1C56

NMR SOLUTION STRUCTURE OF BUTANTOXIN


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 
  • Selection Criteria: LEAST RESTRAINT VIOLATION 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

NMR solution structure of butantoxin.

Holaday Jr., S.K.Martin, B.M.Fletcher Jr., P.L.Krishna, N.R.

(2000) Arch.Biochem.Biophys. 379: 18-27

  • DOI: 10.1006/abbi.2000.1858
  • Primary Citation of Related Structures:  1C55

  • PubMed Abstract: 
  • The NMR structure of a new toxin, butantoxin (BuTX), which is present in the venoms of the three Brazilian scorpions Tityus serrulatus, Tityus bahiensis, and Tityus stigmurus, has been investigated. This toxin was shown to reversibly block the Shaker ...

    The NMR structure of a new toxin, butantoxin (BuTX), which is present in the venoms of the three Brazilian scorpions Tityus serrulatus, Tityus bahiensis, and Tityus stigmurus, has been investigated. This toxin was shown to reversibly block the Shaker B potassium channels (K(d) approximately 660 nM) and inhibit the proliferation of T-cells and the interleukin-2 production of antigen-stimulated T-helper cells. BuTX is a 40 amino acid basic protein stabilized by the four disulfide bridges: Cys2-Cys5, Cys10-Cys31, Cys16-Cys36, and Cys20-Cys38. The latter three are conserved among all members of the short-chain scorpion toxin family, while the first is unique to BuTX. The three-dimensional structure of BuTX was determined using (1)H-NMR spectroscopy. NOESY, phase sensitive COSY (PH-COSY), and amide hydrogen exchange data were used to generate constraints for molecular modeling calculations. Distance geometry and simulated annealing calculations were performed to generate a family of 49 structures free of constraint violations. The secondary structure of BuTX consists of a short 2(1/2) turn alpha-helix (Glu15-Phe23) and a beta-sheet. The beta-sheet is composed of two well-defined antiparallel strands (Gly29-Met32 and Lys35-Cys38) connected by a type-I' beta-turn (Asn33-Asn34). Residues Cys5-Ala9 form a quasi-third strand of the beta-sheet. The N-terminal C2-C5 disulfide bridge unique to this toxin does not appear to confer stability to the protein.


    Organizational Affiliation

    Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294-2041, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BUTANTOXIN
A
40Tityus serrulatusN/A
Find proteins for P59936 (Tityus serrulatus)
Go to UniProtKB:  P59936
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 
  • Selection Criteria: LEAST RESTRAINT VIOLATION 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-07-19
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance