Calvert L A, Ospina M D, Shepherd R J
Centro International de Agricultura Tropical (CIAT), Cali, Colombia.
J Gen Virol. 1995 May;76 ( Pt 5):1271-8. doi: 10.1099/0022-1317-76-5-1271.
Cassava vein mosaic virus (CVMV) was found to be widespread throughout the north-eastern region of Brazil. The complete sequence of CVMV was determined, and the genome was 8158 bp in size. A cytosolic initiator methionine tRNA (tRNA met1)-binding site that probably acts as a primer for minus-strand synthesis was present. The genome contained five open reading frames that potentially encode proteins with predicted molecular masses of 186 kDa, 9 kDa, 77 kDa, 24 kDa and 26 kDa. The putative 186 kDa protein had regions with similarity to the zinc finger-like RNA-binding domain that is a common element in the capsid proteins and similarity to the intercellular transport domain of the plant pararetroviruses. The predicted 77 kDa protein had regions with similarity to aspartic proteases, reverse transcriptase and RNase H of pararetroviruses. This gene order was confirmed by the amplification of similar PCR products from total DNA extracted from CVMV-infected cassava plants. The genomic organization of CVMV was different from the organization of either the caulimoviruses or badnaviruses. In comparisons of the regions with the reverse transcriptase motif, CVMV was grouped between the caulimoviruses and badnaviruses. It appears that CVMV is distinct from the other well-characterized plant pararetroviruses.
木薯叶脉花叶病毒（CVMV）在巴西东北部地区广泛分布。测定了CVMV的完整序列，其基因组大小为8158 bp。存在一个可能作为负链合成引物的胞质起始甲硫氨酸tRNA（tRNA met1）结合位点。该基因组包含五个开放阅读框，可能编码预测分子量分别为186 kDa、9 kDa、77 kDa、24 kDa和26 kDa的蛋白质。推测的186 kDa蛋白质具有与锌指样RNA结合结构域相似的区域，该结构域是衣壳蛋白中的常见元件，并且与植物副逆转录病毒的细胞间运输结构域相似。预测的77 kDa蛋白质具有与副逆转录病毒的天冬氨酸蛋白酶、逆转录酶和核糖核酸酶H相似的区域。通过从感染CVMV的木薯植物中提取的总DNA扩增相似的PCR产物，证实了这种基因顺序。CVMV的基因组结构与花椰菜花叶病毒或杆状DNA病毒的结构不同。在与逆转录酶基序区域的比较中，CVMV被归类于花椰菜花叶病毒和杆状DNA病毒之间。看来CVMV与其他已充分表征的植物副逆转录病毒不同。
