3VC0

Crystal structure of Taipoxin beta subunit isoform 1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural analysis of trimeric phospholipase A(2) neurotoxin from the Australian taipan snake venom.

Cendron, L.Micetic, I.Polverino de Laureto, P.Paoli, M.

(2012) Febs J. 279: 3121-3135

  • DOI: 10.1111/j.1742-4658.2012.08691.x
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Snake pre-synaptic neurotoxins endowed with phospholipase A(2) activity are potent inducers of paralysis through the specific disruption of the neuromuscular junction pre-synaptic membrane and represent a valuable tool for investigating neuronal dege ...

    Snake pre-synaptic neurotoxins endowed with phospholipase A(2) activity are potent inducers of paralysis through the specific disruption of the neuromuscular junction pre-synaptic membrane and represent a valuable tool for investigating neuronal degeneration and recovery. They have different structural complexity and a wide range of lethal potency and enzymatic activity, although they share a similar mechanism of action. Although no correlation has been reported between neurotoxicity and enzymatic activity, toxicity increases with structural complexity and phospholipase A(2) oligomers show 10-fold lower LD(50) values compared to their monomeric counterparts. To date, no structural study has been performed on multimeric SPANs with the aim of shedding light on the correlation between structural complexity and neurotoxicity. In the present study, we investigated the structure of taipoxin, a trimeric phospholipase A(2) neurotoxin, as well as that of its subunits, by X-ray crystallography and small angle X-ray scattering analysis. We present the high-resolution structure of two isoforms of the taipoxin β subunit, which show no neurotoxic activity but enhance the activity of the other subunits in the complex. One isoform shows no structural change that could justify the lack of activity. The other displays three point mutations in critical positions for the catalytic activity. Moreover, we designed a model for the quaternary structure of taipoxin under physiological conditions, in which the three subunits are organized into a flat holotoxin with the substrate binding sockets exposed on the same side of the complex, which suggests a role for this interface in the toxin-membrane interaction.


    Organizational Affiliation

    Department of Biological Chemistry, University of Padova, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phospholipase A2 homolog, taipoxin beta chain
A
118Oxyuranus scutellatus scutellatusMutation(s): 0 
Find proteins for P00615 (Oxyuranus scutellatus scutellatus)
Go to UniProtKB:  P00615
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.189 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 37.890α = 90.00
b = 76.860β = 90.00
c = 104.910γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
MxCuBEdata collection
MOSFLMdata reduction
REFMACrefinement
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-07-25
    Type: Initial release
  • Version 1.1: 2012-09-26
    Type: Database references