Genetic Competence Apparatus of Bacillus Subtilis

描述（由申请人提供）：细菌的自然转化是指外源DNA的吸收和整合，枯草芽孢杆菌在生理状态下可以被外源DNA转化，被称为能力，有能力的细胞能够结合双链DNA，在细胞表面分裂DNA，并在细胞膜上运输单链DNA，我们的长期目标是在分子水平上理解这些过程。本研究探讨了已知参与转化DNA加工和运输（内化）结合的蛋白质的具体作用，其中一些蛋白质（comG基因的七个产物，ComC和ComEA）是DNA与细胞表面结合所必需的，而其他蛋白质（ComEC， ComFA和ComEA）是DNA跨细胞膜运输所必需的。这项工作将探索这些蛋白质之间的相互作用，以及巯基二硫氧化还原酶BdbD和BdbC在这些蛋白质折叠和DNA摄取装置组装中的作用。一个新发现的高阶ComGC复合物的形成和性质将被阐明，并在DNA结合中的作用将被检查。推测的膜通道蛋白ComEC的结构和转运体atp酶ComFA的体外生化活性将进一步表征。在此基础上，我们将研究几种新发现的转化蛋白，并尝试开发一种基于囊泡的体外DNA转运系统。

DESCRIPTION (provided by applicant): Natural transformation in bacteria refers to the uptake and integration of exogenous DNA, Bacillus subtilis can be transformed by exogenous DNA when in a physiological state known as competence, Competent cells are able to bind double stranded DNA, fragment the DNA on the cell surface and transport a single strand across the cell membrane, Our long-term objective is to understand these processes on the molecular level. This proposal explores the specific roles of proteins known to participate in the binding on processing and transport (internalization) of transforming DNA, Several of these proteins (the seven comG gene products, ComC and ComEA) are needed for the binding of DNA to the cell surface while others (ComEC, ComFA and ComEA) are required for transport of DNA across the cell membrane. The proposed work will explore interactions among these proteins and the role of the thiol-disulfide oxidoreductases BdbD and BdbC in the folding of these proteins and in the assembly of the DNA uptake apparatus. The formation and properties of a newly identified higher order ComGC complex will be elucidated and its role in DNA binding will be examined. The structure of the putative membrane channel protein ComEC and the in vitro biochemical activities of the transporter ATPase ComFA will be characterized further. The amounts of these various proteins in the cell will be determined, Several newly identified transformation proteins will be studied, Finally an attempt will be made to develop a vesicle-based in vitro DNA transport system.