Department of Chemistry and Biochemistry, Montana State University, 126 Chemistry Biochemistry Bldg., Bozeman, MT 59717, USA.
Virology. 2011 Sep 1;417(2):362-8. doi: 10.1016/j.virol.2011.06.019. Epub 2011 Jul 20.
One of the outstanding questions in biology today is the origin of viruses. We have discovered a protein in the hyperthermophile Sulfolobus solfataricus while following proteome regulation during viral infection that led to the discovery of a fossil provirus. Characterization of the wild type and recombinant protein revealed that it assembled into virus-like particles with a diameter of ~32nm. Sequence and structural analyses showed that the likely proviral capsid protein, Sso2749, is homologous to a protein from Pyrococcus furiosus that forms virus-like particles using the HK-97 major capsid protein fold. The SsP2-provirus appears mosaic and contains proteins with similarity to, among others, eukaryotic herpesviruses and tailed dsDNA bacteriophage families, reinforcing the hypothesis of a common ancestral gene pool across all three domains of life. This is the first description of the HK-97 fold in a crenarchaeal virus and the first direct genomic connection of linocin-like protein cages to a virus.
今天生物学中一个悬而未决的问题是病毒的起源。我们在研究嗜热古菌 Sulfolobus solfataricus 中的蛋白质组调控时，在病毒感染过程中发现了一种蛋白，进而发现了一种古病毒前病毒。对野生型和重组蛋白的特性分析表明，它组装成直径约为 32nm 的病毒样颗粒。序列和结构分析表明，可能的前病毒衣壳蛋白 Sso2749 与来自 Pyrococcus furiosus 的蛋白具有同源性，后者使用 HK-97 主要衣壳蛋白折叠形成病毒样颗粒。SsP2-前病毒呈现镶嵌结构，包含与真核疱疹病毒和长尾 dsDNA 噬菌体家族等相似的蛋白，这进一步证实了所有生命领域都具有共同的祖先基因库这一假说。这是首次在古菌病毒中描述 HK-97 折叠，也是首次将类林可霉素蛋白笼与病毒直接联系起来。
