X-ray Source Upgrade for Macromolecular Crystallography

描述(由申请人提供)： 科罗拉多大学博尔德分校的大分子X射线衍射设备建议对X射线源进行升级：具体地说，将采用Osmic“蓝色”共焦多层镜的Rigaku RUH2R旋转阳极X射线发生器升级为采用Varimax HR(=“高分辨率”)共焦镜的Rigaku MM007发生器。我们收到了一台二手MM007作为礼物，并要求只为共焦镜的资金。目前，NIH支持的三个主要用户和七个次要用户正在使用X光设备。目前正在进行的结晶学项目包括：大的催化RNA(Cech和PACE)和核糖开关(BATEY)，RNA-蛋白质和DNA-蛋白质复合体，如在端粒酶系统中发现的那些(Cech和Wuttke)和特定识别复合体(McKay)，分子伴侣和完整的膜蛋白(SOSA)，以及参与特定生物过程的几个RNA和蛋白质(Ahn，Copley，Pardi，Falke)。这些项目中的许多在早期阶段都构成了巨大的挑战；通常，必须对大量结构和/或结晶条件中的小初步晶体进行衍射筛选，以确定它们是否值得研究。在筛选冷冻保护剂或合适的阶段化衍生物时，往往会出现额外的挑战。最后，在许多情况下，完整的数据集在内部收集，或者在同步加速器数据收集之前收集，或者作为同步加速器数据收集的替代方案。所要求的升级将把我们的X射线源的亮度提高几倍(根据Rigaku的数据，大约是六倍)，从而增强我们内部设施的晶体筛选和数据收集能力。 公共卫生相关性：具有生物学意义的大分子的三维结构为现代分子医学和合理的药物设计提供了基础。科罗拉多大学博尔德分校的结构研究包括核酶(催化RNA)、端粒酶、膜蛋白结构和折叠以及细菌耐药性，仅举几个例子。需要仪器设备的共享X射线结晶学设施向在校园内进行结构研究的广泛用户提供资源(包括仪器和智力)。

DESCRIPTION (provided by applicant): The macromolecular x-ray diffraction facility of the University of Colorado, Boulder proposes to upgrade an X-ray source: specifically, a Rigaku RUH2R rotating anode X-ray generator with Osmic "blue" confocal multilayer mirrors will be upgraded to a Rigaku MM007 generator with Varimax HR (="high resolution") confocal mirrors. We are receiving a used MM007 as a gift, and request funds only for the confocal mirrors. The x-ray facility is currently used by three major and seven minor NIH-supported users. Crystallographic projects currently underway include: large catalytic RNAs (Cech and Pace) and riboswitches (Batey), RNA- protein and DNA-protein complexes such as those found in the telomerase system (Cech and Wuttke) and specific recognition complexes (McKay), molecular chaperone and integral membrane proteins (Sousa), and several RNAs and proteins involved in specific biological processes (Ahn, Copley, Pardi, Falke). Many of these projects pose significant challenges in their early stages; typically, small preliminary crystals from a large number of constructs and/or crystallization conditions must be screened for diffraction to determine whether they are worth pursuing. Additional challenges often present themselves during screens for cryoprotectants or suitable phasing derivatives. Finally, in many cases, complete datasets are collected in- house, either prior to or as an alternative to synchrotron data collection. The requested upgrade will enhance the brightness of our X-ray source severalfold (approximately sixfold according to Rigaku's data), thereby enhancing the crystal screening and data collection capability of our in-house facilities. PUBLIC HEALTH RELEVANCE: The three-dimensional structures of biologically significant macromolecules provide the foundation for modern molecular medicine and rational drug design. Structural studies at the University of Colorado, Boulder encompass ribozymes (catalytic RNAs), telomerase, membrane protein structure and folding, and bacterial drug resistance, to name a few areas. The shared X-ray crystallography facility, for which instrumentation is requested, provides resources (both instrumental and intellectual) to a broad spectrum of users who pursue structural studies on the campus.