| Sulfide-cytochrome-c reductase (flavocytochrome c) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Structure of the flavocytochrome c sulfide dehydrogenase from the purple phototrophic bacterium Allochromatium vinosum ( PDB: 1FCD ). | |||||||||
| Identifiers | |||||||||
| EC no. | 1.8.2.3 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
| Flavocytochrome c sulfide dehydrogenase, flavin-binding | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | FCSD-flav_bind | ||||||||
| Pfam | PF09242 | ||||||||
| InterPro | IPR015323 | ||||||||
| SCOP2 | 1fcd / SCOPe / SUPFAM | ||||||||
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Flavocytochrome c sulfide dehydrogenase, also known as Sulfide-cytochrome-c reductase (flavocytochrome c) (EC 1.8.2.3), is an enzyme with systematic name hydrogen-sulfide:flavocytochrome c oxidoreductase. [1] [2] [3] [4] [5] [6] It is found in sulfur-oxidising bacteria such as the purple phototrophic bacteria Allochromatium vinosum. [4] [7] This enzyme catalyses the following chemical reaction:
- hydrogen sulfide + 2 ferricytochrome c sulfur + 2 ferrocytochrome c + 2 H+
These enzymes are heterodimers of a flavoprotein (fccB Q06530 ) and a diheme cytochrome (fccA; Q06529 ) that carry out hydrogen sulfide-dependent cytochrome C reduction. The diheme cytochrome folds into two domains, each of which resembles mitochondrial cytochrome c, with the two haem groups bound to the interior of the subunit. The flavoprotein subunit has a glutathione reductase-like fold consisting of a beta(3,4)-alpha(3) core, and an alpha+beta sandwich. The active site of the flavoprotein subunit contains a catalytically important disulfide bridge located above the pyrimidine portion of the flavin ring. The flavoprotein contains a C-terminal domain required for binding to flavin, and subsequent electron transfer. [4] Electrons are transferred from the flavin to one of the haem groups in the cytochrome. Both FAD and heme C are covalently bound to the protein.
