Room temperature X-ray structure of SARS-CoV-2 main protease (Mpro) in complex with PF-07321332

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report

Ligand Structure Quality Assessment 

This is version 2.3 of the entry. See complete history


Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease

Kneller, D.W.Li, H.Phillips, G.Weiss, K.L.Zhang, Q.Arnould, M.A.Jonsson, C.B.Surendranathan, S.Parvathareddy, J.Blakeley, M.P.Coates, L.Louis, J.M.Bonnesen, P.V.Kovalevsky, A.

(2022) Nat Commun 13: 2268

  • DOI: https://doi.org/10.1038/s41467-022-29915-z
  • Primary Citation of Related Structures:  
    7SI9, 7TDU, 7TEH, 7TFR

  • PubMed Abstract: 

    Emerging SARS-CoV-2 variants continue to threaten the effectiveness of COVID-19 vaccines, and small-molecule antivirals can provide an important therapeutic treatment option. The viral main protease (M pro ) is critical for virus replication and thus is considered an attractive drug target. We performed the design and characterization of three covalent hybrid inhibitors BBH-1, BBH-2 and NBH-2 created by splicing components of hepatitis C protease inhibitors boceprevir and narlaprevir, and known SARS-CoV-1 protease inhibitors. A joint X-ray/neutron structure of the M pro /BBH-1 complex demonstrates that a Cys145 thiolate reaction with the inhibitor's keto-warhead creates a negatively charged oxyanion. Protonation states of the ionizable residues in the M pro active site adapt to the inhibitor, which appears to be an intrinsic property of M pro . Structural comparisons of the hybrid inhibitors with PF-07321332 reveal unconventional F···O interactions of PF-07321332 with M pro which may explain its more favorable enthalpy of binding. BBH-1, BBH-2 and NBH-2 exhibit comparable antiviral properties in vitro relative to PF-07321332, making them good candidates for further design of improved antivirals.

  • Organizational Affiliation

    Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, 38103, USA.

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
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
4WI (Subject of Investigation/LOI)
Query on 4WI

Download Ideal Coordinates CCD File 
B [auth A](1R,2S,5S)-N-{(1E,2S)-1-imino-3-[(3S)-2-oxopyrrolidin-3-yl]propan-2-yl}-6,6-dimethyl-3-[3-methyl-N-(trifluoroacetyl)-L-valyl]-3-azabicyclo[3.1.0]hexane-2-carboxamide
C23 H34 F3 N5 O4
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 
  • Space Group: I 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.544α = 90
b = 81.835β = 95.34
c = 91.736γ = 90
Software Package:
Software NamePurpose
CrysalisProdata reduction
Aimlessdata scaling

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2021-10-20
    Type: Initial release
  • Version 2.0: 2021-12-22
    Changes: Atomic model, Author supporting evidence, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2022-03-02
    Changes: Database references
  • Version 2.2: 2022-05-04
    Changes: Database references
  • Version 2.3: 2023-10-18
    Changes: Data collection, Refinement description