Enzymes
UniProtKB help_outline | 6 proteins |
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Namehelp_outline
[DsrC protein]-S-sulfanyl-L-cysteine/L-cysteine
Identifier
RHEA-COMP:11724
Reactive part
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- Name help_outline L-cysteine residue Identifier CHEBI:29950 Charge 0 Formula C3H5NOS SMILEShelp_outline C(=O)(*)[C@@H](N*)CS 2D coordinates Mol file for the small molecule Search links Involved in 123 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-sulfanyl-L-cysteine residue Identifier CHEBI:61963 Charge 0 Formula C3H5NOS2 SMILEShelp_outline C([C@H](CSS)N*)(=O)* 2D coordinates Mol file for the small molecule Search links Involved in 16 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline A Identifier CHEBI:13193 Charge Formula R SMILEShelp_outline * 2D coordinates Mol file for the small molecule Search links Involved in 2,783 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
[DsrC protein]-disulfide
Identifier
RHEA-COMP:11722
Reactive part
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- Name help_outline L-cystine residue Identifier CHEBI:50058 Charge 0 Formula C6H8N2O2S2 SMILEShelp_outline C([C@@H](N*)CSSC[C@@H](C(=O)*)N*)(=O)* 2D coordinates Mol file for the small molecule Search links Involved in 51 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline AH2 Identifier CHEBI:17499 Charge 0 Formula RH2 SMILEShelp_outline *([H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2,713 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline sulfite Identifier CHEBI:17359 (CAS: 14265-45-3) help_outline Charge -2 Formula O3S InChIKeyhelp_outline LSNNMFCWUKXFEE-UHFFFAOYSA-L SMILEShelp_outline [O-]S([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 55 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:47020 | RHEA:47021 | RHEA:47022 | RHEA:47023 | |
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Publications
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The crystal structure of Desulfovibrio vulgaris dissimilatory sulfite reductase bound to DsrC provides novel insights into the mechanism of sulfate respiration.
Oliveira T.F., Vonrhein C., Matias P.M., Venceslau S.S., Pereira I.A.C., Archer M.
Sulfate reduction is one of the earliest types of energy metabolism used by ancestral organisms to sustain life. Despite extensive studies, many questions remain about the way respiratory sulfate reduction is associated with energy conservation. A crucial enzyme in this process is the dissimilator ... >> More
Sulfate reduction is one of the earliest types of energy metabolism used by ancestral organisms to sustain life. Despite extensive studies, many questions remain about the way respiratory sulfate reduction is associated with energy conservation. A crucial enzyme in this process is the dissimilatory sulfite reductase (dSiR), which contains a unique siroheme-[4Fe4S] coupled cofactor. Here, we report the structure of desulfoviridin from Desulfovibrio vulgaris, in which the dSiR DsrAB (sulfite reductase) subunits are bound to the DsrC protein. The alpha(2)beta(2)gamma(2) assembly contains two siroheme-[4Fe4S] cofactors bound by DsrB, two sirohydrochlorins and two [4Fe4S] centers bound by DsrA, and another four [4Fe4S] centers in the ferredoxin domains. A sulfite molecule, coordinating the siroheme, is found at the active site. The DsrC protein is bound in a cleft between DsrA and DsrB with its conserved C-terminal cysteine reaching the distal side of the siroheme. We propose a novel mechanism for the process of sulfite reduction involving DsrAB, DsrC, and the DsrMKJOP membrane complex (a membrane complex with putative disulfide/thiol reductase activity), in which two of the six electrons for reduction of sulfite derive from the membrane quinone pool. These results show that DsrC is involved in sulfite reduction, which changes the mechanism of sulfate respiration. This has important implications for models used to date ancient sulfur metabolism based on sulfur isotope fractionations. << Less
J. Biol. Chem. 283:34141-34149(2008) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.
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The "bacterial heterodisulfide" DsrC is a key protein in dissimilatory sulfur metabolism.
Venceslau S.S., Stockdreher Y., Dahl C., Pereira I.A.
DsrC is a small protein present in organisms that dissimilate sulfur compounds, working as a physiological partner of the DsrAB sulfite reductase. DsrC contains two redox active cysteines in a flexible carboxy-terminal arm that are involved in the process of sulfite reduction or sulfur(1) compound ... >> More
DsrC is a small protein present in organisms that dissimilate sulfur compounds, working as a physiological partner of the DsrAB sulfite reductase. DsrC contains two redox active cysteines in a flexible carboxy-terminal arm that are involved in the process of sulfite reduction or sulfur(1) compound oxidation in sulfur-reducing(2) or sulfur-oxidizing(3) organisms, respectively. In both processes, a disulfide formed between the two cysteines is believed to serve as the substrate of several proteins present in these organisms that are related to heterodisulfide reductases of methanogens. Here, we review the information on DsrC and its possible physiological partners, and discuss the idea that this protein may serve as a redox hub linking oxidation of several substrates to dissimilative sulfur metabolism. In addition, we analyze the distribution of proteins of the DsrC superfamily, including TusE that only requires the last Cys of the C-terminus for its role in the biosynthesis of 2-thiouridine, and a new protein that we name RspA (for regulatory sulfur-related protein) that is possibly involved in the regulation of gene expression and does not need the conserved Cys for its function. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. << Less
Biochim Biophys Acta 1837:1148-1164(2014) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.
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Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur.
Pott A.S., Dahl C.
The sequence of the dsr gene region of the phototrophic sulfur bacterium Chromatium vinosum D (DSMZ 180) was determined to clarify the in vivo role of 'reverse' sirohaem sulfite reductase. The dsrAB genes encoding dissimilatory sulfite reductase are part of a gene cluster, dsrABEFHCMK, that encode ... >> More
The sequence of the dsr gene region of the phototrophic sulfur bacterium Chromatium vinosum D (DSMZ 180) was determined to clarify the in vivo role of 'reverse' sirohaem sulfite reductase. The dsrAB genes encoding dissimilatory sulfite reductase are part of a gene cluster, dsrABEFHCMK, that encodes four small, soluble proteins (DsrE, DsrF, DsrH and DsrC), a transmembrane protein (DsrM) with similarity to haem-b-binding polypeptides and a soluble protein (DsrK) resembling [4Fe-4S]-cluster-containing heterodisulfide reductase from methanogenic archaea. Northern hybridizations showed that expression of the dsr genes is increased by the presence of reduced sulfur compounds. The dsr genes are not only transcribed from a putative promoter upstream of dsrA but primary transcripts originating from (a) transcription start site(s) downstream of dsrB are also formed. Polar insertion mutations immediately upstream of dsrA, and in dsrB, dsrH and dsrM, led to an inability of the cells to oxidize intracellularly stored sulfur. The capability of the mutants to oxidize sulfide, thiosulfate and sulfite under photolithoautotrophic conditions was unaltered. Photoorganoheterotrophic growth was also unaffected. 'Reverse' sulfite reductase and DsrEFHCMK are, therefore, not essential for oxidation of sulfide or thiosulfate, but are obligatory for sulfur oxidation. These results, together with the finding that the sulfur globules of C. vinosum are located in the extracytoplasmic space whilst the dsr gene products appear to be either cytoplasmic or membrane-bound led to the proposal of new models for the pathway of sulfur oxidation in this phototrophic sulfur bacterium. << Less
Microbiology 144:1881-1894(1998) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.
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Siroheme as an active catalyst in sulfite reduction.
Seki Y., Sogawa N., Ishimoto M.
Siroheme extracted by acetone/HCl treatment of sulfite reductase from yeast and purified by column chromatography catalyzed the reduction of sulfite to thiosulfate and sulfide when coupled with a hydrogen-hydrogenase-methyl viologen system. The activity increased with decrease in pH from 7 to 4, a ... >> More
Siroheme extracted by acetone/HCl treatment of sulfite reductase from yeast and purified by column chromatography catalyzed the reduction of sulfite to thiosulfate and sulfide when coupled with a hydrogen-hydrogenase-methyl viologen system. The activity increased with decrease in pH from 7 to 4, and an apparent Km value of 50 mM for sulfite was obtained. In contrast to sirohydrochlorin plus Fe2+, addition of inorganic iron or 2,2'-bipyridine prior to the reduction reaction had scarcely any effect on the sulfite-reducing activity of siroheme. Hydroxylamine was reduced by siroheme at a much faster rate than sulfite, and the rate increased with increase in pH from 6 to 9. Siroheme extracted from Chromatium vinosum strain D sulfite reductase also reduced sulfite to thiosulfate and sulfide. << Less
J Biochem 90:1487-1492(1981) [PubMed] [EuropePMC]
This publication is cited by 5 other entries.
Comments
Multi-step reaction: RHEA:47024 and RHEA:47028.