Figure 4: nsp8₂’s N-terminal domain is not required for RNA synthesis.

A) Model of nsp7 (blue) and nsp8 (red) heterodimer (PDB ID: 7KRP). The black dots and squiggly line depict the nsp8 and nsp7 termini that are fused in nsp8L7. The dashed black line is the site of truncation of nsp80394L7, removing the nsp8₂ N-terminal 79 amino acid RNA binding domain. B) PEDV and C) SARS-CoV-2 polymerase complex activity using the nsp8L7 and nsp8ΔL7 co-factors. Reactions were run in triplicate and percent activity was compared to a wildtype nsp7+nsp8+nsp12 complex. Error bars indicate standard deviation of the triplicates. Each reaction was determined to be significantly different than all other complexes tested (p<0.05) using an unpaired t-test.