title: Derepression of nitrogenase activity in glutamine auxotrophs of Rhodopseudomonas capsulata.
abstract: In contrast to wild-type cells, glutamine auxotrophs of the photosynthetic bacterium Rhodopseudomonas capsulata synthesize nitrogenase, produce H2 (catalyzed by nitrogenase), and continue to reduce dinitrogen to ammonia in the presence of exogenous NH4+. The glutamine synthetase activity of such mutants is less than 2% of that observed in the wild type. It appears that glutamine synthetase plays a significant role in regulation of nitrogenase synthesis in R. capsulata.
mesh_terms: D000641:Ammonia / Q000378:metabolism; D004794:Enzyme Repression; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005973:Glutamine / Q000235:genetics / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D009154:Mutation; D009591:Nitrogenase / Q000378:metabolism*; D010788:Photosynthesis; D012241:Rhodopseudomonas / Q000235:genetics / Q000378:metabolism*
chemical_list: D005973:Glutamine; D000641:Ammonia; D006859:Hydrogen; D009591:Nitrogenase; D005974:Glutamate-Ammonia Ligase