Crystal structure of FPV039:Bik BH3 complex

Experimental Data Snapshot

  • Resolution: 1.35 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.147 
  • R-Value Observed: 0.148 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Structural basis of apoptosis inhibition by the fowlpox virus protein FPV039.

Anasir, M.I.Caria, S.Skinner, M.A.Kvansakul, M.

(2017) J Biol Chem 292: 9010-9021

  • DOI: https://doi.org/10.1074/jbc.M116.768879
  • Primary Citation of Related Structures:  
    5TZP, 5TZQ

  • PubMed Abstract: 

    Programmed cell death or apoptosis of infected host cells is an important defense mechanism in response to viral infections. This process is regulated by proapoptotic and prosurvival members of the B-cell lymphoma 2 (Bcl-2) protein family. To counter premature death of a virus-infected cell, poxviruses use a range of different molecular strategies including the mimicry of prosurvival Bcl-2 proteins. One such viral prosurvival protein is the fowlpox virus protein FPV039, which is a potent apoptosis inhibitor, but the precise molecular mechanism by which FPV039 inhibits apoptosis is unknown. To understand how fowlpox virus inhibits apoptosis, we examined FPV039 using isothermal titration calorimetry, small-angle X-ray scattering, and X-ray crystallography. Here, we report that the fowlpox virus prosurvival protein FPV039 promiscuously binds to cellular proapoptotic Bcl-2 and engages all major proapoptotic Bcl-2 proteins. Unlike other identified viral Bcl-2 proteins to date, FPV039 engaged with cellular proapoptotic Bcl-2 with affinities comparable with those of Bcl-2's endogenous cellular counterparts. Structural studies revealed that FPV039 adopts the conserved Bcl-2 fold observed in cellular prosurvival Bcl-2 proteins and closely mimics the structure of the prosurvival Bcl-2 family protein Mcl-1. Our findings suggest that FPV039 is a pan-Bcl-2 protein inhibitor that can engage all host BH3-only proteins, as well as Bcl-2-associated X, apoptosis regulator (Bax) and Bcl-2 antagonist/killer (Bak) proteins to inhibit premature apoptosis of an infected host cell. This work therefore provides a mechanistic platform to better understand FPV039-mediated apoptosis inhibition.

  • Organizational Affiliation

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

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Bcl-2-like protein FPV039148Fowlpox virus strain NVSLMutation(s): 0 
Gene Names: FPV039
Find proteins for Q9J5G4 (Fowlpox virus (strain NVSL))
Explore Q9J5G4 
Go to UniProtKB:  Q9J5G4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9J5G4
Sequence Annotations
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Bik25Gallus gallusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on SO4

Download Ideal Coordinates CCD File 
J [auth A]
K [auth A]
L [auth A]
M [auth A]
N [auth A]
J [auth A],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
O [auth A]
O4 S
Query on EDO

Download Ideal Coordinates CCD File 
C [auth A]
D [auth A]
E [auth A]
F [auth A]
G [auth A]
C [auth A],
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A]
C2 H6 O2
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.848α = 90
b = 47.848β = 90
c = 74.303γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Australian Research Council (ARC)AustraliaFT130101349

Revision History  (Full details and data files)

  • Version 1.0: 2017-05-03
    Type: Initial release
  • Version 1.1: 2017-06-14
    Changes: Database references
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 1.3: 2024-04-03
    Changes: Data collection, Database references, Derived calculations, Refinement description