7AQC

Structure of the bacterial RQC complex (Decoding State)

7AQC の概要

• エントリーDOI: 10.2210/pdb7aqc/pdb
• 関連するPDBエントリー: 7AQD
• EMDBエントリー: 11862
• 分子名称: 23S ribosomal RNA, 50S ribosomal protein L14, 50S ribosomal protein L15, ... (33 entities in total)
• 機能のキーワード: ribosome, rqch, rqc, rqc2, hsp15, fibronectin-binding protein, nemf, ribosome-associated quality control, ribosome-associated, 50s, alanine-tailing
• 由来する生物種: Bacillus subtilis subsp. subtilis str. 168; 詳細
• タンパク質・核酸の鎖数: 34
• 化学式量合計: 1427904.68

構造登録者

Filbeck, S.,Pfeffer, S. (登録日: 2020-10-21, 公開日: 2020-11-25, 最終更新日: 2024-05-01)

主引用文献

Filbeck, S.,Cerullo, F.,Paternoga, H.,Tsaprailis, G.,Joazeiro, C.A.P.,Pfeffer, S.
Mimicry of Canonical Translation Elongation Underlies Alanine Tail Synthesis in RQC.
Mol.Cell, 81:104-, 2021

PubMed Abstract: Aborted translation produces large ribosomal subunits obstructed with tRNA-linked nascent chains, which are substrates of ribosome-associated quality control (RQC). Bacterial RqcH, a widely conserved RQC factor, senses the obstruction and recruits tRNA to modify nascent-chain C termini with a polyalanine degron. However, how RqcH and its eukaryotic homologs (Rqc2 and NEMF), despite their relatively simple architecture, synthesize such C-terminal tails in the absence of a small ribosomal subunit and mRNA has remained unknown. Here, we present cryoelectron microscopy (cryo-EM) structures of Bacillus subtilis RQC complexes representing different Ala tail synthesis steps. The structures explain how tRNA is selected via anticodon reading during recruitment to the A-site and uncover striking hinge-like movements in RqcH leading tRNA into a hybrid A/P-state associated with peptidyl-transfer. Finally, we provide structural, biochemical, and molecular genetic evidence identifying the Hsp15 homolog (encoded by rqcP) as a novel RQC component that completes the cycle by stabilizing the P-site tRNA conformation. Ala tailing thus follows mechanistic principles surprisingly similar to canonical translation elongation.

PubMed: 33259811
DOI: 10.1016/j.molcel.2020.11.001

実験手法

ELECTRON MICROSCOPY (2.99 Å)