title: Crystallization and preliminary structure determination of the membrane-bound complex cytochrome c nitrite reductase from Desulfovibrio vulgaris Hildenborough.
abstract: The cytochrome c nitrite reductase (cNiR) isolated from Desulfovibrio vulgaris Hildenborough is a membrane-bound complex formed of NrfA and NrfH subunits. The catalytic subunit NrfA is a soluble pentahaem cytochrome c that forms a physiological dimer of about 120 kDa. The electron-donor subunit NrfH is a membrane-anchored tetrahaem cytochrome c of about 18 kDa molecular weight and belongs to the NapC/NirT family of quinol dehydrogenases, for which no structures are known. Crystals of the native cNiR membrane complex, solubilized with dodecylmaltoside detergent (DDM), were obtained using PEG 4K as precipitant. Anomalous diffraction data were measured at the Swiss Light Source to 2.3 A resolution. Crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 79.5, b = 256.7, c = 578.2 A. Molecular-replacement and MAD methods were combined to solve the structure. The data presented reveal that D. vulgaris cNiR contains one NrfH subunit per NrfA dimer.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, ITQB-UNL, Av. República, Apt. 127, 2781-901 Oeiras, Portugal.
authors.forename: M L
authors.initials: ML
authors.lastname: Rodrigues
authors.forename: T
authors.initials: T
authors.lastname: Oliveira
authors.forename: P M
authors.initials: PM
authors.lastname: Matias
authors.forename: I C
authors.initials: IC
authors.lastname: Martins
authors.forename: F M A
authors.initials: FM
authors.lastname: Valente
authors.forename: I A C
authors.initials: IA
authors.lastname: Pereira
authors.forename: M
authors.initials: M
authors.lastname: Archer
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D045263:Cytochromes a1 / Q000737:chemistry*; D003575:Cytochromes c1 / Q000737:chemistry*; D016969:Desulfovibrio vulgaris / Q000201:enzymology*; D008565:Membrane Proteins / Q000737:chemistry*; D009565:Nitrate Reductases / Q000737:chemistry*; D021122:Protein Subunits / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D008565:Membrane Proteins; D021122:Protein Subunits; D045263:Cytochromes a1; D003575:Cytochromes c1; D009565:Nitrate Reductases; C054690:nitrate reductase (cytochrome)