Regulation of nitrogen fixation in Azotobacter vinelandii OP: the role of nitrate reductase.
A number of chlorate-resistant mutants were selected, and one of these, clr68-5, was studied in detail. This mutant cannot utilize nitrate in vivo to overcome the effect of nonmetabolizable repressors of nitrogenase. The reason for this inability was that strain clr68-5 lacked nitrate reductase. Nitrate inhibited the activity of nitrogenase but did not act as a corepressor of nitrogenase in strain clr68-5 as it does in the wild type. Ammonia seemed to act as corepressor of nitrogenase in both strains.
D000641:Ammonia / Q000494:pharmacology; D001395:Azotobacter / Q000201:enzymology*; D002713:Chlorine / Q000494:pharmacology; D004790:Enzyme Induction; D004794:Enzyme Repression; D009154:Mutation; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D009584:Nitrogen; D009586:Nitrogen Fixation; D010088:Oxidoreductases
D009566:Nitrates; D002713:Chlorine; D000641:Ammonia; D010088:Oxidoreductases; D009584:Nitrogen