Quantum mechanics/molecular mechanics simulation of the ligand vibrations of the water-oxidizing Mn₄CaO₅ cluster in photosystem II.

ABSTRACT: During photosynthesis, the light-driven oxidation of water performed by photosystem II (PSII) provides electrons necessary to fix CO₂, in turn supporting life on Earth by liberating molecular oxygen. Recent high-resolution X-ray images of PSII show that the water-oxidizing center (WOC) is composed of an Mn₄CaO₅ cluster with six carboxylate, one imidazole, and four water ligands. FTIR difference spectroscopy has shown significant structural changes of the WOC during the S-state cycle of water oxidation, especially within carboxylate groups. However, the roles that these carboxylate groups play in water oxidation as well as how they should be properly assigned in spectra are unresolved. In this study, we performed a normal mode analysis of the WOC using the q

SUBMITTER: Nakamura S 

PROVIDER: S-EPMC5111704 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature