IUBMB Enzyme Nomenclature


Accepted name: sulfur oxygenase/reductase

Reaction: 4 sulfur + 4 H2O + O2 = 2 hydrogen sulfide + 2 HSO3 + 2 H+

Glossary: bisulfite = HSO3

Other name(s): SOR; sulfur oxygenase; sulfur oxygenase reductase

Systematic name: sulfur:oxygen oxidoreductase (hydrogen-sulfide- and sulfite-forming)

Comments: This enzyme, which is found in thermophilic microorganisms, contains one mononuclear none-heme iron centre per subunit. Elemental sulfur is both the electron donor and one of the two known acceptors, the other being oxygen. Another reaction product is thiosulfate, but this is probably formed non-enzymically at elevated temperature from sulfite and sulfur [1]. This enzyme differs from EC, sulfur dioxygenase and EC, sulfur reductase, in that both activities are found together.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 120598-92-7


1. Kletzin, A. Coupled enzymatic production of sulfite, thiosulfate, and hydrogen sulfide from sulfur: purification and properties of a sulfur oxygenase reductase from the facultatively anaerobic archaebacterium Desulfurolobus ambivalens. J. Bacteriol. 171 (1989) 1638-1643. [PMID: 2493451]

2. Kletzin, A. Molecular characterization of the sor gene, which encodes the sulfur oxygenase/reductase of the thermoacidophilic Archaeum Desulfurolobus ambivalens. J. Bacteriol. 174 (1992) 5854-5859. [PMID: 1522063]

3. Sun, C.W., Chen, Z.W., He, Z.G., Zhou, P.J. and Liu, S.J. Purification and properties of the sulfur oxygenase/reductase from the acidothermophilic archaeon, Acidianus strain S5. Extremophiles 7 (2003) 131-134. [PMID: 12664265]

4. Urich, T., Bandeiras, T.M., Leal, S.S., Rachel, R., Albrecht, T., Zimmermann, P., Scholz, C., Teixeira, M., Gomes, C.M. and Kletzin, A. The sulphur oxygenase reductase from Acidianus ambivalens is a multimeric protein containing a low-potential mononuclear non-haem iron centre. Biochem. J. 381 (2004) 137-146. [PMID: 15030315]

[EC created 2006]

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