Orf virus Apoptosis inhibitor ORFV125

Experimental Data Snapshot

  • Resolution: 2.22 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.244 
  • R-Value Observed: 0.245 

Starting Model: other
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wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Crystal structures of ORFV125 provide insight into orf virus-mediated inhibition of apoptosis.

Suraweera, C.D.Hinds, M.G.Kvansakul, M.

(2020) Biochem J 477: 4527-4541

  • DOI: https://doi.org/10.1042/BCJ20200776
  • Primary Citation of Related Structures:  
    7ADS, 7ADT

  • PubMed Abstract: 

    Premature apoptosis of cells is a strategy utilized by multicellular organisms to counter microbial threats. Orf virus (ORFV) is a large double-stranded DNA virus belonging to the poxviridae. ORFV encodes for an apoptosis inhibitory protein ORFV125 homologous to B-cell lymphoma 2 or Bcl-2 family proteins, which has been shown to inhibit host cell encoded pro-apoptotic Bcl-2 proteins. However, the structural basis of apoptosis inhibition by ORFV125 remains to be clarified. We show that ORFV125 is able to bind to a range of peptides spanning the BH3 motif of human pro-apoptotic Bcl-2 proteins including Bax, Bak, Puma and Hrk with modest to weak affinity. We then determined the crystal structures of ORFV125 alone as well as bound to the highest affinity ligand Bax BH3 motif. ORFV125 adopts a globular Bcl-2 fold comprising 7 α-helices, and utilizes the canonical Bcl-2 binding groove to engage pro-apoptotic host cell Bcl-2 proteins. In contrast with a previously predicted structure, ORFV125 adopts a domain-swapped dimeric topology, where the α1 helix from one protomer is swapped into a neighbouring unit. Furthermore, ORFV125 differs from the conserved architecture of the Bcl-2 binding groove and instead of α3 helix forming one of the binding groove walls, ORFV125 utilizes an extended α2 helix that comprises the equivalent region of helix α3. This results in a subtle variation of previously observed dimeric Bcl-2 architectures in other poxvirus and human encoded Bcl-2 proteins. Overall, our results provide a structural and mechanistic basis for orf virus-mediated inhibition of host cell apoptosis.

  • Organizational Affiliation

    Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Apoptosis inhibitor148Orf virusMutation(s): 0 
Gene Names: ORFV125ORF125
Find proteins for A0A0R8HV90 (Orf virus)
Explore A0A0R8HV90 
Go to UniProtKB:  A0A0R8HV90
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A0R8HV90
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on EDO

Download Ideal Coordinates CCD File 
B [auth A]
C [auth A]
D [auth A]
E [auth A]
F [auth A]
B [auth A],
C [auth A],
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A]
C2 H6 O2
Query on CL

Download Ideal Coordinates CCD File 
N [auth A],
O [auth A]
Query on MG

Download Ideal Coordinates CCD File 
P [auth A],
Q [auth A],
R [auth A],
S [auth A]
Query on NA

Download Ideal Coordinates CCD File 
I [auth A],
J [auth A],
K [auth A],
L [auth A],
M [auth A]
Experimental Data & Validation

Experimental Data

  • Resolution: 2.22 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.244 
  • R-Value Observed: 0.245 
  • Space Group: P 62 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 106.613α = 90
b = 106.613β = 90
c = 60.589γ = 120
Software Package:
Software NamePurpose
DIALSdata reduction
Aimlessdata scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Health and Medical Research Council (NHMRC, Australia)AustraliaAPP1007918

Revision History  (Full details and data files)

  • Version 1.0: 2021-10-06
    Type: Initial release
  • Version 1.1: 2022-11-23
    Changes: Data collection, Database references
  • Version 1.2: 2024-05-01
    Changes: Data collection, Refinement description