Indications for a dimeric organization of the antenna-depleted reaction center core of Photosystem II in thylakoids of intermittent light grown pea plants

Abstract

Presently there is a debate and contradictory results on the supramolecular structure of Photosystem II (PS II) in the thylakoid membranes of cyanobacteria, green algae and higher plants that is related to the question whether PS II exists as dimer or monomer in the different membranes. PS II is composed of several subunits. The core complex, the smallest entity that is able to split water, consists of the subunits D1-D2, cyt b 559, CP43, CP47, and the 33 kDa protein. In vivo, this core complex is connected to peripheral light harvesting complexes: in cyanobacteria to the phycobilisomes and in green algae and higher plants to the Chl a/ b binding protein, the LHC II. In in vitro experiments the supramolecular structure of the core complexes has been found to be dimeric or monomeric depending on a variety of experimental factors.