Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 4.75 kDa 
• Atom Count: 324 
• Modelled Residue Count: 42 
• Deposited Residue Count: 42 
• Unique protein chains: 1

 1PX9

Solution structure of the native CnErg1 Ergtoxin, a highly specific inhibitor of HERG channel

• PDB DOI: 10.2210/pdb1PX9/pdb

• Classification: TOXIN
• Organism(s): Centruroides noxius
• Mutation(s): No 


• Deposited: 2003-07-03 Released: 2004-06-22 
• Deposition Author(s): Frenal, K., Wecker, K., Gurrola, G.B., Possani, L.D., Wolff, N., Delepierre, M.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 10 
• Conformers Submitted: 1 
• Selection Criteria: structures with acceptable covalent geometry, structures with favorable non-bond energy, structures with the least restraint violations, structures with the lowest energy 

Literature

Exploring structural features of the interaction between the scorpion toxinCnErg1 and ERG K+ channels.

Frenal, K., Xu, C.Q., Wolff, N., Wecker, K., Gurrola, G.B., Zhu, S.Y., Chi, C.W., Possani, L.D., Tytgat, J., Delepierre, M.

(2004) Proteins 56: 367-375

• PubMed: 15211519 
• DOI: 10.1002/prot.20102
• Primary Citation of Related Structures:  
  1PX9


• PubMed Abstract: 
  

The gamma-KTx-type scorpion toxins specific for K+ channels were found to interact with ERG channels on the turret region, while alpha-KTx3.2 Agitoxin-2 binds to the pore region of the Shaker K+ channel, and alpha-KTx5.3 BmP05 binds to the intermediate region of the small-conductance calcium-activated K-channel (SK(Ca)). In order to explore the critical residues for gamma-KTx binding, we determined the NMR structure of native gamma-KTx1.1 (CnErg1), a 42 amino acid residues scorpion toxin isolated from the venom of the Mexican scorpion Centruroïdes noxius Hoffmann, and we used computational evolutionary trace (ET) analysis to predict possible structural and functional features of interacting surfaces. The 1H-NMR three-dimensional solution structure of native ergtoxin (CnErg1) was solved using a total of 452 distance constraints, 13 3J(NH-Halpha) and 10 hydrogen bonds. The structure is characterized by 2 segments of alpha-helices and a triple-stranded antiparallel beta-sheet stabilized by 4 disulfide bridges. The ET and structural analysis provided indication of the presence of two important amino acid residue clusters, one hydrophobic and the other hydrophilic, that should be involved in the surface contact between the toxin and the channel. Some features of the proposed interacting surface are discussed.

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Organizational Affiliation: 

Unité de RMN des Biomolécules URA 2185 CNRS, Institut Pasteur, Paris, France.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ergtoxin	A	42	Centruroides noxius	Mutation(s): 0
UniProt
Find proteins for Q86QT3 (Centruroides noxius) Explore Q86QT3  Go to UniProtKB:  Q86QT3

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 10 
• Conformers Submitted: 1 
• Selection Criteria: structures with acceptable covalent geometry, structures with favorable non-bond energy, structures with the least restraint violations, structures with the lowest energy 

Structure Validation

Currently 1PX9 does not have a validation slider image.

Entry History 

Deposition Data

• Released Date: 2004-06-22 
Deposition Author(s): Frenal, K., Wecker, K., Gurrola, G.B., Possani, L.D., Wolff, N., Delepierre, M.

Revision History  

• Version 1.0: 2004-06-22
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2022-03-02
  Changes: Data collection, Database references, Derived calculations