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Hans G. Trüper - One of the best experts on this subject based on the ideXlab platform.
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29 reverse siroheme sulfite reductase from Thiobacillus denitrificans
Methods in Enzymology, 1994Co-Authors: Hans G. TrüperAbstract:Publisher Summary This chapter describes reverse siroheme sulfite reductase from Thiobacillus denitrificans (T. denitrificans). Adenylylsulfate reductase has been found to occur only in the anaerobe T. denitrificans and in the aerobes Thiobacillus thioparus and “Thiobacillus” thiooxidans. A siroheme-containing sulfite reductase in high intracellular concentration is found in T. denitrificans. In contrast to the sulfite reductases in sulfate-reducing bacteria (SRB), in T. denitrificans the enzyme must function in the oxidative—or “reverse”—direction, oxidizing sulfane sulfur to sulfite. Sulfite reductase is measured in a manometric assay in the direction of sulfite reduction with enzymatically reduced methyl viologen as electron donor. The reduction of methyl viologen by hydrogen gas is catalyzed by purified hydrogenase from Desulfovibrio gigas. The consumption of hydrogen is recorded manometrically. The enzyme contains 24 mol of iron and 20 mol of (acid-labile) sulfur per mole of enzyme and can reduce sulfite, but not thiosulfate, dithionate, trithionate, or tetrathionate. Unlike assimilatory sulfite reductases the enzyme does not contain flavin groups.
Jessup M. Shively - One of the best experts on this subject based on the ideXlab platform.
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Two forms of ribulose-1,5-bisphosphate carboxylase/oxygenase from Thiobacillus denitrificans.
Fems Microbiology Letters, 1992Co-Authors: Robert S. English, Christopher A. Williams, Stanley C. Lorbach, Jessup M. ShivelyAbstract:The autotrophic, sulfur-oxidizing bacterium Thiobacillus denitrificans possesses two forms of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase (RuBisCO). The form I and form II genes were isolated from a cosmid library using heterologous DNA probes. Restriction enzyme analysis indicated that the genes are within 17 kbp of each other. Other Calvin cycle enzyme genes are not present. Analysis of T. denitrificans RNA indicated that the form I genes for the large and small subunits are co-transcribed with a length of 2800 nucleotides. The transcript for the form II gene is 1900 nucleotides in length.
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two forms of ribulose 1 5 bisphosphate carboxylase oxygenase from Thiobacillus denitrificans
Fems Microbiology Letters, 1992Co-Authors: Robert S. English, Christopher A. Williams, Stanley C. Lorbach, Jessup M. ShivelyAbstract:The autotrophic, sulfur-oxidizing bacterium Thiobacillus denitrificans possesses two forms of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase (RuBisCO). The form I and form II genes were isolated from a cosmid library using heterologous DNA probes. Restriction enzyme analysis indicated that the genes are within 17 kbp of each other. Other Calvin cycle enzyme genes are not present. Analysis of T. denitrificans RNA indicated that the form I genes for the large and small subunits are co-transcribed with a length of 2800 nucleotides. The transcript for the form II gene is 1900 nucleotides in length.
Andrew J Fisher - One of the best experts on this subject based on the ideXlab platform.
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Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity.
Acta Crystallographica Section D-biological Crystallography, 2009Co-Authors: Irwin H Segel, Andrew J FisherAbstract:APS kinase from Thiobacillus denitrificans contains an inactive N-terminal ATP sulfurylase domain. The structure presented unveils the first hexameric assembly for an APS kinase, and reveals that structural changes in the N-terminal domain disrupt the ATP sulfurylase active site thus prohibiting activity. The Tbd-0210 gene of the chemolithotrophic bacterium Thiobacillus denitrificans is annotated to encode a 60.5 kDa bifunctional enzyme with ATP sulfurylase and APS kinase activity. This putative bifunctional enzyme was cloned, expressed and structurally characterized. The 2.95 A resolution X-ray crystal structure reported here revealed a hexameric assembly with D{sub 3} symmetry. Each subunit contains a large N-terminal sulfurylase-like domain and a C-terminal APS kinase domain reminiscent of the two-domain fungal ATP sulfurylases of Penicillium chrysogenum and Saccharomyces cerevisiae, which also exhibit a hexameric assembly. However, the T. denitrificans enzyme exhibits numerous structural and sequence differences in the N-terminal domain that render it inactive with respect to ATP sulfurylase activity. Surprisingly, the C-terminal domain does indeed display APS kinase activity, indicating that this gene product is a true APS kinase. Therefore, these results provide the first structural insights into a unique hexameric APS kinase that contains a nonfunctional ATP sulfurylase-like domain of unknown function.
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Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity.
Acta crystallographica. Section D Biological crystallography, 2009Co-Authors: Sean C Gay, Irwin H Segel, Andrew J FisherAbstract:The Tbd_0210 gene of the chemolithotrophic bacterium Thiobacillus denitrificans is annotated to encode a 60.5 kDa bifunctional enzyme with ATP sulfurylase and APS kinase activity. This putative bifunctional enzyme was cloned, expressed and structurally characterized. The 2.95 A resolution X-ray crystal structure reported here revealed a hexameric assembly with D(3) symmetry. Each subunit contains a large N-terminal sulfurylase-like domain and a C-terminal APS kinase domain reminiscent of the two-domain fungal ATP sulfurylases of Penicillium chrysogenum and Saccharomyces cerevisiae, which also exhibit a hexameric assembly. However, the T. denitrificans enzyme exhibits numerous structural and sequence differences in the N-terminal domain that render it inactive with respect to ATP sulfurylase activity. Surprisingly, the C-terminal domain does indeed display APS kinase activity, indicating that this gene product is a true APS kinase. Therefore, these results provide the first structural insights into a unique hexameric APS kinase that contains a nonfunctional ATP sulfurylase-like domain of unknown function.
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kinetic properties of atp sulfurylase and aps kinase from Thiobacillus denitrificans
Archives of Biochemistry and Biophysics, 2009Co-Authors: Jennifer L Fribourgh, Paul D Donohoue, Irwin H Segel, Andrew J FisherAbstract:The Thiobacillus denitrificans genome contains two sequences corresponding to ATP sulfurylase (Tbd_0210 and Tbd_0874). Both genes were cloned and expressed protein characterized. The larger protein (Tbd_0210; 544 residues) possesses an N-terminal ATP sulfurylase domain and a C-terminal APS kinase domain and was therefore annotated as a bifunctional enzyme. But, the protein was not bifunctional because it lacked ATP sulfurylase activity. However, the enzyme did possess APS kinase activity and displayed substrate inhibition by APS. Truncated protein missing the N-terminal domain had <2% APS kinase activity suggesting the function of the inactive sulfurylase domain is to promote the oligomerization of the APS kinase domains. The smaller gene product (Tbd_0874; 402 residues) possessed strong ATP sulfurylase activity with kinetic properties that appear to be kinetically optimized for the direction of APS utilization and ATP + sulfate production, which is consistent with an enzyme that functions physiologically to produce inorganic sulfate.
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Kinetic properties of ATP sulfurylase and APS kinase from Thiobacillus denitrificans.
Archives of biochemistry and biophysics, 2009Co-Authors: Sean C Gay, Jennifer L Fribourgh, Paul D Donohoue, Irwin H Segel, Andrew J FisherAbstract:The Thiobacillus denitrificans genome contains two sequences corresponding to ATP sulfurylase (Tbd_0210 and Tbd_0874). Both genes were cloned and expressed protein characterized. The larger protein (Tbd_0210; 544 residues) possesses an N-terminal ATP sulfurylase domain and a C-terminal APS kinase domain and was therefore annotated as a bifunctional enzyme. But, the protein was not bifunctional because it lacked ATP sulfurylase activity. However, the enzyme did possess APS kinase activity and displayed substrate inhibition by APS. Truncated protein missing the N-terminal domain had
Ligy Philip - One of the best experts on this subject based on the ideXlab platform.
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Thiobacillus denitrificans immobilized biotrickling filter for NO_2 removal
Clean Technologies and Environmental Policy, 2005Co-Authors: N. D. V. N. S. Murali Krishna, Ligy PhilipAbstract:Nitrogen dioxide (NO_2) removal efficiency of a biotrikling filter was evaluated under different operating conditions. Activated alumina (AA) was used as the immobilization matrix for Thiobacillus denitrificans ( T. denitrificans ) in the biotrickling filter. Batch studies were conducted to find out the degradation kinetics of nitrate and nitrite for a concentration range of 600–10,000 mg/L expressed as nitrogen. Nitrite exhibited maximum degradation rate followed by nitrate. Electron acceptor in the form of NO_2 gas showed least removal efficiency. Bio-kinetic parameters for T. denitrificans , by utilizing nitrate and nitrite as electron acceptors, were also evaluated. The μ_max (Maximum specific growth rate) and Y_T (Yield coefficient) values for T. denitrificans in the presence of nitrate and nitrite were 1.03 h^−1, 0.275 and 0.63 h^−1, 0.1316 respectively. Column study was conducted to find the adsorption and desorption potential of activated alumina. The adsorbed NO_2 from AA could easily be desorbed using distilled water with an efficiency of 76±0.8%. Once fed batch studies were conducted to evaluate the NO_2 removal efficiency by a biotrickling filter. With an influent NO_2 gas concentration of 2,735 ppm, the reactor could achieve a removal efficiency of 99% within 2 min from gas phase and within 96 h from the liquid phase, with an average biomass concentration of 200 mg/g of AA. The mechanism of NO_2 gas removal in the biotrickling filter seems to be the dissolution of NO_2 in water to form NO _3 ^− , conversion of NO _3 ^− to NO_2 ^−, and finally to N_2 gas.
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Thiobacillus denitrificans immobilized biotrickling filter for NO2 removal
Clean Technologies and Environmental Policy, 2005Co-Authors: N. D. V. N. S. Murali Krishna, Ligy PhilipAbstract:Nitrogen dioxide (NO2) removal efficiency of a biotrikling filter was evaluated under different operating conditions. Activated alumina (AA) was used as the immobilization matrix for Thiobacillus denitrificans (T. denitrificans) in the biotrickling filter. Batch studies were conducted to find out the degradation kinetics of nitrate and nitrite for a concentration range of 600–10,000 mg/L expressed as nitrogen. Nitrite exhibited maximum degradation rate followed by nitrate. Electron acceptor in the form of NO2 gas showed least removal efficiency. Bio-kinetic parameters for T. denitrificans, by utilizing nitrate and nitrite as electron acceptors, were also evaluated. The μmax (Maximum specific growth rate) and YT (Yield coefficient) values for T. denitrificans in the presence of nitrate and nitrite were 1.03 h−1, 0.275 and 0.63 h−1, 0.1316 respectively. Column study was conducted to find the adsorption and desorption potential of activated alumina. The adsorbed NO2 from AA could easily be desorbed using distilled water with an efficiency of 76±0.8%. Once fed batch studies were conducted to evaluate the NO2 removal efficiency by a biotrickling filter. With an influent NO2 gas concentration of 2,735 ppm, the reactor could achieve a removal efficiency of 99% within 2 min from gas phase and within 96 h from the liquid phase, with an average biomass concentration of 200 mg/g of AA. The mechanism of NO2 gas removal in the biotrickling filter seems to be the dissolution of NO2 in water to form NO 3 − , conversion of NO 3 − to NO2 −, and finally to N2 gas.
Robert S. English - One of the best experts on this subject based on the ideXlab platform.
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Two forms of ribulose-1,5-bisphosphate carboxylase/oxygenase from Thiobacillus denitrificans.
Fems Microbiology Letters, 1992Co-Authors: Robert S. English, Christopher A. Williams, Stanley C. Lorbach, Jessup M. ShivelyAbstract:The autotrophic, sulfur-oxidizing bacterium Thiobacillus denitrificans possesses two forms of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase (RuBisCO). The form I and form II genes were isolated from a cosmid library using heterologous DNA probes. Restriction enzyme analysis indicated that the genes are within 17 kbp of each other. Other Calvin cycle enzyme genes are not present. Analysis of T. denitrificans RNA indicated that the form I genes for the large and small subunits are co-transcribed with a length of 2800 nucleotides. The transcript for the form II gene is 1900 nucleotides in length.
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two forms of ribulose 1 5 bisphosphate carboxylase oxygenase from Thiobacillus denitrificans
Fems Microbiology Letters, 1992Co-Authors: Robert S. English, Christopher A. Williams, Stanley C. Lorbach, Jessup M. ShivelyAbstract:The autotrophic, sulfur-oxidizing bacterium Thiobacillus denitrificans possesses two forms of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase (RuBisCO). The form I and form II genes were isolated from a cosmid library using heterologous DNA probes. Restriction enzyme analysis indicated that the genes are within 17 kbp of each other. Other Calvin cycle enzyme genes are not present. Analysis of T. denitrificans RNA indicated that the form I genes for the large and small subunits are co-transcribed with a length of 2800 nucleotides. The transcript for the form II gene is 1900 nucleotides in length.