Structural basis of phage infection and DNA ejection

噬菌体感染和 DNA 喷射的结构基础

基本信息

批准号：
8674769
负责人：
Jun Liu
金额：
$ 32.84万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-05-01 至 2018-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8674769
关键词：
3-Dimensional Adsorption Anti-Bacterial Agents Bacteria Bacterial Infections Bacteriophages Benign Biochemical Biological Biological Process Biology Cell Wall Cell membrane Cells Collaborations Complex Core Protein Cytoplasm DNA DNA Sequence Rearrangement Data Ecosystem Electron Microscopy Escherichia coli Evolution Family Fiber Genes Genetic Genetic Transformation Genome Goals Head Health Horizontal Gene Transfer Human Image Image Analysis Imaging Techniques Infection Injection of therapeutic agent Ion Channel Life Cycle Stages Membrane Membrane Proteins Modeling Molecular Molecular Biology Molecular Genetics Molecular Machines Morphology Myoviridae Nanotechnology Paper Pathogenicity Pathway interactions Penetration Podoviridae Process Property Proteins Recruitment Activity Research Resistance to infection Resolution Science Siphoviridae Structure System T-DNA Tail Toxin Viral Proteins Virion Virulence Factors Virus Diseases Work X-Ray Crystallography base cell envelope comparative directed evolution electron tomography experience gene therapy improved in vivo innovation insight macromolecule microbial community molecular recognition mutant novel novel strategies pathogen public health relevance therapeutic development viral DNA virus host interaction

项目摘要

DESCRIPTION (provided by applicant): Bacteriophages are the most abundant biological entity in the biosphere. They facilitate the evolution of bacterial pathogenicity by imposing selection for resistance to infection and by horizontal gene transfer of host genes to new bacteria. More specifically, phages often carry toxins and virulence factors that convert benign bacteria into human pathogens, facilitating the spread of bacterial infections. Most phages utilize elaborate tail machines to translocate their viral DNA and proteins, across bacterial membranes, into a host cell. In addition, these highly sophisticated molecular machines are responsible for host-cell recognition, attachment, and cell wall penetration. However, initial adsorption and genome ejection remain the least understood aspects of any phage life cycle. The central hypothesis is that the tail machine undergoes a cascade of coordinated conformational changes to efficiently infect a host bacterium. The objective of this application is to document these conformational rearrangements by determining intermediate structures of Podoviridae T7, Myoviridae T4, and Siphoviridae ? during infection by combining high throughput cryo-electron tomography (cryo- ET) with molecular genetics of both phage and host. Comparative structural analysis of these three morphotypes, together with a wealth of biochemical and structural information, will provide new insights into the mechanistic pathways of phage infection at a molecular level.

描述（由申请人提供）：噬菌体是生物圈中最丰富的生物实体。它们通过施加抗性感染和通过宿主基因向新细菌的水平基因转移来促进细菌致病性的进化。更具体地说，噬菌体通常携带毒素和毒力因子，这些因子将良性细菌转化为人类病原体，从而促进细菌感染的传播。大多数噬菌体使用精心制作的尾巴机将其病毒DNA和蛋白质（跨细菌膜）转移到宿主细胞中。此外，这些高度复杂的分子机构负责宿主识别，附着和细胞壁穿透。但是，最初的吸附和基因组射血量仍然是任何噬菌体生命周期中最不理理解的方面。中心假设是，尾巴机经历了一系列协调的构象变化，以有效感染宿主细菌。该应用的目的是通过确定Podoviridae T7，Myoviridae T4和Siphoviridae的中间结构来记录这些构象重排？在感染过程中，通过将高吞吐量冷冻电子断层扫描（冷冻）与噬菌体和宿主的分子遗传学结合结合。这三种形态的比较结构分析，以及大量的生化和结构信息，将为分子水平上噬菌体感染的机械途径提供新的见解。