ジャーナル: EMBO J / 年: 2012 タイトル: Structural insights into initial and intermediate steps of the ribosome-recycling process. 著者: Takeshi Yokoyama / Tanvir R Shaikh / Nobuhiro Iwakura / Hideko Kaji / Akira Kaji / Rajendra K Agrawal / 要旨: The ribosome-recycling factor (RRF) and elongation factor-G (EF-G) disassemble the 70S post-termination complex (PoTC) into mRNA, tRNA, and two ribosomal subunits. We have determined cryo-electron ...The ribosome-recycling factor (RRF) and elongation factor-G (EF-G) disassemble the 70S post-termination complex (PoTC) into mRNA, tRNA, and two ribosomal subunits. We have determined cryo-electron microscopic structures of the PoTC·RRF complex, with and without EF-G. We find that domain II of RRF initially interacts with universally conserved residues of the 23S rRNA helices 43 and 95, and protein L11 within the 50S ribosomal subunit. Upon EF-G binding, both RRF and tRNA are driven towards the tRNA-exit (E) site, with a large rotational movement of domain II of RRF towards the 30S ribosomal subunit. During this intermediate step of the recycling process, domain II of RRF and domain IV of EF-G adopt hitherto unknown conformations. Furthermore, binding of EF-G to the PoTC·RRF complex reverts the ribosome from ratcheted to unratcheted state. These results suggest that (i) the ribosomal intersubunit reorganizations upon RRF binding and subsequent EF-G binding could be instrumental in destabilizing the PoTC and (ii) the modes of action of EF-G during tRNA translocation and ribosome-recycling steps are markedly different.
全体 : T. thermophilus Ribosome Recycling Factor and E. coli Elongation ...
全体
名称: T. thermophilus Ribosome Recycling Factor and E. coli Elongation Factor G
要素
試料: T. thermophilus Ribosome Recycling Factor and E. coli Elongation Factor G
タンパク質・ペプチド: T. thermophilus Ribosome Recycling Factor
タンパク質・ペプチド: E. coli Elongation Factor G
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超分子 #1000: T. thermophilus Ribosome Recycling Factor and E. coli Elongation ...
超分子
名称: T. thermophilus Ribosome Recycling Factor and E. coli Elongation Factor G タイプ: sample / ID: 1000 / 集合状態: Monomer / Number unique components: 2
分子量
理論値: 100 KDa
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分子 #1: T. thermophilus Ribosome Recycling Factor
分子
名称: T. thermophilus Ribosome Recycling Factor / タイプ: protein_or_peptide / ID: 1 / Name.synonym: ttRRF 詳細: This is the excised density corresponding to Thermus thermophilus RRF and E. coli EF-G from the parent map EMD-1917. 組換発現: Yes
由来(天然)
生物種: Thermus thermophilus (バクテリア)
分子量
理論値: 100 KDa
組換発現
生物種: Escherichia coli JM109 / 組換プラスミド: pGEM-T
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分子 #2: E. coli Elongation Factor G
分子
名称: E. coli Elongation Factor G / タイプ: protein_or_peptide / ID: 2 / Name.synonym: ecEFG 詳細: This is the excised density corresponding to Thermus thermophilus RRF and E. coli EF-G from the parent map EMD-1917. 組換発現: Yes