Abstract
PsbY is a membrane protein of ˜4 kDa found in photosystem II (PS II) complexes from cyanobactria to higher plants. However, it is not shown in the current cryatllographic model, and the function is still not clear. In this work, we deleted psbY gene from Synechocystis 6803 and analyzed the function of PsbY.
No difference was observed in the growth curve and the rate of oxygen evolution between the wild-type and mutant cells. However, the rate of oxygen evolution in the purified mutant PS II complexes was much lower compared to that in the purified wild-type PSII complexes. Electrophoretic profile revealed that most part of PsbU and PsbV, and some part of PsbO and PsbQ were lost in the purified mutant PS II complexes. It was concluded that PsbY is important for the stable binding of extrinsic proteins especially for PsbU and PsbV.
