タンパク質の折りたたみにおけるHsp70およびHsp110チャペロンの協力の構造的基礎
Sigrun Polier1, Zdravko Dragovic, F Ulrich Hartl
1Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Cell
|June 17, 2008
まとめ
イーストのヌクレオチド交換因子Sse1p (Hsp110) は,Hsp70と直接相互作用し,ADPの放出と必須タンパク質の折り畳みを促進する. このメカニズムは,正規のHsp70sとは異なり,Sse1ppを強調しています.
科学分野:
- 分子生物学は分子生物学である.
- タンパク質の折りたたみ
- 構造生物学 構造生物学とは
背景:
- Hsp70チャペロンは,タンパク質の折りたたみに不可欠であり,J領域タンパク質や核酸交換因子 (NEF) のようなコチャペロンが制御する.
- NEFは,Hsp70からADPを除去するために不可欠であり,そのATPaseサイクルとチャペロン活性を促進します.
- 酵母Sse1pを含むHsp110タンパク質は,Hsp70sと同型であり,NEFとして機能する.
研究 の 目的:
- 酵母NEF Sse1pがHsp70.0上で核酸交換を促進する構造的メカニズムを解明する.
- Hsp70によるタンパク質折りたたみにおけるSse1pの役割を理解する.
主な方法:
- X線結晶学を用いて,Sse1p-Hsp70核酸結合領域 (NBD) 複合体の構造を決定した.
- Sse1pのNEF活動の機能的意義を評価するために,変異分析が行われました.
主要な成果:
- 結晶構造は,Sse1pのATP結合NBDと,Hsp70NBDを取り巻く3ヘリックスバンドルドメイン (3HBD) を明らかにし,その開きとADPの放出を誘導する.
- Sse1pのNEF活動を妨げる突然変異は致命的であることが判明し,Hsp70の機能におけるその重要な役割を確認しました.
- Sse1pは,正規のHsp70sとは異なるメカニズムで作用し,潜在的に直接の基板相互作用を含むようです.
結論:
- Sse1pは,Hsp70の重要なNEFとして作用し,直接の基板接触を含むことができるメカニズムを通じてタンパク質の折り畳みに不可欠です.
- 構造データは,Hsp110ファミリーメンバーによるHsp70のアロステリック調節に関する洞察を提供します.
- この研究では,Sse1pの重要な機能としてHsp70の核酸交換を定義し,Hsp70補助折り畳みの協力モデルを示唆しています.
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