Rümenapf T, Strauss E G, Strauss J H
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Virology. 1995 Apr 20;208(2):621-33. doi: 10.1006/viro.1995.1193.
Aura virus is an alphavirus present in Brazil and Argentina that is serologically related to Sindbis virus (present throughout the Old World) and to Western equine encephalitis (WEE) virus (present in the Americas). We have previously shown that WEE is a recombinant virus whose glycoproteins and part of whose 3' nontranslated region (NTR) are derived from a Sindbis-like virus, but the remainder of whose genome is derived from Eastern equine encephalitis (EEE) virus. We show here that Aura virus is a Sindbis-like virus that shares considerable organizational and sequence identity with Sindbis virus. Certain nucleotide sequence elements present in Aura RNA that are believed to function as promoters are almost identical to their Sindbis counterparts, repeated elements in the 3' nontranslated region are shared with Sindbis virus, and important antigenic epitopes are conserved between the two viruses. Despite their close relationship, the two viruses have diverged significantly, sharing 73% amino acid sequence identity in the nonstructural proteins and 62% identity in the structural proteins. This is about the same as the identities between EEE and Venezuelan equine encephalitis virus, whose promoter elements, 3' NTRs, and antigenic epitopes have diverged more radically, such that these two viruses are considered to belong to different subgroups. Importantly, the glycoproteins of WEE are more closely related to those of Sindbis than to those of Aura virus. From this we propose that an ancestral Sindbis-like virus present in the Americas (probably South America) diverged 1000-2000 years ago into a lineage that gave rise to Aura virus and a lineage that gave rise to Sindbis virus and to the Sindbis-like parent of WEE. At some time after this divergence, a Sindbis-like virus belonging to the latter lineage was transferred to the Old World where it gave rise to Sindbis viruses distributed throughout the Old World, and in a separate event a Sindbis-like virus belonging to the same lineage underwent recombination with EEE to give rise to WEE.
奥拉病毒是一种存在于巴西和阿根廷的甲病毒，在血清学上与辛德毕斯病毒（存在于整个旧世界）以及西部马脑炎（WEE）病毒（存在于美洲）相关。我们之前已经表明，WEE是一种重组病毒，其糖蛋白和部分3'非翻译区（NTR）源自一种辛德毕斯样病毒，但其基因组的其余部分源自东部马脑炎（EEE）病毒。我们在此表明，奥拉病毒是一种辛德毕斯样病毒，与辛德毕斯病毒具有相当多的结构组织和序列同一性。奥拉RNA中存在的某些被认为起启动子作用的核苷酸序列元件与其辛德毕斯对应元件几乎相同，3'非翻译区的重复元件与辛德毕斯病毒共有，并且两种病毒之间重要的抗原表位是保守的。尽管它们关系密切，但这两种病毒已经显著分化，非结构蛋白的氨基酸序列同一性为73%，结构蛋白的同一性为62%。这与EEE和委内瑞拉马脑炎病毒之间的同一性大致相同，它们的启动子元件、3' NTR和抗原表位分化得更为彻底，以至于这两种病毒被认为属于不同的亚组。重要的是，WEE的糖蛋白与辛德毕斯的糖蛋白比与奥拉病毒的糖蛋白关系更密切。由此我们提出，存在于美洲（可能是南美洲）的一种祖先辛德毕斯样病毒在1000 - 2000年前分化为一个产生奥拉病毒的谱系以及一个产生辛德毕斯病毒和WEE的辛德毕斯样亲本的谱系。在这次分化后的某个时候，属于后一个谱系的一种辛德毕斯样病毒被转移到旧世界，在那里它产生了分布于整个旧世界的辛德毕斯病毒，并且在一个单独的事件中，属于同一谱系的一种辛德毕斯样病毒与EEE发生重组从而产生了WEE。
