Structure and function of replication-hyperstructures in Escherichia coli

DNA复制是所有生物体将其遗传信息作为繁殖的先决条件的过程。大肠杆菌是研究DNA复制基本原理的重要模型系统。循环E.大肠杆菌染色体从一个独特的基因座oriC双向复制。复制周期可以重叠，导致每个细胞中有几个oriC拷贝。协调在不同染色体位点进行的复制和所有oriCs的同步启动对细胞来说是一项艰巨的任务。拟议的研究项目旨在了解参与DNA复制及其调控的组件的物理共定位的作用。出发点是观察到DNA结合蛋白SeqA可以在oriC和复制叉处形成更高级的复合物。含有SeqA的结构（也称为超结构）的实际组成和功能是未知的，并且是本申请的主题。与SeqA相互作用的蛋白质和DNA的分离和表征以及细胞中组分的定位，以及突变株的表征，将有助于理解染色体复制中超结构的功能。

DNA replication is the process by which all living organisms multiply their genetic information as a prerequisite to reproduce. The bacterium Escherichia coli serves as an important model system for investigations of the basic principles underlying DNA replication. The circular E. coli chromosome is replicated bidirectionally from a unique locus, oriC. Replication cycles can overlap resulting in several copies of oriC per cell. Coordination of the ongoing replication at different chromosome sites and the synchronous initiation of all oriCs presents a difficult task for the cell. The proposed research project aims to understand the role of a physical colocalisation of components involved in DNA replication and its regulation. The starting point is the observation that the DNA-binding protein SeqA can form higher order complexes at the oriC and at the replication fork. The actual composition and function of the SeqA containing structure, also termed a hyperstructure, is unknown and subject of this application. Isolation and characterization of proteins and DNA interacting with SeqA and localization of the components in the cell, as well as characterization of mutant strains, will help to understand the function of hyperstructures in chromosome replication.