Feline coronavirus drug inhibits the main protease of SARS-CoV-2 and blocks virus replication

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.201 

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Feline coronavirus drug inhibits the main protease of SARS-CoV-2 and blocks virus replication.

Vuong, W.Khan, M.B.Fischer, C.Arutyunova, E.Lamer, T.Shields, J.Saffran, H.A.McKay, R.T.van Belkum, M.J.Joyce, M.A.Young, H.S.Tyrrell, D.L.Vederas, J.C.Lemieux, M.J.

(2020) Nat Commun 11: 4282-4282

  • DOI: https://doi.org/10.1038/s41467-020-18096-2
  • Primary Citation of Related Structures:  
    6WTJ, 6WTK, 6WTM

  • PubMed Abstract: 

    The main protease, M pro (or 3CL pro ) in SARS-CoV-2 is a viable drug target because of its essential role in the cleavage of the virus polypeptide. Feline infectious peritonitis, a fatal coronavirus infection in cats, was successfully treated previously with a prodrug GC376, a dipeptide-based protease inhibitor. Here, we show the prodrug and its parent GC373, are effective inhibitors of the M pro from both SARS-CoV and SARS-CoV-2 with IC 50 values in the nanomolar range. Crystal structures of SARS-CoV-2 M pro with these inhibitors have a covalent modification of the nucleophilic Cys145. NMR analysis reveals that inhibition proceeds via reversible formation of a hemithioacetal. GC373 and GC376 are potent inhibitors of SARS-CoV-2 replication in cell culture. They are strong drug candidates for the treatment of human coronavirus infections because they have already been successful in animals. The work here lays the framework for their use in human trials for the treatment of COVID-19.

  • Organizational Affiliation

    Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2R3, AB, Canada. lorne.tyrrell@ualberta.ca.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
3C-like proteinase306Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
Gene Names: rep1a-1b
EC: (PDB Primary Data), (UniProt), 3.4.22 (UniProt), (UniProt), (UniProt), (UniProt), 3.1.13 (UniProt), 4.6.1 (UniProt), (UniProt)
Find proteins for P0DTD1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTD1 
Go to UniProtKB:  P0DTD1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTD1
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
K36 (Subject of Investigation/LOI)
Query on K36

Download Ideal Coordinates CCD File 
B [auth A](1S,2S)-2-({N-[(benzyloxy)carbonyl]-L-leucyl}amino)-1-hydroxy-3-[(3S)-2-oxopyrrolidin-3-yl]propane-1-sulfonic acid
C21 H31 N3 O8 S
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.201 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 114.97α = 90
b = 53.81β = 101.742
c = 45.5γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)Canada--
Natural Sciences and Engineering Research Council (NSERC, Canada)Canada549297-2019

Revision History  (Full details and data files)

  • Version 1.0: 2020-05-20
    Type: Initial release
  • Version 1.1: 2020-05-27
    Changes: Derived calculations
  • Version 1.2: 2020-09-09
    Changes: Database references
  • Version 1.3: 2023-10-18
    Changes: Data collection, Database references, Refinement description