9KMO | pdb_00009kmo

HR1 domain from HCoV-OC43 in complex with a pan-CoV inhibitor EK1

  • Classification: VIRAL PROTEIN
  • Organism(s): Human coronavirus OC43
  • Mutation(s): Yes 

  • Deposited: 2024-11-16 Released: 2026-01-14 
  • Deposition Author(s): Yan, L.
  • Funding Organization(s): National Natural Science Foundation of China (NSFC)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 
    0.311 (Depositor), 0.305 (DCC) 
  • R-Value Work: 
    0.282 (Depositor), 0.297 (DCC) 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

Structures of HCoV-OC43 HR1 Domain in Complex with Cognate HR2 or Analogue EK1 Peptide.

He, X.Liu, H.Yang, G.Yan, L.

(2025) Viruses 17

  • DOI: https://doi.org/10.3390/v17030343
  • Primary Citation of Related Structures:  
    8ZX7, 9KMO

  • PubMed Abstract: 

    Human coronavirus OC43 (HCoV-OC43) is usually associated with common colds, but also related to severe disease in the frail. Its envelope glycoproteins spike (S) is responsible for host-cell attachment and membrane fusion. To understand the molecular basis of membrane fusion of HCoV-OC43, we solved the 3.34 Å crystal structure of the post-fusion state formed by two heptad repeat domains (HR1P and HR2P) of OC43-S. This fusion core comprises a parallel trimeric coiled coil of three HR1 helices with 61 Å at length, around which three HR2 helices are entwined in an antiparallel manner, as anticipated. Moreover, a pan-CoV fusion inhibitor EK1 derived from OC43-HR2P was also crystalized with OC43-HR1P in the resolution of 2.71 Å. Parallel comparisons rationalize the design of EK1, maintaining various hydrophobic and charged or hydrophilic interactions formed in the initial fusion core to stabilize the overall conformation. Together, our results not only reveal the critical intrahelical and interhelical interactions underlying the mechanism of action of OC43-S fusion, but also help our understanding on the mechanism of HCoV-OC43 inhibition by analogue HR2 mimic peptide.


  • Organizational Affiliation
    • School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Spike protein S2'
A, B, C
70Human coronavirus OC43Mutation(s): 1 
UniProt
Find proteins for P36334 (Human coronavirus OC43)
Explore P36334 
Go to UniProtKB:  P36334
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP36334
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free:  0.311 (Depositor), 0.305 (DCC) 
  • R-Value Work:  0.282 (Depositor), 0.297 (DCC) 
Space Group: P 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.014α = 90
b = 53.014β = 90
c = 62.175γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXrefinement
HKL-3000data reduction
xia2data scaling
PHENIXphasing

Structure Validation

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Entry History & Funding Information

Deposition Data

  • Released Date: 2026-01-14 
  • Deposition Author(s): Yan, L.

Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China--

Revision History  (Full details and data files)

  • Version 1.0: 2026-01-14
    Type: Initial release