Nature of S-States in the Oxygen-Evolving Complex Resolved by High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy.

ABSTRACT: Photosystem II, the water splitting enzyme of photosynthesis, utilizes the energy of sunlight to drive the four-electron oxidation of water to dioxygen at the oxygen-evolving complex (OEC). The OEC harbors a Mn₄CaO₅ cluster that cycles through five oxidation states S_i (i = 0-4). The S₃ state is the last metastable state before the O₂ evolution. Its electronic structure and nature of the S₂ → S₃ transition are key topics of persisting controversy. Most spectroscopic studies suggest that the S₃ state consists of four Mn(IV) ions, compared to the Mn(III)Mn(IV)₃ of the S₂ state. However, recent crystallographic data have received conflicting interpretations, suggesting ei

SUBMITTER: Chrysina M 

PROVIDER: S-EPMC10690802 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature