title: Overexpression, purification, crystallization and preliminary X-ray diffraction analysis of Cu,Zn superoxide dismutase from Peking duck.
abstract: The cDNA encoding Peking duck Cu,Zn superoxide dismutase (dSOD) was cloned and sequenced. The recombinant enzyme was overexpressed in Escherichia coli, purified to homogeneity and crystallized using the sitting-drop vapour-diffusion technique. Trigonal crystals of dSOD were obtained at 278 K at low ionic strength and around neutral pH. These crystals belong to space group P3(2)21, with unit-cell parameters a = 124.4, c = 163.5 A, gamma = 120 degrees. The asymmetric unit contains four dimers (eight monomers of Cu,Zn dSOD) and has a 56% solvent content, with a V(M) of 2.8 A(3) Da(-1). On a Rigaku R-AXIS IIc image-plate area-detector system, the crystal diffracted to 2.9 A. Unusual supermolecular double-helix packing with 9(2)2 non-crystallographic symmetry in crystals has been observed in the initial structural analysis.
authors.affiliation: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: P W
authors.initials: PW
authors.lastname: Li
authors.forename: G P
authors.initials: GP
authors.lastname: Li
authors.forename: R H
authors.initials: RH
authors.lastname: Zhu
authors.forename: D C
authors.initials: DC
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray; D004372:Ducks; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; D013482:Superoxide Dismutase