PMID: 29021580

Authors:

Chandra V, Wu D, Li S, Potluri N, Kim Y, Rastinejad F

Title:

The quaternary architecture of RARbeta-RXRalpha heterodimer facilitates domain-domain signal transmission.

Journal:

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 beta-retinoic X receptor alpha (RARbeta-RXRalpha) heterodimer bound to DNA, ligands and coactivator peptides, examined through crystallographic, hydrogen-deuterium exchange mass spectrometry, mutagenesis and functional studies. The RARbeta 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 beta-retinoic X receptor alpha (RARbeta-RXRalpha) heterodimer bound to DNA, ligands and coactivator peptides, which shows that NR quaternary architectures are variable.