Dissection of the archaeal DNA replication fork in vivo and in vitro

DNA是生物体的蓝图。任何物种要繁殖，无论是单细胞微生物还是人类，都必须能够复制自己的DNA，从而确保将遗传指令传递给后代。在细胞中，DNA形成双螺旋。为了使分子复制，双螺旋解压缩，两条链被复制以产生两个子分子。DNA解压缩和复制时形成的结构被称为复制叉。这项研究计划描述了一系列旨在研究DNA在复制叉中被解压缩和复制的机制的实验。我们建议研究一类微生物中复制终止的分子基础，称为微生物。我们所研究的这种植物生长在温泉环境中，比如黄石国家公园。因为生物体在80摄氏度下生长，它们的细胞机器异常坚固，这种稳定性大大有助于我们分析生物体的生物化学。此外，在过去的几年里，越来越明显的是，古生物用来复制DNA的机器是我们自己细胞使用的机器的简化版本。因此，除了阐明古细菌中复制终止的过程外，我们的研究也可能对人类细胞中DNA复制叉作用的进化和机制产生宝贵的见解。

DNA is the blueprint for living organisms. For any species to propagate, be it a single celled microbe or a human being, it must be able to duplicate its DNA; thereby ensuring that it passes its genetic instructions onto its progeny. In cells, DNA forms a double helix. For the molecule to replicate, the double helix unzips and both strands are copied to generate two daughter molecules. The structure formed as DNA unzips and is copied is termed the replication fork. This research proposal describes a series of experiments designed to investigate the mechanims by which DNA is unzipped and copied in the replication fork. We propose to study the molecular basis of replication termination in a class of microbe, termed the Archaea. The Archaea we work on grow in hot spring environments, such as found in Yellowstone National Park. Because the organisms grow at 80 degrees centigrade, their cellular machinery is unusually robust and this stability greatly aids our analyses of the organism's biochemistry. Furthermore, over the last few years it has become increasingly apparent that the machinery that Archaea use to duplicate their DNA is a simplified version of the machinery that our own cells use. Therefore, as well as shedding light on the process of replication termination in the archaea, our studies may also yield invaluable insights into the evolution and mechanism of DNA replication fork action in human cells too.