9CEH | pdb_00009ceh

SARS-CoV Papain-like Protease in complex with an inhibitor

  • Classification: VIRAL PROTEIN
  • Organism(s): Severe acute respiratory syndrome coronavirus
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2024-06-26 Released: 2025-12-03 
  • Deposition Author(s): Chua, T.K., Song, Y.
  • Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID), National Institutes of Health/National Cancer Institute (NIH/NCI), Cancer Prevention and Research Institute of Texas (CPRIT)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free: 
    0.293 (Depositor), 0.298 (DCC) 
  • R-Value Work: 
    0.233 (Depositor), 0.235 (DCC) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9CEH

Ligand Structure Quality Assessment 


This is version 1.0 of the entry. See complete history

Literature

Targeting the S1' Pocket of SARS-CoV‐2 Papain-Like Protease Yields Highly Potent Inhibitors.

Garad, D.N.Li, X.Chua, T.K.Moku, B.K.Mishra, C.B.Song, Y.

(2025) ACS Med Chem Lett 16: 2280-2285

  • DOI: https://doi.org/10.1021/acsmedchemlett.5c00482
  • Primary Citation Related Structures: 
    9CEH

  • PubMed Abstract: 

    SARS-CoV-2 and -CoV viruses are major human pathogens. Due to their zoonotic nature as well as emerging drug-resistant mutations, new antivirals are needed. The viral papain-like protease (PLpro) is a drug target. Targeting the mostly hydrophobic S1' pocket of PLpro, we designed and synthesized 21 amide compounds, among which several highly potent PLpro inhibitors were identified with IC 50 values as low as 16 nM. Structure-activity relationship analysis showed that an electron-deficient pyridine-containing amide group can significantly enhance the activity. The X-ray structure of the PLpro-compound 15 complex revealed that the pyridine ring has favorable π-π and electrostatic interactions with the electron-rich indole group of Trp106. Compound 15 is inactive against human ubiquitin-specific protease 7 and noncytotoxic to mammalian cells, showing excellent selectivity. It can potently inhibit cellular replication of SARS-CoV-2 with an EC 50 of 96 nM. These results show that compound 15 represents a novel pharmaceutical lead for further drug development.


  • Organizational Affiliation
    • Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas 77030, United States.

Macromolecule Content 

  • Total Structure Weight: 35.37 kDa 
  • Atom Count: 2,395 
  • Modeled Residue Count: 308 
  • Deposited Residue Count: 310 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Papain-like protease nsp3310Severe acute respiratory syndrome coronavirusMutation(s): 0 
Gene Names: 1a
EC: 3.4.19.12 (PDB Primary Data), 3.4.22 (PDB Primary Data)
UniProt
Find proteins for P0C6U8 (Severe acute respiratory syndrome coronavirus)
Explore P0C6U8 
Go to UniProtKB:  P0C6U8
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0C6U8
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1AWG
(Subject of Investigation/LOI)

Query on A1AWG



Download:Ideal Coordinates CCD File
B [auth A]N-[(2R)-1-(naphthalen-1-yl)propan-2-yl]-2-[3-oxo-3-(2-{4-oxo-4-[(pyridin-3-yl)amino]butanoyl}hydrazin-1-yl)propyl]benzamide
C32 H33 N5 O4
RUTWXOPIDMUTLS-JOCHJYFZSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free:  0.293 (Depositor), 0.298 (DCC) 
  • R-Value Work:  0.233 (Depositor), 0.235 (DCC) 
Space Group: P 32 1 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.238α = 90
b = 88.238β = 90
c = 96.523γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata scaling
XDSdata reduction
PHENIXphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesR21AI159323
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesR01CA266057
Cancer Prevention and Research Institute of Texas (CPRIT)United StatesRP220232

Revision History  (Full details and data files)

  • Version 1.0: 2025-12-03
    Type: Initial release