EC 1.8.99.5 - Dissimilatory sulfite reductase

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IntEnz Enzyme Nomenclature
EC 1.8.99.5

Names

Accepted name:
dissimilatory sulfite reductase
Other names:
siroheme sulfite reductase
hydrogen-sulfide:(acceptor) oxidoreductase (ambiguous)
DsrAB
Systematic name:
hydrogen-sulfide:[DsrC sulfur-carrier protein],acceptor oxidoreductase

Reactions

Cofactor

Comments:

Contain siroheme. The enzyme is essential in prokaryotic sulfur-based energy metabolism, including sulfate/sulfite reducing organisms, sulfur-oxidizing bacteria, and organosulfonate reducers. In sulfur reducers it catalyses the reduction of sulfite to sulfide (reaction 1 in the right to left direction), while in sulfur oxidizers it catalyses the opposite reaction (reaction 2 in the left to right direction) [1]. The reaction involves the small protein DsrC, which is present in all the organisms that contain dissimilatory sulfite reductase. During the process an intramolecular disulfide bond is formed between two L-cysteine residues of DsrC. This disulfide can be reduced by a number of proteins including DsrK and TcmB [5]. This enzyme is different from EC 1.8.1.2, assimilatory sulfite reductase (NADPH), and EC 1.8.7.1, assimilatory sulfite reductase (ferredoxin), which are involved in sulfate assimilation.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot:

References

  1. Schedel, M., Vanselow, M. and Trueper, H.G.
    Siroheme sulfite reductase from Chromatium vinosum. Purification and investigation of some of its molecular and catalytic properties.
    Arch. Microbiol. 121: 29-36 (1979).
  2. Seki, Y., Sogawa, N., Ishimoto, M.
    Siroheme as an active catalyst in sulfite reduction.
    J. Biochem. 90: 1487-1492 (1981). [PMID: 7338517]
  3. Pott, A. S., Dahl, C.
    Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur.
    Microbiology (Reading, Engl.) 144: 1881-1894 (1998). [PMID: 9695921]
  4. Oliveira, T. F., Vonrhein, C., Matias, P. M., Venceslau, S. S., Pereira, I. A., Archer, M.
    The crystal structure of Desulfovibrio vulgaris dissimilatory sulfite reductase bound to DsrC provides novel insights into the mechanism of sulfate respiration.
    J. Biol. Chem. 283: 34141-34149 (2008). [PMID: 18829451]
  5. Venceslau, S. S., Stockdreher, Y., Dahl, C., Pereira, I. A.
    The "bacterial heterodisulfide" DsrC is a key protein in dissimilatory sulfur metabolism.
    Biochim. Biophys. Acta 1837: 1148-1164 (2014). [PMID: 24662917]

[EC 1.8.99.5 created 1972, modified 2015]