Reaction: 2 thiosulfate + 2 ferricytochrome c = tetrathionate + 2 ferrocytochrome c
Other name(s): tsdA (gene name); tetrathionate synthase; thiosulfate oxidase; thiosulfate-oxidizing enzyme; thiosulfate-acceptor oxidoreductase
Systematic name: thiosulfate:ferricytochrome-c oxidoreductase
Comments: The enzyme catalyses the reversible formation of a sulfur-sulfur bond between the sulfane atoms of two thiosulfate molecules, yielding tetrathionate and releasing two electrons. In many bacterial species the enzyme is a diheme c-type cytochrome. In a number of organisms, including Thiomonas intermedia and Sideroxydans lithotrophicus, a second diheme cytochrome (TsdB) acts as the electron acceptor. However, some organisms, such as Allochromatium vinosum, lack TsdB. The electron acceptor in these organisms may be the high-potential iron-sulfur protein (HiPIP).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9076-88-4
1. Fukumori, Y. and Yamanaka, T. A high-potential nonheme iron protein (HiPIP)-linked, thiosulfate-oxidizing enzyme derived from Chromatium vinosum. Curr. Microbiol. 3 (1979) 117-120.
2. Lu, W.-P. and Kelly, D.P. Cellular location and partial purification of the 'thiosulphate-oxidizing enzyme' and 'trithionate hydrolase' from Thiobacillus tepidarius. J. Gen. Microbiol. 134 (1988) 877-885.
3. Liu, Y.W., Denkmann, K., Kosciow, K., Dahl, C. and Kelly, D.J. Tetrathionate stimulated growth of Campylobacter jejuni identifies a new type of bi-functional tetrathionate reductase (TsdA) that is widely distributed in bacteria. Mol. Microbiol. 88 (2013) 173-188. [PMID: 23421726]
4. Brito, J.A., Denkmann, K., Pereira, I.A., Archer, M. and Dahl, C. Thiosulfate dehydrogenase (TsdA) from Allochromatium vinosum: structural and functional insights into thiosulfate oxidation. J. Biol. Chem. 290 (2015) 9222-9238. [PMID: 25673691]
5. Kurth, J.M., Brito, J.A., Reuter, J., Flegler, A., Koch, T., Franke, T., Klein, E.M., Rowe, S.F., Butt, J.N., Denkmann, K., Pereira, I.A., Archer, M. and Dahl, C. Electron accepting units of the diheme cytochrome c TsdA, a bifunctional thiosulfate dehydrogenase/tetrathionate reductase. J. Biol. Chem. 291 (2016) 24804-24818. [PMID: 27694441]