title: Crystallization and preliminary X-ray analysis of AzoR (azoreductase) from Escherichia coli.
abstract: AzoR (azoreductase), an FMN-dependent NADH-azo compound oxidoreductase from Escherichia coli, has been crystallized in the presence of FMN by the sitting-drop vapour-diffusion method using 2-propanol as a precipitant. AzoR catalyzes the reductive cleavage of azo groups. The crystals were found to diffract X-rays to beyond 1.8 A resolution using a synchrotron-radiation source. The crystals belonged to the tetragonal space group P4(2)2(1)2, with unit-cell parameters a = b = 92.2, c = 51.9 A. The crystals are expected to contain one subunit of the homodimer in the asymmetric unit (VM = 2.6 A3 Da(-1)) and to have a solvent content of 51.6%. Data sets were also collected from heavy-atom derivatives for use in phasing. As a result, crystals soaked in a solution containing K2PtCl4 for 23 d were found to be reasonably isomorphous to the native crystals and the presence of Pt atoms could be confirmed. The data sets from the native crystals and the K2PtCl4-derivatized crystals are being evaluated for use in structure determination by single isomorphous replacement with anomalous scattering.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Tokyo 113-8657, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Ito
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Woo-Cheol
authors.initials: WC
authors.lastname: Lee
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasaki
authors.forename: Shuhei
authors.initials: S
authors.lastname: Zenno
authors.forename: Kaoru
authors.initials: K
authors.lastname: Saigo
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kitade
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanokura
mesh_terms: D019840:2-Propanol; D003460:Crystallization / Q000379:methods; D029968:Escherichia coli Proteins / Q000737:chemistry*; D005486:Flavin Mononucleotide; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry*; D009601:Nitroreductases; D014835:Volatilization; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D005486:Flavin Mononucleotide; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase; D019840:2-Propanol