期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：16
页码：9314-9318
DOI：10.1073/pnas.1637860100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：F1-ATPase is an ATP-driven rotary motor in which a rod-shaped {gamma} subunit rotates inside a cylinder made of 3{beta}3 subunits. To elucidate the conformations of rotating F1, we measured fluorescence resonance energy transfer (FRET) between a donor on one of the three {beta}s and an acceptor on {gamma} in single F1 molecules. The yield of FRET changed stepwise at low ATP concentrations, reflecting the stepwise rotation of {gamma}. In the ATP-waiting state, the FRET yields indicated a {gamma} position {approx}40{degrees} counterclockwise (= direction of rotation) from that in the crystal structures of mitochondrial F1, suggesting that the crystal structures mimic a metastable state before product release.
