1BUN

STRUCTURE OF BETA2-BUNGAROTOXIN: POTASSIUM CHANNEL BINDING BY KUNITZ MODULES AND TARGETED PHOSPHOLIPASE ACTION

• PDB DOI: https://doi.org/10.2210/pdb1BUN/pdb

• Classification: TOXIN
• Organism(s): Bungarus multicinctus
• Mutation(s): No 
• Membrane Protein: Yes  OPM


• Deposited: 1995-10-15 Released: 1996-04-03 
• Deposition Author(s): Kwong, P.D., Mcdonald, N.Q., Sigler, P.B., Hendrickson, W.A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.281 
• R-Value Work: 0.193 
• R-Value Observed: 0.193 

Literature

Structure of beta 2-bungarotoxin: potassium channel binding by Kunitz modules and targeted phospholipase action.

Kwong, P.D., McDonald, N.Q., Sigler, P.B., Hendrickson, W.A.

(1995) Structure 3: 1109-1119

• PubMed: 8590005 
• DOI: https://doi.org/10.1016/s0969-2126(01)00246-5


• PubMed Abstract: 
  

  beta-bungarotoxin is a heterodimeric neurotoxin consisting of a phospholipase subunit linked by a disulfide bond to a K+ channel binding subunit which is a member of the Kunitz protease inhibitor superfamily. Toxicity, characterized by blockage of neural transmission, is achieved by the lipolytic action of the phospholipase targeted to the presynaptic membrane by the Kunitz module.

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Organizational Affiliation: 

Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 20.78 kDa 
• Atom Count: 1,523 
• Modelled Residue Count: 181 
• Deposited Residue Count: 181 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
BETA2-BUNGAROTOXIN	A	120	Bungarus multicinctus	Mutation(s): 0  EC: 3.1.1.4 Membrane Entity: Yes
UniProt
Find proteins for P00617 (Bungarus multicinctus) Explore P00617  Go to UniProtKB:  P00617

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
BETA2-BUNGAROTOXIN	B	61	Bungarus multicinctus	Mutation(s): 0  EC: 3.1.1.4 Membrane Entity: Yes
UniProt
Find proteins for P00989 (Bungarus multicinctus) Explore P00989  Go to UniProtKB:  P00989

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NA	C [auth A], D [auth A]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.281 
• R-Value Work: 0.193 
• R-Value Observed: 0.193 
• Space Group: P 4₃ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 52.6	α = 90
b = 52.6	β = 90
c = 177.5	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1996-04-03 
Deposition Author(s): Kwong, P.D., Mcdonald, N.Q., Sigler, P.B., Hendrickson, W.A.

Revision History  

• Version 1.0: 1996-04-03
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance