Oxygen-evolving photosystem II structures during S₁-S₂-S₃ transitions.

ABSTRACT: Photosystem II (PSII) catalyses the oxidation of water through a four-step cycle of S_i states (i = 0-4) at the Mn₄CaO₅ cluster^1-3, during which an extra oxygen (O6) is incorporated at the S₃ state to form a possible dioxygen^4-7. Structural changes of the metal cluster and its environment during the S-state transitions have been studied on the microsecond timescale. Here we use pump-probe serial femtosecond crystallography to reveal the structural dynamics of PSII from nanoseconds to milliseconds after illumination with one flash (1F) or two flashes (2F). Y_Z, a tyrosine residue that connects the reaction centre P680 and the Mn₄CaO₅ cluster, showed structural changes on a nanosecond timescale,

SUBMITTER: Li H 

PROVIDER: S-EPMC10866707 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature