O₂ evolution and recovery of the water-oxidizing enzyme.

ABSTRACT: In photosystem II, light-induced water oxidation occurs at the Mn₄CaO₅ cluster. Here we demonstrate proton releases, dioxygen formation, and substrate water incorporation in response to Mn₄CaO₅ oxidation in the protein environment, using a quantum mechanical/molecular mechanical approach and molecular dynamics simulations. In S₂, H₂O at the W1 site forms a low-barrier H-bond with D1-Asp61. In the S₂-to-S₃ transition, oxidation of O_W1H^- to O_W1^•-, concerted proton transfer from O_W1H^- to D1-Asp61, and binding of a water molecule W_n-W1 at O_W1^•- are observed. In S₄, W _n-W1 facil

SUBMITTER: Kawashima K 

PROVIDER: S-EPMC5871790 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature