SELENIUM & BROMINE DOUBLE EDGE MAD EXPERIMENT FOR AN HSF DNA COMPLEX

我们使用多个异常患者(MAD)来确定 热作用下DNA结合域之间的复合体结构 休克转录因子(HSF)和含有12聚体的DNA 它的同源结合位点。收集的数据显示晶体中含有 硒蛋氨酸取代的蛋白质和溴沙星取代的DNA。 目前的模型包含完整的DNA、大部分蛋白质和100 水分子。蛋白质单体缺失了残基 N-末端和C-末端，以及来自柔性环。当前的R 在6.0到2.5E之间的所有数据的取值为21.0%(自由R值为29.3%)。 不存在Ramachandran异常值，R.M.S偏差为0.009 E 键长为1.5540，键角为1.5540。结构表明， DNA只与磷酸盐骨架接触，与 大多数接触来自假定的识别螺旋 DNA结合域。我们正在解读 该结构的生物学意义。

We have used multiple anomalous disperson (MAD) to determine the structure of a complex between the DNA binding domain of the heat shock transcription factor (HSF) along with a 12-mer of DNA containing its cognate binding site. Data was collected on crystals containing selenomethionine-substituted protein and bromouracil-substituted DNA. The present model contains complete DNA, most of the protein, and 100 water molecules. The protein monomers are missing residues from the N- and C-terminii, as well as from the flexible loop. The current R value is 21.0% (free R is 29.3%) for all data between 6.0 and 2.5 E. There are no Ramachandran outliers, the r.m.s deviations are 0.009 E for bond lengths and 1.5540 for bond angles. The structure shows that the DNA is contacted solely along with phosphate backbone, with the majority of contacts coming from the putative recognition helix of the DNA binding domain. We are in the process of interpreting the biological implications of the structure.