Fumarate reductase (quinol)
Fumarate reductase (quinol) (EC 1.3.5.4, QFR, FRD, menaquinol-fumarate oxidoreductase, quinol:fumarate reductase) is an enzyme with systematic name succinate:quinone oxidoreductase. This enzyme catalyzes the following chemical reaction:
| Fumarate reductase (quinol) | |||||||||
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3D cartoon of the fumarate reductase crystal structure from E. coli. | |||||||||
| Identifiers | |||||||||
| EC no. | 1.3.5.4 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
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| Fumarate reductase respiratory complex | |||||||||||
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Cartoon structure of fumarate reductase flavoprotein subunit A. | |||||||||||
| Identifiers | |||||||||||
| Symbol | Fum_red_TM | ||||||||||
| Pfam | PF01127 | ||||||||||
| Pfam clan | CL0335 | ||||||||||
| InterPro | IPR004224 | ||||||||||
| SCOP2 | 1qla / SCOPe / SUPFAM | ||||||||||
| OPM superfamily | 3 | ||||||||||
| OPM protein | 2bs3 | ||||||||||
| CDD | cd03494 | ||||||||||
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| Fumarate reductase subunit C | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Cartoon structure of fumarate reductase subunits C and D near two menaquinone molecules. | |||||||||
| Identifiers | |||||||||
| Symbol | Fumarate_red_C | ||||||||
| Pfam | PF02300 | ||||||||
| Pfam clan | CL0335 | ||||||||
| InterPro | IPR003510 | ||||||||
| SCOP2 | 1fum / SCOPe / SUPFAM | ||||||||
| CDD | cd00546 | ||||||||
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| Fumarate reductase subunit D | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Cartoon structure of fumarate reductase subunits C and D near two menaquinone molecules. | |||||||||
| Identifiers | |||||||||
| Symbol | Fumarate_red_D | ||||||||
| Pfam | PF02313 | ||||||||
| Pfam clan | CL0335 | ||||||||
| InterPro | IPR003418 | ||||||||
| SCOP2 | 1fum / SCOPe / SUPFAM | ||||||||
| CDD | cd00547 | ||||||||
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Fumarate reductase (QFR) is a key enzyme induced by anaerobic growth of bacteria. By partaking in fumarate respiration, fumarate reductase performs the last step in the microbial anaerobic respiration. It is a membrane bound protein capable of oxidizing a quinone and passing the released electrons to an awaiting fumarate to be reduced. It is activated and synthesized under low oxygen conditions, when aerobic respiration cannot be performed and the cell must perform anaerobic respiration to grow. This reaction is opposite to the reaction that is catalyzed by the related complex II of the respiratory chain (succinate dehydrogenase (SQR)).