1g5y
From Proteopedia
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THE 2.0 ANGSTROM RESOLUTION CRYSTAL STRUCTURE OF THE RXRALPHA LIGAND BINDING DOMAIN TETRAMER IN THE PRESENCE OF A NON-ACTIVATING RETINOIC ACID ISOMER.
Overview
The 9-cis-retinoic acid receptors (RXRalpha, RXRbeta, and RXRgamma) are, nuclear receptors that play key roles in multiple hormone-signaling, pathways. Biochemical data indicate that, in the absence of ligand, RXR, can exist as an inactive tetramer and that its dissociation, induced by, ligand, is important for receptor activation. In this article we report, the inactivated tetramer structures of the RXRalpha ligand-binding domain, (LBD), either in the absence of or in the presence of a nonactivating, ligand. These structures reveal that the RXR LBD tetramer forms a compact, disc-shaped complex, consisting of two symmetric dimers that are packed, along helices 3 and 11. In each monomer, the AF-2 helix protrudes away, from the core domain and spans into the coactivator binding site in the, adjacent monomer of the symmetric dimer. In this configuration, the AF-2, helix physically excludes the binding of coactivators and suggests an, autorepression mechanism that is mediated by the AF-2 helix within the, tetramer. The RXR-tetramer interface is assembled from amino acids that, are conserved across several closely related receptors, including the, HNF4s and COUP transcription factors, and may therefore provide a model, for understanding structure and regulation of this subfamily of nuclear, receptors.
About this Structure
1G5Y is a Single protein structure of sequence from Homo sapiens with REA as ligand. Full crystallographic information is available from OCA.
Reference
Structural basis for autorepression of retinoid X receptor by tetramer formation and the AF-2 helix., Gampe RT Jr, Montana VG, Lambert MH, Wisely GB, Milburn MV, Xu HE, Genes Dev. 2000 Sep 1;14(17):2229-41. PMID:10970886
Page seeded by OCA on Mon Nov 12 17:01:14 2007
