8X1X | pdb_00008x1x

SARS-CoV-2 Papain like protease (PLpro) in complex with inhibitor Lithocholic acid


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 
    0.284 (Depositor), 0.266 (DCC) 
  • R-Value Work: 
    0.239 (Depositor), 0.226 (DCC) 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Deubiquitinase inhibitors: Targeting SARS-CoV-2 papain-like protease with antiviral efficacy in a murine model.

Choudhary, S.Nehul, S.Nagaraj, S.K.Narayan, R.Verma, S.Sharma, S.Kumari, A.Rani, R.Saha, A.Sircar, D.Kaliappan, A.Tripathi, S.Sharma, G.K.Kumar, P.Tomar, S.

(2026) FEBS J 

  • DOI: https://doi.org/10.1111/febs.70399
  • Primary Citation of Related Structures:  
    8X1X, 8XTD

  • PubMed Abstract: 

    SARS-CoV-2 papain-like protease (PLpro) is a key antiviral target as it plays a dual role in viral replication and modulation of innate immune responses by deubiquitinating or deISGylating host proteins. Therefore, therapeutically targeting PLpro may serve as a two-pronged approach to mitigate SARS-CoV-2 infection. Interestingly, PLpro shares structural and functional similarities with cellular deubiquitinating enzymes (DUBs), and this fact was leveraged in our study to identify DUB inhibitors that target the ubiquitin/ISG15-binding site and the known substrate-binding pocket of PLpro. Among the identified compounds, flupenthixol, lithocholic acid, teneligliptin, and linagliptin markedly inhibited the proteolytic activity of purified PLpro and demonstrated potent antiviral effects against SARS-CoV-2 infection in a dose-dependent manner. Treatment with lithocholic acid and linagliptin suppressed the expression of inflammatory mediators, thereby restoring immune responses. Here, crystal structures of SARS-CoV-2 PLpro in complex with linagliptin and with lithocholic acid were determined, revealing insights into the mechanism of inhibition and unique interactions within the ubiquitin/ISG15-binding site (S2 site; Phe69, His73, Asn128, and His175) and the substrate-binding cleft. Additionally, oral and intraperitoneal treatments with linagliptin increased survival, reduced lung viral load, and ameliorated histopathological damage in a mouse-adapted model of SARS-CoV-2 infection. This study demonstrates for the first time that using DUB inhibitors that target the proteolytic activity of PLpro can simultaneously reinstate the host's immune response against SARS-CoV-2, highlighting the potential of this two-pronged therapeutic approach.


  • Organizational Affiliation
    • Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, India.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Papain-like protease nsp3316Severe acute respiratory syndrome coronavirus 2Mutation(s): 1 
Gene Names: rep1a-1b
EC: 3.4.19.12 (PDB Primary Data), 3.4.22 (PDB Primary Data)
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
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
4OA (Subject of Investigation/LOI)
Query on 4OA

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A],
D [auth A]
(3beta,5beta,14beta,17alpha)-3-hydroxycholan-24-oic acid
C24 H40 O3
SMEROWZSTRWXGI-HVATVPOCSA-N
GOL
Query on GOL

Download Ideal Coordinates CCD File 
E [auth A],
F [auth A],
G [auth A]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
NA
Query on NA

Download Ideal Coordinates CCD File 
H [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free:  0.284 (Depositor), 0.266 (DCC) 
  • R-Value Work:  0.239 (Depositor), 0.226 (DCC) 
Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.732α = 90
b = 81.732β = 90
c = 133.689γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
CrysalisProdata reduction
CrysalisProdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Science and Engineering Research Board (SERB)IndiaIPA/2020/000054

Revision History  (Full details and data files)

  • Version 1.0: 2025-05-14
    Type: Initial release
  • Version 1.1: 2026-01-28
    Changes: Database references