Macromolecule Content

• Total Structure Weight: 3.42 kDa 
• Atom Count: 235 
• Residue Count: 30 
• Unique protein chains: 1

1EMX

SOLUTION STRUCTURE OF HPTX2, A TOXIN FROM HETEROPODA VENATORIA SPIDER VENOM THAT BLOCKS KV4.2 POTASSIUM CHANNEL

• DOI: 10.2210/pdb1EMX/pdb
• BMRB: 4755

• Classification: TOXIN
• Organism(s): Heteropoda venatoria
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2000-03-20 Released: 2001-01-24 
• Deposition Author(s): Bernard, C., Legros, C., Ferrat, G., Bishoff, U., Marquardt, A., Pongs, O., Darbon, H.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 30 
• Conformers Submitted: 26 
• Selection Criteria: back calculated data agree with experimental NOESY spectrum 

Literature

Solution structure of hpTX2, a toxin from Heteropoda venatoria spider that blocks Kv4.2 potassium channel.

Bernard, C., Legros, C., Ferrat, G., Bischoff, U., Marquardt, A., Pongs, O., Darbon, H.

(2000) Protein Sci 9: 2059-2067

• PubMed: 11152117 
• Structures With Same Primary Citation


• PubMed Abstract: 
  

HpTX2 is a toxin from the venom of Heteropoda venatoria spider that has been demonstrated to bind on Kv4.2 potassium channel. We have determined the solution structure of recombinant HpTX2 by use of conventional two-dimensional NMR techniques followed by distance-geometry and molecular dynamics. The calculated structure belongs to the Inhibitory Cystin Knot structural family that consists in a compact disulfide-bonded core, from which four loops emerge. A poorly defined two-stranded antiparallel beta-sheet (residues 20-23 and 25-28) is detected. Analysis of the electrostatic charge anisotropy allows us to propose a functional map of HpTX2 different from the one described for kappa-conotoxin PVIIA, but strongly related to the one of charybdotoxin. The orientation of the dipole moment of HpTX2 emerges through K27 which could therefore be the critical lysine residue. Close to this lysine are a second basic residue, R23, an aromatic cluster (F7, W25, W30) and an hydrophobic side chain (L24). The high density in aromatic side chains of the putative functional surface as well as the lack of an asparagine is proposed to be the structural basis of the specificity of HpTX2 toward Kv4.2 channel.

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Organizational Affiliation: 

AFMB, CNRS UMR 6098, IFR1, 31, Chemín Joseph-Aiguier, Marseille, France.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
HETEROPODATOXIN 2	A	30	Heteropoda venatoria	Mutation(s): 0
Find proteins for P58426 (Heteropoda venatoria) Go to UniProtKB:  P58426

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 30 
• Conformers Submitted: 26 
• Selection Criteria: back calculated data agree with experimental NOESY spectrum 
• OLDERADO: 1EMX Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2000-03-20 
• Released Date: 2001-01-24 
Deposition Author(s): Bernard, C., Legros, C., Ferrat, G., Bishoff, U., Marquardt, A., Pongs, O., Darbon, H.

Revision History 

• Version 1.0: 2001-01-24
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance