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Christiane Dahl - One of the best experts on this subject based on the ideXlab platform.
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tsdc a unique lipoprotein from wolinella succinogenes that enhances Tetrathionate reductase activity of tsda
Fems Microbiology Letters, 2017Co-Authors: Julia M Kurth, Jörg Simon, Anja Schuster, Waldemar Seel, Stefanie Herresthal, Christiane DahlAbstract:The diheme cytochromes c of the widespread TsdA family are bifunctional thiosulfate dehydrogenase/Tetrathionate reductases. Here, biochemical information was collected about TsdA from the Epsilonproteobacterium Wolinella succinogenes ( Ws TsdA). The situation in W. succinogenes is unique since TsdA is closely associated with the unprecedented lipoprotein TsdC encoded immediately downstream of tsdA in the same direction of transcription. Ws TsdA purified from Escherichia coli catalyzed both thiosulfate oxidation and Tetrathionate reduction. After co-production of TsdC and Ws TsdA in E. coli , TsdC was found to mediate membrane attachment of TsdA and to ensure its full catalytic activity. This effect was much stronger in the Tetrathionate-reducing than in the thiosulfate-oxidizing direction. It is concluded that the TsdAC complex predominantly acts as a Tetrathionate reductase in vivo .
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Influence of haem environment on the catalytic properties of the Tetrathionate reductase TsdA from Campylobacter jejuni
Bioscience reports, 2016Co-Authors: Julia M Kurth, David J. Kelly, Julea N. Butt, Christiane DahlAbstract:Bifunctional diheme cytochrome c thiosulfate dehydrogenases/Tetrathionate reductases (TsdA) exhibit different catalytic properties depending on the source organism. In the human food-borne intestinal pathogen Campylobacter jejuni , TsdA functions as a Tetrathionate reductase enabling respiration with Tetrathionate as an alternative electron acceptor. Here, evidence is provided that Cys138 and Met255 serve as the sixth ligands of Heme 1 and Heme 2, respectively, in the oxidized Cj TsdA wt protein. Replacement of Cys138 resulted in a virtually inactive enzyme, confirming Heme 1 as the active site heme. Significantly, TsdA variants carrying amino acid exchanges in the vicinity of the electron-transferring Heme 2 (Met255, Asn254 and Lys252) exhibited markedly altered catalytic properties of the enzyme, showing these residues play a key role in the physiological function of TsdA. The growth phenotypes and Tetrathionate reductase activities of a series of Δ tsdA/*tsdA complementation strains constructed in the original host C. jejuni 81116, showed that in vivo , the TsdA variants exhibited the same catalytic properties as the pure, recombinantly produced enzymes. However, variants that catalyzed Tetrathionate reduction more effectively than the wild-type enzyme did not allow better growth.
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Tetrathionate stimulated growth of Campylobacter jejuni identifies a new type of bi-functional Tetrathionate reductase (TsdA) that is widely distributed in bacteria.
Molecular microbiology, 2013Co-Authors: Yang-wei Liu, Christiane Dahl, Kevin Denkmann, Konrad Kosciow, David J. KellyAbstract:Summary Tetrathionate (S4O62−) is used by some bacteria as an electron acceptor and can be produced in the vertebrate intestinal mucosa from the oxidation of thiosulphate (S2O32−) by reactive oxygen species during inflammation. Surprisingly, growth of the microaerophilic mucosal pathogen Campylobacter jejuni under oxygen-limited conditions was stimulated by Tetrathionate, although it does not possess any known type of Tetrathionate reductase. Here, we identify a dihaem cytochrome c (C8j_0815; TsdA) as the enzyme responsible. Kinetic studies with purified recombinant C. jejuni TsdA showed it to be a bifunctional Tetrathionate reductase/thiosulphate dehydrogenase with a high affinity for Tetrathionate. A tsdA null mutant still slowly reduced, but could not grow on, Tetrathionate under oxygen limitation, lacked thiosulphate-dependent respiration and failed to convert thiosulphate to Tetrathionate microaerobically. A TsdA paralogue (C8j_0040), lacking the unusual His–Cys haem ligation of TsdA, had low thiosulphate dehydrogenase and Tetrathionate reductase activities. Our data highlight a hitherto unrecognized capacity of C. jejuni to use Tetrathionate and thiosulphate in its energy metabolism, which may promote growth in the host. Moreover, as TsdA represents a new class of Tetrathionate reductase that is widely distributed among bacteria, we predict that energy conserving Tetrathionate respiration is far more common than currently appreciated.
J. Gijs Kuenen - One of the best experts on this subject based on the ideXlab platform.
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Anaerobic oxidation of thiosulfate to Tetrathionate by obligately heterotrophic bacteria, belonging to the Pseudomonas stutzeri group
FEMS microbiology ecology, 1999Co-Authors: Dimitry Y. Sorokin, Andreas P Teske, Lesley A. Robertson, J. Gijs KuenenAbstract:Abstract A number of strains of heterotrophic bacteria were isolated from various environments on the basis of their potential to oxidize inorganic sulfur compounds to Tetrathionate. The isolates were screened for the ability to oxidize thiosulfate under denitrifying conditions. Many of them could grow anaerobically with acetate and nitrate, and eight strains could oxidize thiosulfate to Tetrathionate under the same conditions. In batch cultures with acetate as carbon and energy source, most active anaerobic thiosulfate oxidation occurred with N2O as electron acceptor. The level of anaerobic thiosulfate-oxidizing activity in cultures and cell suspensions supplied with nitrate correlated with the activity of nitrite reductase in cell suspensions. Some strains converted thiosulfate to Tetrathionate equally well with nitrite, nitrate and N2O as electron acceptors. Others functioned best with N2O during anaerobic thiosulfate oxidation. The latter strains appeared to have a lower level of nitrite reductase activity. Thiosulfate oxidation under anaerobic conditions was much slower than in the presence of oxygen, and was obviously controlled by the availability of organic electron donor. The strains had DNA-DNA similarity levels higher than 30%. Sequence analysis of the 16S rRNA gene of four selected isolates showed their affiliation to specific genomovars of Pseudomonas stutzeri and the proposed new species, Pseudomonas balearica. As shown by 16S rRNA sequence analysis and DNA-DNA hybridization, the previously misnamed ‘Flavobacterium lutescens’ (ATCC 27951) is also a P. stutzeri strain which can oxidize thiosulfate to Tetrathionate aerobically and anaerobically in the presence of N2O. The data suggest that Tetrathionate-forming heterotrophic bacteria, in particular those belonging to the P. stutzeri ‘superspecies’, can play a much more significant role in the biogeochemical cycles than was previously recognized.
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Isolation of the Tetrathionate hydrolase from Thiobacillus acidophilus
European journal of biochemistry, 1997Co-Authors: G.a.h. De Jong, W. Hazeu, P. Bos, J. Gijs KuenenAbstract:An enzyme capable of hydrolysing Tetrathionate was purified from cell-free extracts of Thiobacillus acidophilus. The purified enzyme converts Tetrathionate into thiosulfate, sulfur and sulfate. In addition, pentathionate could also be converted by the same enzyme. Measurement of the enzyme activity during purification is based on the absorbance of the initial intermediates formed from Tetrathionate in the ultraviolet region, which have not been identified. Enzyme activity could also be measured by the scattering of insoluble sulfur in the visible region. The purified enzyme has a pH optimum of 2.5 and a temperature optimum of 65°C. Enzyme activity is strongly stimulated by the presence of sulfate ions. The purified enzyme is a dimer with two identical subunits of 48kDa. The ultraviolet–visible absorption spectra and denaturation experiments indicate the presence of an organic cofactor.
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Research letterMetabolism of Tetrathionate in Thiobacillus acidophilus
Fems Microbiology Letters, 1993Co-Authors: R. Meulenberg, Erik J. Scheer, Jack T. Pronk, W. Hazeu, P. Bos, J. Gijs KuenenAbstract:Cell-free extracts of Thiobacillus acidophilus catalysed the stoichiometric conversion of Tetrathionate to thiosulphate, sulphur and two protons. The pH optimum of the enzyme activity was 3.0 and its temperature optimum 40°C. The enzyme was unstable at 30 and 40°C, at which its activity decreased to zero within 100 and 20 h, respectively. Enzyme activity was not affected by incubation for 1 week on ice or by freezing and thawing of the extract. The Km for Tetrathionate was 0.3 mM. Enzyme activity was stimulated by ammonium sulphate up to a concentration of 1M. The results indicate that trithionate hydrolase cannot account for the observed conversion of Tetrathionate.
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Metabolism of Tetrathionate in Thiobacillus acidophilus
FEMS Microbiology Letters, 1993Co-Authors: R. Meulenberg, Erik J. Scheer, Jack T. Pronk, W. Hazeu, P. Bos, J. Gijs KuenenAbstract:Abstract Cell-free extracts of Thiobacillus acidophilus catalysed the stoichiometric conversion of Tetrathionate to thiosulphate, sulphur and two protons. The pH optimum of the enzyme activity was 3.0 and its temperature optimum 40°C. The enzyme was unstable at 30 and 40°C, at which its activity decreased to zero within 100 and 20 h, respectively. Enzyme activity was not affected by incubation for 1 week on ice or by freezing and thawing of the extract. The K m for Tetrathionate was 0.3 mM. Enzyme activity was stimulated by ammonium sulphate up to a concentration of 1M. The results indicate that trithionate hydrolase cannot account for the observed conversion of Tetrathionate.
Wolfgang Sand - One of the best experts on this subject based on the ideXlab platform.
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Tetrathionate Disproportionation by Thiomonas intermedia K12
Engineering in Life Sciences, 2004Co-Authors: Susanne Wentzien, Wolfgang SandAbstract:Thiomonas intermedia K12, a moderately acidophilic bacterium, which oxidizes S compds., exhibited the capability to use Tetrathionate under oxic and anoxic conditions. Whereas under oxic conditions, the reduced S Tetrathionate compd. was oxidized, under anoxic conditions, the organism disproportionated the compd. In both cases, trithionate and sulfate were produced but in different amts. The results of the Tetrathionate degrdn. expts. under oxic conditions pointed towards a cyclic degrdn. process with a transient formation of trithionate and sulfate as the final products, similar to the mechanism described for acidophilic S compd. oxidizing bacteria. The results of the Tetrathionate degrdn. expts. under anoxic conditions hinted to a partial redn. of Tetrathionate to thiosulfate and a fractional oxidn. to trithionate and sulfate. In this study 4M Tetrathionate were converted to 6M thiosulfate, 1M trithionate, 1M sulfate, and 8M protons. The DG0' of this reaction was -16.1 KJ/mol Tetrathionate degraded. T. intermedia K12 grew under anoxic conditions with Tetrathionate as the sole energy source. The cell nos. increased from 105 as the start value to 107/mL at the end. Org. compds., excluding traces of yeast ext., did not enhance growth. Therefore, it is proposed that Tetrathionate disproportionation is a novel lithotrophic metab., which allowed T. intermedia K12 to survive changing conditions of O supply in S-compd.-rich environments and even to grow during this reaction. The extensive S compd. anal. was carried out by ion-pair chromatog.
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Tetrathionate disproportionation by thiomonas intermedia K12
Chemical Engineering & Technology, 2004Co-Authors: Susanne Wentzien, Wolfgang SandAbstract:Thiomonas intermedia K12, a moderately acidophilic bacterium, which oxidises sulphur compounds, - exhibited the capability to use Tetrathionate under oxic and anoxic conditions. Whereas under oxic conditions, the reduced sulphur Tetrathionate compound was oxidised, under anoxic conditions, the organism disproportionated the compound. In both cases, trithionate and sulphate were produced but in different amounts. The results of the Tetrathionate degradation experiments under oxic conditions pointed towards a cyclic degradation process with a transient formation of trithionate and sulphate as the final products, similar to the mechanism described for acidophilic sulphur compound oxidising bacteria. The results of the Tetrathionate degradation experiments under anoxic conditions hinted to a partial reduction of Tetrathionate to thiosulphate and a fractional oxidation to trithionate and sulphate. 4 M Tetrathionate were converted to 6 M thiosulphate, 1 M trithionate, 1 M sulphate, and 8 M protons. The ΔG 0 ' of this reaction was found to be -16.1 kJ per mol Tetrathionate degraded. Additionally, Thiomonas intermedia K12 grew under anoxic conditions with Tetrathionate as the sole energy source. The cell numbers increased from 10 5 as the start value to 10 7 /mL at the end. Organic compounds, excluding traces of yeast extract, did not enhance growth. Therefore, it is proposed that Tetrathionate disproportionation is a novel lithotrophic metabolism, which allowed Thiomonas intermedia K12 to survive changing conditions of oxygen supply in sulphur-compound-rich environments and even to grow during this reaction. The extensive sulphur compound analysis was carried out by ion-pair chromatography.
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Thiosulfate and Tetrathionate degradation as well as biofilm generation by Thiobacillus intermedius and Thiobacillus versutus studied by microcalorimetry, HPLC, and ion-pair chromatography
Archives of Microbiology, 1994Co-Authors: Susanne Wentzien, Wolfgang Sand, Angela Albertsen, Ralf SteudelAbstract:The growth of Thiobacillus (T.) intermedius strain K12 and Thiobacillus versutus strain DSM 582 on thiosulfate and Tetrathionate was studied combining on-line measurements of metabolic activity and sulfur compound analysis. Most results indicate that T. intermedius oxidized thiosulfate via Tetrathionate to sulfate. Concomittantly, sulfur compound intermediates like triand pentathionate were detectable. The formation is probably the result of highly reactive sulfane monosulfonic acids. The formation of Tetrathionate allows the cells to buffer temporarily the proton excretion from sulfuric acid production. With T. versutus intermediate sulfur compounds were not detectable, however, sulfur was detectable. The possibility of a thiosulfate oxidation via dithionate, S_2O _inf6 ^sup2- , is discussed. The on-line measurement of metabolic activity by microcalorimetry enabled us to detect that cells of T. intermedius adhere to surfaces and produce a biofilm by a metabolic process whereas those of T. versutus fail to do so. The importance of the finding is discussed.
Julia M Kurth - One of the best experts on this subject based on the ideXlab platform.
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tsdc a unique lipoprotein from wolinella succinogenes that enhances Tetrathionate reductase activity of tsda
Fems Microbiology Letters, 2017Co-Authors: Julia M Kurth, Jörg Simon, Anja Schuster, Waldemar Seel, Stefanie Herresthal, Christiane DahlAbstract:The diheme cytochromes c of the widespread TsdA family are bifunctional thiosulfate dehydrogenase/Tetrathionate reductases. Here, biochemical information was collected about TsdA from the Epsilonproteobacterium Wolinella succinogenes ( Ws TsdA). The situation in W. succinogenes is unique since TsdA is closely associated with the unprecedented lipoprotein TsdC encoded immediately downstream of tsdA in the same direction of transcription. Ws TsdA purified from Escherichia coli catalyzed both thiosulfate oxidation and Tetrathionate reduction. After co-production of TsdC and Ws TsdA in E. coli , TsdC was found to mediate membrane attachment of TsdA and to ensure its full catalytic activity. This effect was much stronger in the Tetrathionate-reducing than in the thiosulfate-oxidizing direction. It is concluded that the TsdAC complex predominantly acts as a Tetrathionate reductase in vivo .
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Influence of haem environment on the catalytic properties of the Tetrathionate reductase TsdA from Campylobacter jejuni
Bioscience reports, 2016Co-Authors: Julia M Kurth, David J. Kelly, Julea N. Butt, Christiane DahlAbstract:Bifunctional diheme cytochrome c thiosulfate dehydrogenases/Tetrathionate reductases (TsdA) exhibit different catalytic properties depending on the source organism. In the human food-borne intestinal pathogen Campylobacter jejuni , TsdA functions as a Tetrathionate reductase enabling respiration with Tetrathionate as an alternative electron acceptor. Here, evidence is provided that Cys138 and Met255 serve as the sixth ligands of Heme 1 and Heme 2, respectively, in the oxidized Cj TsdA wt protein. Replacement of Cys138 resulted in a virtually inactive enzyme, confirming Heme 1 as the active site heme. Significantly, TsdA variants carrying amino acid exchanges in the vicinity of the electron-transferring Heme 2 (Met255, Asn254 and Lys252) exhibited markedly altered catalytic properties of the enzyme, showing these residues play a key role in the physiological function of TsdA. The growth phenotypes and Tetrathionate reductase activities of a series of Δ tsdA/*tsdA complementation strains constructed in the original host C. jejuni 81116, showed that in vivo , the TsdA variants exhibited the same catalytic properties as the pure, recombinantly produced enzymes. However, variants that catalyzed Tetrathionate reduction more effectively than the wild-type enzyme did not allow better growth.
Susanne Wentzien - One of the best experts on this subject based on the ideXlab platform.
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Tetrathionate Disproportionation by Thiomonas intermedia K12
Engineering in Life Sciences, 2004Co-Authors: Susanne Wentzien, Wolfgang SandAbstract:Thiomonas intermedia K12, a moderately acidophilic bacterium, which oxidizes S compds., exhibited the capability to use Tetrathionate under oxic and anoxic conditions. Whereas under oxic conditions, the reduced S Tetrathionate compd. was oxidized, under anoxic conditions, the organism disproportionated the compd. In both cases, trithionate and sulfate were produced but in different amts. The results of the Tetrathionate degrdn. expts. under oxic conditions pointed towards a cyclic degrdn. process with a transient formation of trithionate and sulfate as the final products, similar to the mechanism described for acidophilic S compd. oxidizing bacteria. The results of the Tetrathionate degrdn. expts. under anoxic conditions hinted to a partial redn. of Tetrathionate to thiosulfate and a fractional oxidn. to trithionate and sulfate. In this study 4M Tetrathionate were converted to 6M thiosulfate, 1M trithionate, 1M sulfate, and 8M protons. The DG0' of this reaction was -16.1 KJ/mol Tetrathionate degraded. T. intermedia K12 grew under anoxic conditions with Tetrathionate as the sole energy source. The cell nos. increased from 105 as the start value to 107/mL at the end. Org. compds., excluding traces of yeast ext., did not enhance growth. Therefore, it is proposed that Tetrathionate disproportionation is a novel lithotrophic metab., which allowed T. intermedia K12 to survive changing conditions of O supply in S-compd.-rich environments and even to grow during this reaction. The extensive S compd. anal. was carried out by ion-pair chromatog.
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Tetrathionate disproportionation by thiomonas intermedia K12
Chemical Engineering & Technology, 2004Co-Authors: Susanne Wentzien, Wolfgang SandAbstract:Thiomonas intermedia K12, a moderately acidophilic bacterium, which oxidises sulphur compounds, - exhibited the capability to use Tetrathionate under oxic and anoxic conditions. Whereas under oxic conditions, the reduced sulphur Tetrathionate compound was oxidised, under anoxic conditions, the organism disproportionated the compound. In both cases, trithionate and sulphate were produced but in different amounts. The results of the Tetrathionate degradation experiments under oxic conditions pointed towards a cyclic degradation process with a transient formation of trithionate and sulphate as the final products, similar to the mechanism described for acidophilic sulphur compound oxidising bacteria. The results of the Tetrathionate degradation experiments under anoxic conditions hinted to a partial reduction of Tetrathionate to thiosulphate and a fractional oxidation to trithionate and sulphate. 4 M Tetrathionate were converted to 6 M thiosulphate, 1 M trithionate, 1 M sulphate, and 8 M protons. The ΔG 0 ' of this reaction was found to be -16.1 kJ per mol Tetrathionate degraded. Additionally, Thiomonas intermedia K12 grew under anoxic conditions with Tetrathionate as the sole energy source. The cell numbers increased from 10 5 as the start value to 10 7 /mL at the end. Organic compounds, excluding traces of yeast extract, did not enhance growth. Therefore, it is proposed that Tetrathionate disproportionation is a novel lithotrophic metabolism, which allowed Thiomonas intermedia K12 to survive changing conditions of oxygen supply in sulphur-compound-rich environments and even to grow during this reaction. The extensive sulphur compound analysis was carried out by ion-pair chromatography.
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Thiosulfate and Tetrathionate degradation as well as biofilm generation by Thiobacillus intermedius and Thiobacillus versutus studied by microcalorimetry, HPLC, and ion-pair chromatography
Archives of Microbiology, 1994Co-Authors: Susanne Wentzien, Wolfgang Sand, Angela Albertsen, Ralf SteudelAbstract:The growth of Thiobacillus (T.) intermedius strain K12 and Thiobacillus versutus strain DSM 582 on thiosulfate and Tetrathionate was studied combining on-line measurements of metabolic activity and sulfur compound analysis. Most results indicate that T. intermedius oxidized thiosulfate via Tetrathionate to sulfate. Concomittantly, sulfur compound intermediates like triand pentathionate were detectable. The formation is probably the result of highly reactive sulfane monosulfonic acids. The formation of Tetrathionate allows the cells to buffer temporarily the proton excretion from sulfuric acid production. With T. versutus intermediate sulfur compounds were not detectable, however, sulfur was detectable. The possibility of a thiosulfate oxidation via dithionate, S_2O _inf6 ^sup2- , is discussed. The on-line measurement of metabolic activity by microcalorimetry enabled us to detect that cells of T. intermedius adhere to surfaces and produce a biofilm by a metabolic process whereas those of T. versutus fail to do so. The importance of the finding is discussed.
