Potent broad-spectrum anti-coronaviral frameshift inhibitors from virtual screen of RNA binding

Coronavirus genomes contain an RNA pseudoknot that directs −1 programmed ribosomal frameshifting (−1 PRF) to control expression of viral proteins crucial for replication. Ligands that inhibit −1 PRF can thus attenuate viral propagation and have potential as drugs for limiting coronavirus infections. To search for novel small-molecule frameshift inhibitors with anticoronaviral activity, we computationally screened over 14 million compounds for binding to the SARS-CoV-2 pseudoknot, followed by experimental validation of the top hits for inhibition of −1 PRF and viral replication. We identified multiple potent −1 PRF inhibitors, effective at nM concentrations, some of which significantly suppressed SARS-CoV-2 replication in cell culture. Several compounds also inhibited −1 PRF in multiple representative bat coronaviruses, indicating broad-spectrum activity. These results showcase the promise of viral RNA structures like frameshift-stimulatory pseudoknots as targets for broad-spectrum antiviral drugs.