The RXR-alpha C-terminus T462 is a NMR sensor for coactivator peptide binding

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Minghe Chen (Creator)

David P. Cistola (Creator)

Gregory T. DeKoster (Creator)

Ellen Li (Creator)

Jianyun Lu (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: The C-terminal activation function-2 (AF-2) helix plays a crucial role in retinoid X receptor alpha (RXRα)-mediated gene expression. Here we report a nuclear magnetic resonance (NMR) study of the RXRα ligand-binding domain complexed with 9-cis-retinoic acid and a glucocorticoid receptorinteracting protein 1 peptide. The AF-2 helix and most of the C-terminal residues were undetectable due to a severe line-broadening effect. Due to its outstanding signal-to-noise ratio the C-terminus esidue threonine 462 (T462) exhibited two distinct crosspeaks during peptide titration suggesting that peptide binding was in a slow exchange regime on the chemical shift timescale. Consistently he Kd derived from T462 intensity decay agreed with that derived from isothermal titration calorimetry. Furthermore the exchange contribution to the 15N transverse relaxation rate was measurable in either T462 or the bound peptide. These results suggest that T462 is a sensor for oactivator binding and is a potential probe for AF-2 helix mobility. Originally published Biochemical and Biophysical Research Communications Vol. 366 No. 4 Feb 2008

Additional Information

Publication

Other

Biochemical and Biophysical Research Communications. 366:4(February 2008) p. 932-937.

Language: English

Date: 2011

Keywords

RXR alpha, activation, GRIP1, coactivator, NMR, Isothermal titration calorimetry

Email this document to