3.4.1 RNA-dependent RNA polymerase (RdRp)
The most important conserved protein in the coronavirus replication/transcription complex is RNA-dependent RNA polymerase (RdRp) (nsp12) or RNA replicase (Gao et al., 2020). Genome multiplication is critical in the viral life cycle and can be an attractive target for the intervention in the infection progress.
The antiviral agents of remdesivir, favipiravir, penciclovir can inhibit the RNA-dependent RNA polymerase (RdRp) of many RNA viruses, specially the influenza virus. Wang et al. determined the efficiency of these agents on infected Vero E6 cells with 2019-nCoVBetaCoV (Li and De Clercq, 2020; Wang et al., 2020; Zhang et al., 2020b). The high concentrations of penciclovir (EC50 = 95.96 μM) and favipiravir (EC50 = 61.88 μM) were required to reduce the viral infection while remdesivir (EC50 = 0.77 μM) potently blocked the virus infection at low-micromolar concentration.