Genetic analysis of the form and function of photosystem I and photosystem II

Abstract

Photosystem I (PSI) and photosystem II (PSII) are two multisubunit pigment-protein complexes in the thylakoid membranes in the chloroplasts of plants, algae, and in cyanobacteria. In recent years, directed mutagenesis has been used to specifically modify individual polypeptide components of both PSI and PSII in cyanobacteria and the green alga, Chlamydomonas. Biochemical and spectroscopic analyses of such mutants have produced a rich source of information regarding the structure and function of these two protein complexes. In addition, the natural transformation systems of certain cyanobacterial strains have been exploited to unravel novel genetic loci that regulate the biogenesis and function of these proteins. This review article discusses recent key findings in these areas.