Redox Regulation of Rotation of the Cyanobacterial F1-ATPase Containing Thiol Regulation Switch

• Published in: The Journal of biological chemistry Vol. 286; no. 11; pp. 9071 - 9078
• Main Authors: Kim, Yusung, Konno, Hiroki, Sugano, Yasushi, Hisabori, Toru
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18.03.2011; American Society for Biochemistry and Molecular Biology
• Subjects: Adenosine Diphosphate - chemistry; Adenosine Diphosphate - metabolism; Adenosine Triphosphate - chemistry; Adenosine Triphosphate - metabolism; ADP-inhibition; ATP Synthase; ATPases; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bioenergetics; Chloroplast; Coupling Factors; Cyanobacteria - enzymology; Cyanobacteria - genetics; Disulfides - chemistry; Disulfides - metabolism; Hydrolysis; Molecular Motors; Oxidation-Reduction; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Proton-Translocating ATPases - chemistry; Proton-Translocating ATPases - genetics; Proton-Translocating ATPases - metabolism; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Redox Regulation; Spinacia oleracea - enzymology; Spinacia oleracea - genetics; Sulfhydryl Compounds - chemistry; Sulfhydryl Compounds - metabolism; Molecular Motors; ATP Synthase; Redox Regulation; ATPases; ADP-inhibition; Chloroplast; Coupling Factors
• ISSN: 0021-9258; 1083-351X; 1083-351X
• DOI: 10.1074/jbc.M110.200584

F1-ATP synthase (F1-ATPase) is equipped with a special mechanism that prevents the wasteful reverse reaction, ATP hydrolysis, when there is insufficient proton motive force to drive ATP synthesis. Chloroplast F1-ATPase is subject to redox regulation, whereby ATP hydrolysis activity is regulated by formation and reduction of the disulfide bond located on the γ subunit. To understand the molecular mechanism of this redox regulation, we constructed a chimeric F1 complex (α3β3γredox) using cyanobacterial F1, which mimics the regulatory properties of the chloroplast F1-ATPase, allowing the study of its regulation at the single molecule level. The redox state of the γ subunit did not affect the ATP binding rate to the catalytic site(s) and the torque for rotation. However, the long pauses caused by ADP inhibition were frequently observed in the oxidized state. In addition, the duration of continuous rotation was relatively shorter in the oxidized α3β3γredox complex. These findings lead us to conclude that redox regulation of CF1-ATPase is achieved by controlling the probability of ADP inhibition via the γ subunit inserted region, a sequence feature observed in both cyanobacterial and chloroplast ATPase γ subunits, which is important for ADP inhibition (Sunamura, E., Konno, H., Imashimizu-Kobayashi, M., Sugano, Y., and Hisabori, T. (2010) Plant Cell Physiol. 51, 855–865).