Structural dynamics in the water and proton channels of photosystem II during the S₂ to S₃ transition.

ABSTRACT: Light-driven oxidation of water to molecular oxygen is catalyzed by the oxygen-evolving complex (OEC) in Photosystem II (PS II). This multi-electron, multi-proton catalysis requires the transport of two water molecules to and four protons from the OEC. A high-resolution 1.89 Å structure obtained by averaging all the S states and refining the data of various time points during the S₂ to S₃ transition has provided better visualization of the potential pathways for substrate water insertion and proton release. Our results indicate that the O1 channel is the likely water intake pathway, and the Cl1 channel is the likely proton release pathway based on the structural rearrangements of water molecules and amino acid side chains along these channels. In particular in the Cl1

SUBMITTER: Hussein R 

PROVIDER: S-EPMC8585918 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature