1. Academic Validation
  2. The quaternary architecture of RARβ-RXRα heterodimer facilitates domain-domain signal transmission

The quaternary architecture of RARβ-RXRα heterodimer facilitates domain-domain signal transmission

  • Nat Commun. 2017 Oct 11;8(1):868. doi: 10.1038/s41467-017-00981-y.
Vikas Chandra 1 Dalei Wu 1 2 Sheng Li 3 Nalini Potluri 1 Youngchang Kim 4 Fraydoon Rastinejad 5
Affiliations

Affiliations

  • 1 Integrative Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL, 32827, USA.
  • 2 Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Qingdao, Shandong, 266237, China.
  • 3 Department of Medicine and UCSD DXMS Proteomics Resource, University of California, San Diego, La Jolla, CA, 92023, USA.
  • 4 Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL, 60439, USA.
  • 5 Integrative Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL, 32827, USA. [email protected].
Abstract

Assessing the physical connections and allosteric communications in multi-domain nuclear receptor (NR) polypeptides has remained challenging, with few crystal structures available to show their overall structural organizations. Here we report the quaternary architecture of multi-domain retinoic acid receptor β-retinoic X receptor α (RARβ-RXRα) heterodimer bound to DNA, ligands and coactivator Peptides, examined through crystallographic, hydrogen-deuterium exchange mass spectrometry, mutagenesis and functional studies. The RARβ ligand-binding domain (LBD) and DNA-binding domain (DBD) are physically connected to foster allosteric signal transmission between them. Direct comparisons among all the multi-domain NRs studied crystallographically to date show significant variations within their quaternary architectures, rather than a common architecture adhering to strict rules. RXR remains flexible and adaptive by maintaining loosely organized domains, while its heterodimerization partners use a surface patch on their LBDs to form domain-domain interactions with DBDs.Nuclear receptors (NR) are multidomain proteins, which makes their crystallization challenging. Here the authors present the crystal structure of the retinoic acid receptor β-retinoic X receptor α (RARβ-RXRα) heterodimer bound to DNA, ligands and coactivator Peptides, which shows that NR quaternary architectures are variable.

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