1GIB

MU-CONOTOXIN GIIIB, NMR


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Three-dimensional solution structure of mu-conotoxin GIIIB, a specific blocker of skeletal muscle sodium channels.

Hill, J.M.Alewood, P.F.Craik, D.J.

(1996) Biochemistry 35: 8824-8835

  • DOI: 10.1021/bi960073o
  • Primary Citation of Related Structures:  
    1GIB

  • PubMed Abstract: 
  • The three-dimensional solution structure of mu-conotoxin GIIIB, a 22-residue polypeptide from the venom of the piscivorous cone snail Conus geographus, has been determined using 2D 1H NMR spectroscopy. GIIIB binds with high affinity and selectivity to skeletal muscle sodium channels and is a valuable tool for characterizing both the structure and function of these channels ...

    The three-dimensional solution structure of mu-conotoxin GIIIB, a 22-residue polypeptide from the venom of the piscivorous cone snail Conus geographus, has been determined using 2D 1H NMR spectroscopy. GIIIB binds with high affinity and selectivity to skeletal muscle sodium channels and is a valuable tool for characterizing both the structure and function of these channels. Structural restraints consisting of 289 interproton distances inferred from NOEs and 9 backbone and 5 side chain dihedral angle restraints from spin-spin coupling constants were used as input for simulated annealing calculations and energy minimization in the program X-PLOR. In addition to the 1H NMR derived information, the 13C resonances of GIIIB were assigned at natural abundance, and hydroxyproline C beta and C gamma chemical shifts were used to distinguish between the cis and trans peptide bond conformations. The final set of 20 structures had mean pairwise rms differences over the whole molecule of 1.22 A for the backbone atoms and 2.48 A for all heavy atoms. For the well-defined region encompassing residues 3-21, the corresponding values were 0.74 and 2.54 A, respectively. GIIIB adopts a compact structure consisting of a distorted 310-helix, a small beta-hairpin, a cis-hydroxyproline, and several turns. The molecule is stabilized by three disulfide bonds, two of which connect the helix and the beta-sheet, forming a structural core with similarities to the CS alpha beta motif [Cornet, B., Bonmatin, J.-M., Hetru, C., Hoffmann, J. A., Ptak, M., & Vovelle, F. (1995) Structure 3, 435-448]. This motif is common to several families of small proteins including scorpion toxins and insect defensins. Other structural features of GIIIB include the presence of eight arginine and lysine side chains that project into the solvent in a radial orientation relative to the core of the molecule. These cationic side chains form potential sites of interaction with anionic sites on sodium channels. The global fold is similar to that reported for mu-conotoxin GIIIA, and the structure of GIIIB determined in this study provides the basis for further understanding of the structure-activity relationships of the mu-conotoxins and for their binding to skeletal muscle sodium channels.


    Related Citations: 
    • Structure-Activity Relationships of Mu-Conotoxin Giiia: Structure Determination of Active and Inactive Sodium Channel Blocker Peptides by NMR and Simulated Annealing Calculations
      Wakamatsu, K., Kohda, D., Hatanaka, H., Lancelin, J.M., Ishida, Y., Oya, M., Nakamura, H., Inagaki, F., Sato, K.
      (1992) Biochemistry 31: 12577
    • Solution Structure of Mu-Conotoxin Giiia Analysed by 2D-NMR and Distance Geometry Calculations
      Ott, K.H., Becker, S., Gordon, R.D., Ruterjans, H.
      (1991) FEBS Lett 278: 160
    • Tertiary Structure of Conotoxin Giiia in Aqueous Solution
      Lancelin, J.M., Kohda, D., Tate, S., Yanagawa, Y., Abe, T., Satake, M., Inagaki, F.
      (1991) Biochemistry 30: 6908

    Organizational Affiliation

    Centre for Drug Design and Development, University of Queensland, Brisbane, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MU-CONOTOXIN GIIIBA22Conus geographusMutation(s): 0 
UniProt
Find proteins for P01524 (Conus geographus)
Explore P01524 
Go to UniProtKB:  P01524
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
HYP
Query on HYP
AL-PEPTIDE LINKINGC5 H9 N O3PRO
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 
  • OLDERADO: 1GIB Olderado

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-11-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance