23kDa polypeptide of the oxygen evolving complex of photosystem II n=5 Tax=Sonneratia RepID=A9XNJ0_9MYRT; IPR002683 (Photosystem II PsbP, oxygen evolving complex); GO:0005509 (calcium ion binding), GO:0009523 (photosystem II), GO:0009654 (photosystem II oxygen evolving complex), GO:0015979 (photosynthesis), GO:0019898 (extrinsic component of membrane)