Institute of Biotechnology and Department of Biosciences, Biocenter 3, P.O. Box 65 (Viikinkaari 1), FI-00014 University of Helsinki, Helsinki, Finland.
J Virol. 2010 May;84(9):4747-54. doi: 10.1128/JVI.02156-09. Epub 2010 Feb 17.
Archaea often live in extreme, harsh environments such as acidic hot springs and hypersaline waters. To date, only two icosahedrally symmetric, membrane-containing archaeal viruses, SH1 and Sulfolobus turreted icosahedral virus (STIV), have been described in detail. We report the sequence and three-dimensional structure of a third such virus isolated from a hyperthermoacidophilic crenarchaeon, Sulfolobus strain G4ST-2. Characterization of this new isolate revealed it to be similar to STIV on the levels of genome and structural organization. The genome organization indicates that these two viruses have diverged from a common ancestor. Interestingly, the prominent surface turrets of the two viruses are strikingly different. By sequencing and mass spectrometry, we mapped several large insertions and deletions in the known structural proteins that could account for these differences and showed that both viruses can infect the same host. A combination of genomic and proteomic analyses revealed important new insights into the structural organization of these viruses and added to our limited knowledge of archaeal virus life cycles and host-cell interactions.
古菌通常生活在极端、恶劣的环境中，如酸性温泉和高盐度水域。迄今为止，只有两种二十面体对称、含膜的古菌病毒，即 SH1 和 Sulfolobus 塔式二十面体病毒（STIV），被详细描述过。我们报告了从一种高温嗜酸古菌 Sulfolobus 菌株 G4ST-2 中分离出的第三种此类病毒的序列和三维结构。对这种新分离物的特征分析表明，它在基因组和结构组织水平上与 STIV 相似。基因组组织表明，这两种病毒是从一个共同的祖先中分化出来的。有趣的是，这两种病毒表面明显的塔状结构截然不同。通过测序和质谱分析，我们在已知的结构蛋白中发现了几个大的插入和缺失，这些缺失可能导致了这些差异，并表明这两种病毒可以感染相同的宿主。基因组和蛋白质组分析的结合为这些病毒的结构组织提供了重要的新见解，并增加了我们对古菌病毒生命周期和宿主细胞相互作用的有限认识。
