@article {Peng332205, author = {Yi Peng and Shufen Cao and Janna Kiselar and Xiangzhu Xiao and Zhanwen Du and An Hsien and Soobin Ko and Yinghua Chen and Prashansa Agrawal and Wenwei Zheng and Wuxian Shi and Wei Jiang and Lin Yang and Mark R. Chance and Witold K. Surewicz and Matthias Buck and Sichun Yang}, title = {A metastable contact and structural disorder in the estrogen receptor transactivation domain}, elocation-id = {332205}, year = {2018}, doi = {10.1101/332205}, publisher = {Cold Spring Harbor Laboratory}, abstract = {The N-terminal transactivation domain (NTD) of estrogen receptor alpha, a well-known member of the family of intrinsically disordered proteins (IDPs), mediates the receptor{\textquoteright}s transactivation function to regulate gene expression. However, an accurate molecular dissection of NTD{\textquoteright}s structure-function relationships remains elusive. Here, using small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR), circular dichroism, and hydrogen exchange mass spectrometry, we show that NTD adopts a mostly disordered, unexpectedly compact conformation that undergoes structural expansion upon chemical denaturation. By combining SAXS, hydroxyl radical protein footprinting and computational modeling, we derive the ensemble-structures of the NTD and determine its ensemble-contact map that reveals metastable regional and long-range contacts, including interactions between residues I33 and S118. We show that mutation at S118, a known phosphorylation site, promotes conformational changes and increases coactivator binding. We further demonstrate via fluorine-19 (19F) NMR that mutations near residue I33 alter 19F chemical shifts at residue S118, confirming the proposed I33-S118 contact in the ensemble of structural disorder. These findings extend our understanding of IDPs{\textquoteright} structure-function relationship, and how specific metastable contacts mediate critical functions of disordered proteins.HighlightsA compact disorder is observed for the N-terminal domain (NTD) of estrogen receptorMulti-technique modeling elucidates the NTD ensemble structuresEnsemble-based contact map reveals metastable contacts between I33 and S11819F-NMR data validate the proposed I33-S118 contact in the IDP}, URL = {https://www.biorxiv.org/content/early/2018/09/06/332205}, eprint = {https://www.biorxiv.org/content/early/2018/09/06/332205.full.pdf}, journal = {bioRxiv} }