recAタンパク質-ADP複合体の構造
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511.
Nature
|January 23, 1992
まとめ
recAタンパク質は recAタンパク質と呼ばれる.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
背景:
- recAタンパク質はDNA修復と再結合に不可欠であり,アロステル酵素として機能します.
- そのATP酵素の活性性はDNAに依存しており,ATP結合はDNA親和性を高め,ADP結合はDNA親和度を低下させる.
- recAの機能におけるATP水解の正確な役割は不明である.
研究 の 目的:
- recAタンパク質結晶内のADP結合の構造的基礎を解明する.
- ATPによるDNA結合のアロステリック調節のメカニズムを理解する.
- recAのヌクレオチド結合機構を他のNTPasesと比較する.
主な方法:
- 結合されたADPを持つrecAの原子構造を決定するX線結晶学.
- バイオケミカルアッセイは,DNA結合とATPアゼ活性を研究するものです.
- 既知の核酸結合タンパク質との構造比較.
主要な成果:
- 結合されたADPリン酸は,保存されたG/AXXXXGKT/Sモチーフを持つ他のNTPアースのリン酸と類似して相互作用する.
- 構造モデルによると,recAタンパク質はATPの水解により構造変化を起こすという.
- このメカニズムは,ras腫瘍遺伝子のp21タンパク質に類似しています.
結論:
- ATPの水解は,三鎖DNA中間物質の製品への移行を促す可能性がある.
- ATPによるDNA結合のアロステリック刺激は,構造変化モデルによって説明される.
- recAにおけるリガンド結合と核酸三リン酸水解の結合のメカニズムは,関連するNTPasesの間に保存され得る.
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