Elucidating the Mechanisms of DNA Recombination

同源重组是细胞修复双链DNA断裂(DSB)的途径。 未能修复DSB会导致大的染色体重排，这是肿瘤发生的标志，以及 如果这一基本修复途径不起作用，可能会导致几种疾病，包括多种癌症 恰到好处。这里提出的研究目标集中在理解同源的一些早期步骤 重组途径。将特别强调表征由 人类蛋白质RAD51，并检测该蛋白质如何与同源的DNA分子对齐。为了促进这一点 分析我们正在开发独特的系统，用于研究DMA重组的实时动力学 使用全内反射荧光显微镜(TIRFM)检测单个生化反应的水平。 这项拟议的研究背后的假设是，RAD51使用一种机制来比对DMA序列 称为节间转移。具体目标是： 1)确定RAD51和RecA蛋白比对DNA序列的机制。 2)确定序列比对与重组中其他步骤之间的时间关系 反应。 3)确定在染色质的背景下DNA比对过程是如何受到影响的。

Homologous recombination is a pathway that cells use to repair double-stranded DMAbreaks (DSBs). Failure to repair DSBs results in gross chromosomal rearrangements, a hallmark of tumorogenesis, and several diseases, including many types of cancer, can result if this essential repair pathway is not working properly. The research goals presented here focus on understanding some early steps in the homologous recombination pathway. Particular emphasis will be placed on characterizing the reaction catalyzed by the human protein Rad51 and examining how this protein aligns homologous DMAmolecules. To facilitate this analysis we are developing unique systems for studying the real-time dynamics of DMA recombination at the level of single biochemical reactions using using total internal reflection fluorescence microscopy (TIRFM). The hypothesis behind the proposed research is that Rad51 aligns DMAsequences using a mechanism called intersegmental transfer. The specific aims are to: 1) Determine the mechanism by which the Rad51 and RecA proteins align DNA sequences. 2) Determine the temporal relationship between sequence alignment and other steps in the recombination reaction. 3) Determine how the DNA alignment process is affected in the context of chromatin.