Genetic competence apparatus of Bacillus subtilis

描述（由申请人提供）：枯草芽孢杆菌和许多其他细菌在处于称为感受态的生理状态时可以被外源DNA转化。感受态细胞可以结合DNA，在细胞表面将其片段化，并将单链DNA运输穿过膜。一旦内化，单链可以整合在受体染色体上的同源位点。我们的长期目标是在分子水平上理解这些过程，通过表征所涉及的20种蛋白质及其相互作用以及与DNA的相互作用。我们已经表明，转化主要发生在细胞两极。该建议探讨了许多感受态蛋白之间的相互作用，以及它们作为极性复合物的定位和离域。最近发现的作用，McsA和McsB在离域将被探讨。我们还将在转化过程的各个阶段检测这些蛋白质和DNA之间的接触，并确定接触发生的细胞地址。本文将探讨拟纤毛感受态的结构、组成和作用。将确定驱动转化DNA运输的能量来源。基因筛选将用于发现两种尚未鉴定的感受态蛋白;降解非转化链的核酸酶和第二种细胞表面DNA结合蛋白。转化为病原体之间抗生素抗性和毒力基因的水平转移提供了一种机制。了解通过转化的基因转移机制将提供对这些重要过程的见解。许多细菌可以在一个称为转化的过程中从环境中接受DNA。这为病原体之间抗生素抗性和毒力基因的水平转移提供了机制。理解这种通过转化的基因转移过程将提供对这些重要过程的见解。

DESCRIPTION (provided by applicant): Bacillus subtilis and many other bacteria can be transformed by exogenous DNA when in a physiological state known as competence. Competent cells can bind DNA, fragment it on the cell surface and transport a single strand of DNA across the membrane. Once internalized, the single strand can integrate at a homologous site on the recipient chromosome. Our long-term objective is to understand these processes on the molecular level, by characterizing the 20 proteins involved and their interactions with one another and with DNA. We have shown that transformation takes place mostly at the cell poles. This proposal explores the interactions among many of the competence proteins, as well as their localization and delocalization as polar complexes. The recently discovered role of McsA and McsB in delocalization will be explored. We will also detect contacts between these proteins and DNA at various stages in the transformation process and determine the cellular addresses at which the contacts occur. The structure, composition and role of the competence pseudopilus will be explored. The sources of energy driving the transport of transforming DNA will be identified. Genetic screens will be used to find two competence proteins that have not been identified; the nuclease that degrades the non-transforming strand, and a second cell surface DNA binding protein. Transformation provides a mechanism for the horizontal transfer of antibiotic resistance and virulence genes among pathogens. Understanding the mechanism of gene transfer by transformation will provide insights into these important processes. Many bacteria can accept DNA from the environment in a process known as transformation. This provides a mechanism for the horizontal transfer of antibiotic resistance and virulence genes among pathogens. Understanding this process of gene transfer by transformation will provide insights into these important processes.