McGuire John V, Horowitz Scott
Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA.
RNA Biol. 2025 Dec;22(1):1-10. doi: 10.1080/15476286.2025.2501714. Epub 2025 May 30.
Nsp15 is an EndoU nuclease that is partially responsible for SARS-CoV-2's ability to evade the immune system response. Despite its importance, the sequence specificity of Nsp15 remains difficult to fully determine. In this work, we use a systematic approach to measure Nsp15's sequence specificity by testing all 16 dinucleotides for cleavage activity. The results show a preference for uridine in the first dinucleotide position, but with varying specificity in the second position. Using Alphafold3 predictions to examine the structural basis of this specificity suggests important contacts 3' of the dinucleotide sequence as well as contacts to the dinucleotides that agree with the cleavage specificity.
Nsp15是一种内切核酸酶U，它对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）逃避免疫系统反应的能力负有部分责任。尽管其很重要，但Nsp15的序列特异性仍难以完全确定。在这项工作中，我们采用一种系统方法，通过测试所有16种二核苷酸的切割活性来测量Nsp15的序列特异性。结果表明，在第一个二核苷酸位置上偏好尿苷，但在第二个位置上具有不同的特异性。使用Alphafold3预测来研究这种特异性的结构基础，结果表明二核苷酸序列3'处存在重要的接触，以及与符合切割特异性的二核苷酸的接触。
