State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Synth Biol. 2021 Oct 15;10(10):2617-2627. doi: 10.1021/acssynbio.1c00232. Epub 2021 Sep 20.
A large number of fuselloviruses have been found in acidic hot springs around the globe. They share a set of highly conserved genes (core genes) and possess a varying number of less-conserved genes (non-core genes). However, the functions of most of these genes are unknown. Recent studies show that as many as half of these genes tolerate mutation. In this study, we conducted a genetic analysis on spindle-shaped virus 22 (SSV22), an alphafusellovirus with fewer open reading frames (ORFs) than most of the isolated fuselloviruses. Both deletion and frame-shift mutations were introduced into nearly all of the 26 ORFs of the viral genome. A total of 17 ORFs were indispensable, and two additional ORFs were required for the optimal infectivity of the virus. Deletion of either VP2 or VP3, the two structural proteins, did not affect the morphology or infectivity of the virus. An infectious SSV22 derivative carrying a minimal genome of 20 ORFs was obtained. The SSV22 capsid was capable of accommodating a genome as large as ∼18 kb, or ∼7 kb larger than that of the wild-type virus. The viral capsid varied in both the length and width, but not in shape, with the size of the genome. Our results will facilitate the analysis of crucial protein-protein interactions between SSV22 and the host during viral infection and help explore the use of SSV22 as a vector for DNA delivery in potential applications.
在全球范围内的酸性温泉中发现了大量的纺锤形病毒。它们共享一套高度保守的基因（核心基因），并拥有数量不等的较少保守的基因（非核心基因）。然而，这些基因的大多数功能仍然未知。最近的研究表明，多达一半的这些基因能够容忍突变。在这项研究中，我们对纺锤形病毒 22（SSV22）进行了遗传分析，这是一种阿尔法纺锤形病毒，其开放阅读框（ORF）比大多数分离的纺锤形病毒少。我们几乎在病毒基因组的 26 个 ORF 中都引入了缺失和移框突变。共有 17 个 ORF 是必不可少的，另外两个 ORF 是病毒最佳感染性所必需的。缺失病毒的两个结构蛋白 VP2 或 VP3 并不影响病毒的形态或感染力。我们获得了一种携带最小基因组 20 个 ORF 的可感染 SSV22 衍生物。SSV22 衣壳能够容纳大小约为 18kb 的基因组，比野生型病毒大约 7kb。病毒衣壳的长度和宽度都有所变化，但形状不变，与基因组的大小有关。我们的结果将有助于分析 SSV22 在病毒感染过程中与宿主之间的关键蛋白-蛋白相互作用，并有助于探索 SSV22 作为 DNA 递送载体在潜在应用中的用途。
