A complex, composed of a cluster of manganese, calcium and chloride ions bound to extrinsic proteins, that catalyzes the splitting of water to O2 and 4 H+. In cyanobacteria there are five extrinsic proteins in OEC (PsbO, PsbP-like, PsbQ-like, PsbU and PsbV), while in plants there are only three (PsbO, PsbP and PsbQ).
photosystem II reaction center
phycobilisome
plasma membrane protein complex +
plasma membrane-derived thylakoid membrane
plasma membrane-derived thylakoid photosystem II
plastid thylakoid membrane +
pore complex +
pre-B cell receptor complex
procollagen-proline 4-dioxygenase complex +
protein C inhibitor-acrosin complex
proton-transporting ATP synthase, catalytic core +