Kundu Anirban, Roychowdhury Amlan, Bose Madhuparna, Das Amit Kumar, Ghosh Ananta K
Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
J Gen Virol. 2016 Jul;97(7):1709-1719. doi: 10.1099/jgv.0.000463. Epub 2016 Mar 23.
Antheraea mylitta cytoplasmic polyhedrosis virus is a segmented dsRNA virus of the family Reoviridae. Segment 2 (S2)-encoded RNA-dependent RNA polymerase (RdRp) helps the virus to propagate its genome in the host cell of the silkworm, Antheraea mylitta. Cloning, expression, purification and functional analysis of individual domains of RdRp have demonstrated that the purified domains interact in vitro. The central polymerase domain (PD) shows nucleotide binding properties, but neither the N-terminal domain (NTD) nor the C-terminal domain (CTD). Isolated PD does not exhibit RdRp activity but this activity can be reconstituted when all three domains are included in the reaction mixture. Molecular dynamics simulation suggests that the isolated PD has increased internal motions in comparison to when it is associated with the NTD and CTD. The motions of the separated PD may lead to the formation of a less accessible RNA template-binding channel and, thus, impair RdRp activity.
蓖麻蚕细胞质多角体病毒是呼肠孤病毒科的一种分段双链RNA病毒。第2节段（S2）编码的RNA依赖性RNA聚合酶（RdRp）有助于该病毒在蓖麻蚕的宿主细胞中传播其基因组。对RdRp各个结构域的克隆、表达、纯化及功能分析表明，纯化后的结构域在体外相互作用。中央聚合酶结构域（PD）具有核苷酸结合特性，而N端结构域（NTD）和C端结构域（CTD）均不具有此特性。分离出的PD不表现出RdRp活性，但当反应混合物中包含所有三个结构域时，该活性可以重建。分子动力学模拟表明，与与NTD和CTD结合时相比，分离出的PD内部运动增加。分离的PD的运动可能导致形成一个较难接近的RNA模板结合通道，从而损害RdRp活性。
