Biology:Dissimilatory sulfite reductase
| dissimilatory sulfite reductase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC number | 1.8.1.22 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
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Dissimilatory sulfite reductase (EC 1.8.1.22) is an enzyme that participates in sulfur metabolism in dissimilatory sulfate reduction.[1]
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); while in sulfur oxidizers, it catalyses the opposite reaction (reaction 2).[2] The reaction involves the small protein DsrC, which is present in all the organisms that contain dissimilatory sulfite reductase.[3] During the process, an intramolecular trisulfide is formed between two L-cysteine residues of DsrC and the sulfur atom from sulfite.[4] This trisulfide can be reduced by a number of proteins including DsrK and TcmB.[5]
DsrAB has been found in 32 bacterial and 4 to 5 archaeal phyla.[6] DsrA and DsrC have been found as auxiliary metabolic genes in bacteriophages.[7]
Reaction in organisms performing dissimilatory sulfate reduction:
SO2−
3 + [DsrC]-(SH)
2 + 2 acceptor
red + 2H+
→ H
2S + [DsrC]-S
2 + 2 acceptor
ox + 3H
2O
[DsrC]-Cys-S-HS* → H
2S + [DsrC]-S
2
Reaction in organisms performing sulfur oxidation:
[DsrC]-Cys-S-HS* + 3 acceptor
ox + 3H
2O → SO2−
3 + [DsrC]-S
2 + 3 acceptor
red + 2H+
[DsrC]-Cys-S-HS* + 3 acceptor
ox + 3H
2O → [DsrC]-Cys-S-SO
3 + 3 acceptor
red + H+
[DsrC]-Cys-S-SO
3 → SO2−
3 + [DsrC]-S
2 + H+
The systematic name of this enzyme class is hydrogen-sulfide:[DsrC sulfur-carrier protein],acceptor oxidoreductase.
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.
References
This article incorporates text available under the CC BY 4.0 license. Template:BRENDA
- ↑ "Reaction cycle of the dissimilatory sulfite reductase from Archaeoglobus fulgidus". Biochemistry 49 (41): 8912–21. October 2010. doi:10.1021/bi100781f. PMID 20822098.
- ↑ "Siroheme sulfite reductase isolated from Chromatium vinosum. Purification and investigation of some of its molecular and catalytic properties". Archives of Microbiology 121 (1): 29–36. 1979. doi:10.1007/BF00409202. Bibcode: 1979ArMic.121...29S.
- ↑ "The crystal structure of Desulfovibrio vulgaris dissimilatory sulfite reductase bound to DsrC provides novel insights into the mechanism of sulfate respiration". The Journal of Biological Chemistry 283 (49): 34141–9. December 2008. doi:10.1074/jbc.M805643200. PMID 18829451.
- ↑ "A protein trisulfide couples dissimilatory sulfate reduction to energy conservation". Science 350 (6267): 1541–5. December 2015. doi:10.1126/science.aad3558. PMID 26680199. Bibcode: 2015Sci...350.1541S.
- ↑ "The "bacterial heterodisulfide" DsrC is a key protein in dissimilatory sulfur metabolism". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1837 (7): 1148–64. July 2014. doi:10.1016/j.bbabio.2014.03.007. PMID 24662917.
- ↑ "The evolution and spread of sulfur cycling enzymes reflect the redox state of the early Earth". Science Advances 9 (27). July 2023. doi:10.1126/sciadv.ade4847. PMID 37418533.
- ↑ "Ecology of inorganic sulfur auxiliary metabolism in widespread bacteriophages". Nature Communications 12. June 2021. doi:10.1038/s41467-021-23698-5.
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