Fig. 2: SARS-CoV-2 Nsp15 mutant (H234A) in vitro characterization.
From: SARS-CoV-2 EndoU-ribonuclease regulates RNA recombination and impacts viral fitness
a Sequence alignment of Nsp15 endoribonuclease domain from different coronaviruses. b SARS-CoV-2 Nsp15 hexamer (grey) with catalytic amino acid residues labeled (blue). The histidine-to-alanine mutation at amino acid position 234 is in red. c Schematic of the Nsp15 structure showing the N-terminal domain (ND), middle domain (MD), and endoribonuclease domain (endoU). Nucleotides in red represent the 2-bp substitution in the H234A mutant. d Viral replication in Vero E6 cells infected with WT (black) or H234A (red) at MOI = 0.01. e Viral replication of Calu-3 2B4 cells infected with WT (black) or H234A (red) at MOI = 0.01. f Vero E6 cells were treated with control (solid) or 100 U type I interferon (IFN) (hashed) 16 h prior to infection with WT (black) or H234A (red) at MOI = 0.01. Viral replication was measured at 48 h post infection. The fold change relative to control is shown in brackets for each virus. d–f Data are presented as mean ± SD. Statistics are conducted with two-tailed Student’s t-test, α = 0.05, N = 6 from two experiments with three biological replicates each.
