Complete sequence of two tick-borne flaviviruses isolated from Siberia and the UK: Analysis and significance of the 5' and 3'-UTRs
Complete sequence of two tick-borne flaviviruses isolated from Siberia and the UK: Analysis and significance of the 5' and 3'-UTRs
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DOI：
10.1016/s0168-1702(97)01451-2
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发表时间：
1997-05-01
期刊：
影响因子：
5
通讯作者：
Gould, EA
中科院分区：
文献类型：
--
作者：
Gritsun, TS;Venugopal, K;Gould, EA
两种蜱传黄病毒，来自西伯利亚的Vasilchenko（Vs）和来自英国的louping ill（LI）的完整核苷酸序列已经确定。基因组长度分别为10928和10871个核苷酸（nt）。蜱传黄病毒的编码策略和功能性蛋白质序列基序在Vs和LI病毒中都有呈现。基于最大似然法、最大简约法和距离分析的多聚蛋白的同源性分析，将Vs病毒鉴定为黄病毒科黄病毒属蜱传血清复合物中的蜱传脑炎病毒亚组的成员。3 '-非翻译区的比较比对显示，对于所有蜱传病毒，终止密码子下游基本上相同位置处存在不同长度的缺失。在3 '端有两个27个核苷酸的重复序列，仅在Vs和LI病毒中发现。在缺失后立即在病毒基因组的3 '-非编码端观察到具有相对保守的一级结构（67 - 94%同一性）的332 - 334 nt区域。核苷酸序列数据的成对比较揭示了编码区与基因组的5 '和3'末端之间相似的变异水平，这意味着对翻译区和非翻译区具有同等的强选择性控制。事实上，预测的5 '和3'-非翻译区的折叠揭示了所有蜱传黄病毒保守的茎和环结构的模式，表明纯化选择用于保留可能参与翻译控制和复制的必需RNA二级结构。这些研究结果的可能影响进行了讨论。(C)1997年Elsevier Science B.V.
The complete nucleotide sequence of two tick-transmitted flaviviruses, Vasilchenko (Vs) from Siberia and louping ill (LI) from the UK, have been determined. The genomes were respectively, 10928 and 10871 nucleotides (nt) in length. The coding strategy and functional protein sequence motifs of tick-borne flaviviruses are presented in both Vs and LI viruses. The phylogenies based on maximum likelihood, maximum parsimony and distance analysis of the polyproteins, identified Vs virus as a member of the tick-borne encephalitis virus subgroup within the tick-borne serocomplex, genus Flavivirus, family Flaviviridae. Comparative alignment of the 3'-untranslated regions revealed deletions of different lengths essentially at the same position downstream of the stop codon for all tick-borne viruses. Two direct 27 nucleotide repeats at the 3'-end were found only for Vs and LI virus. Immediately following the deletions a region of 332-334 nt with relatively conserved primary structure (67-94% identity) was observed at the 3'-non-coding end of the virus genome. Pairwise comparisons of the nucleotide sequence data revealed similar levels of variation between the coding region, and the 5' and 3'-termini of the genome, implying an equivalent strong selective control for translated and untranslated regions. Indeed the predicted folding of the 5' and 3'-untranslated regions revealed patterns of stem and loop structures conserved for all tick-borne flaviviruses suggesting a purifying selection for preservation of essential RNA secondary structures which could be involved in translational control and replication. The possible implications of these findings are discussed. (C) 1997 Elsevier Science B.V.