X-ray structure of the orphan nuclear receptor RORbeta ligand-binding domain in the active conformation.
The retinoic acid-related orphan receptor beta (RORbeta) exhibits a highly restricted neuronal-specific expression pattern in brain, retina and pineal gland. So far, neither a natural RORbeta target gene nor a functional ligand have been identified, and the physiological role of the receptor is not well understood. We present the crystal structure of the ligand-binding domain (LBD) of RORbeta containing a bound stearate ligand and complexed with a coactivator peptide. In the crystal, the monomeric LBD adopts the canonical agonist-bound form. The fatty acid ligand-coactivator peptide combined action stabilizes the transcriptionally active conformation. The large ligand-binding pocket is strictly hydrophobic on the AF-2 side and more polar on the beta-sheet side where the carboxylate group of the ligand binds. Site-directed mutagenesis experiments validate the significance of the present structure. Homology modeling of the other isotypes will help to design isotype-selective agonists and antagonists that can be used to characterize the physiological functions of RORs. In addition, our crystallization strategy can be extended to other orphan nuclear receptors, providing a powerful tool to delineate their functions.
Stehlin
C
C
Laboratoire de Biologie et Génomique Structurales (CNRS Unité Propre de Recherche 9004), Institut de Génétique et de Biologie Moléculaire et Cellulaire (CNRS/INSERM/Université Louis Pasteur), 1 rue Laurent Fries, BP 163, 67404 Illkirch, France.
Wurtz
J M
JM
Steinmetz
A
A
Greiner
E
E
Schüle
R
R
Moras
D
D
Renaud
J P
JP
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D018360:Crystallography, X-Ray; D051548:Histone Acetyltransferases; D008024:Ligands; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D056920:Nuclear Receptor Coactivator 1; D057095:Nuclear Receptor Subfamily 1, Group F, Member 2; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013229:Stearic Acids / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry*
D008024:Ligands; D046911:Macromolecular Substances; D057095:Nuclear Receptor Subfamily 1, Group F, Member 2; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D013229:Stearic Acids; D014157:Transcription Factors; C031183:stearic acid; D051548:Histone Acetyltransferases; D056920:Nuclear Receptor Coactivator 1