Investigation of the mechanism of conversion from proton motive force to rotational energy in ATP synthase.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06514
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: Osaka University
• Principal Investigator: Kishikawa Jun-ichi 大阪大学, 蛋白質研究所, 助教 (80599241)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 回転分子モーター / V-ATPase / クライオ電子顕微鏡 / 単粒子解析 / 膜タンパク質

Outline of Final Research Achievements

ATP synthase plays a crucial role in synthesizing ATP by converting the proton-motive force across inside and outside of membrane into rotational energy. We investigated the energy conversion mechanism of ATP synthase by analyzing the high-resolution structure of the transmembrane domain from a thermophilic bacterium. Through single particle analysis using cryo-electron microscopy, we determined the protonation state of key residues involved in proton transport. Molecular simulations were then conducted to explore the energy conversion process. Our findings provide insights into how ATP synthase converts proton-motive force into rotational energy, contributing to a deeper understanding of this fundamental process in bioenergetics. These insights have potential applications in bioengineering.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

ATP合成酵素は、ATPの合成とプロトン輸送を回転によって共役するユニークなタンパク質である。親水性部分でATPの合成、膜内在性部分でイオンの輸送を行う。親水性部分は、一分子回転観察などにより詳細に調べられている。一方で、膜内在性でのプロトン輸送機構は不明な点が多かった。本研究で得られた知見は、この輸送機構の原子レベルでの解明に光を当てるものであり、学術的な意義が深い。また、回転分子モーターは非常に精密な機械と捉えることもでき、その機構が分かることは、生物工学的にも興味深い。