野田村病毒RNA的复制机制

RNA replication mechanism of nodaviruses

摘要:

野田村病毒科Nodaviradae分为2个属, 分别为主要感染昆虫的α野田村病毒属(Alphanodavirus)和主要感染鱼类的β野田村病毒属(Betanodavirus)。野田村病毒的基因组由2条单链正义RNA分子(RNA1和RNA2)所组成, RNA1编码蛋白A, 即病毒负责复制病毒两条基因组的依赖RNA的RNA聚合酶催化亚基。RNA2编码衣壳前体蛋白α, 此前体蛋白α先组装成原病毒粒子, 再经历一次自我催化的成熟切割成2个病毒的衣壳蛋白β和γ, 就成了成熟的有感染性的病毒粒子。在RNA复制过程中, 从RNA1的3′末端会合成一个不被包装进病毒粒子的亚基因组RNA3。RNA1能在无RNA2的情况下自我复制, 并持续地产生亚基因组RNA3，RNA3的合成采取的是提前终止机制。本文还介绍了野田村病毒复制的调节、非结构蛋白的功能和病毒复制在细胞内的定位。

Abstract:

The family Nodaviridae contains two genera, Alphanodaviruses and Betanodaviruses, which predominantly infect insects and fish, respectively. The genome of nodaviruse consists of two sin-gle-strand positive-sense RNAs (RNA1 and RNA2). RNA1 encodes protein A, catalytic subunit of RNA-dependent RNA polymerase (RdRp), and RNA2 encodes coat precursor protein which undergoes an autocatalytic mature cleavage into two viral capsid proteins β and γ. During the course of RNA rep-lication, a sub-genome RNA3 is synthesized which is not packaged into the virion from the 3’ termini of RNA1. RNA1 can self-replicate automatically absence of RNA2 and produce the sub-genome RNA3 persistently. The mechanism of RNA3 synthesis is the mechanism of premature termination. The paper also reviewed the regulation of RNA replication, the functions of non-structural proteins and the local-ization of RNA replication of the nodaviruses.