One of the components of the core complex of photosystem II (PSII). It binds chlorophyll and helps catalyze the primary light-induced photochemical processes of PSII. PSII is a light-driven water:plastoquinone oxidoreductase, using light energy to abstract electrons from H(2)O, generating O(2) and a proton gradient subsequently used for ATP formation. Binds multiple chlorophylls and provides some of the ligands for the Ca-4Mn-5O cluster of the oxygen-evolving complex. It may also provide a ligand for a Cl- that is required for oxygen evolution. PSII binds additional chlorophylls, carotenoids and specific lipids. PSII is composed of 1 copy each of membrane proteins PsbA, PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK, PsbL, PsbM, PsbT, PsbX, PsbY, PsbZ, Ycf12, at least 3 peripheral proteins of the oxygen-evolving complex and a large number of cofactors. It forms dimeric complexes. Phosphorylated in both bundle sheath and mesophyll cells, phosphorylation increases when cells are grown under high rather than low light regimes (70 vs 900 umol photons/m-2/s). Belongs to the PsbB/PsbC family. PsbC subfamily.