チャペロニンGroELによる非原生基板タンパク質の多価結合
G W Farr1, K Furtak, M B Rowland
1Howard Hughes Medical Institute and Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA.
Cell
|March 18, 2000
まとめ
Chaperonin GroELは,Rubiscoのような厳格なタンパク質に少なくとも3つの結合部位を必要とします. ロダネスなどのより厳格でないタンパク質は,より少ない部位に結合し,GroELを示します.
科学分野:
- 分子チャペロンである分子チャペロン.
- 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,非原生基板に結合することによって,タンパク質の折り畳みを促進します.
- GroELのメカニズムは,ATP結合とコチャペロニンのGroES相互作用を含む.
- 基板結合に関与するGroELアピカルドメインの数は不明である.
研究 の 目的:
- GroELのアピカルドメインに結合する非原生タンパク質のステキオメトリを調査する.
- 基板の相互作用に必要な結合効率の高いドメインの最小数と配置を決定する.
主な方法:
- ワイルド型と結合欠陥のある変異性アピカルドメインの組み合わせによるGroELリングを使用した.
- 厳格な (マレート脱水素酵素,ルビスコ) とより厳格な (ロダネス) 基板タンパク質によるバイナリ複合体の形成を評価した.
- ルビスコの多価結合を物理的に確認するために酸化クロスリンクを用いました.
主要な成果:
- 厳格な基板の効率的な結合には,少なくとも3つの連続した野生型の頂点領域が必要でした.
- ローダネスは,配列に関係なく,2つの結合ドメインのみを必要とした.
- 多価ルビスコがGroELと結合する直接的な証拠は,クロスリンクで得られた.
結論:
- GroELの基板結合は多価であり,複数の相互作用部位を必要とする厳格なタンパク質を有する.
- 必要な結合ドメインの数は,基質の強度と相関する.
- この研究では,GroELチャペロニンシステムによる基質認識の定量的な側面を明らかにしています.
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