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The assimilatory nitrate reductase of the phototrophic bacterium Rhodopseudomonas capsulata strain AD2 was purified to homogeneity by a combination of ammonium sulfate fractionation, chromatography on DEAE-cellulose and isoelectric focusing (isoelectric point of 4.8). The purified enzyme was active only with reduced viologen dyes or reduced flavin as(More)
In Rhodospirillum rubrum, inorganic pyrophosphatase activity is observed in both the cytoplasmic and membrane fractions. The soluble enzyme accounts for about 80% of the total activity in crude extracts, and is the subject of this report. Zn(2+) is required for both activity and stability of the enzyme, which has a molecular weight of approximately 90,000(More)
Transposon Tn5 mutagenesis was used to isolate mutants of Rhodospirillum rubrum which lack uptake hydrogenase (Hup) activity. Three Tn5 insertions mapped at different positions within the same 13-kb EcoRI fragment (fragment E1). Hybridization experiments revealed homology to the structural hydrogenase genes hupSLM from Rhodobacter capsulatus and hupSL from(More)
The pyruvate dehydrogenase complex from the photosynthetic bacterium Rhodospirillum rubrum was associated with the membrane fraction both in heterotrophically and photosynthetically grown cells. The complex was separated from the membranes and partially purified by precipitation with MgSO4 and gelfiltration through Sepharose 4B. The purified complex had a(More)
Soluble inorganic pyrophosphatases of five species of nonsulfur purple bacteria were investigated in respect to reaction kinetics, regulatory behavior, and other characteristics. The enzymes appear to fall into two groups with correlated properties. The pyrophosphatases of Rhodopseudomonas capsulata and R. spheroides have molecular weights of approximately(More)
The assimilatory nitrate reductase was purified 60-fold from a newly isolated, nitrate assmilating strain of the photosynthetic bacterium Rhodopseudomonas capsulata. The enzyme had a molecular weight of about 180 000 dalton and was typically prokaryotic in that it was not active with reduced pyridine nucleotides but rather with reduced flavins.
  • J H Klemme
  • 1976
The conservation of the phosphoanhydride-energy of inorganic pyrophosphate (PP) in microbial metabolism requires a stringent metabolic control of the intracellular pyrophosphatases (PPases, EC In this article, the rate of intracellular PP-liberation during biosynthesis of cellular constituents is calculated from the specific growth rate and the(More)
  • M Preuss, J H Klemme
  • 1983
A dissimilatory nitrite reductase from the facultatively phototrophic bacterium, Rhodopseudomonas palustris strain 1a1 was studied. A basic level of the enzyme (10-50 mU/mg protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A marked derepression of enzyme synthesis occurred under conditions of oxygen limitation (200-300 mU/mg(More)