Structure of the intact PPAR-γ–RXR-α nuclear receptor complex on DNA

By V. Chandra, Pengxiang Huang*, Y. Hamuro, S. Raghuram, Yongjun Wang, T. Burris, F. Rastinejad. Nature, 2008

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Nuclear receptors are multi-domain transcription factors that bind to DNA elements from which they regulate gene expression. The peroxisome proliferator-activated receptors (PPARs) form heterodimers with the retinoid X receptor (RXR), and PPAR-γ has been intensively studied as a drug target because of its link to insulin sensitization. Previous structural studies have focused on isolated DNA or ligand-binding segments, with no demonstration of how multiple domains cooperate to modulate receptor properties. Here we present structures of intact PPAR-γ and RXR-α as a heterodimer bound to DNA, ligands and coactivator peptides. PPAR-γ and RXR-α form a non-symmetric complex, allowing the ligand-binding domain (LBD) of PPAR-γ to contact multiple domains in both proteins. Three interfaces link PPAR-γ and RXR-α, including some that are DNA dependent. The PPAR-γ LBD cooperates with both DNA-binding domains (DBDs) to enhance response-element binding. The A/B segments are highly dynamic, lacking folded substructures despite their gene-activation properties.

Subfields: Molecular Biology, Oncology

View Paper: https://www.semanticscholar.org/paper/7aab5352fe3bb71e68cbf1f947215d5b8a55d774