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 
  • R-Value Observed: 0.172 

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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:  
    1ZU3, 1ZVG, 1ZVE, 1ZUT, 1ZYW, 1ZYV

  • 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 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 ...

    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Alpha-like neurotoxin BmK-IA66Mesobuthus martensiiMutation(s): 1 
Gene Names: BMK M1
UniProt
Find proteins for P45697 (Mesobuthus martensii)
Explore P45697 
Go to UniProtKB:  P45697
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.33 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.237α = 90
b = 43.069β = 90
c = 25.463γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PROTEUM PLUSdata reduction
PROTEUM PLUSdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

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