1KBA

CRYSTAL STRUCTURE OF KAPPA-BUNGAROTOXIN AT 2.3-ANGSTROM RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Work: 0.196 

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This is version 1.2 of the entry. See complete history

Literature

Crystal structure of kappa-bungarotoxin at 2.3-A resolution.

Dewan, J.C.Grant, G.A.Sacchettini, J.C.

(1994) Biochemistry 33: 13147-13154


  • PubMed Abstract: 
  • kappa-Neurotoxins display a very low affinity for neuromuscular receptors, but bind tightly to, and inhibit, nicotinic acetylcholine receptors in neuronal tissue such as the chick ciliary ganglia. In contrast, alpha-neurotoxins bind with high affinit ...

    kappa-Neurotoxins display a very low affinity for neuromuscular receptors, but bind tightly to, and inhibit, nicotinic acetylcholine receptors in neuronal tissue such as the chick ciliary ganglia. In contrast, alpha-neurotoxins bind with high affinity and inhibit nicotinic acetylcholine receptors at the neuromuscular junction. The origin of this difference in specificity has been a long-studied question in the field. Here we report the first crystal structure of a kappa-neurotoxin, kappa-bungarotoxin. Unlike the NMR structure previously reported [Sutcliffe, M. J., Dobson, C. M., & Oswald, R. E. (1992) Biochemistry 31, 2962-2970], the present crystal structure more accurately defines the polypeptide fold and the nature of the interaction between subunits in the active dimer, which is a unique feature of the kappa-neurotoxins. The structure has been refined to R = 19.6% with X-ray diffraction data extending to a resolution of 2.3 A. There are two independent protein molecules (66 amino acid residues each) in the asymmetric unit that are arranged as a dimer with the two subunits related by a rotation of 178.6 degrees. Each subunit consists of three main-chain loops. Three of the five beta-strands of each subunit form an antiparallel beta-sheet which becomes an extended six-stranded antiparallel beta-sheet, by virtue of the approximate 2-fold symmetry of the dimer. The interactions at the dimer interface consist of six main-chain-main-chain hydrogen bonds, as well as three other hydrogen-bonding interactions involving side chains.(ABSTRACT TRUNCATED AT 250 WORDS)


    Organizational Affiliation

    Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
KAPPA-BUNGAROTOXIN
A, B
66Bungarus multicinctusMutation(s): 0 
Find proteins for P01398 (Bungarus multicinctus)
Go to UniProtKB:  P01398
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Work: 0.196 
  • Space Group: P 6
Unit Cell:
Length (Å)Angle (°)
a = 80.200α = 90.00
b = 80.200β = 90.00
c = 39.600γ = 120.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORrefinement
TNTrefinement
X-PLORmodel building

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-12-20
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance