1KTX

KALIOTOXIN (1-37) SHOWS STRUCTURAL DIFFERENCES WITH RELATED POTASSIUM CHANNEL BLOCKERS


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 11 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Kaliotoxin (1-37) shows structural differences with related potassium channel blockers.

Fernandez, I.Romi, R.Szendeffy, S.Martin-Eauclaire, M.F.Rochat, H.Van Rietschoten, J.Pons, M.Giralt, E.

(1994) Biochemistry 33: 14256-14263


  • PubMed Abstract: 
  • The three-dimensional structure of kaliotoxin (1-37), KTX(1-37), a toxin from the scorpion Androctonus mauretanicus mauretanicus that blocks calcium-dependent potassium channels, has been determined by NMR. This toxin is homologous with other scorpio ...

    The three-dimensional structure of kaliotoxin (1-37), KTX(1-37), a toxin from the scorpion Androctonus mauretanicus mauretanicus that blocks calcium-dependent potassium channels, has been determined by NMR. This toxin is homologous with other scorpion toxins such as charybdotoxin (ChTX) or iberiotoxin (IbTX) for which the structures are already known, but the presence of prolines in the expected alpha-helical region suggested that there may be some major difference in the structure of KTX that could be related to its different selectivity. Proline residues are also found in the homologous region of other scorpion toxins such as noxiustoxin or margatoxin. Our results indicate that KTX(1-37) contains the same sequence of secondary structure elements as ChTX but that the helical region is shorter and distorted due to the presence of two prolines. The distortion consists of a bending in the alpha-helix and in the presence of a 3(10) helix turn in the last three residues. Furthermore, the increased length of the extended structure preceding the helix favors a different packing of this part of the molecule with respect to the secondary structure elements. This change in folding modifies the accessibility of the conserved 27Lys which is known, from mutation studies, to be involved in channel blocking by ChTX.


    Related Citations: 
    • Kaliotoxin, a Novel Peptidyl Inhibitor of Neuronal Bk-Type Ca(2+)-Activated K+ Channels Characterized from Androctonus Mauretanicus Mauretanicus Venom
      Crest, M.,Jacquet, G.,Gola, M.,Zerrouk, H.,Benslimane, A.,Rochat, H.,Mansuelle, P.,Martin-Eauclaire, M.-F.
      (1992) J.Biol.Chem. 267: 1640


    Organizational Affiliation

    Department of Organic Chemistry, University of Barcelona, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
KALIOTOXIN
A
38Androctonus mauritanicus mauritanicusN/A
Find proteins for P24662 (Androctonus mauritanicus mauritanicus)
Go to UniProtKB:  P24662
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 11 
  • Olderado: 1KTX Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1995-01-26
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other