Form and function of the bacterial nucleoid: structural studies using cryo-ET

项目摘要/摘要： 所有的有机体都共享一个共同的遗传密码。从哺乳动物细胞的核到类核蛋白 最小的细菌，我们都使用DNA来编码驱动生命多样性的特征和细胞过程 在地球上。传递一个人的基因组是这个过程中遗传和错误的最基本形式 可能会产生可怕的后果。因此，所有生物进行可靠的复制是非常重要的 和细胞分裂过程中DNA的分离，以及生物体保持保护核材料的方法 在细胞压力的情况下。为了研究DNA结构的形式和功能，我建议利用 冷冻电子断层扫描(CRYO-ET)方法在显示细菌方面的最新进展 类核，作为了解体内染色体结构的模型并开发工具和最佳 实践是研究细胞最重要的分子。利用低温电子资源 威斯康星大学麦迪逊分校的显微镜研究中心，模式生物球形红杆菌将 允许研究体内的核结构。球形红杆菌是研究球状红杆菌的理想菌种。 类核，不仅因为它的大小可以冷冻，还因为它的两条染色体需要 独特的复制动态。这项工作试图观察类核的结构和相互作用 球藻的细胞周期。其结果有很强的潜力提供翻译中断 通过并将建立具有超越细菌学的相关性的分子工具和方法。 此外，这项工作还将研究在生理应激和压力下细菌核仁的紧致。 抗生素治疗，初步数据已经显示。重要的是，研究核压实 抗生素应激后的材料有望产生新的知识，从而更好地理解 细菌在抗生素治疗期间生存和存活的机制。可能会影响这项研究 关于抗生素耐药性。

Project Summary/Abstract: All organisms share a common genetic code. From the nucleus of mammalian cells to the nucleoid of the smallest bacterium, we all use DNA to encode the traits and cellular processes that drive the diversity of life on earth. Passing along one’s genome is the most fundamental form of heritability and errors in this process can have dire consequences. It is therefore of great importance that all organisms carry out reliable replication and segregation of DNA during cell division, and that organisms maintain methods to protect nuclear material in the event of cellular stress. To study the form and function of DNA structures, I propose taking advantage of the recent advancements in cryoelectron tomography (cryo-ET) methodology to visualize the bacterial nucleoid, as a model for understanding in vivo chromosome structure and to develop the tools and best practices for the study of the cells most important molecule. Using the resources of the Cryoelectron Microscopy Research Center at UW-Madison, cryo-ET of the model organism Rhodobacter sphaeroides will allow the study of in vivo nuclear structures. Rhodobacter sphaeroides is an ideal organism for studying the nucleoid, not only because its size is amenable to cryo-ET, but also because its two chromosomes require unique replication dynamics. This work seeks to observe the structure and interactions of the nucleoid during the cell cycle of R. sphaeroides. The results of which have a strong potential to provide translational break throughs and will build up molecular tools and methods that will have relevance beyond bacteriology. Additionally, this work will study the compaction of the bacterial nucleoid during physiological stress and antibiotic treatments, preliminary data have been shown. Importantly, studying the compaction of nuclear material following antibiotic stress is expected to generate new knowledge leading to a better understanding of the mechanisms bacteria use to survive and persist during antibiotic treatment. Potentially impacting the study on antibiotic resistance.