UNDERSTANDING RECOMBINATION FROM THE CRYSTALLOGRAPHIC ANALYSIS OF THE E COLI RE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 细菌DNA修复系统是理解自然的典范-S保护遗传信息的能力。特别是，RecA蛋白是大肠杆菌最重要的基因组哨兵，因为它在重组DNA修复中起着至关重要的作用。在过去的二十年里，人们对这种引人注目的蛋白质--S的活性进行了广泛的研究。然而，我们的知识中仍然存在着明显的差距。也就是说，RecA细丝的活性结构是什么，RecA蛋白到底是如何与DNA相互作用的？对RecA蛋白的结晶学分析将使我们能够全面了解重组DNA修复的分子机制。我们已经在没有和存在激活镁离子的情况下结晶了E.ColiRecA蛋白。与已发表的研究相反，这些晶体的初步结构揭示了(以前)无序区域的结构，其中一些与DNA结合有关。此外，我们还有潜在的RecA蛋白与ATP类似物结合的共晶，可以激活RecA细丝。对于这些脆弱的、辐射敏感的晶体来说，同步辐射是必要的，以确定活性RecA构象的高分辨率结构。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bacterial DNA repair systems serve as a paradigm for understanding nature?s ability to protect genetic information. In particular, the RecA protein is the premier genomic sentinel of E. coli because it plays a crucial role in recombinational DNA repair. This remarkable protein?s activities have been studied extensively over the last twenty years. However, there remain conspicuous gaps in our knowledge. Namely, what is the active structure of the RecA filament and how exactly does the RecA protein interact with DNA? Crystallographic analysis of the RecA protein will enable a comprehensive understanding of the molecular mechanism of recombinational DNA repair. We have crystallized the E. coli RecA protein both in the absence and presence of the activating Mg2+ cation. In contrast to published studies, the preliminary structure from these crystals reveals the structure of (previously) disordered regions some of which are implicated in DNA binding. Furthermore, we have potential co-crystals of the RecA protein bound to ATP analogues that can activate the RecA filament. Synchrotron radiation is necessary for these fragile, radiation sensitive crystals to determine a high-resolution structure of the active RecA conformation.