Nettles Kendall W, Bruning John B, Gil German, Nowak Jason, Sharma Sanjay K, Hahm Johnnie B, Kulp Kristen, Hochberg Richard B, Zhou Haibing, Katzenellenbogen John A, Katzenellenbogen Benita S, Kim Younchang, Joachmiak Andrzej, Greene Geoffrey L
Department of Cancer Biology, The Scripps Research Institute, 5353 Parkside Drive, Jupiter, Florida 33458, USA.
Nat Chem Biol. 2008 Apr;4(4):241-7. doi: 10.1038/nchembio.76. Epub 2008 Mar 16.
Our understanding of how steroid hormones regulate physiological functions has been significantly advanced by structural biology approaches. However, progress has been hampered by misfolding of the ligand binding domains in heterologous expression systems and by conformational flexibility that interferes with crystallization. Here, we show that protein folding problems that are common to steroid hormone receptors are circumvented by mutations that stabilize well-characterized conformations of the receptor. We use this approach to present the structure of an apo steroid receptor that reveals a ligand-accessible channel allowing soaking of preformed crystals. Furthermore, crystallization of different pharmacological classes of compounds allowed us to define the structural basis of NFkappaB-selective signaling through the estrogen receptor, thus revealing a unique conformation of the receptor that allows selective suppression of inflammatory gene expression. The ability to crystallize many receptor-ligand complexes with distinct pharmacophores allows one to define structural features of signaling specificity that would not be apparent in a single structure.
结构生物学方法极大地推动了我们对类固醇激素如何调节生理功能的理解。然而，异源表达系统中配体结合域的错误折叠以及干扰结晶的构象灵活性阻碍了研究进展。在此，我们表明，类固醇激素受体常见的蛋白质折叠问题可通过稳定受体特征明确构象的突变来规避。我们运用这种方法展示了无配体类固醇受体的结构，该结构揭示了一个配体可及通道，允许预先形成的晶体进行浸泡。此外，不同药理类化合物的结晶使我们能够确定通过雌激素受体进行NFκB选择性信号传导的结构基础，从而揭示了受体的独特构象，该构象允许选择性抑制炎症基因表达。能够使许多具有不同药效基团的受体 - 配体复合物结晶，使得人们能够定义信号特异性的结构特征，而这些特征在单一结构中并不明显。
