title: Crystal structure of Escherichia coli QOR quinone oxidoreductase complexed with NADPH.
abstract: The crystal structure of the homodimer of quinone oxidoreductase from Escherichia coli has been determined using the multiple isomorphous replacement method at 2.2 A resolution and refined to an R-factor of 14.1% The crystallographic asymmetric unit contains one functional dimer with the two subunits being related by a non-crystallographic 2-fold symmetry axis. The model consists of two polypeptide chains (residues 2 through 327), one NADPH molecule and one sulphate anion per subunit, and 432 water molecules. Each subunit consists of two domains: a catalytic domain and a nucleotide-binding domain with the NADPH co-factor bound in the cleft between domains. Quinone oxidoreductase has an unusual nucleotide-binding fingerprint motif consisting of the sequence AXXGXXG. The overall structure of quinone oxidoreductase shows strong structural homology to that of horse liver alcohol dehydrogenase.
authors.affiliation: Centre for Molecular Structure and Function, Research School of Chemistry, Australian National University, Canberra.
authors.forename: J M
authors.initials: JM
authors.lastname: Thorn
authors.forename: J D
authors.initials: JD
authors.lastname: Barton
authors.forename: N E
authors.initials: NE
authors.lastname: Dixon
authors.forename: D L
authors.initials: DL
authors.lastname: Ollis
authors.forename: K J
authors.initials: KJ
authors.lastname: Edwards
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D017433:Protein Structure, Secondary
chemical_list: D009249:NADP; D009247:NADH, NADPH Oxidoreductases