Tetrad Graduate Program, University of California, San Francisco, California, USA.
Nat Struct Mol Biol. 2013 Jul;20(7):876-83. doi: 10.1038/nsmb.2595. Epub 2013 Jun 2.
Glucocorticoid receptor (GR) binds to genomic response elements and regulates gene transcription with cell and gene specificity. Within a response element, the precise sequence to which the receptor binds has been implicated in directing its structure and activity. Here, we use NMR chemical-shift difference mapping to show that nonspecific interactions with bases at particular positions in the binding sequence, such as those of the 'spacer', affect the conformation of distinct regions of the rat GR DNA-binding domain. These regions include the DNA-binding surface, the 'lever arm' and the dimerization interface, suggesting an allosteric pathway that signals between the DNA-binding sequence and the associated dimer partner. Disrupting this pathway by mutating the dimer interface alters sequence-specific conformations, DNA-binding kinetics and transcriptional activity. Our study demonstrates that GR dimer partners collaborate to read DNA shape and to direct sequence-specific gene activity.
糖皮质激素受体 (GR) 与基因组反应元件结合，并具有细胞和基因特异性地调节基因转录。在反应元件内，受体结合的精确序列与指导其结构和活性有关。在这里，我们使用 NMR 化学位移差映射显示，与结合序列中特定位置碱基的非特异性相互作用，例如“间隔区”的碱基，会影响大鼠 GR DNA 结合结构域的不同区域的构象。这些区域包括 DNA 结合表面、“杠杆臂”和二聚化界面，提示存在一种变构途径，可在 DNA 结合序列和相关二聚体伴侣之间传递信号。通过突变二聚化界面破坏这种途径会改变序列特异性构象、DNA 结合动力学和转录活性。我们的研究表明，GR 二聚体伴侣协同作用以读取 DNA 形状并指导序列特异性基因活性。
