Membrane-associated DNA transport machines in Bacillus subtilis

摘要 在染色体分离完成之前形成分裂隔膜的细菌细胞将面临 完成DNA分离过程的非凡拓扑和机械挑战 成功了。细胞分裂膜，一种DNA转运膜蛋白的复合体，以及 大的、圆形的染色体底物必须结合在一起才能成功地分选和 分离复制的染色体。对细菌细胞分裂的关键成分进行了研究 几十年来，但染色体的结构和功能的基本特征 种族隔离机制仍未得到探索。这个项目的长期目标是将各种 用实时活细胞成像进行生化结构-功能研究的关键是理解分子 机械术语染色体DNA如何成功地跨细胞分裂隔膜分割。 DNA底物通过分离机制的路径是什么？这些综合体是如何 共同发挥作用，将ATP水解循环与DNA运动结合起来？当循环结束时 染色体到达后，DNA的环是如何在分裂平面上分解的？做这些事吧 蛋白质在孤立状态下真正发挥作用是因为它们的DNA移位活性，还是存在额外的细胞 涉及哪些组件？这些领域的进步将产生一个全面的模式 DNA分离过程中涉及的分子结构和相关的生化事件。

Abstract Bacterial cells that form a division septum prior to completion of chromosome segregation face an extraordinary topological and mechanistic challenge to complete the DNA segregation process successfully. The cell division membranes, a complex of DNA-translocating membrane proteins, and the large, circular chromosome substrates all must come together in concert to successfully sort and separate the replicated chromosomes. Critical components of bacterial cell division have been studied for several decades, and yet fundamental features of the structure and function of the chromosome segregation machinery remain unexplored. The long-term goal of this project which combines a variety of biochemical structure-function studies with real-time, live-cell imaging is to understand in molecular mechanistic terms how chromosomal DNA is successfully partitioned across a cellular division septum. What is the path of the DNA substrate through the segregation machinery? How do the complexes function together to couple the ATP hydrolysis cycle with DNA movement? When the end of the circular chromosome is reached, how are the loops of DNA resolved across the division plane? Do these proteins truly function in isolation for their DNA translocation activity, or are there additional cellular components that are involved? Advances in these areas will produce a comprehensive model of the molecular architecture and associated biochemical events involved in this DNA segregation process.