STRUCTURE/FUNCTION OF BACTERIAL ADHESION PILI

本研究的目的是了解结构和组装 在致病菌上发现粘附皮利，从而提供洞察力 这些皮利的结构如何支持它们作为一种 毒力因子 细菌的存活和定植需要 细菌对宿主的附着。 在许多染色中，该过程是 由皮利发起和维持的;在大肠杆菌中， 肾盂肾炎、粘附和毒力依赖于P菌毛。 希卜菌毛 表达于流感嗜血杆菌介导的H.流感的 上呼吸道的定植，因此其能够 导致儿童脑膜炎、中耳炎和肺炎等疾病 老年人。随着细菌对传统抗生素的抵抗力越来越强， 抗生素，重要的是要开发新的治疗方法， 感染. 关于粘附皮利的结构信息将提供 未来合理设计新疗法以预防细菌感染的基础 结合或去除与人体宿主结合的病原菌。 的 拟议的研究通过结构性研究来实现这一长期目标。 细菌粘附皮利的研究。这些研究集中在：1）电子 显微镜和三维（3-D）螺旋重建的P-菌毛 保存在玻璃冰中，Hib-pili阴性染色，2）对照 皮利的损伤/恢复，以研究重新形成的可能性 完整螺旋丝的3-D结构的调查， P-菌毛与突变结构蛋白（菌毛蛋白），以检查区域 PapA菌毛蛋白对于它们组装成紧密卷曲螺旋是必需的 细丝，4）细菌附着测定，以评估 突变和损伤对细菌结合的影响，以及5）体外 从分子伴侣-菌毛蛋白复合物重构异菌毛蛋白聚合物， 为了提高我们对生物组装过程的理解， 原型大分子

The aim of this research is to understand the structure and assembly of adhesion pili found on pathogenic bacteria, thereby providing insight into how the architecture of these pili supports their role as a virulence factor. Bacterial survival and colonization require attachment of the bacteria to hosts. In many stains, this process is initiated and maintained by pili; in Escherichia coli that cause pyelonephritis, adhesion and virulence depend on P-pili. Hib-pili expressed on the surface of Haemophilus influenzae mediate H. flu's colonization of the upper respiratory tract, and thus its ability to cause diseases such as childhood meningitis, otitis media, and pneumonia of the elderly. As bacteria become more resistant to traditional antibiotics, it is important to develop new therapies against bacterial infections. Structural information about adhesion pili will provide a basis for future rational design of new therapies to prevent bacterial binding or to remove pathogenic bacteria bound to the human host. The proposed research addresses this long-term goal through structural studies of bacterial adhesion pili. These studies focus on: 1) electron microscopy and three-dimensional (3-D) helical reconstruction of P-pili preserved in vitreous ice and of Hib-pili negative stain, 2) controlled damage/recovery of pili to investigate the possibility of re-formation of intact helical filaments, 3) investigation of the 3-D structure of P-pili with mutant structural proteins (pilins), to examine regions of the PapA pilin essential for their assembly into tightly coiled helical filaments, 4) bacterial attachment assays, to assess the effect of mutations and the effect of damage on bacterial binding, and 5) in vitro reconstitution of hetero-pilin polymers from chaperone-pilin complexes, to improve our understanding of the bioassembly process of a prototypical macromolecule.