リボソームに結合するArfAとRF2による共同翻訳品質管理の構造的基礎

Fuxing Zeng¹, Yanbo Chen¹, Jonathan Remis²

¹Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.

Nature

|January 13, 2017

まとめ

バクテリアの品質管理は停止コードンが欠けている停滞したリボソームを救出します ArfAタンパク質は,タンパク質合成の完全性を確保するために,翻訳を終了するために,解放因子 RF2を募集します.

科学分野:

分子生物学
構造生物学
生物化学

背景:

タンパク質合成は品質管理によってエラーを排除します
絶え間ないmRNA監視は,ArfAとRF2を含む重要な経路です.
リボソームにおけるArfAとRF2の正確な分子相互作用は,以前は知られていなかった.

研究の目的:

絶え間ないmRNA監視におけるArfA-RF2相互作用の分子メカニズムを解明する.
ArfAのRF2の特定採用のための構造的基盤を決定する.
この複合体は,欠陥のあるmRNAの翻訳の終了をどのように促進するのかを理解する.

主な方法:

電子冷凍顕微鏡 (冷凍EM) で高解像度構造を決定する.
運動データを検証する生化学分析
70SリボソームとノンストップmRNAによるArfAとRF2複合体の構造分析

主要な成果:

クリオ-EM構造は,ArfAがRF2をリボソームにどのように誘導するかを明らかにしています.
ArfAのC末端ドメインはmRNAエントリーチャネルと結合し,N末端ドメインはRF2と相互作用する.
ArfA- RF2複合体はリボソーム解読センターの構造変化を誘導し,ペプチドの放出を促進する.

結論:

この研究は,ArfAによるRF2の採用と機能の構造的枠組みを提供する.
このメカニズムは,ノンストップmRNAの翻訳の終了を保証し,プロテオームの完全性を保ちます.
リボソームが翻訳エラーを認識し反応する仕組みの理解を深めています

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