Polymerase coordination at the Pol III replication fork

描述(申请人提供)：基因组信息的成功复制对细胞分裂和病毒繁殖至关重要。加深我们对基因组复制的理解的研究对于推进癌症以及细菌、寄生虫和病毒感染的治疗至关重要。大肠杆菌是一种研究DNA复制的模型系统，因为它易于操作和遗传操作，提供了大量关于这一生物的信息，而且它在机制上与真核复制系统有许多相似之处。大肠杆菌复制酶DNA Pol III全酶由10个不同的蛋白质亚基组成。虽然许多亚基的化学计量、定位和一般功能已经确定，但亚基之间动态相互作用的意义还没有完全被理解。这项研究的目的是进一步阐明DNA Pol III复制酶内影响复制分叉上领先和滞后链聚合酶协调的通信机制。重组的DNA复制系统将与Biacore生物传感器和荧光各向异性技术结合使用，以识别在滞后链上信号聚合酶循环的效应器。不同的信号机制导致聚合酶从DNA解离的速率将被测量，以确定它们的生理相关性。此外，将使用一种新的滚环复制系统来研究复制叉处两个聚合酶之间的通信，在该系统中，可以测量当滞后链聚合酶的行为发生变化时对前导链合成的影响。

DESCRIPTION (provided by applicant): The successful duplication of genomic information is essential for cell division and viral propagation. Research that deepens our understanding of genomic replication is crucial for advance in the treatment of cancer as well as infection by bacteria, parasites, and viruses. The bacterium Escherichia coli (E. coli) is a model system for studying DNA replication due to its ease of handling and genetic manipulation, the large amount of information available about this organism, and its many mechanistic similarities with eukaryotic replication systems. The E. coli replicase, DNA Pol III holoenzyme, is composed of 10 different protein subunits. While the stoichiometry, placement, and general function have been determined for many subunits, the significance of dynamic interactions between subunits has yet to be fully understood. The goal of the research proposed here is to further elucidate the communication mechanisms within the DNA Pol III replicase that affect coordination of the leading and lagging strand polymerases at the replication fork. A reconstituted DNA replication system will be used in conjunction with BIAcore biosensor and fluorescence anisotropy techniques to identify the effectors that signal polymerase cycling on the lagging strand. The rates at which different signaling mechanisms cause polymerase dissociation from DNA will be measured in order to determine their physiological relevance. Additionally, communication between the two polymerases at the replication fork will be studied using a novel rolling circle replication system in which the affects on leading strand synthesis can be measured while the behavior of the lagging strand polymerase is varied.