Structural and functional studies of the Legionella pneumophila dot T4SS

嗜肺军团菌 dot T4SS 的结构和功能研究

基本信息

批准号：
9910576
负责人：
Clarissa Lynn Durie
金额：
$ 6.53万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2022-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9910576
关键词：
Address Anti-Bacterial Agents Antibiotic Resistance Architecture Bacteria Bartonella Biochemical Bordetella pertussis Brucella Cells Collaborations Complex Coxiella Cryo-electron tomography Cryoelectron Microscopy DNA Data Data Set Defect Escherichia coli Eukaryotic Cell Goals Gram-Negative Bacteria Grant Hand Helicobacter pylori Legionella pneumophila Maps Mass Spectrum Analysis Membrane Microbial Biofilms Modeling Molecular Names Negative Staining Nucleic Acids Oncogenes Organelles Pathogenesis Pilum Plasmids Protein Export Pathway Protein Secretion Proteins Publishing Resolution Rhizobium radiobacter Sampling Structure Substrate Specificity System Titan Toxin Type IV Secretion System Pathway War Work Xanthomonas density extracellular genetic approach global health host colonization human disease in vivo insight molecular modeling mutant particle pathogen pathogenic bacteria periplasm prototype resistance gene three dimensional structure trafficking treatment strategy weapons

项目摘要

Project Abstract Bacterial pathogens are a threat to global health and have evolved elaborate strategies to infect their hosts. One potent bacterial weapon in the war between host and pathogen is the Type IV secretion system (T4SS), found in a wide variety of bacterial species, including those that cause human disease, such as Legionella pneumophila, Helicobacter pylori, Bordetella pertussis, Brucella, Bartonella, and Coxiella. The L. pneumophila, T4SS translocates 100s of effector proteins into the host cell and is essential for pathogenesis. T4SSs are challenging complexes to work with because they span the inner and outer membranes of Gram-negative bacteria and contain a minimum of 12 proteins. Studies in prototype systems, such as E. coli plasmids and A. tumefaciens show that T4SSs are generally organized into an outer membrane core complex (OMCC), an inner membrane complex (IMC), and in some species an extracellular pilus. While there are no published high- resolution (sub-3.5 Å) structures of an entire T4SS; there are sub-3.5 Å structures of OMCCs from both the Xanthomonas citri and conjugation system that translocate DNA. In contrast to the DNA-translocating T4SSs, the L. pneumophila T4SS is composed of ~26 components and low resolution (~30 Å) cryo-electron tomography studies show that this T4SS has an enlarged OMCC and contains periplasmic densities not seen in the structures of minimized E. coli and X. citri T4SSs. The lack of detailed structural information limits our mechanistic understanding of how the L. pneumophila T4SS functions and contributes to pathogenesis. The focus of this proposal is to use a combination of structural and genetic approaches to construct the first detailed molecular map of the organization of the L. pneumophila T4SS. These high resolution models will be used to address fundamental questions such as whether there are conserved structural components shared among T4SSs that can be exploited for new anti-bacterial treatment strategies, how T4SSs are tuned to export proteins versus nucleic acids, and how export of effectors is regulated.

项目摘要细菌病原体对全球健康构成威胁，并已进化出复杂的策略来感染宿主。宿主与病原体之间的战争中一种有效的细菌武器是 IV 型分泌系统（T4SS），存在于多种细菌中，包括引起人类疾病的细菌，例如军团菌嗜肺军团菌、幽门螺杆菌、百日咳博德特氏菌、布鲁氏菌、巴尔通体和嗜肺军团菌。 T4SS 将数百个效应蛋白转移到宿主细胞中，对于发病机制至关重要。复合物的处理具有挑战性，因为它们跨越革兰氏阴性菌的内膜和外膜细菌并含有至少 12 种蛋白质的原型系统研究，例如大肠杆菌质粒和 A. 根瘤菌表明 T4SS 通常组织成外膜核心复合体 (OMCC)，内膜复合体（IMC），以及某些物种的细胞外菌毛，虽然没有发表高。整个 T4SS 的分辨率（亚 3.5 埃）结构；两个 OMCC 的结构均低于 3.5 埃柑橘黄单胞菌和 DNA 易位接合系统与 DNA 易位 T4SS 相比，嗜肺军团菌 T4SS 由约 26 个组件和低分辨率 (约 30 Å) 低温电子组成断层扫描研究表明，该 T4SS 具有增大的 OMCC，并包含未见的周质密度在最小化的大肠杆菌和 X. citri T4SS 的结构中，缺乏详细的结构信息限制了我们的研究。了解嗜肺军团菌 T4SS 如何发挥作用并促进发病机制的机制。该提案的重点是结合使用结构和遗传方法来构建第一个这些高分辨率模型将提供嗜肺军团菌 T4SS 组织的详细分子图。用于解决基本问题，例如是否存在共享的保守结构成分在可用于新抗菌治疗策略的 T4SS 中，如何调整 T4SS 的输出蛋白质与核酸，以及如何调节效应子的输出。