Here we report the discovery of Yaravirus, a lineage of amoebal virus with a puzzling origin and evolution. Yaravirus presents 80-nm-sized particles and a 44,924-bp dsDNA genome encoding for 74 predicted proteins. Yaravirus genome annotation showed that none of its genes matched with sequences of known organisms at the nucleotide level; at the amino acid level, six predicted proteins had distant matches in the nr database. Complimentary prediction of three-dimensional structures indicated possible function of 17 proteins in total. Furthermore, we were not able to retrieve viral genomes closely related to Yaravirus in 8,535 publicly available metagenomes spanning diverse habitats around the globe. The Yaravirus genome also contained six types of tRNAs that did not match commonly used codons. Proteomics revealed that Yaravirus particles contain 26 viral proteins, one of which potentially representing a divergent major capsid protein (MCP) with a predicted double jelly-roll domain. Structure-guided phylogeny of MCP suggests that Yaravirus groups together with the MCPs of Pleurochrysis endemic viruses. Yaravirus expands our knowledge of the diversity of DNA viruses. The phylogenetic distance between Yaravirus and all other viruses highlights our still preliminary assessment of the genomic diversity of eukaryotic viruses, reinforcing the need for the isolation of new viruses of protists.

在这里，我们报道了雅拉病毒的发现，雅拉病毒是一种具有令人困惑的起源和进化的变形虫病毒谱系。雅拉病毒呈现80纳米大小的粒子和一个44924 bp的dsDNA基因组，编码74种预测的蛋白质。雅拉病毒基因组注释显示，其基因均未在核苷酸水平上与已知生物的序列匹配。在氨基酸水平上，六个预测的蛋白质在nr数据库中具有远距离的匹配。三维结构的免费预测表明总共可能有17种蛋白质的功能。此外，我们无法在跨越全球不同栖息地的8,535个可公开获得的元基因组中检索与雅拉病毒密切相关的病毒基因组。雅拉病毒基因组还包含六种与常用密码子不匹配的tRNA。蛋白质组学显示，雅拉病毒颗粒包含26种病毒蛋白，其中一种可能代表具有预测的双胶卷结构域的不同主要衣壳蛋白（MCP）。MCP的结构指导系统发育表明，雅拉病毒组与MCP的MCP一起胸膜炎地方病毒。雅拉病毒扩大了我们对DNA病毒多样性的认识。雅拉病毒与所有其他病毒之间的系统发育距离突显了我们对真核病毒基因组多样性的初步评估，从而增强了分离新的原生生物病毒的需要。