PACKAGING OF THE SEGMENTED GENOME OF BACTERIOPHAGE PHI 6

噬菌体 PHI 6 分段基因组的包装

• 批准号: 2391966
• 负责人: LEONARD E MINDICH
• 金额: $ 28.43万
• 依托单位: PUBLIC HEALTH RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-01-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2391966
• 关键词: DNA replication; Escherichia coli; Pseudomonas; RNA biosynthesis; bacterial virus; binding proteins; complementary DNA; enzyme mechanism; gene expression; genetic transcription; genetic translation; genome; host organism interaction; hydrolase; molecular cloning; mutant; nucleic acid sequence; nucleocapsid; plasmids; replicase; tissue /cell culture; virus genetics; virus replication

Bacteriophage theta6 contains three pieces of double-stranded RNA (S, M and L) in its nucleocapsid. The pieces possess different genetic information but have similar termini. The packaging of the genomic segments is precise in that virions contain one each of the three normal segments. The aim of this proposal is to determine how the packing system is able to select one of each of the chromosomes and how the system acts to replicate the genome. The entire genome of theta6 has been cloned as cDNA and completely sequenced. Procapsids are produced from cDNA copies of segment L in both Escherichia coli and Pseudomonas phaseolicola, the natural host of theta6. These procapsids care capable of packaging single stranded viral RNA, synthesizing the complementary minus strand to form double stranded RNA and then transcribing this dsRNA to form plus ssRNA. Procapsids will be isolated and used to study both the replicase and packaging reactions. RNA transcripts made from cDNA constructions of the genomic segments can be packaged by the procapsids. The regions of the RNA involved with packaging will be manipulated so as to clarify the interaction between the RNA and the packaging and replication machinery. We will test a new model of packaging that involves retention of the correct complement of genomic segments by the formation of a ternary complex inside the procapsid after non selective entry. A system has been developed that facilitates the isolation and analysis of mutants in three of the replicase proteins. We will use this system to define the domains in proteins P2, P4 and P7 that are involved in packaging, minus and plus strand synthesis. The nature of the mechanisms of the mechanisms of selective packaging in viruses of segmented genomes is currently unknown. We have developed a novel model that explains the specific packaging. The elucidation of the mechanism for theta6 has relevance to the packaging of other segmented- genome viruses. Several members of the reoviridae, e.g. rotavirus and blue tongue virus, are the etiologic agents of important human and animal diseases.

噬菌体theta6包含三个双链RNA（s，m 和l）在其核包膜中。 这些作品具有不同的遗传 信息，但有类似的末端。 基因组的包装 细分是精确的，因为病毒体包含三个正常 细分市场。 该建议的目的是确定包装系统 能够选择每个染色体之一以及系统如何作用 复制基因组。 theta6的整个基因组已被克隆为cDNA，并且完全 测序。 procapsids均来自两个片段L的cDNA副本。 theta6的天然寄主。 这些procapsids关心能够包装单链病毒RNA， 合成互补的负链形成双链RNA 然后将此dsRNA转录为形成ssRNA。 Procapsids将是 分离并用于研究复制酶和包装反应。 由基因组片段的cDNA构造制成的RNA转录本可以 被Procapsids包装。 RNA的区域涉及 包装将被操纵，以阐明 RNA以及包装和复制机械。 我们将测试一个新模型 涉及保留基因组正确补体的包装 通过在procapsid内部形成三元复合物的段 非选择性条目。 已经开发了一个系统，以促进隔离和分析 三种复制酶蛋白中的突变体。 我们将使用此系统 定义蛋白质P2，P4和P7中涉及的结构域 包装，负和链合成。 选择性包装机制的机制的性质 分段基因组的病毒目前尚不清楚。 我们已经开发了 解释特定包装的新型模型。 阐明 theta6的机制与其他分段的包装相关 基因组病毒。 依伏地病的几个成员，例如轮状病毒和 蓝舌病毒是重要人和动物的病因学剂 疾病。