DNA Replication and Gene Expression of Chlorella Viruses

描述（由申请人提供）：大（>330 kb）dsDNA、空斑形成的埃氏杆菌病毒在过去20年中提供了新的和意想不到的基因产物，包括几种医学相关蛋白质。 该提案的目标是朝着了解这些病毒的结构和功能方面以及其相关基因和基因产物的长期目标迈出的一步。 许多雷氏杆菌病毒蛋白是其功能类别中最小的代表。 因此，这些蛋白质中的一些是强烈的物理和生物化学研究的主题，例如II型DNA拓扑异构酶和钾离子通道蛋白Kcv。这一提议集中在与病毒进入细胞和子代病毒成熟相关的两个重要问题上。 本提案的具体目的是：i）检查来自广泛的雷氏杆菌病毒的kcv基因及其相应蛋白，作为探索钾离子通道中结构/功能关系的替代方法; ii）评价病毒主要衣壳蛋白Vp 54的不寻常病毒编码的翻译后修饰。 除了表征七种推定的病毒编码的糖基转移酶外，还将确定附着于主要衣壳蛋白的六种聚糖的结构。 病毒蛋白质将在生理、分子生物学和生物化学水平上进行研究，包括结构分析。 这些研究有望揭示钾离子通道分子内和分子间相互作用的新概念，以及蛋白质糖基化和肉豆蔻酰化的新机制。 系统发育分析表明，遗传多样性，但形态上难以区分的病毒有很长的进化历史，可能可以追溯到真核生物和原核生物分离的时间。 因此，埃氏杆菌病毒是研究大型核质双链DNA病毒的重要模型，因为它们与重要的哺乳动物病毒（如痘病毒和隔离的非洲猪瘟病毒）有进化联系。

DESCRIPTION (provided by applicant): The large (>330 kb) dsDNA, plaque-forming chlorella viruses have provided new and unexpected gene products for the past 20 years, including several medically relevant proteins. The objectives of this proposal are a step toward the long-term goal of understanding the structural and functional aspects of these viruses, as well as their associated genes and gene products. Many chlorella virus proteins are the smallest representatives of their functional class. Consequently, some of these proteins are the subject of intense physical and biochemical investigation, e.g. a type II DNA topoisomerase and a potassium ion channel protein Kcv. This proposal focuses on two important problems associated with virus entry into the cell and maturation of progeny viruses. The specific aims of this proposal are to: i) examine kcv genes and their corresponding proteins from a broad range of chlorella viruses as an alternate approach for exploring structure/function relationships in potassium ion channels and ii) evaluate unusual virus-encoded posttranslational modifications of the virus major capsid protein, Vp54. In addition to characterizing the seven putative virus-encoded glycosyltransferases, the structures of the six glycans attached to the major capsid protein will be determined. The viral proteins will be investigated at physiological, molecular biological and biochemical levels, including structural analyses. These studies are expected to reveal new concepts in intra- and inter-molecular interactions of potassium ion channels, and also novel mechanisms for protein glycosylation and myristoylation. Phylogenetic analyses indicate the genetically diverse but morphologically indistinguishable chlorella viruses have a long evolutionary history, possibly dating back to the time eukaryotes and prokaryotes separated. Thus, chlorella viruses are an important model for studying large nucleocytoplasmic dsDNA viruses because they have evolutionary ties to important mammalian viruses, such as the pox viruses and the quarantined African swine fever virus.