Johnstone Bronte A, Hardy Joshua M, Ha Jungmin, Butkovic Anamarija, Koszalka Paulina, Accurso Cathy, Venugopal Hariprasad, de Marco Alex, Krupovic Mart, Coulibaly Fasséli
Infection Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.
Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.
Sci Adv. 2024 Dec 20;10(51):eado2631. doi: 10.1126/sciadv.ado2631. Epub 2024 Dec 18.
Baculovirus is the most studied insect virus owing to a broad ecological distribution and ease of engineering for biotechnological applications. However, its structure and evolutionary place in the virosphere remain enigmatic. Using cryo-electron microscopy, we show that the nucleocapsid forms a covalently cross-linked helical tube protecting a highly compacted 134-kilobase pair DNA genome. The ends of the tube are sealed by the base and cap substructures, which share a 126-subunit hub but differ in components that promote actin tail-mediated propulsion and nuclear entry of the nucleocapsid, respectively. Unexpectedly, sensitive searches for hidden evolutionary links show that the morphogenetic machinery and conserved oral infectivity factors originated within the lineage of baculo-like viruses (class ). The unique viral architecture and structural atlas of hallmark proteins firmly place these viruses into a separate new realm, the highest taxonomy rank, and provide a structural framework to expand their use as sustainable bioinsecticides and biomedical tools.
杆状病毒是研究最多的昆虫病毒，因其具有广泛的生态分布且易于进行生物技术应用的工程改造。然而，其在病毒圈中的结构和进化地位仍然成谜。利用冷冻电子显微镜，我们发现核衣壳形成了一个共价交联的螺旋管，保护着高度压缩的134千碱基对的DNA基因组。管的两端由基部和帽状亚结构封闭，它们共享一个126亚基的中心，但在分别促进肌动蛋白尾介导的推进和核衣壳核进入的成分上有所不同。出乎意料的是，对隐藏进化联系的敏感搜索表明，形态发生机制和保守的经口感染因子起源于杆状样病毒谱系（类）之内。独特的病毒结构和标志性蛋白质的结构图谱将这些病毒牢固地置于一个单独的新领域，即最高分类等级，并提供了一个结构框架，以扩大它们作为可持续生物杀虫剂和生物医学工具的用途。
