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-Structure paper
タイトル | Time-resolved cryo-EM visualizes ribosomal translocation with EF-G and GTP. |
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ジャーナル・号・ページ | Nat Commun, Vol. 12, Issue 1, Page 7236, Year 2021 |
掲載日 | 2021年12月13日 |
著者 | Christine E Carbone / Anna B Loveland / Howard B Gamper / Ya-Ming Hou / Gabriel Demo / Andrei A Korostelev / |
PubMed 要旨 | During translation, a conserved GTPase elongation factor-EF-G in bacteria or eEF2 in eukaryotes-translocates tRNA and mRNA through the ribosome. EF-G has been proposed to act as a flexible motor that ...During translation, a conserved GTPase elongation factor-EF-G in bacteria or eEF2 in eukaryotes-translocates tRNA and mRNA through the ribosome. EF-G has been proposed to act as a flexible motor that propels tRNA and mRNA movement, as a rigid pawl that biases unidirectional translocation resulting from ribosome rearrangements, or by various combinations of motor- and pawl-like mechanisms. Using time-resolved cryo-EM, we visualized GTP-catalyzed translocation without inhibitors, capturing elusive structures of ribosome•EF-G intermediates at near-atomic resolution. Prior to translocation, EF-G binds near peptidyl-tRNA, while the rotated 30S subunit stabilizes the EF-G GTPase center. Reverse 30S rotation releases Pi and translocates peptidyl-tRNA and EF-G by ~20 Å. An additional 4-Å translocation initiates EF-G dissociation from a transient ribosome state with highly swiveled 30S head. The structures visualize how nearly rigid EF-G rectifies inherent and spontaneous ribosomal dynamics into tRNA-mRNA translocation, whereas GTP hydrolysis and Pi release drive EF-G dissociation. |
リンク | Nat Commun / PubMed:34903725 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.9 - 3.9 Å |
構造データ | EMDB-25405, PDB-7ss9: EMDB-25407, PDB-7ssd: EMDB-25409, PDB-7ssl: EMDB-25410, PDB-7ssn: EMDB-25411, PDB-7sso: EMDB-25415, PDB-7ssw: EMDB-25418, PDB-7st2: EMDB-25420, PDB-7st6: EMDB-25421, PDB-7st7: |
化合物 | ChemComp-GDP: ChemComp-PO4: ChemComp-FME: ChemComp-PRO: |
由来 |
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キーワード | RIBOSOME / EF-G / GTP / Translocation / GDP / Hybrid / Classical / RIBOSOME/ANTIBIOTIC / Ribosome-Antibiotic complex / Viomycin |