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-Structure paper
Title | Structure of the ribosome with elongation factor G trapped in the pretranslocation state. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 110, Issue 52, Page 20994-20999, Year 2013 |
Publish date | Dec 24, 2013 |
Authors | Axel F Brilot / Andrei A Korostelev / Dmitri N Ermolenko / Nikolaus Grigorieff / |
PubMed Abstract | During protein synthesis, tRNAs and their associated mRNA codons move sequentially on the ribosome from the A (aminoacyl) site to the P (peptidyl) site to the E (exit) site in a process catalyzed by ...During protein synthesis, tRNAs and their associated mRNA codons move sequentially on the ribosome from the A (aminoacyl) site to the P (peptidyl) site to the E (exit) site in a process catalyzed by a universally conserved ribosome-dependent GTPase [elongation factor G (EF-G) in prokaryotes and elongation factor 2 (EF-2) in eukaryotes]. Although the high-resolution structure of EF-G bound to the posttranslocation ribosome has been determined, the pretranslocation conformation of the ribosome bound with EF-G and A-site tRNA has evaded visualization owing to the transient nature of this state. Here we use electron cryomicroscopy to determine the structure of the 70S ribosome with EF-G, which is trapped in the pretranslocation state using antibiotic viomycin. Comparison with the posttranslocation ribosome shows that the small subunit of the pretranslocation ribosome is rotated by ∼12° relative to the large subunit. Domain IV of EF-G is positioned in the cleft between the body and head of the small subunit outwardly of the A site and contacts the A-site tRNA. Our findings suggest a model in which domain IV of EF-G promotes the translocation of tRNA from the A to the P site as the small ribosome subunit spontaneously rotates back from the hybrid, rotated state into the nonrotated posttranslocation state. |
External links | Proc Natl Acad Sci U S A / PubMed:24324137 / PubMed Central |
Methods | EM (single particle) |
Resolution | 5.9 - 7.6 Å |
Structure data | EMDB-5796: EMDB-5797: EMDB-5798: |
Chemicals | ChemComp-ZN: |
Source |
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Keywords | TRANSLATION / EF-G / single particle analysis / pre-translocation translation complex / viomycin / TRANSLATION/antibiotic / TRANSLATION-antibiotic complex |