Department of Biosciences and Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland.
Proc Natl Acad Sci U S A. 2013 Jun 25;110(26):10604-9. doi: 10.1073/pnas.1303047110. Epub 2013 Jun 3.
It has been proposed that viruses can be divided into a small number of structure-based viral lineages. One of these lineages is exemplified by bacterial virus Hong Kong 97 (HK97), which represents the head-tailed dsDNA bacteriophages. Seemingly similar viruses also infect archaea. Here we demonstrate using genomic analysis, electron cryomicroscopy, and image reconstruction that the major coat protein fold of newly isolated archaeal Haloarcula sinaiiensis tailed virus 1 has the canonical coat protein fold of HK97. Although it has been anticipated previously, this is physical evidence that bacterial and archaeal head-tailed viruses share a common architectural principle. The HK97-like fold has previously been recognized also in herpesviruses, and this study expands the HK97-like lineage to viruses from all three domains of life. This is only the second established lineage to include archaeal, bacterial, and eukaryotic viruses. Thus, our findings support the hypothesis that the last common universal ancestor of cellular organisms was infected by a number of different viruses.
有人提出，病毒可以分为少数几个基于结构的病毒谱系。其中一个谱系由细菌病毒香港 97（HK97）代表，它代表了有尾的双链 DNA 噬菌体。看似相似的病毒也感染古菌。在这里，我们通过基因组分析、电子 cryomicroscopy 和图像重建表明，新分离的古菌 Haloarcula sinaiiensis 长尾病毒 1 的主要外壳蛋白折叠具有 HK97 的典型外壳蛋白折叠。尽管之前已经预料到了，但这是细菌和古菌有尾病毒共享共同建筑原则的物理证据。HK97 样折叠以前也在疱疹病毒中被识别，本研究将 HK97 样谱系扩展到来自生命三个领域的病毒。这只是第二个建立的谱系，包括古菌、细菌和真核病毒。因此，我们的发现支持这样的假设，即细胞生物的最后一个共同祖先被多种不同的病毒感染。
