PH-Dependent Conformational Switch Impacts Stability of the PsbS Dimer.

ABSTRACT: The photosystem II PsbS protein triggers the photoprotective mechanism of plants by sensing the acidification of the thylakoid lumen. Despite the mechanism of action of PsbS would require a pH-dependent monomerization of the dimeric form, a clear connection between the pH-induced structural changes and the dimer stability is missing. Here, by applying constant pH coarse-grained and all-atom molecular dynamics simulations, we investigate the pH-dependent structural response of the PsbS dimer. We find that the pH variation leads to structural changes in the lumen-exposed helices, located at the dimeric interface, providing an effective switch between PsbS inactive and active form. Moreover, the monomerization free energies reveal that in the neutral pH conformation, where the n

SUBMITTER: Chiariello MG 

PROVIDER: S-EPMC9900633 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature