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-Structure paper
Title | Structures of tmRNA and SmpB as they transit through the ribosome. |
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Journal, issue, pages | Nat Commun, Vol. 12, Issue 1, Page 4909, Year 2021 |
Publish date | Aug 13, 2021 |
Authors | Charlotte Guyomar / Gaetano D'Urso / Sophie Chat / Emmanuel Giudice / Reynald Gillet / |
PubMed Abstract | In bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), ...In bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), a hybrid RNA known to have both a tRNA-like and an mRNA-like domain. Here we present four cryo-EM structures of the ribosome during trans-translation at resolutions from 3.0 to 3.4 Å. These include the high-resolution structure of the whole pre-accommodated state, as well as structures of the accommodated state, the translocated state, and a translocation intermediate. Together, they shed light on the movements of the tmRNA-SmpB complex in the ribosome, from its delivery by the elongation factor EF-Tu to its passage through the ribosomal A and P sites after the opening of the B1 bridges. Additionally, we describe the interactions between the tmRNA-SmpB complex and the ribosome. These explain why the process does not interfere with canonical translation. |
External links | Nat Commun / PubMed:34389707 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.08 - 3.44 Å |
Structure data | EMDB-11710, PDB-7abz: EMDB-11713, PDB-7ac7: EMDB-11717, PDB-7acj: EMDB-11718, PDB-7acr: |
Chemicals | ChemComp-MG: ChemComp-KIR: ChemComp-GDP: ChemComp-ZN: |
Source |
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Keywords | TRANSLATION / Trans-translation / tmRNA / SmpB / Ribosome |