Purification of a Modified Flagellar Export Apparatus

描述（由申请人提供）：细菌鞭毛是一种自组装的、质子驱动的旋转纳米机器，它驱动运动，允许趋化。它包含一个专用的III型分泌（T3S）装置。同源T3S系统被致病菌用来影响毒力，是许多细菌性疾病如伤寒和细菌性痢疾的基础。以肠沙门氏菌为模型系统，我们将通过分子生物学、遗传学和生物化学技术（包括光学生物传感）研究鞭毛蛋白之间的动态相互作用，这些蛋白质允许出口底物的膜易位。具体目的是利用光学生物传感作为主要工具，完成出口器械蛋白之间相互作用的动力学调查，以检查更好地反映体内动力学的高于成对相互作用，并进一步发展体外T3S测定。最终开发一种体外出口试验将具有巨大的意义，因为它将使我们能够检验目前无法实现的T3SS功能的假设。由于鞭毛输出装置与毒力T3S系统高度相似，该项目将有助于我们对细菌发病机制的理解。区域计划的目标是改善研究环境，让学生接触到有价值的研究，这个项目将很好地服务。

DESCRIPTION (provided by applicant): The bacterial flagellum is a self-assembling, proton-powered rotary nanomachine that drives motility, allowing chemotaxis. It contains a dedicated type III secretion (T3S) apparatus. Homologous T3S systems are used by pathogenic bacteria to effect virulence, underlying many bacterial diseases such as typhoid fever and bacterial dysentery. Using Salmonella enterica as a model system, we will investigate dynamic interactions among flagellar proteins that allow membrane translocation of export substrates through use of molecular biology, genetics and biochemical techniques including optical biosensing. The specific aims are to complete a kinetic survey of interactions among export apparatus proteins using optical biosensing as the primary tool, to examine higher-than-pairwise interactions that better reflect in vivo dynamics and to further the development of an in vitro T3S assay. Eventual development of an in vitro export assay will be of tremendous significance because it would allow us to examine hypotheses addressing T3SS function currently out of reach. Since the flagellar export apparatus is highly similar to virulence T3S systems, the project will contribute significantly to our understanding of bacterial pathogenesis. AREA program goals of enhancing the research environment and exposing students to meritorious research will be well-served by this project.