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水稻矮缩病病毒(RDV)具有多种蛋白质和RNA构成的核衣壳结构,但是特异性的RNA与蛋白质、蛋白质与蛋白质之间的相互作用和结合,即有关病毒粒子的装配机理还没有完全阐明。从细胞内和细胞外两个研究层次详细研究了RNA与蛋白质相互结合情况,研究发现,P7蛋白能特异并牢固地与RDV基因组的全部12条双链RNA结合;推定为RNA聚合酶的P1蛋白、鸟苷酰转移酶的P5蛋白和P7蛋白被包裹在病毒核内,根据体外结合实验,它们能与病毒转录产物mRNA结合;从病毒感染的组织中能够提取得到完整的、有感染活性的病毒粒子,以及缺失P1,P5,P7蛋白和基因组双链RNA,没有感染活性的空壳病毒粒子;在病毒粒子中P7蛋白能够与P1蛋白和P3内衣壳蛋白形成蛋白复合物。这些结果揭示了RDV病毒粒子装配的一种可能的模型,即核心蛋白和病毒mRNA首先相互结合形成一个整体,以筛选和富集病毒RNA,接着包装成为完整的、具有感染活性的病毒粒子。
Rice dwarf virus (RDV) has a variety of proteins and RNA nucleocapsid structure, but the specific RNA and protein, protein and protein interactions and binding, that the assembly mechanism of the virus particles is not yet complete Clarify. The intracellular and extracellular levels of RNA and protein were studied in detail at two levels of interaction. It was found that P7 protein specifically and strongly bound to all 12 double-stranded RNAs of the RDV genome; it was presumed that the P1 protein of RNA polymerase , The P5 and P7 proteins of guanylyltransferase are encapsulated in the viral nucleus and, according to the in vitro binding experiments, they bind to the mRNA of the viral transcript; the intact, infectiously active virus can be extracted from the virus-infected tissue Particles, as well as empty virions lacking infectious activity of P1, P5, P7 proteins and genomic double-stranded RNA; P7 protein is capable of forming a protein complex with P1 protein and P3 capsid protein in virions. These results reveal a possible model for particle assembly of RDV viruses in which the core protein and viral mRNA are first combined with each other to screen and enrich viral RNA and then packaged into intact and infectious virus particles.