7JT3

Rotated 70S ribosome stalled on long mRNA with ArfB-1 and ArfB-2 bound in the A site (+9-IV)

これはPDB形式変換不可エントリーです。

7JT3 の概要

• エントリーDOI: 10.2210/pdb7jt3/pdb
• EMDBエントリー: 22466 22469 22472
• 分子名称: 50S ribosomal protein L2, 50S ribosomal protein L14, 50S ribosomal protein L15, ... (57 entities in total)
• 機能のキーワード: ribosome, arfb, mrna, translation
• 由来する生物種: Escherichia coli (strain K12); 詳細
• タンパク質・核酸の鎖数: 58
• 化学式量合計: 2222876.16

構造登録者

Carbone, C.E.,Korostelev, A.A. (登録日: 2020-08-17, 公開日: 2020-11-11, 最終更新日: 2024-03-06)

主引用文献

Carbone, C.E.,Demo, G.,Madireddy, R.,Svidritskiy, E.,Korostelev, A.A.
ArfB can displace mRNA to rescue stalled ribosomes
Nat Commun, 11:5552-5552, 2020

PubMed Abstract: Ribosomes stalled during translation must be rescued to replenish the pool of translation-competent ribosomal subunits. Bacterial alternative rescue factor B (ArfB) releases nascent peptides from ribosomes stalled on mRNAs truncated at the A site, allowing ribosome recycling. Prior structural work revealed that ArfB recognizes such ribosomes by inserting its C-terminal α-helix into the vacant mRNA tunnel. In this work, we report that ArfB can efficiently recognize a wider range of mRNA substrates, including longer mRNAs that extend beyond the A-site codon. Single-particle cryo-EM unveils that ArfB employs two modes of function depending on the mRNA length. ArfB acts as a monomer to accommodate a shorter mRNA in the ribosomal A site. By contrast, longer mRNAs are displaced from the mRNA tunnel by more than 20 Å and are stabilized in the intersubunit space by dimeric ArfB. Uncovering distinct modes of ArfB function resolves conflicting biochemical and structural studies, and may lead to re-examination of other ribosome rescue pathways, whose functions depend on mRNA lengths.

PubMed: 33144582
DOI: 10.1038/s41467-020-19370-z

実験手法

ELECTRON MICROSCOPY (3.7 Å)