Proton-powered subunit rotation in single membrane-bound F0F1-ATP synthase
Proton-powered subunit rotation in single membrane-bound F0F1-ATP synthase
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DOI：
10.1038/nsmb718
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发表时间：
2004-02-01
影响因子：
16.8
通讯作者：
Gräber, P
中科院分区：
文献类型：
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作者：
Diez, M;Zimmermann, B;Gräber, P
由ADP和磷酸盐合成ATP，由F0 F1-ATP酶催化，是几乎任何细胞中最丰富的生理反应。F0 F1-ATP脱氢酶是膜结合酶，其使用来自电化学质子梯度的能量用于ATP形成。我们将来自大肠杆菌的双标记F0 F1-ATP酶掺入脂质体中，并测量ATP合成和水解过程中的单分子荧光共振能量转移（FRET）。γ亚基在质子转运驱动的ATP合成过程中逐步旋转，在重复序列中显示到B亚基的三个不同距离。这些步骤的平均持续时间对应于ATP合成和ATP水解时的催化周转时间。ATP合成时的旋转方向与ATP水解时的方向相反。
Synthesis of ATP from ADP and phosphate, catalyzed by F0F1-ATP synthases, is the most abundant physiological reaction in almost any cell. F0F1-ATP synthases are membrane-bound enzymes that use the energy derived from an electrochemical proton gradient for ATP formation. We incorporated double-labeled F0F1-ATP synthases from Escherichia coli into liposomes and measured single-molecule fluorescence resonance energy transfer (FRET) during ATP synthesis and hydrolysis. The gamma subunit rotates stepwise during proton transport powered ATP synthesis, showing three distinct distances to the b subunits in repeating sequences. The average durations of these steps correspond to catalytic turnover times upon ATP synthesis as well as ATP hydrolysis. The direction of rotation during ATP synthesis is opposite to that of ATP hydrolysis.