Literature summary for 1.3.5.1 extracted from

Starbird, C.A.; Tomasiak, T.M.; Singh, P.K.; Yankovskaya, V.; Maklashina, E.; Eisenbach, M.; Cecchini, G.; Iverson, T.M.
New crystal forms of the integral membrane Escherichia coli quinol fumarate reductase suggest that ligands control domain movement (2018), J. Struct. Biol., 202, 100-104 .

Crystallization (Commentary)

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

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

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/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
succinate + menaquinone	Escherichia coli	-	fumarate + menaquinol	-	?

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P00363 AND P0AC47 AND P0A8Q0 AND P0A8Q3	subunits frdA, frdB, frdC, and frdD	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
succinate + menaquinone	-	Escherichia coli	fumarate + menaquinol	-	?

Subunits

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

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

Cofactor	Comment	Organism	Structure
FAD	bound to flavoprotein FrdA	Escherichia coli
Fe-S center	iron-sulfur protein FrdB	Escherichia coli

General Information

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