芽生えた酵母からのDicersの内外メカニズム
David E Weinberg1, Kotaro Nakanishi, Dinshaw J Patel
1Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
Cell
|July 26, 2011
まとめ
芽生える酵母のDicer酵素 (Dcr1) は,小さな干渉RNAs (siRNAs) を生成するためにユニークな内部から外部への処理メカニズムを使用します. この発見は,RNAの干渉における分子支配者の新しいモデルを示しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 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
背景:
- ディサーリボヌクレアースIII (RNaseIII) 酵素はRNA干渉において決定的な役割を果たし,二重鎖RNA (dsRNA) を小さな干渉RNA (siRNA) に処理する.
- 非正規のディサー酵素は,芽生えた酵母のようなものですが,加工メカニズムでは正規のディサーと異なります.
研究 の 目的:
- Kluyveromyces polysporus Dcr1 (非正規のディサー) の触媒的に活性化した断片の構造と機能を明らかにする.
- 芽生えた酵母 Dicers が siRNAs を生成するメカニズムを理解するために.
主な方法:
- Dcr1断片のホモディメール構造を決定するX線結晶学.
- dsRNAの結合と処理活動を研究するための生化学的分析.
主要な成果:
- 結晶構造は,ユニークなN末端ドメインと保存された触媒残基を持つホモダイマーを示した.
- Dcr1ジメルはdsRNAを協力的に結合し,相互作用するサイト距離がsiRNAの長さを決定する.
- 芽生える酵母 Dicersは,端末から内側へと処理する kanonical Dicersとは異なり,内部から外側へと dsRNAを処理します.
結論:
- 芽生える酵母のDicer酵素は,siRNA生成のための独特なメカニズムを採用し,カノニカルDicerと異なる.
- このユニークな処理メカニズムは,分子支配者のパラダイムを確立し,基板特異性に影響を与えます.
- この発見は,RNA干渉経路と芽生えた酵母における生物学的機能の理解に意味を持つ.
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