MsbA媒介のリポポリサカリド輸送の構造的基礎
Wei Mi1, Yanyan Li2, Sung Hwan Yoon3
1Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|September 5, 2017
まとめ
研究者達は,MsbAという重要なトランスポーターが,リポポリサッカリド (LPS) をバクテリアの膜に逆転させる仕組みの構造的基礎を明らかにした. これはバクテリアの細胞封筒の組み立てと 潜在的な薬物の標的に関する新しい洞察を提供します.
科学分野:
- 生物化学
- 構造生物学
- 微生物学
背景:
- リポポリサッカリド (LPS) は,グラム陰性細菌の外膜の重要な成分です.
- MsbAはATP結合用カセットトランスポーターで,LPSを内側から外側へと転移させます.
- MsbAによるLPS輸送の構造的メカニズムはまだ十分に理解されていません.
研究 の 目的:
- MsbAによるLPSのリッピングの構造的メカニズムを解明する.
- 異なる機能状態の MsbA の構造を決定する.
- MsbAによるLPSの承認と拘束力を理解する.
主な方法:
- 単粒子の冷凍電子顕微鏡 (冷凍EM)
- MsbAの脂質ナノディスク分解
- ヌクレオチドフリー状態,ADP-ヴァナデート結合状態,ADP-結合状態におけるMsbA構造の決定
主要な成果:
- 3つの異なる機能状態のMsbAの高解像度の冷凍-EM構造が得られた.
- LPSはMsbAの奥深くに結合し,水性および水害性の残留物と相互作用することが判明しました.
- LPS輸送中の外向き,内向き,閉じた形状の間の MsbA 移行.
結論:
- この研究は,LPSの拘束力とMsbAによる承認の構造的基盤を明らかにしています.
- MsbAの形状の変化は,LPSが内膜を横切るには極めて重要です.
- これらの発見は,他の脂質フリッパースを理解し,新しい抗菌戦略を開発するための基礎を提供します.
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