Replication and Encapsidation of Nodavirus RNAs

诺达病毒 RNA 的复制和衣壳化

• 批准号: 6477853
• 负责人: L A BALL
• 金额: $ 37.76万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-08-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6477853
• 关键词: RNA virus; X ray crystallography; cryoelectron microscopy; enzyme activity; enzyme structure; molecular cloning; nucleic acid sequence; nucleocapsid; polymerase chain reaction; protein structure function; replicase; small nuclear ribonucleoproteins; tissue /cell culture; virion; virus RNA; virus assembly; virus replication

DESCRIPTION (provided by applicant): Nodaviruses are small icosahedral viruses with bipartite, single-stranded, positive-sense RNA genomes. Containing only 4.5 kb, their genomes are among the smallest and simplest of all known animal viruses, yet they replicate up to 100-fold more abundantly than most other viral RNAs, and can do so in cells from vertebrates, insects, plants, and even yeast. Because of this, steps in nodavirus replication and assembly can be examined at levels of resolution that cannot yet be achieved with any other RNA viruses of animals. Advances in our understanding of the dynamic RNA-protein interactions involved in nodavirus replication and assembly can be confidently expected to illuminate studies of many medically important positive-strand RNA viruses. Moreover, because of the simplicity, robustness, and extraordinary amplifying power of the nodavirus RNA replicases, they are promising candidates for development as components of expression vectors for a wide range of applications. The work described in this proposal will focus on the basic mechanisms of replication and encapsidation of nodavirus RNAs. We will undertake detailed studies of these processes by combining genetic, biochemical, and structural approaches to examine the interactions of the viral RNAs with the RNA-dependent RNA polymerase during replication and with the capsid protein precursor during virus assembly. In the area of RNA replication, we will examine the structures and functions of nodavirus RNA replication complexes; the template roles of covalent homo- and heterodimers of the viral RNAs; how the subgenomic RNA is synthesized and how it coordinates the replication of the viral genome segments; the structure of the RdRp and its ability to replicate RNA in vitro; and the viral guanylyl- and methyltransferase activities involved in RNA capping. In the area of capsid assembly and structure, we will examine: the arrangement of RNAs 1 and 2 in virions of Pariacoto virus (PaV), a newlydescribed nodavirus in which a significant fraction of the viral RNA is visible at 3A resolution in virus particles; the properties, structures, and encapsidated RNAs of immature PaV provirions and virus-like particles of PaV; the design of RNAs to compete for encapsidation with PaV RNAs 1 and 2; the roles in virion assembly of specific domains in the PaV capsid proteins; and the creation of PaV particles that have different versions of the capsid protein in the different quasi-equivalent positions of the capsid.

性状（由申请方提供）：野田病毒属小型二十面体病毒 具有二分的、单链的、正义的RNA基因组。仅含有 4.5它们的基因组是所有已知动物中最小和最简单的 病毒，但他们复制高达100倍，比大多数其他丰富 病毒RNA，并且可以在脊椎动物，昆虫，植物，甚至 酵母正因为如此，诺达病毒复制和组装的步骤可以是 在任何其他RNA都无法达到的分辨率水平上进行检查 动物的病毒动态RNA蛋白质的研究进展 可以确信， 有望阐明许多医学上重要的正链RNA的研究 病毒此外，由于其简单、健壮和非凡的 野田病毒RNA复制酶的放大能力，它们是有希望的候选者 用于开发作为广泛的表达载体的组分， 应用. 本提案所述的工作将侧重于以下基本机制： 诺达病毒RNA的复制和降解。我们将详细 通过结合遗传、生物化学和结构来研究这些过程 研究病毒RNA与RNA依赖的 RNA聚合酶在复制过程中和与衣壳蛋白前体在 病毒组装在RNA复制领域，我们将研究 和功能的诺达病毒RNA复制复合物;模板的作用， 病毒RNA的共价同源和异源二聚体;亚基因组RNA是如何 以及它如何协调病毒基因组的复制 片段; RdRp的结构及其在体外复制RNA的能力; 以及RNA中涉及的病毒鸟苷酰和甲基转移酶活性， 封顶在衣壳组装和结构方面，我们将研究： Pariacoto病毒（PaV）病毒粒子中RNA 1和2的排列， 新描述的野田病毒，其中病毒RNA的显著部分是 在病毒颗粒中以3A分辨率可见; 未成熟PaV前病毒粒子和PaV病毒样颗粒的固定RNA; 设计RNA与PaV RNA 1和2竞争腺苷酸化; 在PaV衣壳蛋白中特定结构域的病毒体组装中的作用;以及 产生具有不同版本衣壳的PaV颗粒 蛋白质在衣壳的不同准等价位置。