title: Crystallization of the NADH-oxidizing domain of the Na+-translocating NADH:ubiquinone oxidoreductase from Vibrio cholerae.
abstract: The Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) from pathogenic and marine bacteria is a respiratory complex that couples the exergonic oxidation of NADH by quinone to the transport of Na+ across the membrane. The NqrF subunit oxidizes NADH and transfers the electrons to other redox cofactors in the enzyme. The FAD-containing domain of NqrF has been expressed, purified and crystallized. The purified NqrF FAD domain exhibited high rates of NADH oxidation and contained stoichiometric amounts of the FAD cofactor. Initial crystallization of the flavin domain was achieved by the sitting-drop technique using a Cartesian MicroSys4000 robot. Optimization of the crystallization conditions yielded yellow hexagonal crystals with dimensions of 30 x 30 x 70 microm. The protein mainly crystallizes in long hexagonal needles with a diameter of up to 30 microm. Crystals diffract to 2.8 A and belong to space group P622, with unit-cell parameters a = b = 145.3, c = 90.2 A, alpha = beta = 90, gamma = 120 degrees.
authors.affiliation: Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Minli
authors.initials: M
authors.lastname: Tao
authors.forename: Karin
authors.initials: K
authors.lastname: Türk
authors.forename: Joachim
authors.initials: J
authors.lastname: Diez
authors.forename: Markus G
authors.initials: MG
authors.lastname: Grütter
authors.forename: Günter
authors.initials: G
authors.lastname: Fritz
authors.forename: Julia
authors.initials: J
authors.lastname: Steuber
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D005420:Flavoproteins; D009243:NAD / Q000737:chemistry* / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases; D010084:Oxidation-Reduction; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D011808:Quinone Reductases / Q000737:chemistry* / Q000378:metabolism; D014734:Vibrio cholerae / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D005420:Flavoproteins; D021122:Protein Subunits; D009243:NAD; D009247:NADH, NADPH Oxidoreductases; C099916:Nqrf protein, Vibrio alginolyticus; C084142:sodium-translocating NADH-quinone reductase; D011808:Quinone Reductases