title: Cyanobacterial psbA gene family: optimization of oxygenic photosynthesis.
abstract: The D1 protein of Photosystem II (PSII), encoded by the psbA genes, is an indispensable component of oxygenic photosynthesis. Due to strongly oxidative chemistry of PSII water splitting, the D1 protein is prone to constant photodamage requiring its replacement, whereas most of the other PSII subunits remain ordinarily undamaged. In cyanobacteria, the D1 protein is encoded by a psbA gene family, whose members are differentially expressed according to environmental cues. Here, the regulation of the psbA gene expression is first discussed with emphasis on the model organisms Synechococcus sp. and Synechocystis sp. Then, a general classification of cyanobacterial D1 isoforms in various cyanobacterial species into D1m, D1:1, D1:2, and D1' forms depending on their expression pattern under acclimated growth conditions and upon stress is discussed, taking into consideration the phototolerance of different D1 forms and the expression conditions of respective members of the psbA gene family.
authors: Laboratory of Plant Physiology and Molecular Biology, Department of Biology, Biocity A, University of Turku, 20520 Turku, Finland. pmulo@utu.fi
authors: Paula
authors: P
authors: Mulo
authors: Cosmin
authors: C
authors: Sicora
authors: Eva-Mari
authors: EM
authors: Aro
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D046940:Synechococcus / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D045332:Photosystem II Protein Complex; D020033:Protein Isoforms; D014764:Viral Proteins; C422369:photosystem II, psbA subunit; D010100:Oxygen