Using site-directed mutagenesis to probe the role of the D2 carotenoid in the secondary electron-transfer pathway of photosystem II.

ABSTRACT: Secondary electron transfer in photosystem II (PSII), which occurs when water oxidation is inhibited, involves redox-active carotenoids (Car), as well as chlorophylls (Chl), and cytochrome b 559 (Cyt b 559), and is believed to play a role in photoprotection. CarD2 may be the initial point of secondary electron transfer because it is the closest cofactor to both P680, the initial oxidant, and to Cyt b 559, the terminal secondary electron donor within PSII. In order to characterize the role of CarD2 and to determine the effects of perturbing CarD2 on both the electron-transfer events and on the identity of the redox-active cofactors, it is necessary to vary the properties of CarD2 selectively without affecting the ten other Car per PSII. To this end, site-directed mutations around the bindin

SUBMITTER: Shinopoulos KE 

PROVIDER: S-EPMC3961632 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature