D1-Asn-298 in photosystem II is involved in a hydrogen-bond network near the redox-active tyrosine Y_Z for proton exit during water oxidation.

ABSTRACT: In photosynthetic water oxidation, two water molecules are converted into one oxygen molecule and four protons at the Mn₄CaO₅ cluster in photosystem II (PSII) via the S-state cycle. Efficient proton exit from the catalytic site to the lumen is essential for this process. However, the exit pathways of individual protons through the PSII proteins remain to be identified. In this study, we examined the involvement of a hydrogen-bond network near the redox-active tyrosine Y_Z in proton transfer during the S-state cycle. We focused on spectroscopic analyses of a site-directed variant of D1-Asn-298, a residue involved in a hydrogen-bond network near Y_Z We found that the D1-N298A mutant of Synechocystis sp. PCC 6803 exhibits an O₂ evolu

SUBMITTER: Nagao R 

PROVIDER: S-EPMC5723994 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature