パー-6 PDZのアロステリック活性化は,部分展開の移行を経由して起こります
Dustin S Whitney1, Francis C Peterson, Evgenii L Kovrigin
1Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States.
Journal of the American Chemical Society
|May 28, 2013
まとめ
分割欠陥6 (Par-6) タンパク質の柔軟性は,その機能にとって極めて重要です. 予期せぬことに,PDZドメインの部分的な展開は,アロステル調節を促進し,タンパク質ダイナミクスの新しいメカニズムを明らかにします.
科学分野:
- タンパク質の生化学
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- タンパク質は,機能のために本来の状態と展開状態のバランスをとり,時には柔軟性のために安定性を犠牲にします.
- 分割欠陥6 (Par-6) タンパク質は,そのCdc42/Rac相互作用結合PSD-95/Dlg/ZO-1 (CRIB-PDZ) モジュールを通じてPar極性複合体を調節する.
- Par-6のアロステリック調節は,CRIB:PDZインターフェースの再配置を含み,PDZリガンド結合に影響を与えます.
研究 の 目的:
- アロステル調節中のPar-6 PDZドメインのダイナミクスと熱力学的安定性を調査する.
- Par-6.の L164/K165 サイドチェーン交換の基礎となる構造的メカニズムを解明する.
- Par-6.のアロステリックメカニズムにおけるタンパク質展開の役割を調査する.
主な方法:
- マイクロ秒からミリ秒までの時間スケールのダイナミクス測定.
- PDZ領域内の局所的な構造的安定性の分析.
- PDZドメインの熱力学安定性評価.
主要な成果:
- Par-6のL164/K165サイドチェーンの交換には,予想以上に大きな構造的な再配置が必要です.
- PDZドメインは温和な熱力学的安定性 (∼3 kcal/mol) を表しており,CRIBドメインの相互作用によりさらに減少しています.
- PDZドメインの部分的な展開は,三次接触を妨害し,アロステル活性化に不可欠なL / Kスイッチを可能にします.
結論:
- 部分的ネイティブ状態の展開は,Par-6アロステリックメカニズムの不可欠な構成要素です.
- この発見は,ネイティブ状態の展開が,他の限界的に安定したタンパク質の機能的調節のための一般的なメカニズムである可能性があることを示唆しています.
- 触媒と結合に不可欠なタンパク質の柔軟性は,制御された部分展開イベントを通じて達成できます.
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