Fig. 2: NHC incorporation does not stall SARS-CoV-2 RdRp.
From: Mechanism of molnupiravir-induced SARS-CoV-2 mutagenesis
a, The RNA template–product duplex (as in Fig. 1c) allows for RNA extension by four nucleotides. The direction of RNA extension is indicated. The 5′ end of the RNA product contains a FAM fluorescent label. C* at the 3′ end of the template indicates dideoxy-C (ddC). b, RNA elongation to the end of the template in a is possible when MTP replaces either CTP or UTP in the presence of adenosine triphosphate (ATP). The experiment was performed once. c, The RNA template–product hairpin duplex allows for RNA extension by 11 nucleotides. d, RNA elongation stalls at the expected positions when the cognate NTP is withheld from the reaction. Extension to the end of the template is possible when MTP replaces either CTP or UTP in the presence of other substrate NTPs, showing that incorporation of M does not prevent RNA extension. Note that more efficient RNA extension is seen at higher NTP/MTP concentrations, and also for MTP replacing UTP (not shown). The experiment was performed once. Uncropped gel images for b and d are available as source data.
