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的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 研究中心，而研究中心不一定是研究者所在的机构。 细菌DNA修复系统作为理解自然的范例？保护基因信息的能力。特别是RecA蛋白是大肠杆菌的首要基因组前哨。因为它在重组DNA修复中起着至关重要的作用。这种神奇的蛋白质？在过去的二十年里，人们广泛地研究了它的活动。然而，在我们的知识中仍然存在明显的差距。也就是说，RecA细丝的活性结构是什么，RecA蛋白质究竟如何与DNA相互作用？RecA蛋白的晶体学分析将使人们能够全面了解重组DNA修复的分子机制。我们已经使E结晶化。coli RecA蛋白在不存在和存在活化Mg 2+阳离子的情况下。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，我们有潜在的共晶体的RecA蛋白结合ATP类似物，可以激活RecA丝。同步辐射是必要的，这些脆弱的，辐射敏感的晶体，以确定一个高分辨率的结构的活性RecA构象。

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.