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Updated: Aug 8, 2026
08:44
Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
Published on: January 22, 2019
Chemomechanical coupling in single-molecule F-type ATP synthase
Ryota Iino1, Yannick Rondelez, Masasuke Yoshida
1The Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.
Journal of Bioenergetics and Biomembranes
|May 13, 2006
Summary
The epsilon subunit significantly boosts ATP synthesis efficiency in F(1)-ATPase by up to 77%. This study reveals epsilon
Area of Science:
- Biochemistry
- Molecular Biology
- Biophysics
Background:
- F(1)-ATPase is a key enzyme in cellular energy production.
- The chemomechanical coupling efficiency of ATP synthesis is crucial for biological energy transfer.
- The role of the epsilon subunit in F(0)F(1)-ATP synthase efficiency was previously unclear.
Purpose of the Study:
- To investigate the mechanism by which the epsilon subunit enhances the ATP synthesis efficiency of F(1)-ATPase.
- To determine the conformational dynamics of the epsilon subunit in response to nucleotide binding.
- To elucidate the role of epsilon subunit conformational changes in regulating F(0)F(1)-ATP synthase activity.
Main Methods:
- Development of a femtoliter-scale reaction chamber for single-molecule detection.
- Encapsulation of single F(1)-ATPase molecules with substrates (ADP, inorganic phosphate).
- Measurement of conformational dynamics using single-molecule fluorescence resonance energy transfer (FRET).
Main Results:
- The alpha3beta3gamma subcomplex of F(1)-ATPase exhibited low ATP synthesis efficiency (~10%).
- Inclusion of the epsilon subunit increased ATP synthesis efficiency to 77%.
- The epsilon subunit undergoes nucleotide-dependent conformational changes in its C-terminus helices.
Conclusions:
- The epsilon subunit plays a critical role in enhancing the chemomechanical coupling efficiency of F(1)-ATPase.
- Nucleotide-dependent conformational changes in the epsilon subunit are likely responsible for switching the catalytic mode of F(0)F(1)-ATP synthase.
- This mechanism supports highly coupled ATP synthesis, essential for cellular energy production.
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