Biological Assembly 1  

 3D View: Structure | Electron Density

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 19.45 kDa 
• Atom Count: 1455 
• Residue Count: 175 
• Unique protein chains: 1

1TZQ

Crystal structure of the equinatoxin II 8-69 double cysteine mutant

• DOI: 10.2210/pdb1TZQ/pdb

• Classification: TOXIN
• Organism(s): Actinia equina
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2004-07-11 Released: 2004-09-28 
• Deposition Author(s): Kristan, K., Podlesek, Z., Hojnik, V., Gutirrez-Aguirre, I., Guncar, G., Turk, D.A., Gonzalez-Maas, J.M., Lakey, J.H., Anderluh, G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.274 
• R-Value Work: 0.192 
• R-Value Observed: 0.195 

Literature

Pore formation by equinatoxin, a eukaryotic pore-forming toxin, requires a flexible N-terminal region and a stable beta-sandwich

Kristan, K., Podlesek, Z., Hojnik, V., Gutierrez-Aguirre, I., Guncar, G., Turk, D.A., Gonzalez-Manas, J.M., Lakey, J.H., Macek, P., Anderluh, G.

(2004) J Biol Chem 279: 46509-46517

• PubMed: 15322132 
• DOI: 10.1074/jbc.M406193200
• Primary Citation of Related Structures:  
  1TZQ


• PubMed Abstract: 
  

Actinoporins are eukaryotic pore-forming proteins that create 2-nm pores in natural and model lipid membranes by the self-association of four monomers. The regions that undergo conformational change and form part of the transmembrane pore are currently being defined. It was shown recently that the N-terminal region (residues 10-28) of equinatoxin, an actinoporin from Actinia equina, participates in building of the final pore wall. Assuming that the pore is formed solely by a polypeptide chain, other parts of the toxin should constitute the conductive channel and here we searched for these regions by disulfide scanning mutagenesis. Only double cysteine mutants where the N-terminal segment 1-30 was attached to the beta-sandwich exhibited reduced hemolytic activity upon disulfide formation, showing that other parts of equinatoxin, particularly the beta-sandwich and importantly the C-terminal alpha-helix, do not undergo large conformational rearrangements during the pore formation. The role of the beta-sandwich stability was independently assessed via destabilization of a part of its hydrophobic core by mutations of the buried Trp117. These mutants were considerably less stable than the wild-type but exhibited similar or slightly lower permeabilizing activity. Collectively these results show that a flexible N-terminal region and stable beta-sandwich are pre-requisite for proper pore formation by the actinoporin family.

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Organizational Affiliation: 

Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, 1000 Ljubljana, Slovenia.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Equinatoxin II	A	175	Actinia equina	Mutation(s): 2
Find proteins for P61914 (Actinia equina) Explore P61914  Go to UniProtKB:  P61914

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.274 
• R-Value Work: 0.192 
• R-Value Observed: 0.195 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 36.585	α = 90
b = 52.682	β = 92.26
c = 39.789	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SCALEPACK	data scaling
AMoRE	phasing
MAIN	refinement
HKL-2000	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-07-11 
• Released Date: 2004-09-28 
Deposition Author(s): Kristan, K., Podlesek, Z., Hojnik, V., Gutirrez-Aguirre, I., Guncar, G., Turk, D.A., Gonzalez-Maas, J.M., Lakey, J.H., Anderluh, G.

Revision History 

• Version 1.0: 2004-09-28
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance