Rrp6-RNAエクソソーム複合体の構造は,ポリ(A) RNAに結合している
Elizabeth V Wasmuth1, Kurt Januszyk2, Christopher D Lima3
11] Structural Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, New York 10065, USA [2] Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA.
Nature
|July 22, 2014
まとめ
RNA処理に不可欠なRNAエクソソーム複合体は,基板をRrp6またはRrp44酵素に誘導する. この研究は,Rrp6の構造的基盤を明らかにしています.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- バイオケミストリー バイオケミストリー
背景:
- ユーカリオットRNAエクソソームは,RNAの処理と分解を担当する複数のサブユニット複合体です.
- コア複合体 (Exo9) と触媒性エクソリボンucleases (Rrp6とRrp44) を含んでおり,それぞれの活動が異なっている.
- RNA基板がRrp6に導かれるメカニズムと,中央エクソソームチャネルを利用するかどうかについては,未だに不明です.
研究 の 目的:
- Rrp6エクソリボヌクレアースサブユニットによるRNA基板の結合の構造的メカニズムを解明する.
- RNAエクソソーム複合体内のRrp6を含むRNA結合と処理経路を決定する.
- RNAを異なる触媒サブユニットに誘導するエクソソームのコア構造の役割を調査する.
主な方法:
- 10つのサブユニットRNAエクソソーム複合体 (Exo9核+Rrp6) のX線結晶図で,3.3 Å解像度でポリ(A) RNAに結合しています.
- 酵母とヒトRNAのエクソソーム複合体を用いた生化学分析と溶液研究.
- Rrp6活性部位とエクソソーム核に対するRNA位置の構造分析.
主要な成果:
- 結晶構造は,Rrp6の触媒ドメインがExo9 S1/KHリングの頂上に位置し,RNA 3'端がRrp6の活性部位に固定されていることを明らかにしました.
- 結合RNAは,Rrp44.4で観測されたものと異なる方向でS1/KH環を横断する.
- 溶液の研究は,Rrp6へのRNA経路が保存され,S1/KHリングの整合性に依存することを示しました.
- In vitroでは,Rrp6またはRrp44へのRNA経路選択はストキャスティックである.
結論:
- Rrp6エクソリボヌクレアゼは,中央チャネルの上に位置するRNAエクソソームの明確な結合部位を使用します.
- エクソソームの中核のS1/KHリングは,Rrp6へのRNAアクセスを媒介する上で重要な役割を果たします.
- in vitro経路はストキャスティックであるが,in vivoでは基板標的化がRNA結合コファクターによって影響される可能性がある.
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