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-Structure paper
タイトル | Mechanism of ribosome rescue by alternative ribosome-rescue factor B. |
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ジャーナル・号・ページ | Nat Commun, Vol. 11, Issue 1, Page 4106, Year 2020 |
掲載日 | 2020年8月14日 |
著者 | Kai-Hsin Chan / Valentyn Petrychenko / Claudia Mueller / Cristina Maracci / Wolf Holtkamp / Daniel N Wilson / Niels Fischer / Marina V Rodnina / |
PubMed 要旨 | Alternative ribosome-rescue factor B (ArfB) rescues ribosomes stalled on non-stop mRNAs by releasing the nascent polypeptide from the peptidyl-tRNA. By rapid kinetics we show that ArfB selects ...Alternative ribosome-rescue factor B (ArfB) rescues ribosomes stalled on non-stop mRNAs by releasing the nascent polypeptide from the peptidyl-tRNA. By rapid kinetics we show that ArfB selects ribosomes stalled on short truncated mRNAs, rather than on longer mRNAs mimicking pausing on rare codon clusters. In combination with cryo-electron microscopy we dissect the multistep rescue pathway of ArfB, which first binds to ribosomes very rapidly regardless of the mRNA length. The selectivity for shorter mRNAs arises from the subsequent slow engagement step, as it requires longer mRNA to shift to enable ArfB binding. Engagement results in specific interactions of the ArfB C-terminal domain with the mRNA entry channel, which activates peptidyl-tRNA hydrolysis by the N-terminal domain. These data reveal how protein dynamics translate into specificity of substrate recognition and provide insights into the action of a putative rescue factor in mitochondria. |
リンク | Nat Commun / PubMed:32796827 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.6 - 3.7 Å |
構造データ | EMDB-10905, PDB-6ysr: EMDB-10906, PDB-6yss: EMDB-10907, PDB-6yst: EMDB-10908, PDB-6ysu: |
化合物 | ChemComp-MG: ChemComp-ZN: ChemComp-CL: ChemComp-NA: ChemComp-HOH: |
由来 |
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キーワード | RIBOSOME / translation / rescue / release |