Cryo-electron Microscopy and Exploratory Antisense Targeting of the 28-kDa Frameshift Stimulation Element from the SARS-CoV-2 RNA Genome.

摘要: Drug discovery campaigns against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are beginning to target the viral RNA genome 1, . The frameshift stimulation element (FSE) of SARS-CoV-2 is required for balanced expression essential proteins and highly conserved, making it a potential candidate antiviral targeting by small molecules oligonucleotides 3-6 To aid global efforts focusing on frameshifting, we report exploratory results from frameshifting cellular replication experiments with locked nucleic acid (LNA) antisense (ASOs), which support FSE as therapeutic but highlight difficulties in achieving strong inactivation. understand current limitations, applied cryogenic electron microscopy (cryo-EM) Ribosolve 7 pipeline determine three-dimensional structure FSE, validated through an nanostructure tagging method. This smallest macromolecule (88 nt; 28 kDa) resolved single-particle cryo-EM at subnanometer resolution date. tertiary model, defined estimated accuracy 5.9 A, presents topologically complex fold 5' end threads ring formed inside three-stem pseudoknot. Our suggest updated model well binding sites that may be targeted next generation ASOs molecules.