Recruitment and activation of DnaB helicase in Escherichia coli DNA replication

描述（由申请人提供）：所有细胞生物都依赖于一种名为复制体的多蛋白分子机器来复制它们的基因组。在复制起点，染色体DNA复制的复制体组装是一个高度调控的事件，与细胞周期协调。在大肠杆菌中，DnaA蛋白通过协调一个分步过程启动染色体DNA复制，该过程导致两个DNA解旋酶与每条亲本DNA链结合，这是染色体起源的双向叉运动所必需的。然后，复制体的其他组成部分在新形成的复制叉上组装。接着是基因组的复制。复制解旋酶在染色体原点的募集是DNA复制起始阶段的关键步骤。本研究的长期目标是通过遗传学、生物化学和分子生物学的方法，了解大肠杆菌复制解旋酶DnaB的募集和激活的分子机制。因为所有的自由生物都使用类似的起始机制，这些研究应该提供对这一事件如何在高等生物中发生的深入了解。

DESCRIPTION (provided by applicant): All cellular organisms rely on a multi-protein molecular machine named the replisome to duplicate their genomes. At replication origins, assembly of replisomes for chromosomal DNA replication is a highly regulated event that is coordinated with the cell cycle. In Escherichia coli, DnaA protein initiates chromosomal DNA replication by orchestrating a step-wise process that leads to two DNA helicases bound to each parental DNA strand, which is necessary for bidirectional fork movement from the chromosomal origin. Other components of the replisome then assemble at the newly formed replication fork. Duplication of the genome follows. The recruitment of the replicative helicase to the chromosomal origin is a critical step during the initiation stage of DNA replication. The long-term objective of this research is to understand the molecular mechanism of recruitment and activation of DnaB, the replicative helicase of Escherichia coli, via genetic, biochemical and molecular biological methods. Because all free-living organisms use a similar mechanism of initiation, these studies should provide insight into how this event occurs in higher organisms.