MECHANISMS OF ESCHERICHIA COLI CHROMOSOMAL REPLICATION

大肠杆菌染色体复制的启动是大肠杆菌 细菌的生长周期。 本建议的长期目标 研究的目的是从生物化学的角度了解DNA的起始 复制及其对细胞生长的协调作用。 dnaA蛋白质起着 在启动过程中的核心作用，似乎决定了时间， 细菌的细胞周期，当开始复制发生。 这 蛋白质似乎也在多次复制中同步这一过程 起源于快速生长的细胞，并调节其自身的表达。 基因和E.杆菌 一种方法是进一步 了解大肠杆菌中dnaA蛋白的作用是通过生产 和分析的突变形式的dnaA蛋白质与其野生型相比， 类型对应物。 第二个涉及的相互作用的突变形式， dnaA蛋白与dnaK、grpE和dnaJ热休克蛋白， 影响复制活动，并可能代表一种调节机制 的初始化过程。 第三种方法涉及以下相关性： dnaA蛋白的结构域与其各种活性的关系， 单克隆抗体和通过位点特异性诱变。 虽然这项研究解决了一个基本的生物化学问题， 有助于理解染色体复制的机制及其 在高等生物中的调节。 这些发现可能对设计有帮助 促进或干扰植物细胞生长的药剂， 动物

Initiation of Escherichia coli chromosomal replication is a key event in the bacterial growth cycle. The long term objectives of this proposed research are to obtain a biochemical understanding of the initiation of DNA replication and its coordination to cell growth. dnaA protein plays a central role in the initiation process and appears to determine the time in the bacterial cell cycle when initiation of replication occurs. This protein also appears to synchronize this process at multiple replication origins in a rapidly growing cell, and regulates the expression of its own gene and of several other genes of e. coli. One approach to further understanding of the role of dnaA protein in E coli is by the production and analysis of mutant forms of dnaA protein in comparison with its wild type counterpart. The second involves the interaction of mutant forms of dnaA protein with dnaK, grpE, and dnaJ heat shock proteins which appear to influence replication activity and may represent a mechanism for regulation of the initiation process. The third approach involves correlation of structural domains of dnaA protein to its various activities by use of monoclonal antibodies and by site-specific mutagenesis. While this research addresses a basic biochemical problem such findings may be useful in understanding the mechanism of chromosomal replication and its regulation in higher organisms. These findings may be useful in the design of agents which promote or interfere with cell growth in plants and animals.