EC Number   |
General Information |
Reference |
|---|
   1.8.2.2 | evolution |
the enzyme belongs to the thiosulfate dehydrogenase (TsdA) family. Axial ligation by histidine and cysteine is typical for the active site of TsdA proteins |
-, 742899 |
| 1.8.2.2 | metabolism |
enzyme activity is detected in strains grown on tetrathionate or sulfur, but no activity is detected in ferrous iron-grown cells |
724028 |
| 1.8.2.2 | metabolism |
the enzyme oxidizes thiosulfate in a bifurcated manner and uses two different pathways. The primary pathway is Sox (Kelly-Friedrich) pathway, which operates under normal physiological condition and oxidizes thiosulfate to sulfate and transfers electron to cytochrome c to cytochrome c oxidase. However, under acidic condition (pH less than 6.0) and low concentration of thiosulfate, this bacterium may use quinone for thiosulfate oxidation by transferring electron through quinone pool to bd oxidase |
-, 763985 |
| 1.8.2.2 | more |
Cys96 is an essential residue for catalysis |
742887 |
| 1.8.2.2 | more |
thiosulfate dehydrogenase is a periplasmic, monomeric 27.2 kDa diheme c-type cytochrome with an activity optimum at pH 4.0 |
-, 741526 |
| 1.8.2.2 | physiological function |
a gene deletion mutant does not produce any tetrathionate from thiosulfate during growth at pH 7.2 or 6.9 |
-, 724861 |
| 1.8.2.2 | physiological function |
growth of the microaerophilic mucosal pathogen Campylobacter jejuni under oxygen-limited conditions is stimulated by tetrathionate. A tsdA null mutant still slowly reduces, but can not grow on, tetrathionate under oxygen limitation, lacks thiosulfate-dependent respiration and fails to convert thiosulfate to tetrathionate microaerobically. Physiological role for Campylobacter jejuni TsdA is a tetrathionate reductase |
-, 726008 |
| 1.8.2.2 | physiological function |
the enzyme catalyzes the oxidative condensation of two thiosulfate anions, a reaction that is widespread among prokaryotes |
-, 741526 |
| 1.8.2.2 | physiological function |
thiosulfate dehydrogenases (TsdAs) are bidirectional bacterial di-heme enzymes that catalyze the interconversion of tetrathionate and thiosulfate at measurable rates in both directions, cf. EC 1.8.2.2, thiosulfate dehydrogenase. The active site heme 1 in the enzyme has His/Cys ligation in the ferric and ferrous states In Allochromatium vinosum TsdA, heme 2 reduction triggers a switch from His/Lys ligation to His/Met, but the rates of interconversion are such that His/Lys ligation is retained during turnover. Thiosulfate oxidation by enzyme AvTsdA provides electrons for photosynthesis |
-, 765056 |
