A stromal region of cytochrome b₆f subunit IV is involved in the activation of the Stt7 kinase in Chlamydomonas.

ABSTRACT: The cytochrome (cyt) b₆f complex and Stt7 kinase regulate the antenna sizes of photosystems I and II through state transitions, which are mediated by a reversible phosphorylation of light harvesting complexes II, depending on the redox state of the plastoquinone pool. When the pool is reduced, the cyt b₆f activates the Stt7 kinase through a mechanism that is still poorly understood. After random mutagenesis of the chloroplast petD gene, coding for subunit IV of the cyt b₆f complex, and complementation of a ΔpetD host strain by chloroplast transformation, we screened for impaired state transitions in vivo by chlorophyll fluorescence imaging. We show that residues Asn122, Tyr124, and Arg125 in the stroma

SUBMITTER: Dumas L 

PROVIDER: S-EPMC5692589 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature