1MTX

DETERMINATION OF THE THREE-DIMENSIONAL STRUCTURE OF MARGATOXIN BY 1H, 13C, 15N TRIPLE-RESONANCE NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 23 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Determination of the three-dimensional structure of margatoxin by 1H, 13C, 15N triple-resonance nuclear magnetic resonance spectroscopy.

Johnson, B.A.Stevens, S.P.Williamson, J.M.

(1994) Biochemistry 33: 15061-15070


  • PubMed Abstract: 
  • The solution structure of the 39-residue peptide margatoxin, a scorpion toxin that selectively blocks the voltage-gated potassium-channel Kv1.3, has been determined by NMR spectroscopy. The toxin was isotopically labeled with 13C and 15N and studied ...

    The solution structure of the 39-residue peptide margatoxin, a scorpion toxin that selectively blocks the voltage-gated potassium-channel Kv1.3, has been determined by NMR spectroscopy. The toxin was isotopically labeled with 13C and 15N and studied using two-dimensional homonuclear and three- and four-dimensional heteronuclear NMR spectroscopy. The final structure was determined using 501 constraints, comprising 422 NOE constraints, 60 dihedral angle constraints, 9 disulfide constraints, and 10 hydrogen bond constraints. Structures were initially determined with the program PEGASUS and subsequently refined with X-PLOR. The average rms deviation from a calculated average structure for the backbone atoms of residues 3-38 is 0.40 A. A helix is present from residues 11 to 20 and includes two proline residues at positions 15 and 16. A loop at residues 21-24 leads into a two-strand antiparallel sheet from residues 25 to 38 with a turn at residues 30-33. Residues 3-6 run adjacent to the 33-38 strand but do not form a canonical beta-strand. The two additional residues of margatoxin, relative to the related toxins charybdotoxin and iberiotoxin, insert in a manner that extends the beta-sheet by one residue. Otherwise, the global structure is very similar to that of these two other toxins. The longer sheet may have implications for channel selectivity.


    Organizational Affiliation

    Department of Biophysical Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MARGATOXIN
A
39Centruroides margaritatusMutation(s): 0 
Find proteins for P40755 (Centruroides margaritatus)
Go to UniProtKB:  P40755
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 23 
  • Olderado: 1MTX Olderado
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORrefinement
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1995-11-14
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance