Structure and Function of the Bacterial Primosome

DNA复制重启途径将细胞DNA复制复合物重新加载到复制上 被过早抛弃的叉子这些途径构成了 DNA修复（通常是重组修复）和复制。这些蛋白质 反应，被称为primosome或复制重启蛋白，必须识别 废弃的复制叉的结构，重新装载DNA复制机器 特别是在这些网站上。这一过程受到严格控制，以确保加载保真度， 避免在不适当的DNA结构上启动复制而引起的过度复制。在 尽管这一过程具有广泛的生物学重要性，但DNA的潜在机制 复制重启及其调节仍然知之甚少。此外， 哪些复制重启途径与核心细胞DNA修复过程整合， 目前未知。我们的建议结合了结构，生物化学和遗传学方法， 以互补的方式定义DNA复制重新启动的机制。我们的第一个整体 本申请的目的是确定支配DNA的结构机制 复制重新启动，从识别废弃的DNA复制叉，到启动子 组装，最后重新装载DNA复制机器的第一个组件。要求1 利用我们的初步数据来定义DNA中每个步骤的结构快照 复制重新启动。我们的第二个目标是系统地定义遗传机制， 支持DNA复制重启。目的二是寻找与双链DNA协调的基因 中断修复与复制重新启动，并将定义的情况下，主要 在细胞中利用复制重启途径。此外， 将检查复制重新启动抑制器。

DNA replication restart pathways reload cellular DNA replication complexes onto replication forks that have been prematurely abandoned. These pathways form an essential link between DNA repair (often recombinational repair) and replication. The proteins that drive these reactions, referred to as the primosome or the Replication Restart Proteins, must recognize the structures of abandoned replication forks and reload the DNA replication machinery specifically at these sites. This process is heavily regulated to ensure loading fidelity and to avoid over-replication that could arise from initiating replication at improper DNA structures. In spite of the broad biological importance of this process, the mechanisms underlying DNA replication restart and its regulation remain poorly understood. Additionally, the mechanisms by which replication restart pathways are integrated with core cellular DNA repair processes are currently unknown. Our proposal combines structural, biochemical, and genetic approaches to define the mechanisms of DNA replication restart in complementary ways. Our first overall objective of this application is to determine the structural mechanisms that govern DNA replication restart, from recognition of abandoned DNA replication forks, to primosome assembly, and finally to reloading the first component of the DNA replication machinery. Aim 1 takes advantage of our preliminary data to define structural snapshots of each step in DNA replication restart. Our second goal is to systematically define the genetic mechanisms that support DNA replication restart. Aim 2 will identify the genes that coordinate double-strand DNA break repair with replication restart and will define circumstances under which the major replication restart pathways are utilized in cells. Additionally, the mechanisms underlying replication restart suppressors will be examined.