@article{f1f3d171cff64ce4bd86897f0e2df02d,
title = "An Evolutionarily Conserved Structural Platform for PRC2 Inhibition by a Class of Ezh2 Inhibitors",
abstract = "Polycomb repressive complex 2 (PRC2) mediates trimethylation of histone H3K27 (H3K27me3), an epigenetic hallmark for repressed chromatin. Overactive mutants of the histone lysine methyltransferase subunit of PRC2, Ezh2, are found in various types of cancers. Pyridone-containing inhibitors such as GSK126 compete with S-adenosylmethionine (SAM) for Ezh2 binding and effectively inhibit PRC2 activity. PRC2 from the thermophilic fungus Chaetomium thermophilum (ct) is functionally similar to the human version in several regards and has the added advantage of producing high-resolution crystal structures, although inhibitor-bound structures of human or human/chameleon PRC2 are also available at up to 2.6 {\AA} resolution. We solved crystal structures of both human and ctPRC2 bound to GSK126 and the structurally similar inhibitor GSK343. While the two organisms feature a disparate degree of inhibitor potency, surprisingly, GSK126 binds in a similar manner in both structures. Structure-guided protein engineering of the drug binding pocket allowed us to introduce humanizing mutations into ctEzh2 to produce a ctPRC2 variant that is more susceptible to GSK126 inhibition. Additional analysis indicated that an evolutionarily conserved structural platform dictates a unique mode of GSK126 binding, suggesting a mechanism of drug selectivity. The existing drug scaffold may thus be used to probe the function and cellular regulation of PRC2 in a wide spectrum of organisms, ranging from fungi to humans.",
author = "Matthew Bratkowski and Xin Yang and Xin Liu",
note = "Funding Information: We thank the staff of the Structural Biology Center at Argonne National Laboratory for assistance with data collection. We thank Diana Tomchick and Zhe Chen of the Structural Biology Laboratory at UT Southwestern for organizing collection time at APS beamline 19ID. We thank Lianying Jiao for providing wild-type ctPRC2 that was used in IC50assays and for collecting data for the hmPRC2-GSK343 structure. The cDNA of human PRC2 subunits used for cloning were kindly provided by Dr. Robert Kingston of Harvard University. This research was supported by the Welch Foundation research grant I-1790, CPRIT research grant R1119, Rita Allen Foundation research grant, UT Southwestern Medical Center Endowed Scholar fund, and NIH Grants GM114576 and GM121662 to X.L. X.L. is a W. W. Caruth, Jr. Scholar in Biomedical Research. This research also received support from the Cecil H. and Ida Green Center Training Program in Reproductive Biology Sciences Research. This research used resources of the Advanced Photon Source, a U.S. Department of Energy Office (DOE) of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02–06CH11357. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. DOE under contract no. DE-AC02–76SF00515. The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research, and by the National Institutes of Health, National Institute of General Medical Sciences (including P41GM103393). The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of NIGMS or NIH. Publisher Copyright: {\textcopyright} 2018 The Author(s).",
year = "2018",
month = dec,
day = "1",
doi = "10.1038/s41598-018-27175-w",
language = "English (US)",
volume = "8",
journal = "Scientific reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",
}