Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recently identified coronavirus that causes the respiratory disease known as coronavirus disease 2019 (COVID-19). Despite the urgent need, we still do not fully understand the molecular basis of SARS-CoV-2 pathogenesis. Here, we comprehensively define the interactions between SARS-CoV-2 proteins and human RNAs. NSP16 binds to the mRNA recognition domains of the U1 and U2 splicing RNAs and acts to suppress global mRNA splicing upon SARS-CoV-2 infection. NSP1 binds to 18S ribosomal RNA in the mRNA entry channel of the ribosome and leads to global inhibition of mRNA translation upon infection. Finally, NSP8 and NSP9 bind to the 7SL RNA in the signal recognition particle and interfere with protein trafficking to the cell membrane upon infection. Disruption of each of these essential cellular functions acts to suppress the interferon response to viral infection. Our results uncover a multipronged strategy utilized by SARS-CoV-2 to antagonize essential cellular processes to suppress host defenses.

lactose permease ͉ major facilitator superfamily ͉ single-molecule spectroscopy ͉ transporters T he lactose permease of Escherichia coli (LacY), a member of the major facilitator superfamily, utilizes free energy stored in an electrochemical H ϩ gradient (⌬ Hϩ ) to drive active transport by coupling the downhill, stoichiometric translocation of H ϩ with ⌬ Hϩ to the uphill accumulation of galactopyranosides. Conversely, in the absence of ⌬ Hϩ , LacY utilizes free energy released from downhill translocation of galactosides in either direction to drive uphill translocation of H ϩ with generation of ⌬ Hϩ (reviewed in ref.

We describe a high-throughput, automated single-molecule measurement system, equipped with microfluidics. the microfluidic mixing device has integrated valves and pumps to accurately accomplish titration of biomolecules with picoliter resolution. We demonstrate that the approach enabled rapid sampling of biomolecule conformational landscape and of enzymatic activity, in the form of transcription by Escherichia coli RNA polymerase, as a function of the chemical environment.