BAM複合体上で折りたたむ新生膜タンパク質の構造
David Tomasek1,2, Shaun Rawson3, James Lee1,2,4
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
Nature
|June 13, 2020
まとめ
バクテリアのベータ・バレル・アセンブリ・マシン (BAM) は 自身のベータ・バレル構造を使って 他のタンパク質を折りたたむ. このメカニズムは タンパク質の急速な折り畳みと外膜からの放出を可能にします
科学分野:
- 構造生物学
- 分子微生物学
- タンパク質の折りたたみ機構
背景:
- グラム陰性細菌,ミトコンドリア,クロロプラストの外膜はベータバレルタンパク質を使用する.
- ベータ・バレル・アセンブリ・マシン (BAM) コンプレックスは,これらのタンパク質の挿入と折り畳みを容易にする.
- BAMのエネルギー依存の折りたたみメカニズムを理解することは,膜生物学にとって極めて重要です.
研究 の 目的:
- タンパク質の折りたたみ中のBAM複合体の構造的メカニズムを解明する.
- BAM複合体がATPの水解なしに効率的な折り畳みをどのように達成するか調査する.
- 折り畳み中のBAM複合体とその基板の相互作用を特徴付ける.
主な方法:
- ベータ・バレルタンパク質 (BamA) を折りたたむ時にEscherichia coli BAM複合体の構造を決定した.
- BAM複合体の触媒と基板タンパク質の構造的インターフェースを分析した.
- 複合体を安定させ,基質の放出を促進する水素結合相互作用を調査した.
主要な成果:
- BAM複合触媒は,基板BAMAと非対称なハイブリッドβバレルを形成する.
- 6つの水素結合によって安定した安定したインターフェースは,折り畳みを容易にするが,放出を阻害する.
- 基板の端にある特定の特徴は,段階的な水素結合交換によって放出を促進します.
結論:
- BAM複合体は タンパク質の効率的な折りたたみのための 独特のハイブリッドベータバーレル構造を使用しています
- BAM複合体の急速な周回を説明する基板支援製品リリースメカニズムです.
- このメカニズムは,細菌と臓器の膜タンパク質の生体形成に洞察を与えます.
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