Masuta C, Zuidema D, Hunter B G, Heaton L A, Sopher D S, Jackson A O
Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA.
Virology. 1987 Aug;159(2):329-38. doi: 10.1016/0042-6822(87)90471-5.
The relatedness of the genomes of satellite panicum mosaic virus (SPMV) and its helper virus, panicum mosaic virus (PMV), were investigated by nucleic acid hybridization. The results show that the satellite and helper virus RNAs have no appreciable homology or complementarity as assessed by hybridization with cDNA probes derived from the genomes of PMV and SPMV and with a probe complementary to the 3' terminus of SPMV RNA. The complete nucleotide sequence of SPMV RNA reveals that the genome is 826 nucleotides (nt) long. The ability to label SPMV RNA with polynucleotide kinase only after phosphatase treatment suggests that the 5' terminus is phosphorylated, but the extent of phosphorylation was not determined. The first open reading frame (ORF), encountered after an 88-nt 5'-untranslated region, encodes a 17,000 mol wt protein of a size and amino acid composition that are consistent with analysis of SPMV coat protein. An additional short ORF, located near the 3' end of the RNA, could encode a 6300 mol wt polypeptide. The minus strand also contains two ORFs that could potentially encode polypeptides of 7100 and 11,000 mol wt. No evidence is available to determine whether the second positive-strand ORF or the two minus-strand ORFs are expressed. The data presented here clearly show the SPMV RNA is distinct from the RNAs of other satellite viruses, in both size and nucleotide sequence. However, the 5'-untranslated portions of SPMV and satellite tobacco mosaic virus RNAs share some structural features that may be important in initiation of translation.
通过核酸杂交研究了卫星黍花叶病毒（SPMV）及其辅助病毒黍花叶病毒（PMV）基因组的相关性。结果表明，用源自PMV和SPMV基因组的cDNA探针以及与SPMV RNA 3'末端互补的探针进行杂交评估，卫星病毒和辅助病毒RNA没有明显的同源性或互补性。SPMV RNA的完整核苷酸序列显示，基因组长度为826个核苷酸（nt）。仅在磷酸酶处理后才能用多核苷酸激酶标记SPMV RNA，这表明5'末端被磷酸化，但磷酸化程度未确定。在88 nt的5'非翻译区之后遇到的第一个开放阅读框（ORF）编码一种17,000 mol wt的蛋白质，其大小和氨基酸组成与SPMV外壳蛋白的分析结果一致。位于RNA 3'末端附近的另一个短ORF可能编码一种6300 mol wt的多肽。负链也包含两个ORF，可能编码7100和11,000 mol wt的多肽。没有证据可确定第二个正链ORF或两个负链ORF是否表达。此处提供的数据清楚地表明，SPMV RNA在大小和核苷酸序列上均与其他卫星病毒的RNA不同。然而，SPMV和卫星烟草花叶病毒RNA的5'非翻译部分具有一些结构特征，这些特征可能在翻译起始中很重要。
