Janowski Andrew B, Jiang Hongbing, Fujii Chika, Owen Macee C, Bricker Traci L, Darling Tamarand L, Harastani Houda H, Seehra Kuljeet, Tahan Stephen, Jung Ana, Febles Binita, Blatter Joshua A, Handley Scott A, Parikh Bijal A, Lulla Valeria, Boon Adrianus Cm, Wang David
bioRxiv. 2022 May 2:2022.04.30.486882. doi: 10.1101/2022.04.30.486882.
The stem-loop II motif (s2m) is an RNA element present in viruses from divergent viral families, including astroviruses and coronaviruses, but its functional significance is unknown. We created deletions or substitutions of the s2m in astrovirus VA1 (VA1), classic human astrovirus 1 (HAstV1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For VA1, recombinant virus could not be rescued upon partial deletion of the s2m or substitutions of G-C base pairs. Compensatory substitutions that restored the G-C base-pair enabled recovery of VA1. For HAstV1, a partial deletion of the s2m resulted in decreased viral titers compared to wild-type virus, and reduced activity in a replicon system. In contrast, deletion or mutation of the SARS-CoV-2 s2m had no effect on the ability to rescue the virus, growth , or growth in Syrian hamsters. Our study demonstrates the importance of the s2m is virus-dependent.
茎环II基序（s2m）是一种存在于多种不同病毒科病毒中的RNA元件，包括星状病毒和冠状病毒，但其功能意义尚不清楚。我们对星状病毒VA1（VA1）、经典人类星状病毒1型（HAstV1）和严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的s2m进行了缺失或替换。对于VA1，在s2m部分缺失或G-C碱基对被替换后，重组病毒无法拯救成功。恢复G-C碱基对的补偿性替换使VA1得以拯救成功。对于HAstV1，与野生型病毒相比，s2m的部分缺失导致病毒滴度降低，并且在复制子系统中的活性降低。相比之下，SARS-CoV-2 s2m的缺失或突变对病毒拯救能力、生长以及在叙利亚仓鼠中的生长均无影响。我们的研究表明，s2m的重要性因病毒而异。
