バクテリアの外膜介護者 (FimD) による成長ピルスの引き渡し機構
Minge Du1, Zuanning Yuan1, Hongjun Yu1
1Structural Biology Program, Van Andel Research Institute, Grand Rapids, MI, USA.
Nature
|October 5, 2018
まとめ
この研究は,E. coliのような病原菌が シャパロン・ウッシャー経路を使ってピリを作る方法を明らかにしています 凍結EMは FimDのウッシャータンパク質の 移転サブユニットを示し ピルス・アセンブリを安定させる
科学分野:
- 微生物学
- 構造生物学
- 生物化学
背景:
- 病原性細菌は,宿主細胞の粘着のために表面皮 (フィムブリア) を利用する.
- タイプ1のピリ・アセンブリは,保存されたチャペロン・ウッシャー経路に依存しています.
研究 の 目的:
- FimDのN端からC端のドメインへのピルスサブユニット移転のメカニズムを解明する.
- ピルス生殖過程におけるサブユニットポリメリゼーションのタイミングを理解する.
主な方法:
- クリオ電子顕微鏡 (cryo-EM) を用いて,鍵となるピルス組立の中間物質を視覚化した.
- FimD-FimC-FimF-FimG-FimH複合体の構造分析
主要な成果:
- 構造的な中間物質がFimDをキャプチャし,ピルスの末端をC端領域 (CTD1とCTD2) に転送する.
- FimDのN端領域は,チャペロン-FimFの接触を維持しながらCTD2を結合し,サブユニットへのアクセスを容易にする.
- FimDのN端尾は,交付時にCTD2を結合するためにヘリックスからループに移行します.
結論:
- この研究は,FimDのドメインの二重結合を介して,ピルスアセンブリ中間物質を安定させるメカニズムを提案している.
- この安定化は,多数のサブユニットの組み込み中にピルス繊維の解離を防ぐ.
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