4nqa
From Proteopedia
Crystal structure of liganded hRXR-alpha/hLXR-beta heterodimer on DNA
Structural highlights
FunctionRXRA_HUMAN Receptor for retinoic acid. Retinoic acid receptors bind as heterodimers to their target response elements in response to their ligands, all-trans or 9-cis retinoic acid, and regulate gene expression in various biological processes. The RAR/RXR heterodimers bind to the retinoic acid response elements (RARE) composed of tandem 5'-AGGTCA-3' sites known as DR1-DR5. The high affinity ligand for RXRs is 9-cis retinoic acid. RXRA serves as a common heterodimeric partner for a number of nuclear receptors. The RXR/RAR heterodimers bind to the retinoic acid response elements (RARE) composed of tandem 5'-AGGTCA-3' sites known as DR1-DR5. In the absence of ligand, the RXR-RAR heterodimers associate with a multiprotein complex containing transcription corepressors that induce histone acetylation, chromatin condensation and transcriptional suppression. On ligand binding, the corepressors dissociate from the receptors and associate with the coactivators leading to transcriptional activation. The RXRA/PPARA heterodimer is required for PPARA transcriptional activity on fatty acid oxidation genes such as ACOX1 and the P450 system genes.[1] [2] [3] [4] Publication Abstract from PubMedNuclear receptors (NRs) are conditional transcription factors with common multidomain organization that bind diverse DNA elements. How DNA sequences influence NR conformation is poorly understood. Here we report the crystal structure of the human retinoid X receptor alpha-liver X receptor beta (RXRalpha-LXRbeta) heterodimer on its cognate element, an AGGTCA direct repeat spaced by 4 nt. The complex has an extended X-shaped arrangement, with DNA- and ligand-binding domains crossed, in contrast to the parallel domain arrangement of other NRs that bind an AGGTCA direct repeat spaced by 1 nt. The LXRbeta core binds DNA via canonical contacts and auxiliary DNA contacts that enhance affinity for the response element. Comparisons of RXRalpha-LXRbetas in the crystal asymmetric unit and with previous NR structures reveal flexibility in NR organization and suggest a role for RXRalpha in adaptation of heterodimeric complexes to DNA. Structure of the retinoid X receptor alpha-liver X receptor beta (RXRalpha-LXRbeta) heterodimer on DNA.,Lou X, Toresson G, Benod C, Suh JH, Philips KJ, Webb P, Gustafsson JA Nat Struct Mol Biol. 2014 Mar;21(3):277-81. doi: 10.1038/nsmb.2778. Epub 2014 Feb, 23. PMID:24561505[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Synthetic construct | Benod C | Gustafsson JA | Lou XH | Phillips KJ | Suh JH | Toresson G | Webb P
