1ZU3

Crystal Structure Of Mutant K8A Of Scorpion alpha-Like Neurotoxin Bmk M1 From Buthus Martensii Karsch


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.33 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis for the voltage-gated Na+ channel selectivity of the scorpion alpha-like toxin BmK M1

Ye, X.Bosmans, F.Li, C.Zhang, Y.Wang, D.C.Tytgat, J.

(2005) J.Mol.Biol. 353: 788-803

  • DOI: 10.1016/j.jmb.2005.08.068
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Scorpion alpha-like toxins are proteins that act on mammalian and insect voltage-gated Na+ channels. Therefore, these toxins constitute an excellent target for examining the foundations that underlie their target specificity. With this motive we diss ...

    Scorpion alpha-like toxins are proteins that act on mammalian and insect voltage-gated Na+ channels. Therefore, these toxins constitute an excellent target for examining the foundations that underlie their target specificity. With this motive we dissected the role of six critical amino acids located in the five-residue reverse turn (RT) and C-tail (CT) of the scorpion alpha-like toxin BmK M1. These residues were individually substituted resulting in 11 mutants and were subjected to a bioassay on mice, an electrophysiological characterization on three cloned voltage-gated Na+ channels (Nav1.2, Nav1.5 and para), a CD analysis and X-ray crystallography. The results reveal two molecular sites, a couplet of residues (8-9) in the RT and a hydrophobic surface consisting of residues 57 and 59-61 in the CT, where the substitution with specific residues can redirect the alpha-like characteristics of BmK M1 to either total insect or much higher mammal specificity. Crystal structures reveal that the pharmacological ramification of these mutants is accompanied by the reshaping of the 3D structure surrounding position 8. Furthermore, our results also reveal that residues 57 and 59-61, located at the CT, enclose the critical residue 58 in order to form a hydrophobic "gasket". Mutants of BmK M1 that interrupt this hydrophobic surface significantly gain insect selectivity.


    Organizational Affiliation

    Center for Structural and Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People's Republic of China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-like neurotoxin BmK-I
A
66Mesobuthus martensiiMutation(s): 1 
Find proteins for P45697 (Mesobuthus martensii)
Go to UniProtKB:  P45697
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.33 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.172 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 47.237α = 90.00
b = 43.069β = 90.00
c = 25.463γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
PROTEUM PLUSdata scaling
PROTEUM PLUSdata reduction
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-05-23
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance