9HHG | pdb_00009hhg

A rare open conformation for Ubl2 domain of papain-like protease of SARS-CoV2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 
    0.221 (Depositor), 0.221 (DCC) 
  • R-Value Work: 
    0.187 (Depositor), 0.187 (DCC) 
  • R-Value Observed: 
    0.189 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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This is version 1.2 of the entry. See complete history

Literature

Structural analysis of the flexibility of the Ubl2 domain within the papain-like protease of SARS-CoV-2.

Freiherr von Scholley, G.L.Schaefer, M.Tully, M.D.Hograindleur, M.A.Soler-Lopez, M.Hillig, R.C.Mueller-Dieckmann, C.Kandiah, E.

(2026) Acta Crystallogr F Struct Biol Commun 82: 222-230

  • DOI: https://doi.org/10.1107/S2053230X26003699
  • Primary Citation Related Structures: 
    9HHG, 9HHH, 9HHI

  • PubMed Abstract: 

    The papain-like protease (PLpro) of SARS-CoV-2 is part of the multi-domain nonstructural protein 3 (NSP3) and consists of two domains: a ubiquitin-like domain 2 (Ubl2) and a protease domain. PLpro plays a crucial role in the replication cycle of SARS-CoV-2, facilitating host immune-system evasion and the formation of double-membrane vesicles where replication occurs. While the function of the Ubl2 domain is still not clear, it is critical for the stability and the functional efficiency of PLpro. Despite its predicted inherent flexibility, nearly all SARS-CoV-1 and SARS-CoV-2 PLpro crystal structures deposited in the Protein Data Bank show the Ubl2 domain in a highly similar, closed conformation against the catalytic domain. Here, we present a crystal structure of PLpro exhibiting Ubl2 in two distinct conformations: the well characterized closed state, where Ubl2 is positioned near the PLpro domain, and an as yet uncharacterized open state, where Ubl2 is displaced by 4 Å from the PLpro core. This conformational variability in our structure appears to be related to the occupancy of a zinc ion within the zinc-finger domain. These results provide new insights into the flexibility of Ubl2, suggesting potential avenues for targeting and harnessing this dynamic behaviour for drug discovery.


  • Organizational Affiliation
    • European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000 Grenoble, France.

Macromolecule Content 

  • Total Structure Weight: 73.54 kDa 
  • Atom Count: 5,667 
  • Modeled Residue Count: 632 
  • Deposited Residue Count: 644 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Papain-like protease nsp3
A, B
322Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
EC: 3.4.19.12 (PDB Primary Data), 3.4.22 (PDB Primary Data)
UniProt
Find proteins for P0DTC1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTC1 
Go to UniProtKB:  P0DTC1
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTC1
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free:  0.221 (Depositor), 0.221 (DCC) 
  • R-Value Work:  0.187 (Depositor), 0.187 (DCC) 
  • R-Value Observed: 0.189 (Depositor) 
Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 100.09α = 90
b = 106.517β = 90
c = 72.329γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
autoPROCdata reduction
autoPROCdata scaling
PHASERphasing

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
H2020 Marie Curie Actions of the European CommissionEuropean Union847439

Revision History  (Full details and data files)

  • Version 1.0: 2025-12-03
    Type: Initial release
  • Version 1.1: 2026-05-27
    Changes: Database references
  • Version 1.2: 2026-06-10
    Changes: Database references