Effects of pH on the S3 state of the oxygen evolving complex in photosystem II probed by EPR split signal induction
The electrons extracted from the CaMn4 cluster during water oxidation in photosystem II are transferred to P680+ via the redox-active tyrosine D1-Tyr161 (YZ). Upon YZ oxidation a proton moves in a hydrogen bond toward D1-His190 (HisZ). The deprotonation and reprotonation mechanism of YZ-OH/Y Z-O is of key importance for the catalytic turnover of photosystem II. By light illumination at liquid heli