Bradel B G, Preil W, Jeske H
Biologisches Institut, Abt. für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Germany.
Virology. 2000 Jun 5;271(2):289-97. doi: 10.1006/viro.2000.0335.
Sequence comparison and genome organisation of poinsettia mosaic virus (PnMV), a putative member of the tymoviruses, revealed a closer relationship to marafiviruses. The complete nucleotide sequence of PnMV was determined. The 6099-nt RNA genome encodes a putative 221-kDa polyprotein that lacks a stop codon between the replicase and the coat protein genes, as in most tymovirus RNAs. The genomic RNA has a poly(A) tail at its 3'-terminus in contrast to the tRNA-like structure found in the RNA of most tymoviruses, and no homology was observed to the conserved noncoding region of the tymoviral 3'-termini. The tymobox of PnMV, a 16-nt region of the subgenomic RNA (sgRNA) promoter shared by most tymoviruses, differs in 3 nt from the RNA sequence of tymoviruses but is identical to the sequence of marafiviruses. At least three sgRNAs were found in PnMV-infected Euphorbia pulcherrima and in isolated PnMV particles; one that is 650 nt long encodes the 21.4-kDa coat protein, and the others are about 3.5 and 1.7 kb and contain the 5'- and the 3'-terminal parts of genomic RNA, respectively. Like tymoviruses, PnMV particles sediment as top and bottom components. The particles of the top component contain the sgRNA (650 nt) encoding the coat protein, and those of bottom component contain both genomic and sgRNAs.
一品红花叶病毒（PnMV）是番茄丛矮病毒属的一个假定成员，其序列比较和基因组结构显示与马拉病毒有更密切的关系。测定了PnMV的完整核苷酸序列。6099个核苷酸的RNA基因组编码一个假定的221 kDa多蛋白，该多蛋白在复制酶基因和外壳蛋白基因之间没有终止密码子，这与大多数番茄丛矮病毒RNA的情况相同。与大多数番茄丛矮病毒RNA中发现的类似tRNA的结构不同，基因组RNA在其3'末端有一个聚腺苷酸尾巴，并且未观察到与番茄丛矮病毒3'末端保守非编码区的同源性。大多数番茄丛矮病毒共有的亚基因组RNA（sgRNA）启动子的16个核苷酸区域——番茄丛矮病毒框，与番茄丛矮病毒的RNA序列在3个核苷酸上不同，但与马拉病毒的序列相同。在感染PnMV的一品红和分离的PnMV颗粒中发现了至少三种sgRNA；一种650 nt长的sgRNA编码21.4 kDa的外壳蛋白，其他的约为3.5 kb和1.7 kb，分别包含基因组RNA的5'和3'末端部分。与番茄丛矮病毒一样，PnMV颗粒沉降为顶部和底部组分。顶部组分的颗粒包含编码外壳蛋白的sgRNA（650 nt），底部组分的颗粒包含基因组RNA和sgRNA。
