title: Genetic inactivation of the psaB gene in Synechocystis sp. PCC 6803 disrupts assembly of photosystem I.
abstract: The reaction center of photosystem (PS) I is comprised of a heterodimer of homologous polypeptides, PsaA and PsaB. In order to investigate the biogenesis of PS I, the psaB gene was inactivated by targeted mutagenesis in the unicellular cyanobacterium Synechocystis 6803. This mutation resulted in disruption of stable PS I assembly, but PSI II assembled normally. Expression of the psaA gene was not affected by the mutation, but PsaA protein was not detected, indicating that stable PsaA homodimers did not form. The ability to inactivate psaB makes it a viable target for site-directed mutagenesis.
authors.affiliation: M.S.U.-D.O.E. Plant Research Laboratory and Genetics Program, East Lansing 48824-1312.
authors.forename: L B
authors.initials: LB
authors.lastname: Smart
authors.forename: L
authors.initials: L
authors.lastname: McIntosh
mesh_terms: D002734:Chlorophyll / Q000032:analysis / Q000378:metabolism; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant; D045342:Light-Harvesting Protein Complexes; D016297:Mutagenesis, Site-Directed; D009876:Operon; D010100:Oxygen / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics* / Q000378:metabolism; D045331:Photosystem I Protein Complex; D015183:Restriction Mapping
chemical_list: D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D002734:Chlorophyll; D010100:Oxygen