title: Structure and mechanism of NOV1, a resveratrol-cleaving dioxygenase.
abstract: Stilbenes are diphenyl ethene compounds produced naturally in a wide variety of plant species and some bacteria. Stilbenes are also derived from lignin during kraft pulping. Stilbene cleavage oxygenases (SCOs) cleave the central double bond of stilbenes, forming two phenolic aldehydes. Here, we report the structure of an SCO. The X-ray structure of NOV1 from Novosphingobium aromaticivorans was determined in complex with its substrate resveratrol (1.89 Å), its product vanillin (1.75 Å), and without any bound ligand (1.61 Å). The enzyme is a seven-bladed β-propeller with an iron cofactor coordinated by four histidines. In all three structures, dioxygen is observed bound to the iron in a side-on fashion. These structures, along with EPR analysis, allow us to propose a mechanism in which a ferric-superoxide reacts with substrate activated by deprotonation of a phenol group at position 4 of the substrate, which allows movement of electron density toward the central double bond and thus facilitates reaction with the ferric superoxide electrophile. Correspondingly, NOV1 cleaves a wide range of other stilbene-like compounds with a 4'-OH group, offering potential in processing some solubilized fragments of lignin into monomer aromatic compounds.
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608; rpmcandrew@lbl.gov PDAdams@lbl.gov.|Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: McAndrew
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.|Department of Chemical Engineering, University of Louisville, Louisville, KY 40292.|Conn Center for Renewable Energy Research, University of Louisville, Louisville, KY 40292.
authors.forename: Noppadon
authors.initials: N
authors.lastname: Sathitsuksanoh
authors.affiliation: Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, WI 53706.|Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI 53706.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Mbughuni
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Heins
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
authors.forename: Jose H
authors.initials: JH
authors.lastname: Pereira
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551.
authors.forename: Anthe
authors.initials: A
authors.lastname: George
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA 94551.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Sale
authors.affiliation: Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, WI 53706.|Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI 53706.
authors.forename: Brian G
authors.initials: BG
authors.lastname: Fox
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608.|Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
authors.forename: Blake A
authors.initials: BA
authors.lastname: Simmons
authors.affiliation: Joint BioEnergy Institute, Emeryville, CA 94608; rpmcandrew@lbl.gov PDAdams@lbl.gov.|Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.|Department of Bioengineering, University of California, Berkeley, CA 94720.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Adams
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D049308:Dioxygenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D008958:Models, Molecular; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000077185:Resveratrol; D042301:Sphingomonadaceae / Q000201:enzymology / Q000235:genetics; D013267:Stilbenes / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D013267:Stilbenes; D049308:Dioxygenases; D000077185:Resveratrol
keywords: carotenoid; dioxygenase; stilbene; structure