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.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • HEK293 Cells
  • Humans
  • Protein Structure, Quaternary
  • Receptors, Retinoic Acid / chemistry*
  • Retinoid X Receptor alpha / chemistry*

Substances

  • Receptors, Retinoic Acid
  • Retinoid X Receptor alpha
  • retinoic acid receptor beta