Electron-Transfer Route in the Early Oxidation States of the Mn₄CaO₅ Cluster in Photosystem II.

ABSTRACT: The electron transfer from the oxygen-evolving Mn₄CaO₅ cluster to the electron acceptor D1-Tyr161 (TyrZ) is a prerequisite for water oxidation and O₂ evolution. Here, we analyzed the electronic coupling in the rate-limiting electron-transfer transitions using a combined quantum mechanical/molecular mechanical/polarizable continuum model approach. In the S₀ to S₁ transition, the electronic coupling between the electron-donor Mn3(III) and TyrZ is small (2 meV). In contrast, the electronic coupling between the dangling Mn4(III) and TyrZ is significantly large (172 meV), which suggests that the electron transfer proceeds from Mn3(III) to TyrZ via Mn4(III). In the S₁ to S₂ transition, the electronic coupling between Mn

SUBMITTER: Tamura H 

PROVIDER: S-EPMC9841979 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature