EPR studies of the oxygen-evolving complex reveal a light-adaptation process in Photosystem II

摘要

Photosystem II (PSII) catalyzes the light-driven oxidation of water, evolving one molecule of O_2 and four protons per two H_2O molecules oxidized. The site of water oxidation is the oxygen-evolving complex (OEC), situated on the lumenal side of themembrane-spanning protein complex, containing four Mn ions and a Ca and a Cl ion. Although the structure of PSII was recently determined by X-ray crystallography (Zouni et al., 2001), the resolution is not yet high enough to unambiguously determine the detailed structure of the OEC.