Skip to main content
. Author manuscript; available in PMC: 2021 Apr 9.
Published in final edited form as: Nature. 2020 Aug 27;586(7830):560–566. doi: 10.1038/s41586-020-2708-8

Figure 1. Generation of mouse adapted SARS-CoV-2 MA.

Figure 1.

(A) Amino acid (AA) table of group 2B spike receptor binding domain (RBD) hACE2 interaction residues. AA positions are numbered relative to SARS-CoV-1 (above) and SARS-CoV-2 (below). Green residues are contacts as determined by published crystal structures. AAs colored by BLOSUM62 conservation score relative to SARS-CoV-1 Urbani (red=least conserved; blue=most conserved). SARS-CoV-1 Urbani, SARS-CoV-1 MA15, WIV1, and SHC014 can utilize mACE2 as a functional receptor whereas SARS-CoV-2 cannot. Red box indicates Q498 in SARS-CoV-2 that is a hACE2 contact for both SARS-CoV-1 and SARS-CoV-2, and is uniquely divergent in SARS-CoV-2. (B) SARS-CoV-2 WT RBD and hACE2 interface (PDB: 6m0j). SARS-CoV-2 Q498 (red) interacts with Q42 (magenta) of hACE2. (C) Modelling of SARS-CoV-2 WT RBD and mACE2. SARS-CoV-2 Q498 no longer interacts with Q42 of mACE2. (D) Modelling of SARS-CoV-2 Q498Y and P499T (orange) substitutions restore interaction with Q42 of mACE2. (E) Modelling of SARS-CoV-2 Q498Y/P499T maintains interaction with Q42 of hACE2. (F–G) Single step growth curve of SARS-CoV-2 WT and SARS-CoV-2 MA in Vero E6 cells (F) and differentiated primary human bronchiolar epithelial cells (HAEs) (G). Dotted line represents limit of detection (LOD). Log transformed data analyzed by 2-way ANOVA followed by Sidak’s multiple comparisons. (F) ‘*’ denotes p=0.0053 (36 hours). (H) Non-permissive DBT-9 cells were transfected to express hACE2 or mACE2 and infected with SARS-CoV-2 WT and SARS-CoV-2 MA. Viral RNA was quantified by qRT-PCR at 24 hours post infection and scaled to empty vector transfected cells. Log transformed data analyzed by 2-way ANOVA followed by Dunnett’s multiple comparisons. ‘*’ denotes p=0.0322 (hACE2), <0.0001 (mACE2). (F-H) n=3 techical replicates for each group, representative of 2 independent experiments. Error bars represent standard deviation about the mean.