Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology


LAST UPDATE 2022/09/20

  • 研究者氏名
    Researcher Name

    近藤久益子 Kumiko KONDO
    特任助教 Specially-appointed Assistant Professor
  • 所属
    Professional Affiliation

    Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology

    Department of Molecular Bioscience
  • 研究キーワード
    Research Keywords

    ATP synthase
Research Subject
The regulation mechanism of ATP synthase unique to photosynthetic organisms

研究の背景 Background


ATP synthase (FoF1) is an enzyme that exists in biological membranes, and produces ATP from ADP and inorganic phosphate by utilizing the electrochemical proton gradient across the membrane. In photosynthetic thylakoid membrane, illumination activates photosynthetic electron transport, generating proton motive force (pmf) across the thylakoid, which drives ATP synthesis. In the dark, FoF1 hydrolyzes ATP as the reverse reaction. Therefore, it is reasonable to assume that these organisms have evolved a unique mechanism for regulating FoF1 activity that utilizes pmf for synthesizing ATP.

研究の目標 Outcome


Using cyanobacteria, which are oxygen-evolving photosynthetic bacteria, I will elucidate the regulatory mechanisms unique to phototrophs. I will also create a highly efficient ATP synthase by introducing site-directed mutations. This is expected to contribute to the social implementation of material production using photosynthetic microorganisms.

研究図Research Figure

Fig.1. A schematic diagram of FoF1 ATP synthase from Spinacia oleracea (PDB ID: 6FKF).

Fig.2. Comparison of the γ subunits from various organisms. Upper: The domain architecture of the γ subunit from the phototrophs. They possess a unique insertion sequence within the Rossmann-fold domain, between the N-terminal and C-terminal a helices. Lower: A partial alignment of amino acid sequences around the insertion region. Cyanobacteria and red algae have phototroph-specific insertion, which forms a β-hairpin structure (Hairpin 2). Green plants and green algae have an additional β-hairpin structure (Hairpin 1). We reported that Hairpin 2 critically contributes to its ATP synthesis activity and suppresses ATP hydrolysis.


文献 / Publications

Kondo, K., Izumi, M., Inabe, K., Yoshida, K., Imashimizu, M., Suzuki, T., and Hisabori, T., J. Biol. Chem. 475:2925-2939 (2021).
Kondo, K., Takeyama, Y., Sunamura, E.I., Madoka, Y., Fukaya, Y., Isu, A., Hisabori, T., Biochim. Biophys. Acta. 1859:319-325 (2018).