STRUCTURAL STUDIES OF MACROMOLECULES USING SYNCHROTRON RADIATION

我们对大肠杆菌DNA拓扑异构酶I和III进行了长时间的研究 并提出了一种催化机制。我们是 研究拓扑异构酶I与DNA的相互作用 突变蛋白的结构，可能有助于揭示 这种反应。我们解决了两个重复的鸡脑的结构 ？-使用SSRL收集的数据，在1997年使用了血影蛋白。该结构 揭示了两个亚基的相对排列和性质 链接器区域。原始晶体的衍射率仅为4.0E 决议和许多问题都不能由此回答 结构。然而，该结构允许我们重新设计我们的 构建并获得更好的晶体。我们现在有三个新水晶 衍射到高分辨率的形式。第三个项目是 与核糖核酸酶RNA组分的结构域I有关 这个结构域有154个碱基长，晶体在3.8E处衍射 一个同步加速器源。它是最大的核糖核酸分子之一 明确，并应使我们能够回答关于 RNaseP的催化机制以及对一般RNA结构的影响。

We have been studying E. coli DNA topoisomerase I and III for a number of years and have proposed a catalytic mechanism. We are studying the interactions of topoisomerase I with DNA and also the structure of mutant proteins that could shed light on the details of the reaction. We solved the structure of two repeats of chicken brain ?-spectrin in 1997 using data collected at SSRL. The structure revealed the relative arrangement of the two subunits and the nature of the linker region. The original crystals diffract to only 4.0 E resolution and many questions could not be answered from this structure. Nevertheless the structure allowed us to redesign our construct and obtain better crystals. We have now three new crystal forms that diffract to high resolution. The third project is concerned with the structure of domain I of the RNA component of RNase P. This domain is 154 bases long and the crystals diffract to 3.8 E at a synchrotron source. It is one of the largest RNA molecules crystallized and should allow us to answer important questions on the catalytic mechanism of RNase P and also on RNA structure in general.