Mari Jocelyne, Poulos Bonnie T, Lightner Donald V, Bonami Jean-Robert
UMR 5098, CNRS/IFREMER/UM2, cc080, Place East Bataillon, 34095 Montpellier Cedex 5, France2.
Aquaculture Pathology Group, Department of Veterinary Science and Microbiology, The University of Arizona, 1117 East Lowell Street, Tucson, Arizona 85721, USA1.
J Gen Virol. 2002 Apr;83(Pt 4):915-926. doi: 10.1099/0022-1317-83-4-915.
The single-stranded genomic RNA of Taura syndrome virus (TSV) is 10205 nucleotides in length, excluding the 3' poly(A) tail, and contains two large open reading frames (ORFs) that are separated by an intergenic region of 207 nucleotides. The ORFs are flanked by a 377 nucleotide 5' untranslated region (UTR) and a 226 nucleotide 3' UTR followed by a poly(A) tail. The predicted amino acid sequence of ORF1 revealed sequence motifs characteristic of a helicase, a protease and an RNA-dependent RNA polymerase, similar to the non-structural proteins of several plant and animal RNA viruses. In addition, a short amino acid sequence located in the N-terminal region of ORF1 presented a significant similarity with a baculovirus IAP repeat (BIR) domain of inhibitor of apoptosis proteins from double-stranded DNA viruses and from animals. The presence of this BIR-like sequence is the first reported in a single-stranded RNA virus, but its function is unknown. The N-terminal amino acid sequence of three TSV capsid proteins (55, 40 and 24 kDa) were mapped in ORF2, which is not in the same reading frame as ORF1 and possesses an AUG codon upstream of the structural genes. However, the intergenic region shows nucleotide sequence similarity with those of the genus Cricket paralysis-like viruses, suggesting a similar non-AUG-mediated translation mechanism. The structure of the TSV genome [5' UTR-non-structural proteins-intergenic UTR-structural proteins-3' UTR-poly(A) tail] is similar to those of small insect-infecting RNA viruses, which were recently regrouped into a new virus genus, Cricket paralysis-like viruses.
桃拉综合征病毒（TSV）的单链基因组RNA长度为10205个核苷酸，不包括3' 聚腺苷酸尾，包含两个大的开放阅读框（ORF），它们被一个207个核苷酸的基因间隔区隔开。这些开放阅读框两侧分别是一个377个核苷酸的5' 非翻译区（UTR）和一个226个核苷酸的3' UTR，随后是一个聚腺苷酸尾。ORF1的预测氨基酸序列显示出解旋酶、蛋白酶和RNA依赖性RNA聚合酶的特征序列基序，类似于几种植物和动物RNA病毒的非结构蛋白。此外，位于ORF1 N端区域的一段短氨基酸序列与双链DNA病毒和动物凋亡抑制蛋白的杆状病毒IAP重复（BIR）结构域具有显著相似性。这种类似BIR序列的存在是首次在单链RNA病毒中报道，但其功能尚不清楚。三种TSV衣壳蛋白（55、40和24 kDa）的N端氨基酸序列定位在ORF2中，ORF2与ORF1不在同一阅读框内，且在结构基因上游有一个AUG密码子。然而，基因间隔区与蟋蟀麻痹样病毒属的核苷酸序列相似，提示存在类似的非AUG介导的翻译机制。TSV基因组的结构[5' UTR - 非结构蛋白 - 基因间隔UTR - 结构蛋白 - 3' UTR - 聚腺苷酸尾]与最近重新归类为一个新病毒属——蟋蟀麻痹样病毒的小型昆虫感染RNA病毒的结构相似。
