6N1D

X-ray Crystal complex showing Spontaneous Ribosomal Translocation of mRNA and tRNAs into a Chimeric Hybrid State

これはPDB形式変換不可エントリーです。

6N1D の概要

• エントリーDOI: 10.2210/pdb6n1d/pdb
• 分子名称: 16S rRNA, 50S ribosomal protein L9, 50S ribosomal protein L13, ... (58 entities in total)
• 機能のキーワード: ribosome
• 由来する生物種: Thermus thermophilus HB27; 詳細
• タンパク質・核酸の鎖数: 111
• 化学式量合計: 4451769.72

構造登録者

Noller, H.F.,Donohue, J.P.,Lancaster, L.,Zhou, J. (登録日: 2018-11-08, 公開日: 2019-04-03, 最終更新日: 2023-10-11)

主引用文献

Zhou, J.,Lancaster, L.,Donohue, J.P.,Noller, H.F.
Spontaneous ribosomal translocation of mRNA and tRNAs into a chimeric hybrid state.
Proc. Natl. Acad. Sci. U.S.A., 116:7813-7818, 2019

PubMed Abstract: The elongation factor G (EF-G)-catalyzed translocation of mRNA and tRNA through the ribosome is essential for vacating the ribosomal A site for the next incoming aminoacyl-tRNA, while precisely maintaining the translational reading frame. Here, the 3.2-Å crystal structure of a ribosome translocation intermediate complex containing mRNA and two tRNAs, formed in the absence of EF-G or GTP, provides insight into the respective roles of EF-G and the ribosome in translocation. Unexpectedly, the head domain of the 30S subunit is rotated by 21°, creating a ribosomal conformation closely resembling the two-tRNA chimeric hybrid state that was previously observed only in the presence of bound EF-G. The two tRNAs have moved spontaneously from their A/A and P/P binding states into ap/P and pe/E states, in which their anticodon loops are bound between the 30S body domain and its rotated head domain, while their acceptor ends have moved fully into the 50S P and E sites, respectively. Remarkably, the A-site tRNA translocates fully into the classical P-site position. Although the mRNA also undergoes movement, codon-anticodon interaction is disrupted in the absence of EF-G, resulting in slippage of the translational reading frame. We conclude that, although movement of both tRNAs and mRNA (along with rotation of the 30S head domain) can occur in the absence of EF-G and GTP, EF-G is essential for enforcing coupled movement of the tRNAs and their mRNA codons to maintain the reading frame.

PubMed: 30936299
DOI: 10.1073/pnas.1901310116

実験手法

X-RAY DIFFRACTION (3.2 Å)