Molecular Biology Program, Sloan-Kettering Institute, New York, New York, USA.
Structural Biology Program, Sloan-Kettering Institute, New York, New York, USA.
Mol Cell Biol. 2019 Jun 13;39(13). doi: 10.1128/MCB.00132-19. Print 2019 Jul 1.
Pho7 is the fission yeast ZnCys transcriptional factor that drives a response to phosphate starvation in which phosphate acquisition genes are upregulated. Here we report a crystal structure at 1.6-Å resolution of the Pho7 DNA-binding domain (DBD) bound at its target site 2 in the promoter (5'-TCGGAAATTAAAAA). Comparison to the previously reported structure of Pho7 DBD in complex with its binding site in the promoter (5'-TCGGACATTCAAAT) reveals shared determinants of target site specificity as well as variations in the protein-DNA interface that accommodate different promoter DNA sequences. Mutagenesis of Pho7 amino acids at the DNA interface identified nucleobase contacts at the periphery of the footprint that are essential for the induction of expression in response to phosphate starvation and for Pho7 binding to site 1 in the promoter.
Pho7 是裂殖酵母的 ZnCys 转录因子，可驱动对磷酸盐饥饿的响应，在此过程中上调磷酸盐获取基因。在这里，我们报告了 Pho7 DNA 结合域（DBD）与其靶位点 2 在 启动子（5'-TCGGAAATTAAAAA）结合的 1.6-Å 分辨率的晶体结构。与先前报道的 Pho7 DBD 与 启动子中其结合位点（5'-TCGGACATTCAAAT）的复合物结构的比较显示，靶位点特异性的共享决定因素以及蛋白质-DNA 界面的变化，以适应不同的启动子 DNA 序列。Pho7 氨基酸在 DNA 界面的突变鉴定了足迹外围的核碱基接触，这些接触对于诱导磷酸盐饥饿时的 表达以及 Pho7 与 启动子中位点 1 的结合是必需的。
