Prp5がプレ-mRNAブランチサイトを校正する方法に関する構造的洞察
Zhenwei Zhang1, Norbert Rigo2, Olexandr Dybkov2
1Department of Structural Dynamics, MPI for Biophysical Chemistry, Göttingen, Germany.
Nature
|August 5, 2021
まとめ
この研究では,スプライソームのヘリケーズであるPrp5が,間接的にブランチサイトを校正することによって,正確なプレ-mRNAスプライシングを保証する方法を明らかにしました. Hsh155タンパク質が再構成されるまで 組み立てをブロックし 信頼性を確保します
科学分野:
- 分子生物学
- RNA スプライシング
- 構造生物学
背景:
- スプライソームA複合体へのU2小核リボ核タンパク質 (snRNP) の統合は,mRNA前スプライシングに不可欠である.
- DEAD-boxヘリケーズPrp5は,不明なメカニズムを通じてU2のブランチサイトヘリクスを校正して,U2のsnRNP統合を容易にする.
- スプライソームの組立と忠誠性メカニズムを理解することは,遺伝子発現の調節を理解するために不可欠である.
研究 の 目的:
- スプライソームの組み立て中にPrp5がプレ-mRNAブランチサイトを校正するメカニズムを解明する.
- Prp5 と Hsh155 の役割を理解するために,プレア複合物の3次元構造を決定する.
- spliceosomal helicase が mRNA 前スプライシングの忠誠度を向上させる仕組みについて,構造的な洞察を提供するためです.
主な方法:
- 酵母抽出物におけるスプライソームの組み立てを遅らせるためのプレ-mRNA変異 (ブランチサイトアデノシン欠損または変異) の生成.
- 凍結電子顕微鏡で 3D構造を決定する
- pre-A複合体内のU1/U2 snRNP,Prp5,Hsh155タンパク質の相互作用の構造分析
主要な成果:
- U2ブランチサイトヘリックスを含む,開かれたHsh155HEATドメインを持つ,プレ-A複合中間物質が特定された.
- A複合体の形成に必要な,U1とU2のsnRNPの大規模な再定位は,プレ-A複合体のPrp5によって阻害された.
- Hsh155 HEATドメインの閉塞は,ブランチサイトアデノシンへの結合によって引き起こされ,Prp5の結合を不安定化し,間接的な校閲を示唆する.
結論:
- Prp5は,Hsh155が再構成されるまでスプライソームの組み立てを阻害して,間接的にブランチサイトを校正し,正しいブランチサイト認識を確保します.
- 構造は,Hsh155の構造変化がPrp5を放出し,スプライソームの成熟を可能にするメカニズムを示しています.
- この研究は,プレ-mRNAスプライシング中のスプライソームヘリコースのフィデリティメカニズムに関する重要な構造的洞察を提供します.
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