PDF(Pubmed)
Abstract：
Archaeal pleomorphic viruses belonging to the Pleolipoviridae family represent an enigmatic group as they exhibit unique genomic features and are thought to have evolved through recombination with different archaeal plasmids. However, most of our understanding of the diversity and evolutionary trajectories of this clade comes from a handful of isolated representatives. Here we present 164 new genomes of pleolipoviruses obtained from metagenomic data of Australian hypersaline lakes and publicly available metagenomic data. We perform a comprehensive analysis on the diversity and evolutionary relationships of the newly discovered viruses and previously described pleolipoviruses. We propose to classify the viruses into five genera within the Pleolipoviridae family, with one new genus represented only by virus genomes retrieved in this study. Our data support the current hypothesis that pleolipoviruses reshaped their genomes through recombining with multiple different groups of plasmids, which is reflected in the diversity of their predicted replication strategies. We show that the proposed genus Epsilonpleolipovirus has evolutionary ties to pRN1-like plasmids from Sulfolobus, suggesting that this group could be infecting other archaeal phyla. Interestingly, we observed that the genome size of pleolipoviruses is correlated to the presence or absence of an integrase. Analyses of the host range revealed that all but one virus exhibit an extremely narrow range, and we show that the predicted tertiary structure of the spike protein is strongly associated with the host family, suggesting a specific adaptation to the host S-layer glycoprotein organization.
摘要：
属于支链病毒科的古细菌多形性病毒代表了一个神秘的群体，因为它们表现出独特的基因组特征，并被认为是通过与不同的古细菌质粒重组而进化而来的。然而,我们对这个进化枝的多样性和进化轨迹的大部分理解来自少数孤立的代表。在这里，我们介绍了从澳大利亚高盐湖泊的宏基因组数据和公开可用的宏基因组数据获得的164个新的多脂病毒基因组。我们对新发现的病毒和先前描述的多脂病毒的多样性和进化关系进行了全面分析。我们建议将这些病毒分类为pleolipoviridae家族中的五个属，与一个新的属只代表病毒基因组在这项研究中检索。我们的数据支持当前的假设，即半乳脂病毒通过与多个不同的质粒组重组来重塑其基因组，这反映在他们预测的复制策略的多样性上。我们表明，拟议的Epsilonpleolipovirus属与来自Sulfolobus的pRN1样质粒具有进化联系，这表明这个群体可能感染了其他古细菌门。有趣的是,我们观察到，多脂病毒的基因组大小与整合酶的存在或不存在相关。对宿主范围的分析表明，除一种病毒外，所有病毒都表现出极窄的范围，我们发现预测的刺突蛋白的三级结构与宿主家族密切相关，表明对宿主S层糖蛋白组织的特定适应。
