9ART image
Entry Detail
PDB ID:
9ART
Title:
Crystal structure of SARS-CoV-2 main protease A191T mutant in complex with an inhibitor 5h
Biological Source:
PDB Version:
Deposition Date:
2024-02-23
Release Date:
2024-04-24
Method Details:
Experimental Method:
Resolution:
1.49 Å
R-Value Free:
0.23
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:3C-like proteinase nsp5
Mutations:A191T
Chain IDs:A, B (auth: D)
Chain Length:305
Number of Molecules:2
Biological Source:Severe acute respiratory syndrome coronavirus 2
Ligand Molecules
Primary Citation
Structural and virologic mechanism of the emergence of resistance to M pro inhibitors in SARS-CoV-2.
Proc.Natl.Acad.Sci.USA 121 e2404175121 e2404175121 (2024)
PMID: 39236245 DOI: 10.1073/pnas.2404175121

Abstact

We generated SARS-CoV-2 variants resistant to three SARS-CoV-2 main protease (Mpro) inhibitors (nirmatrelvir, TKB245, and 5h), by propagating the ancestral SARS-CoV-2WK521WT in VeroE6TMPRSS2 cells with increasing concentrations of each inhibitor and examined their structural and virologic profiles. A predominant E166V-carrying variant (SARS-CoV-2WK521E166V), which emerged when passaged with nirmatrelvir and TKB245, proved to be resistant to the two inhibitors. A recombinant SARS-CoV-2E166V was resistant to nirmatrelvir and TKB245, but sensitive to 5h. X-ray structural study showed that the dimerization of Mpro was severely hindered by E166V substitution due to the disruption of the presumed dimerization-initiating Ser1'-Glu166 interactions. TKB245 stayed bound to MproE166V, whereas nirmatrelvir failed. Native mass spectrometry confirmed that nirmatrelvir and TKB245 promoted the dimerization of Mpro, and compromised the enzymatic activity; the Ki values of recombinant MproE166V for nirmatrelvir and TKB245 were 117±3 and 17.1±1.9 µM, respectively, indicating that TKB245 has a greater (by a factor of 6.8) binding affinity to MproE166V than nirmatrelvir. SARS-CoV-2WK521WT selected with 5h acquired A191T substitution in Mpro (SARS-CoV-2WK521A191T) and better replicated in the presence of 5h, than SARS-CoV-2WK521WT. However, no significant enzymatic or structural changes in MproA191T were observed. The replicability of SARS-CoV-2WK521E166V proved to be compromised compared to SARS-CoV-2WK521WT but predominated over SARS-CoV-2WK521WT in the presence of nirmatrelvir. The replicability of SARS-CoV-2WK521A191T surpassed that of SARS-CoV-2WK521WT in the absence of 5h, confirming that A191T confers enhanced viral fitness. The present data should shed light on the understanding of the mechanism of SARS-CoV-2's drug resistance acquisition and the development of resistance-repellant COVID-19 therapeutics.

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