Elucidation of photosynthetic electron transfer mechanism by ultra-high resolution x-ray structural analysis.

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06524
• 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: Tanaka Hideaki 大阪大学, 蛋白質研究所, 准教授 (40346169)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: Ｘ線結晶構造解析 / 中性子結晶構造解析 / 光合成電子伝達 / フェレドキシン / 精密構造解析

Outline of Final Research Achievements

In this study, we targeted the electron transfer protein ferredoxin (Fd) and its partner protein FNR, and worked on ultra-high resolution X-ray crystallography and neutron crystallography, paying attention to their redox states. For the oxide-type crystals of Fd and FNR, ultra-high resolution diffraction intensity data were successfully collected using multiple crystals with an X-ray irradiation of 0.1 MGy. For Fd, we also succeeded in collecting ultra-high resolution diffraction intensity data for the reduced form. Furthermore, in the experiment of neutron crystallography of oxidized FNR, a full set of neutron diffraction intensity data was successfully collected at J-PARC, and the structural analysis is in progress.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

本来、電子伝達複合体は酸化還元により解離・会合するのが活性型である。本研究では、FdとFNRについて酸化還元状態に留意した構造解析（酸化型Fd 、還元型Fd、酸化型FNR、還元型FNR）を進めてきた。これらの構造を水素原子の位置も含めて決定することで、実験の都合で無視されてきた、酸化還元状態と水素原子の構造を正確に記述することができ、アミノ酸だけでは議論することができなかった新規情報を提供することが可能となる。