Efficient ATP synthesis by thermophilic Bacillus FoF 1-ATP synthase

Naoki Soga, Kazuhiko Kinosita, Masasuke Yoshida, Toshiharu Suzuki

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    18 Citations (Scopus)

    Abstract

    FoF1-ATP synthase (FoF1) synthesizes ATP in the F1 portion when protons flow through F o to rotate the shaft common to F1 and Fo. Rotary synthesis in isolated F1 alone has been shown by applying external torque to F1 of thermophilic origin. Proton-driven ATP synthesis by thermophilic Bacillus PS3 FoF1 (TF oF1), however, has so far been poor in vitro, of the order of 1 s-1 or less, hampering reliable characterization. Here, by using a mutant TFoF1 lacking an inhibitory segment of the μ-subunit, we have developed highly reproducible, simple procedures for the preparation of active proteoliposomes and for kinetic analysis of ATP synthesis, which was driven by acid-base transition and K+-diffusion potential. The synthesis activity reached ∼ 16 s-1 at 30 °C with a Q10 temperature coefficient of 3-4 between 10 and 30 °C, suggesting a high level of activity at the physiological temperature of ∼ 60 °C. The Michaelis-Menten constants for the substrates ADP and inorganic phosphate were 13 μm and 0.55 mm, respectively, which are an order of magnitude lower than previous estimates and are suited to efficient ATP synthesis.

    Original languageEnglish
    Pages (from-to)2647-2654
    Number of pages8
    JournalFEBS Journal
    Volume278
    Issue number15
    DOIs
    Publication statusPublished - 2011 Aug

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    Keywords

    • ATP synthesis
    • Michaelis-Menten constants
    • reconstitution
    • temperature
    • TF F

    ASJC Scopus subject areas

    • Biochemistry
    • Cell Biology
    • Molecular Biology

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