4LFQ

High resolution x-ray crystal structure of L-ShK toxin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.059 Å
  • R-Value Free: 0.160 
  • R-Value Work: 0.131 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Native Chemical Ligation at Asx-Cys, Glx-Cys: Chemical Synthesis and High-Resolution X-ray Structure of ShK Toxin by Racemic Protein Crystallography.

Dang, B.Kubota, T.Mandal, K.Bezanilla, F.Kent, S.B.

(2013) J.Am.Chem.Soc. 135: 11911-11919

  • DOI: 10.1021/ja4046795
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • We have re-examined the utility of native chemical ligation at -Gln/Glu-Cys- [Glx-Cys] and -Asn/Asp-Cys- [Asx-Cys] sites. Using the improved thioaryl catalyst 4-mercaptophenylacetic acid (MPAA), native chemical ligation could be performed at -Gln-Cys ...

    We have re-examined the utility of native chemical ligation at -Gln/Glu-Cys- [Glx-Cys] and -Asn/Asp-Cys- [Asx-Cys] sites. Using the improved thioaryl catalyst 4-mercaptophenylacetic acid (MPAA), native chemical ligation could be performed at -Gln-Cys- and Asn-Cys- sites without side reactions. After optimization, ligation at a -Glu-Cys- site could also be used as a ligation site, with minimal levels of byproduct formation. However, -Asp-Cys- is not appropriate for use as a site for native chemical ligation because of formation of significant amounts of β-linked byproduct. The feasibility of native chemical ligation at -Gln-Cys- enabled a convergent total chemical synthesis of the enantiomeric forms of the ShK toxin protein molecule. The D-ShK protein molecule was ~50,000-fold less active in blocking the Kv1.3 channel than the L-ShK protein molecule. Racemic protein crystallography was used to obtain high-resolution X-ray diffraction data for ShK toxin. The structure was solved by direct methods and showed significant differences from the previously reported NMR structures in some regions of the ShK protein molecule.


    Organizational Affiliation

    Department of Chemistry, Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium channel toxin ShK
A
35Stichodactyla helianthusMutation(s): 0 
Find proteins for P29187 (Stichodactyla helianthus)
Go to UniProtKB:  P29187
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.059 Å
  • R-Value Free: 0.160 
  • R-Value Work: 0.131 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 41.161α = 90.00
b = 49.491β = 90.00
c = 27.770γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
HKL-2000data scaling
PHASERphasing
DENZOdata reduction
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-08-14
    Type: Initial release
  • Version 1.1: 2013-09-04
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Refinement description