CRC 1078/1: Structural Basis of Proton Release in Water Oxidation by Photosystem II: Crystallization, X-Ray and Neutron Diffraction Analysis of Chloride-Modified and Site-Directed Variants (SP A05)

In oxygenic photosynthesis, water is oxidised and dioxygen is formed at the Mn4Ca complex of Photosystem II (PSII). The last ten years have seen a constant refinement of the structural details of PSII, which now provide a solid basis for further work on the underlying proton dynamics. We want to focus on the coupling between electron and proton transfer during photosynthetic water oxidation. To achieve our aims we will combine conventional and room temperature femtosecond X-ray diffraction on chloride-modified PSII variants and site-directed mutants in a collaborative effort.