Analysis of the water splitting and oxigen evolving mechanis of Photosystem II comples using serial femto-second crystallography

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K21181
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry; Plant molecular biology/Plant physiology
• Research Institution: Okayama University
• Principal Investigator: Akita Fusamichi 岡山大学, 異分野基礎科学研究所, 准教授 (50751418)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 光合成

Outline of Final Research Achievements

Photosystem II is a supercomplex, and catalyzes water-splitting, leading to the generation of electrons, protons and oxygen. Since no intermediate structures of the S-state has been solved, the mechanism of water-splitting is still not clear. To analyze the structures of the intermediate S-states, we prepared PSII microcrystals and collected their diffraction images using time-resolved serial femtosecond crystallography with X-ray free electron laser at SACLA. We obtained two-flashes illuminated PSII structure at 2.35 angstrom resolution. By comparing with the S1-state structure, it was revealed that a new oxygen atom was inserted into a position close to one of the oxo-bridges (O5) within Mn cluster.

Free Research Field

構造生物学