チャペロニンGroELのダブルリング内のシスおよびトランスATPの異なる作用
H S Rye1, S G Burston, W A Fenton
1Howard Hughes Medical Institute, Department of Genetics, School of Medicine, Yale University, New Haven, Connecticut 06510, USA.
Nature
|August 21, 1997
まとめ
チャペロニンGroELは,シスリングでATPの水解により基質を放出し,効率的なタンパク質折り畳みを可能にします. このシスリングにおけるATPの必要性は,GroELにとって極めて重要です.
科学分野:
- 分子生物学は分子生物学である.
- タンパク質の折りたたみ
- バイオケミストリー バイオケミストリー
背景:
- チャペロニンGroELは,そのダブルリング構造の中でタンパク質の折り畳みを促進します.
- GroELはコチャペロンGroESとアデニン核酸で機能する.
- 以前の研究では,ATPの役割は主に基板の退去のためのトランスリングにあると示唆されていました.
研究 の 目的:
- GroELのシス・リングとトランス・リングにおけるATP結合と水解の特定の役割を調査する.
- タンパク質の折りたたみのための cis リングのATPの必要性を決定する.
- GroELのダブルリング機能のメカニズムを解明するために.
主な方法:
- 利用されたGroELの変異形態はATP水解に欠陥がある.
- マラート脱水素酵素とルビスコの折り畳みを研究した.
- GroEL-ATP-GroES複合体の安定性を分析しました.
主要な成果:
- マラート脱水素酵素とルビスコの折りたたみのためのシスリングにおけるATPの絶対的な要求を示した.
- cisにおけるATP結合とGroES結合が,安定した複合体で折り畳みを開始することを示した.
- cis環におけるATPの水解が,GroESとポリペプチドの放出のための複合体を不安定化するために必要であることが明らかになった.
結論:
- シスリングのATP水解は,GroESと基板の排出に不可欠です.
- シス・リングとトランス・リングにおける ATP 結合と水解のシーケンスメカニズムが,GroEL の機能を説明する.
- GroELのダブルリング構造は,効率的なタンパク質折り畳みサイクルに不可欠です.
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