Abstract
Recently, it have been demonstrated that several proteins are involved in the assembly of the Photosystem II (PSII) complex. One of these proteins, Psb28, which is conserved from cyanobacteria to higher plants, predicted to be an extrinsic protein bound to cytosolic side of the PSII complex.
In this study, we constructed psb28-deletion mutant of Synechocystis sp. PCC 6803 to elucidate the role of the Psb28 protein. The mutant showed normal photoautotrophic growth and oxygen-evolving activity under normal growth conditions. Analysis of the PSII complex purified from the strain expressing a His-tagged Psb28 protein revealed that Psb28 is mainly associated with assembly intermediates of PSII lacking CP43 which binds antenna chlorophylls.
Based on these observations, the role of Psb28 in the assembly of the PSII complex is discussed.
