‐EM structures reveals eEF3’s requirement during late steps of ribosomal translocation/ translation. |
| Databáze: | OpenAIRE |
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