Insights into the origin of the high energy-conversion efficiency of F1-ATPase.
Kwangho NamMartin KarplusPublished in: Proceedings of the National Academy of Sciences of the United States of America (2019)
Our understanding of the rotary-coupling mechanism of F1-ATPase has been greatly enhanced in the last decade by advances in X-ray crystallography, single-molecular imaging, and theoretical models. Recently, Volkán-Kacsó and Marcus [S. Volkán-Kacsó, R. A. Marcus, Proc. Natl. Acad. Sci. U.S.A. 112, 14230 (2015)] presented an insightful thermodynamic model based on the Marcus reaction theory coupled with an elastic structural deformation term to explain the observed γ-rotation angle dependence of the adenosine triphosphate (ATP)/adenosine diphosphate (ADP) exchange rates of F1-ATPase. Although the model is successful in correlating single-molecule data, it is not in agreement with the available theoretical results. We describe a revision of the model, which leads to consistency with the simulation results and other experimental data on the F1-ATPase rotor compliance. Although the free energy liberated on ATP hydrolysis by F1-ATPase is rapidly dissipated as heat and so cannot contribute directly to the rotation, we show how, nevertheless, F1-ATPase functions near the maximum possible efficiency. This surprising result is a consequence of the differential binding of ATP and its hydrolysis products ADP and Pi along a well-defined pathway.
Keyphrases
- single molecule
- endoplasmic reticulum
- high resolution
- total knee arthroplasty
- electronic health record
- big data
- magnetic resonance imaging
- heat stress
- room temperature
- computed tomography
- atomic force microscopy
- magnetic resonance
- mass spectrometry
- anaerobic digestion
- machine learning
- data analysis
- total hip arthroplasty
- artificial intelligence
- transcription factor
- preterm birth
- dna binding
- electron transfer