Crystallization (Comment) | Organism |
---|---|
purified enzyme QFR alone r with bound FLiG in two crystal forms, one grown from the lipidic cubic phase and one grown from dodecyl maltoside micelles, the first exhibiting crystal packing similar to previous crystal forms, while the latter displays a unique crystal packing providing the view of the QFR active site without a dicarboxylate ligand. For LCP crystallization 25 mg/ml protein (QFR or QFR-FliG) is mixed in a 40:60 ratio with 1-(9Z-octadecenoyl)-rac-glycerol (9.9 MAG), crystals are grown using 50 nl mesophase and 800 nl precipitant containing 200 mM NH4F, 100 mM Bis-Tris pH 7.5, 22% PEG 400, and 5% pentaerythritol propoxylate, crystals of QFR grow using the same conditions as crystals of QFR-FliG, with the crystals from the QFR-FliG mixture being better suited to diffraction analysis. For micellar crystallization of QFR-FliG in 20 mM Tris pH 7.4, 0.02% DDM, sitting drop vapor diffusion method is used, mixing of with 200 nl of 25 mg/ml protein and 200 nl of reservoir solution, containing 10-20% PEG 400-900, 15-50 mM divalent cation (CaCl2, Ca(CH3COO)2, or MgCl2), and 50 mM Bis-Tris, pH 6.5, X-ray diffraction structure determination and analysis at 7.5 and 3.35 A resolution, respectively | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | QFR is an integral membrane protein with membrane-spanning subunits FrdC and FrdD | Escherichia coli | 16020 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
succinate + menaquinone | Escherichia coli | - |
fumarate + menaquinol | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P00363 AND P0AC47 AND P0A8Q0 AND P0A8Q3 | subunits frdA, frdB, frdC, and frdD | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
succinate + menaquinone | - |
Escherichia coli | fumarate + menaquinol | - |
? |
Subunits | Comment | Organism |
---|---|---|
tetramer | enzyme QFR is composed of four polypeptide chains, two of which are soluble (flavoprotein, FrdA and iron-sulfur protein, FrdB) and two of which are membrane-spanning (FrdC and FrdD) | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
Complex II homolog | - |
Escherichia coli |
FRdABCD | - |
Escherichia coli |
menaquinol-1 fumarate reductase | - |
Escherichia coli |
QFR | - |
Escherichia coli |
quinol:fumarate reductase | - |
Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | bound to flavoprotein FrdA | Escherichia coli | |
Fe-S center | iron-sulfur protein FrdB | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | quinol:fumarate reductase (QFR) is a member of the respiratory complex II superfamily | Escherichia coli |
additional information | FrdAR287 is essential for catalytic protonation/deprotonation of fumarate/succinate, an intriguing mechanism for substrate control of capping domain position is via the charge on the dicarboxylate affecting the pKa of FrdAR287. Ligand control of domain position suggests a mechanism for ingress and egress of substrate facilitated by the changes in the locations of active site residues | Escherichia coli |
physiological function | in addition to its role in bioenergetics, QFR binds to the FliG subunit of the switch-motor of the bacterial flagellar rotor and promotes clockwise rotation of the flagellum, which is essential for chemotaxis | Escherichia coli |