Genetic competence apparatus of Bacillus subtilis

描述(申请人提供)：枯草芽孢杆菌和许多其他细菌可以通过外源DNA在一种称为竞争能力的生理状态下转化。有能力的细胞可以结合DNA，在细胞表面将其碎片化，然后将单链DNA穿过细胞膜。一旦内化，单链就可以整合到受体染色体上的同源位置。我们的长期目标是通过描述参与其中的20种蛋白质及其相互作用和与DNA的相互作用，在分子水平上了解这些过程。我们已经证明，变化主要发生在细胞极点。这一建议探索了许多功能蛋白之间的相互作用，以及它们作为极性复合体的定位和非定位。我们将探讨最近发现的MCSA和MCSB在去局部化中的作用。我们还将在转化过程的不同阶段检测这些蛋白质与DNA之间的接触，并确定接触发生的细胞地址。我们将探讨能力假乳头的结构、组成和作用。推动转化DNA运输的能量来源将被确定。基因筛选将被用来寻找两种尚未鉴定的能力蛋白：降解非转化链的核酸酶，以及第二种细胞表面DNA结合蛋白。转化为抗生素耐药性和毒力基因在病原菌之间的水平转移提供了一种机制。了解通过转化进行基因转移的机制将有助于对这些重要过程的深入了解。许多细菌可以在一个被称为转化的过程中接受环境中的DNA。这为抗生素耐药性和毒力基因在病原菌之间的水平转移提供了一种机制。了解这一通过转化进行基因转移的过程将为我们提供对这些重要过程的洞察。

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.