IUBMB Enzyme Nomenclature


Accepted name: S-disulfanyl-L-cysteine oxidoreductase

Reaction: [SoxY protein]-S-disulfanyl-L-cysteine + 6 ferricytochrome c + 3 H2O = [SoxY protein]-S-sulfosulfanyl-L-cysteine + 6 ferrocytochrome c + 6 H+

Other name(s): SoxCD; sulfur dehydrogenase

Systematic name: [SoxY protein]-S-disulfanyl-L-cysteine:cytochrome-c oxidoreductase

Comments: The enzyme is part of the Sox enzyme system, which participates in a bacterial thiosulfate oxidation pathway that produces sulfate. The enzyme from the bacterium Paracoccus pantotrophus contains a molybdoprotein component and a diheme c-type cytochrome component. The enzyme successively oxidizes the outer sulfur atom in [SoxY protein]-S-disulfanyl-L-cysteine, using three water molecules and forming [SoxY protein]-S-sulfosulfanyl-L-cysteine. During the process, six electrons are transferred to the electron chain via cytochrome c.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Friedrich, C.G., Rother, D., Bardischewsky, F., Quentmeier, A. and Fischer, J. Oxidation of reduced inorganic sulfur compounds by bacteria: emergence of a common mechanism. Appl. Environ. Microbiol. 67 (2001) 2873-2882. [PMID: 11425697]

2. Bardischewsky, F., Quentmeier, A., Rother, D., Hellwig, P., Kostka, S. and Friedrich, C.G. Sulfur dehydrogenase of Paracoccus pantotrophus: the heme-2 domain of the molybdoprotein cytochrome c complex is dispensable for catalytic activity. Biochemistry 44 (2005) 7024-7034. [PMID: 15865447]

3. Grabarczyk, D.B. and Berks, B.C. Intermediates in the Sox sulfur oxidation pathway are bound to a sulfane conjugate of the carrier protein SoxYZ. PLoS One 12 (2017) e0173395. [PMID: 28257465]

[EC created 2018]

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