title: Insertional inactivation of the psbO gene encoding the manganese stabilizing protein of photosystem II in the cyanobacterium Synechococcus PCC7942. Effect on photosynthetic water oxidation and L-amino acid oxidase activity.
abstract: A Synechococcus PCC7942 mutant in which the psbO gene was inactivated by insertion of a chloramphenicol interposon and which did not contain any detectable manganese stabilizing protein in immunoblot experiments, was constructed. Such a Synechococcus mutant was able to grow under photoautotrophic conditions. Isolated thylakoid membranes from the mutant required addition of CaCl2 and MnCl2 for photosynthetic O2 evolution, and the detectable L-amino acid oxidase activity in the isolated thylakoid membranes from the mutant was approximately four times higher than in wild-type thylakoids. The results are discussed with respect to our model suggesting that the water-oxidizing enzyme may have evolved from a flavoprotein with L-amino acid dehydrogenase/oxidase activity.
authors.affiliation: Lehstuhl für Zellphysiologie, Universität Bielefeld, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Bockholt
authors.forename: B
authors.initials: B
authors.lastname: Masepohl
authors.forename: E K
authors.initials: EK
authors.lastname: Pistorius
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D002122:Calcium Chloride / Q000494:pharmacology; D002712:Chlorides; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics; D007700:Kinetics; D008345:Manganese / Q000378:metabolism* / Q000494:pharmacology; D017895:Manganese Compounds; D016254:Mutagenesis, Insertional; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011506:Proteins; D015183:Restriction Mapping
chemical_list: D002712:Chlorides; D004251:DNA Transposable Elements; D017895:Manganese Compounds; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011506:Proteins; C054266:photosystem II manganese-stabilizing protein; D008345:Manganese; D000594:Amino Acid Oxidoreductases; C040983:arginine oxidase; D002122:Calcium Chloride; C025340:manganese chloride