Basnayake Veronica R, Sit Tim L, Lommel Steven A
Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA.
Virology. 2006 Feb 20;345(2):532-9. doi: 10.1016/j.virol.2005.10.017. Epub 2005 Nov 17.
Red clover necrotic mosaic virus (RCNMV) is a small icosahedral plant virus with a bipartite RNA genome. While the RCNMV genome consists of two RNAs, it has not been definitively established whether these RNAs are co-packaged into a single virion or packaged individually into separate virions. Biochemical evidence exists to support both hypotheses. To determine the genomic RNA complement within RCNMV, virions were subjected to heat treatments and UV crosslinking. A stable RNA-1:RNA-2 heterodimer was formed with both treatments establishing that RCNMV genomic RNAs are co-packaged into a single virion. Furthermore, RNA-2 homodimer and homotrimers were also observed indicating that some virions contain multiple copies of RNA-2 exclusively. These results indicate that RCNMV virions consist of two distinct populations: (i) virions containing both genomic RNAs; and (ii) virions with multiple copies of RNA-2. This type of hybrid packaging arrangement was unexpected and appears to be unique among the multipartite RNA viruses.
红三叶草坏死花叶病毒（RCNMV）是一种具有二分体RNA基因组的小型二十面体植物病毒。虽然RCNMV基因组由两个RNA组成，但这些RNA是共同包装到单个病毒粒子中还是分别包装到单独的病毒粒子中尚未得到明确证实。有生化证据支持这两种假设。为了确定RCNMV内的基因组RNA组成，对病毒粒子进行了热处理和紫外线交联处理。两种处理都形成了稳定的RNA-1:RNA-2异二聚体，这表明RCNMV基因组RNA共同包装到单个病毒粒子中。此外，还观察到了RNA-2同二聚体和同三聚体，这表明一些病毒粒子仅含有多个RNA-2拷贝。这些结果表明，RCNMV病毒粒子由两个不同的群体组成：（i）含有两种基因组RNA的病毒粒子；（ii）含有多个RNA-2拷贝的病毒粒子。这种类型的混合包装安排出乎意料，在多分体RNA病毒中似乎是独特的。
