DNA packaging and delivery by dsDNA viruses

双链DNA病毒的DNA包装和递送

• 批准号: 7572926
• 负责人: Sherwood R. Casjens
• 金额: $ 37.63万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7572926
• 关键词: ATP phosphohydrolase; Adenoviruses; Bacteriophage P22; Bacteriophages; Binding; Biochemical; Biological Models; Biology; Capsid; Capsid Proteins; Catalysis; Cells; Chromosomes; DNA; DNA Packaging; Double Stranded DNA Virus; Ecology; Genetic; Head; Health; Herpesviridae; Human; Injection of therapeutic agent; Knowledge; Left; Life; Life Cycle Stages; Location; Medical; Modeling; Molecular; Molecular Conformation; Molecular Machines; Motor; Needles; Pathogenicity; Principal Investigator; Process; Protein Binding; Proteins; Recruitment Activity; Research; Role; Scaffolding Protein; Site; Structure; System; Tail; Virion; Virus; Virus Assembly; Work; design; frontier; microbial; nuclease; polypeptide; public health relevance; research study; scaffold; terminase

DESCRIPTION (provided by applicant): The long term objective of this project is to increase our knowledge of the life cycle of dsDNA viruses through study of the molecular mechanisms by which their virions assemble and function. The viruses chosen for this study, the tailed-bacteriophages, have direct medical importance since they are the most abundant `life form' on Earth and have huge importance in bacterial pathogenicity and microbial ecology. They also serve as very important models for similar processes in less experimentally accessible eukaryotic viruses such as Herpesviruses, Iridopoxviruses and Adenoviruses. Thus the proposed research is relevant to human health. The P22 bacteriophage system utilized in this project is one of the most genetically and biochemically well-developed of all virus systems, and so is ideal for obtaining new knowledge about the assembly of virus particles. This type of virus first assembles a protein shell, called a procapsid, and then inserts the dsDNA chromosome into this shell to form a virion. The P22 procapsid contains three critical polypeptides, a coat protein that forms the external shell, an internal scaffolding protein which is required to build the procapsid but leaves before DNA enters, and a portal protein which forms a ring through which DNA enters the coat protein shell. A P22-encoded `terminase' interacts with procapsids and is critical to the DNA recognition and entry processes, and three additional proteins bind to stabilize the packaged DNA. The procapsid with its scaffold and terminase are central features of the assembly strategy of most if not all large dsDNA viruses, but many features of their assembly and function remain unknown. The role of the scaffolding protein in procapsid assembly is one focus of this proposal. It guides coat protein's assembly into a closed shell by co-assembling with it, and it recruits other proteins into the structure. After co-assembly with coat protein to form procapsids, scaffolding protein is released from the procapsid before the DNA insertion step, and so it functions catalytically in virion assembly. The other focuses of the proposal are aimed at understanding the structure and function of the components of the DNA packaging/injection molecular machine which include the terminase DNA packaging motor and proteins that are injected into cells with the DNA. The aims of the project will be pursued through a combination of genetic, biochemical, biophysical and structural analysis strategies. PUBLIC HEALTH RELEVANCE: The proposed work on virus particle assembly and function focuses on the study of the proteins that are part of the portal vertex molecular machine of bacteriophage P22. The roles of these proteins, which form the motor that packages DNA and releases DNA during injection, are studied by genetic, biochemical and structural analysis

描述（由申请人提供）：该项目的长期目标是通过研究其病毒体组装和功能的分子机制来提高我们对DSDNA病毒的生命周期的了解。为这项研究选择的病毒，即尾部 - 细菌噬细胞具有直接的医学重要性，因为它们是地球上最丰富的“生命形式”，并且在细菌致病性和微生物生态学中具有巨大的重要性。它们还充当非常重要的模型，用于在实验性较低的真核病毒（例如疱疹病毒，铱病毒和腺病毒）中的类似过程中。因此，拟议的研究与人类健康有关。该项目中使用的p22噬菌体系统是所有病毒系统中最具遗传和生物化学良好发达的p22噬菌体系统，因此非常适合获取有关病毒颗粒组装的新知识。这种类型的病毒首先组装出称为procapsid的蛋白质壳，然后将dsDNA染色体插入该壳中形成病毒粒子。 p22 procapsid包含三种临界多肽，一种形成外壳的外套蛋白，一种内部脚手架蛋白，这是构建procapsid所需的，但在DNA进入之前离开的叶子，以及形成DNA的门蛋白，该环通过该环进入外套蛋白质壳。 P22编码的“末端酶”与procapsids相互作用，对于DNA识别和进入过程至关重要，并且另外三种蛋白质结合以稳定包装的DNA。具有脚手架和末端酶的procapsid是大多数（即使不是大的DSDNA病毒）组装策略的核心特征，但是它们的组装和功能的许多特征仍然未知。脚手架蛋白在procapsid组装中的作用是该提案的重点。它通过与之共组装将蛋白质的组件引导成封闭的外壳，并将其他蛋白质募集到结构中。与外套蛋白共组装以形成procapsids之后，在DNA插入步骤之前从procapsid释放了脚手架蛋白，因此它在病毒体组装中催化起作用。该提案的另一个重点旨在了解DNA包装/注入分子机的组件的结构和功能，其中包括末端酶DNA包装电机和蛋白质，并注入了带有DNA的细胞中。该项目的目的将通过遗传，生化，生物物理和结构分析策略的结合来实现。公共卫生相关性：关于病毒颗粒组装和功能的拟议工作集中在研究蛋白质的研究，这些蛋白是噬菌体P22的门户顶点分子机器的一部分。这些蛋白质的作用形成了包装DNA并在注射过程中释放DNA的电动机，并通过遗传，生化和结构分析来研究