Differential sensitivity of bicarbonate-reversible formate effects on herbicide-resistant mutants of Synechocystis 6714.
Herbicide-resistant mutants of the cyanobacterium Synechocystis 6714, that are altered in specific amino acids in their D-1 protein, shows differential sensitivity to formate treatment. Measurements on oxygen yield in a sequence of flashes, chlorophyll (Chl) a fluorescence transients and Chl a fluorescence yield decay after a flash reveal that the resistance of cells to formate treatment is in the following (highest to lowest) order: [double mutant] A251V/F211S (Az V) greater than [single mutant] F211S (Az I) congruent to wild type greater than [single mutant] S264A (DCMU II-A). Significance of these results in terms of overlapping between the herbicide and bicarbonate binding niches on the D-1 protein is discussed.
Govindjee
Department of Physiology and Biophysics, University of Illinois, Urbana-Champaign 61801.
Vernotte
C
C
Peteri
B
B
Astier
C
C
Etienne
A L
AL
D001639:Bicarbonates / Q000494:pharmacology*; D002734:Chlorophyll / Q000032:analysis / Q000235:genetics*; D000458:Cyanobacteria / Q000187:drug effects* / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D005561:Formates / Q000494:pharmacology*; D006540:Herbicides / Q000494:pharmacology*; D008027:Light; D045342:Light-Harvesting Protein Complexes; D009154:Mutation; D010100:Oxygen / Q000032:analysis; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins / Q000235:genetics*; D013050:Spectrometry, Fluorescence
D001639:Bicarbonates; D005561:Formates; D006540:Herbicides; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins; C030544:formic acid; D002734:Chlorophyll; D010100:Oxygen