トランスロケーション独立RNAポリメラーゼをターミネーターATPアゼで無活性化するためのステップ
Nelly Said1, Tarek Hilal2, Nicholas D Sunday3
1Laboratory of Structural Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
まとめ
タンパク質複合体であるRho (ρ) 因子はRNAポリメラーゼを捕まえて遺伝子転写を終了させます. Cryo-EM構造は,RhoがNusAとNusGタンパク質と相互作用してDNAを解き放ち,RNAを放出し,転写を停止する方法を明らかにします.
科学分野:
- 分子生物学
- 構造生物学
- 生物化学
背景:
- トランスクリプションの終結は遺伝子調節に不可欠ですが,そのメカニズムは不明です.
- 変異因子依存の終結には,Rho (ρ) のようなタンパク質因子が転写機構と相互作用する.
研究 の 目的:
- Rho依存転写終結の構造的メカニズムを解明する.
- 終了時にRho,Nusa,NusG,RNAポリメラーゼの間のダイナミックな相互作用を視覚化する.
主な方法:
- 高解像度構造を決定するための冷凍電子顕微鏡 (冷凍EM).
- タンパク質と核酸の相互作用と機能的影響を分析する生化学的分析
主要な成果:
- Cryo-EM構造は,Rho (ρ) が NusA,NusG,RNAポリメラーゼと相互作用してトランスクリプション終結複合体で捕獲された.
- Rhoのヘクサメリクリング構造はDNAを捕まえて解き放つものとして観察され,NusaはRNAを封じ込めます.
- NusAの回転とRhoクランプの開封を含む連続的なメカニズムは,RNAの放出と転写の不活性化につながる.
結論:
- Rho依存の転写終結は,多段階のアロステリックメカニズムを含みます.
- Rhoは,トランスクリプション複合体を捕まえて無効にするための構造的戦略を使用し,これは終結因子にわたって潜在的に保存されるメカニズムです.
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