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Environmental pH and a Glu364 to Gln mutation in the chlorophyll‐binding CP 47 protein affect redox‐active TyrD and charge recombination in Photosystem II
Author(s) -
Morris Jaz N.,
Kovács Sándor,
Vass Imre,
Summerfield Tina C.,
EatonRye Julian J.
Publication year - 2019
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13307
Subject(s) - photosystem ii , chemistry , redox , synechocystis , oxygen evolution , photosynthesis , p700 , photosystem i , biophysics , mutant , ligand (biochemistry) , plastoquinone , oxygen evolving complex , biochemistry , biology , chloroplast , receptor , electrochemistry , thylakoid , electrode , organic chemistry , gene
In Photosystem II , loop E of the chlorophyll‐binding CP 47 protein is located near a redox‐active tyrosine, Y D , forming a symmetrical analog to loop E in CP 43, which provides a ligand to the oxygen‐evolving complex ( OEC ). A Glu364 to Gln substitution in CP 47, near Y D , does not affect growth in the cyanobacterium Synechocystis sp. PCC 6803; however, deletion of the extrinsic protein PsbV in this mutant leads to a strain displaying a pH ‐sensitive phenotype. Using thermoluminescence, chlorophyll fluorescence, and flash‐induced oxygen evolution analyses, we demonstrate that Glu364 influences the stability of Y D and the redox state of the OEC , and highlight the effects of external pH on photosynthetic electron transfer in intact cyanobacterial cells.