DNA packaging and delivery by dsDNA viruses

双链DNA病毒的DNA包装和递送

• 批准号: 7493876
• 负责人: Sherwood R. Casjens
• 金额: $ 37.42万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7493876
• 关键词: ATP phosphohydrolase; Adenoviruses; Bacteriophage P22; Bacteriophages; Binding; Biochemical Genetics; Biological Models; Biology; Capsid; Capsid Proteins; Catalysis; Cells; Chromosomes; Class; DNA; DNA Packaging; Double Stranded DNA Virus; Ecology; Health; Herpesviridae; Human; Injection of therapeutic agent; Knowledge; Left; Life; Life Cycle Stages; Location; Medical; Modeling; Molecular; Molecular Conformation; Molecular Machines; Motor; Pathogenicity; Principal Investigator; Process; Protein Binding; Proteins; Recruitment Activity; Research; Role; Scaffolding Protein; Simplexvirus; Site; Structure; System; Tail; Virion; Virus; Virus Assembly; design; frontier; microbial; nuclease; polypeptide; protein structure function; research study; scaffold; terminase

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 welldeveloped 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 DMA 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 a major 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.

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。为此选择的病毒 研究是尾部 - 细菌噬菌体，具有直接的医学重要性，因为它们是最丰富的“生命形式” 在地球上，在细菌致病性和微生物生态学中具有巨大的重要性。他们也是 在较少实验可访问的真核病毒中，类似过程的非常重要的模型，例如 疱疹病毒，虹膜病毒和腺病毒。因此，拟议的研究与人类健康有关。 该项目中使用的p22噬菌体系统是遗传和生化良好开发的最多的一种 在所有病毒系统中，非常适合获取有关病毒组装的新知识 颗粒。这种类型的病毒首先组装蛋白质壳，称为procapsid，然后插入dsDNA 染色体进入该壳以形成病毒体。 p22 procapsid包含三个关键多肽，一层 形成外壳的蛋白质，一种内部脚手架蛋白 但是在DNA进入之前留下的叶子，以及形成环DMA进入外套的环蛋白 蛋白质壳。 P22编码的“末端酶”与procapsids相互作用，对于DNA识别至关重要 进入过程，另外三种蛋白质结合以稳定包装的DNA。 Procapsid及其 脚手架和末端酶是大多数（如果不是全部）DSDNA病毒的组装策略的核心特征， 但是它们的组装和功能的许多功能仍然未知。脚手架蛋白在 Procapsid大会是该提案的主要重点。它通过 与之共同组装，并将其他蛋白质募集到结构中。与外套蛋白共同组装后 形成procapsids，脚手架蛋白在DNA插入步骤之前从procapsid中释放出来，因此 在病毒体组装中催化功能。该提案的其他重点旨在理解 DNA包装/注入分子机的组件的结构和功能，其中包括 用DNA注入细胞的末端酶DNA包装运动和蛋白质。目的 项目将通过遗传，生化，生物物理和结构分析的结合来追求 策略。