無傷のThermus thermophilus H+駆動ATP合成酵素のサブナノメートルの解像度構造
Wilson C Y Lau1, John L Rubinstein
1Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
Nature
|December 20, 2011
まとめ
研究者らは,陽子駆動型ATP合成酵素の構造を明らかにし,イオンフローが細胞のエネルギー生産にどのように力を貸すかを詳細に説明しました. この画期的な発見は,回転性ATPアゼで陽子の運動力を回転に変換するメカニズムを明らかにした.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 分子生物物理学 分子生物物理学
背景:
- イオン転位回転ATPaaseは,イオングラデントを使用してATPを合成するか,ATP水解を使用してイオンをポンプする重要な酵素です.
- これらの酵素には2つの回転モーターがあり,一つはイオン転位,もう一つはATP合成/水解に使用されます.
- これらのATPasesの無傷の膜領域の構造モデルは,以前には利用できませんでした.
研究 の 目的:
- Thermus thermophilus.からのH ((+)) 駆動ATP合成酵素の膜結合領域の高解像度構造を決定する.
- 超膜陽子の運動力が機械的な回転に変換されるメカニズムを解明する.
主な方法:
- 単粒子電子冷凍顕微鏡 (cryo-EM) を使用して,9.7 Åの解像度マップを取得しました.
- この研究では,A ((3) B ((3) CDE ((2) FG ((2) IL ((12)) のサブユニット組成を持つ600キロダルトンの複合体を分析した.
主要な成果:
- 膜結合モーターは12Lサブユニットと8つのトランスメブランヘリクを持つサブユニットIのリングで構成されています.
- 膜の中央のL(12) リングとサブユニットIの間に小さな接触領域が観察されました.
- サブユニットIのトランスメブランヘリクスはバンドルを形成し,陽子半チャネルとして作用し,イオン流れを促進する可能性がある.
結論:
- 決定された構造は,ATP合成酵素の回転機構に関する前例のない洞察を提供します.
- この発見は,陽子の転位が中心ローターの回転をどのように誘導するかのモデルを示唆している.
- この研究は,これらの重要な細胞機械のエネルギー変換を理解するための基礎を築いています.
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