GroEL-GroESサイクリング:折りたたみ活性リングのATPと非原生ポリペプチドの直接交代
1Howard Hughes Medical Institute, and Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA.
Cell
|May 13, 1999
まとめ
チャペロニンGroELはATPの水解を用いて,タンパク質の折り畳み環を交互に作る. このサイクルは,GroESの前にノンネイティブポリペプチドを結合し,チャペロニンニンを最適化することで,効率的なタンパク質リフォールドを保証します.
科学分野:
- 分子生物学は分子生物学である.
- タンパク質の生化学
- 携帯電話の機械は
背景:
- 二重環のチャペロニンGroELは,中心腔内でのタンパク質の折り畳みを促進する.
- このプロセスは,ATPとコチャペロニン (GroES) の結合を伴う.
- 折りたたみ活性状態間のGroELの機能サイクルの正確なメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- チャペロニンGroELの機能サイクルを制御する連続的な出来事を明らかにする.
- ATPの水解とリングの形状の変化に対する基質とコチャペロニンの結合の順序を決定する.
- 連続したタンパク質の折り畳みサイクル間のGroELの移行方法を理解する.
主な方法:
- ATPの水解速度をモニタリングする生化学分析.
- ポリペプチドとGroES結合運動学の分析.
- GroELのアピカル領域における構造変化の観測.
主要な成果:
- cis環におけるATPの水解は,非原生ポリペプチドまたはGroESがトランス環に結合するための前提条件である.
- この水解の出来事は,トランスリングの頂点領域の方向転換と結びつきます.
- 新しく開かれたトランスリングへのポリペプチド結合は,既存のcis複合体の解離を刺激し,GroESの結合とその後の折り畳みを促進します.
結論:
- GroELの機能サイクルには,ATPの水解,ポリペプチド結合,GroES結合という厳密な順序のイベントが含まれる.
- チャペロニンは2つのリングを交互に交換し,各リングは連続して折り畳み活性型シス複合体として機能します.
- この交代メカニズムは,非原生タンパク質の存在下での折り畳みイベントごとに7つのATPの1つのサイクルのみを使用して,効率的なタンパク質折り畳みを可能にします.
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