Structural basis of phage infection and DNA ejection

噬菌体感染和 DNA 喷射的结构基础

• 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
• 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

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。它们通过对感染的抗性进行选择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，细菌通常携带毒素和毒力因子，将良性细菌转化为人类病原体，促进细菌感染的传播。最实用 一种精巧的尾部机器，将病毒的DNA和蛋白质穿过细菌膜转移到宿主细胞中。此外，这些高度复杂的分子机器负责宿主细胞识别，附着和细胞壁穿透。然而，初始吸附和基因组排出仍然是任何噬菌体生命周期中最不为人所知的方面。中心假设是尾机经历了一系列协调的构象变化，以有效地感染宿主细菌。本申请的目的是通过确定短尾病毒科T7，肌尾病毒科T4和Siphoviridae的中间结构来记录这些构象重排？通过结合高通量冷冻电子断层扫描（cryo-ET）与噬菌体和宿主的分子遗传学，在感染期间对噬菌体进行冷冻电子断层扫描。这三种形态型的比较结构分析，以及丰富的生化和结构信息，将提供新的见解噬菌体感染的机制途径在分子水平上。