1R1G

Crystal Structure of the Scorpion Toxin BmBKTtx1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.166 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structure of the scorpion toxin BmBKTtx1 solved from single wavelength anomalous scattering of sulfur.

Szyk, A.Lu, W.Xu, C.Lubkowski, J.

(2004) J.Struct.Biol. 145: 289-294

  • DOI: 10.1016/j.jsb.2003.11.012

  • PubMed Abstract: 
  • This report describes the crystal structure of the K(+) channel-blocking toxin, BmBKTx1, isolated recently from the venom of the scorpion Buthus martensi Karsch. This is only the second structure of the short-chain K(+) channel-blocking toxin from sc ...

    This report describes the crystal structure of the K(+) channel-blocking toxin, BmBKTx1, isolated recently from the venom of the scorpion Buthus martensi Karsch. This is only the second structure of the short-chain K(+) channel-blocking toxin from scorpion solved by means of X-ray crystallography. Additionally, reductive dimethylation of folded BmBKTx1 employed to induce its crystallization and solution of the structure based on the anomalous signal from the sulfur atoms make this example quite unique. The monomer of BmBKTx1 is formed by 31 amino acid residues, including 6 cysteines connected in 3 disulfide bridges. Crystals of this toxin belong to the space group P2(1) with two molecules present in the asymmetric unit. The unit cell parameters are a = 21.40 A, b=39.70 A, c=29.37 A, and beta-94.13 grades. Based on the high-quality dataset (anomalous signal) collected to the resolution 1.72A using the conventional X-radiation generator (lambda Cu, K alpha = 1.5478 A), the positions of sulfur atoms contributed by 12 cysteine residues have been identified, and subsequent improvement of the experimental phases have allowed structure solution. The final model was refined to the crystallographic R-factor of 0.166. The methyl groups on several lysine residues could be easily modeled into the electron density.


    Organizational Affiliation

    Macromolecular Crystallography Laboratory, National Cancer Institute at Frederick, Frederick, MD 21702, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Neurotoxin BmK37
A, B
31Mesobuthus martensiiMutation(s): 0 
Find proteins for P83407 (Mesobuthus martensii)
Go to UniProtKB:  P83407
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
LAL
Query on LAL
A, B
L-PEPTIDE LINKINGC5 H11 N O2ALA
MLY
Query on MLY
A, B
L-PEPTIDE LINKINGC8 H18 N2 O2LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.166 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 21.397α = 90.00
b = 39.695β = 94.13
c = 29.368γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SHELXDphasing
XPREPdata reduction
HKL-2000data scaling
MAR345data collection
DMphasing
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-03-02
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description