Crystal structural analysis of photosystem II in pH dependence for trapping S2 intermediate state

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H05588
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Structural biochemistry
• Research Institution: Okayama University
• Principal Investigator: Umena Yasufumi 岡山大学, 異分野基礎科学研究所, 特別契約職員(准教授) (10468267)
• Co-Investigator(Renkei-kenkyūsha): Furutani Yuji 分子科学研究所, 生体分子情報研究部門, 准教授 (80432285)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 結晶構造解析 / 光合成 / 光化学系II蛋白質 / pH / 反応中間状態

Outline of Final Research Achievements

Crystal structures of cyanobacterium Photosystem II (PSII) in pH4 or pH9 condition were solved at 2.0-angstrom resolution. These acidic or basic PSII crystals changed from the neutral state were obtained by using the mixture solution of three kinds of buffers for the linear pH gradient without changing the composition of crystal mother liquid. Whole structures were no differences among neutral, acidic and basic structure. However, the pH-dependant structure changes were observed on the proton pathways from the active site of water-oxidation. The each of structural change was in the different locations between acidic and basic structure, respectively. We concluded that these parts were essential for proton transfer from the water-splitting reaction in PSII.

Free Research Field

構造生物学