CRYSTALLOGRAPHIC STUDIES OF KU70 & 80

我们已经获得了小晶体的Ku 70/80，一种Ku 70和 Ku 80，与DNA结合并与ATP结合。 两种蛋白质Ku 70和K80 共同形成DNA依赖性蛋白激酶的调节成分 （DNA-PK），一种460 kD的蛋白质，对DNA损伤有反应。 Ku70/80 复合物与双链断裂结合， 双链到单链的转变。 一旦绑定， Ku 70/80复合物募集DNA-PK的催化亚基。 突变 在Ku 70/80或在催化亚单元中的缺陷导致 修复双链DNA断裂。 我们计划把水晶 到光束线7-1来评估它们的质量 主要原因是， 实验必须在同步加速器上进行， 非常小-最大的是0.1 x 0.1 x 0.1 mm。晶体 看起来是立方的。 这些晶体的衍射几乎无法检测到 在我们的家乡。 我们预计，单位细胞将有 尺寸在300-400 E的量级。

We have obtained small crystals of Ku70/80, a complex of Ku70 and Ku80, bound to DNA and bound to ATP. The two proteins Ku70 and K80 together form the regulatory component of DNA-dependent protein kinase (DNA-PK), a 460 kD protein that responds to DNA damage. The Ku70/80 complex binds to double-stranded breaks and to double-stranded-to-single-stranded transitions. Once bound, the Ku70/80 complex recruits the catalytic subunit of DNA-PK. Mutations in either Ku70/80 or in the catalytic subunit result in defects in repair of double-stranded DNA breaks. We plan to bring our crystals to beamline 7-1 to assess their quality. The principal reason this experiment has to be done at a synchrotron is that the crystals are extremely small -- the largest are 0.1 x 0.1 x 0.1 mm. The crystals appear cubic. Diffraction from these crystals can barely be detected at our home source. We anticipate that the unit cell will have dimensions on the order of 300-400 E.