Isolation of Functional Photosystem II Core Particles From the Cyanobacterium <I>Synechocystis <I>sp. PCC 6803

This chapter contains the description of several methods used for the isolation of functional photosystem (PS)II core particles from wild-type (wt), PSI-less, and CP47 histidine-tagged cells of the cyanobacterium Synechocystis sp. PCC 6803. These protocols discuss the cultivation of PSI-containing and PSI-less cells, isolation of thylakoid membranes, purification of PSII core particles using a weak cation exchange or metal affinity column chromatography, and characterization of the final preparation. The described isolation procedures, which normally yield PSII particles highly active in oxygen evolution, can be easily adapted for obtaining preparations from different types of Synechocystis mutants with modified PSII.