title: The palindromic DNA-bound USP/EcR nuclear receptor adopts an asymmetric organization with allosteric domain positioning.
abstract: Nuclear receptors (NRs) regulate gene expression through DNA- and ligand-binding and thus represent crucial therapeutic targets. The ultraspiracle protein/ecdysone receptor (USP/EcR) complex binds to half-sites with a one base pair spaced inverted repeat (IR1), a palindromic DNA response element (RE) reminiscent of IRs observed for vertebrate steroid hormone receptors. Here we present the cryo electron microscopy structure of the USP/EcR complex bound to an IR1 RE which provides the first description of a full IR-bound NR complex. The structure reveals that even though the DNA is almost symmetric, the complex adopts a highly asymmetric architecture in which the ligand-binding domains (LBDs) are positioned 5' off-centred. Additional interactions of the USP LBD with the 5'-flanking sequence trigger transcription activity as monitored by transfection assays. The comparison with DR-bound NR complexes suggests that DNA is the major allosteric driver in inversely positioning the LBDs, which serve as the main binding-site for transcriptional regulators.
authors.affiliation: 1] Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, 67404 Illkirch, France [2] Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France [3] Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France [4] Université de Strasbourg, 67404 Strasbourg, France.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Maletta
authors.affiliation: 1] Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, 67404 Illkirch, France [2] Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France [3] Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France [4] Université de Strasbourg, 67404 Strasbourg, France.
authors.forename: Igor
authors.initials: I
authors.lastname: Orlov
authors.affiliation: 1] SOLEIL Synchrotron, L'Orme des Merisiers Saint-Aubin, 91192 Gif-sur-Yvette, France [2] INRA-URBIA, Rue de la Geraudière, 44316 Nantes, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Roblin
authors.affiliation: 1] Institut de recherche de l'Ecole de biotechnologie de Strasbourg, UMS 3286-Plateforme de Chimie Biologique Intégrative de Strasbourg, Université de Strasbourg, 67412 Illkirch, France [2] Laboratoire de Biochimie, Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, 75231 Paris Cedex 05, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Beck
authors.affiliation: 1] Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, 67404 Illkirch, France [2] Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France [3] Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France [4] Université de Strasbourg, 67404 Strasbourg, France.
authors.forename: Dino
authors.initials: D
authors.lastname: Moras
authors.affiliation: 1] Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, 67404 Illkirch, France [2] Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France [3] Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France [4] Université de Strasbourg, 67404 Strasbourg, France.
authors.forename: Isabelle M L
authors.initials: IM
authors.lastname: Billas
authors.affiliation: 1] Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, 67404 Illkirch, France [2] Centre National de la Recherche Scientifique (CNRS) UMR 7104, 67404 Illkirch, France [3] Institut National de la Santé et de la Recherche Médicale (INSERM) U964, 67404 Illkirch, France [4] Université de Strasbourg, 67404 Strasbourg, France.
authors.forename: Bruno P
authors.initials: BP
authors.lastname: Klaholz
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D055029:Inverted Repeat Sequences; D009036:Moths / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011987:Receptors, Steroid / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements
chemical_list: D004268:DNA-Binding Proteins; D019476:Insect Proteins; D011987:Receptors, Steroid; C055469:ecdysone receptor; D004247:DNA