Structure and Function of the Bacterial Primosome

摘要： DNA复制重新启动途径将细胞DNA复制复合体重新加载到 已被提前终止的复制分叉，形成了必不可少的链接 在DNA修复和复制之间。驱动这些反应的蛋白质，指的是 作为原始体或复制重新启动蛋白，识别 放弃复制叉子并重新加载DNA复制机制，具体地址为 这些网站。对复制重启过程进行了规范，以确保加载保真度和 避免因在不正确的DNA处启动复制而导致的过度复制 结构。尽管这一过程具有广泛的生物学意义，但其机制 潜在的DNA复制重新开始及其调控仍然知之甚少。我们的 该提案结合了结构、生化和遗传方法来定义结构 DNA复制的细胞机制重新启动。我们的总体目标是确定 管理进程每一步的机制，从认识到不同的 废弃的DNA复制叉子的结构，到原始体组装，最后到 重新加载DNA复制机器。目标1将定义原始体的结构 与复制分叉的复合体，这将为特定结构提供新的见解 对DNA复制分叉和DNA复制调控机制的认识 重新启动。结构上的进步与基因研究相结合，这将定义细胞 细菌中原始体蛋白的作用机制。Aim 2混合了结构和 遗传学研究将重点放在原粒复合体的成熟及其在 将复制解旋酶重新加载到复制叉子上。完成我们的特定任务 AIMS将定义调节和调节的分子和细胞机制 细菌DNA复制重新开始。

Abstract: DNA replication restart pathways reload cellular DNA replication complexes onto replication forks that have been prematurely terminated, forming an essential link between DNA repair and replication. The proteins that drive these reactions, referred to as the primosome or the Replication Restart Proteins, recognize the structures of abandoned replication forks and reload the DNA replication machinery specifically at these sites. The replication restart process is 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. Our proposal combines structural, biochemical, and genetic approaches to define the structural and cellular mechanisms of DNA replication restart. Our overall objective is to determine the mechanisms that govern each step of the process, from recognition of diverse structures of abandoned DNA replication forks, to primosome assembly, and finally to reloading the DNA replication machinery. Aim 1 will define the structures of primosome complexes with replication forks, which will provide new insights into structure-specific recognition of DNA replication forks and the mechanisms that regulate DNA replication restart. Structural advances are coupled to genetic studies that will define the cellular mechanisms of action of primosome proteins in bacteria. Aim 2 blends structural and genetic studies to focus on maturation of primosome complexes and their activities in reloading the replicative helicase back onto replication forks. Completion of our specific aims will define the molecular and cellular mechanisms that mediate and regulate bacterial DNA replication restart.