Comparison of the structure of the extrinsic 33 kDa protein from different organisms.

The psbO gene encoding the extrinsic 33 kDa protein of oxygen-evolving photosystem II (PSII) complex was cloned and sequenced from a red alga, Cyanidium caldarium. The gene encodes a polypeptide of 333 residues, of which the first 76 residues served as transit peptides for transfer across the chloroplast envelope and thylakoid membrane. The mature protein consists of 257 amino acids with a calculated molecular mass of 28,290 Da.

A domain of the manganese-stabilizing protein from Synechococcus elongatus involved in functional binding to photosystem II.

Site-directed mutagenesis was performed to investigate whether the two protease-sensitive sequences Phe(156)-Gly(163) and Arg(184)-Ser(191), of the manganese-stabilizing protein (MSP) from a thermophilic cyanobacterium, Synechococcus elongatus (Motoki, A., Shimazu, T., Hirano, M.