EmrE マルチドラッグトランスポーターのX線構造は,基板との複合体で
Owen Pornillos1, Yen-Ju Chen, Andy P Chen
1Department of Molecular Biology, The Scripps Institute, 10550 North Torrey Pines Road, CB-105, Jolla, CA 92037, USA.
Science (New York, N.Y.)
|December 24, 2005
まとめ
EmrEはE. coliの多剤輸送体であり,薬物を排出するために非対称な構造を使用しています. そのユニークなダイマーアーキテクチャは,陽子依存メカニズムを通じて片方向の輸送を促進します.
科学分野:
- 構造生物学 構造生物学とは
- 分子微生物学 分子微生物学
- バイオケミストリー バイオケミストリー
背景:
- EmrEは,Small Multidrug Resistance (SMR) 家族の主要なトランスポーターである.
- これは,Escherichia coli.の内膜から,陽性電荷の水害剤を積極的に排出する.
- EmrEのメカニズムを理解することは,多剤耐性との闘いにおいて極めて重要です.
研究 の 目的:
- EmrEトランスポーターのX線結晶構造を決定する.
- 基板結合と輸送の構造的基礎を解明する.
- 陽子に依存した流出メカニズムのモデルを提案する.
主な方法:
- 3.7アングストームの解像度のX線結晶学.
- EmrEと基質テトラフェニルフォスフォニウムとの共結晶化.
- EmrE基板複合体の構造分析.
主要な成果:
- 結晶構造は EmrE を二重化界面でホモディメア型トランスポーター結合基質として示しています.
- ダイマーは非対称であり,サブユニットは反対の膜方向とわずかに異なる折りたたみを持っています.
- この非対称なアーキテクチャは,一方的な転位経路を生み出します.
結論:
- EmrEの非対称な反並列二元構造は,その片方向の薬物輸送の鍵です.
- 構造データに基づいて,陽子に依存した流出メカニズムのモデルが提案されています.
- この研究は,SMRトランスポーターの機能に関する重要な洞察を提供します.
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