1AWY

NMR STRUCTURE OF CALCIUM BOUND CONFORMER OF CONANTOKIN G, MINIMIZED AVERAGE STRUCTURE


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 25 
  • Conformers Submitted: 
  • Selection Criteria: LOWEST ENERGY 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Role of gamma-carboxyglutamic acid in the calcium-induced structural transition of conantokin G, a conotoxin from the marine snail Conus geographus.

Rigby, A.C.Baleja, J.D.Li, L.Pedersen, L.G.Furie, B.C.Furie, B.

(1997) Biochemistry 36: 15677-15684

  • DOI: 10.1021/bi9718550

  • PubMed Abstract: 
  • Conantokin G is a gamma-carboxyglutamic acid- (Gla-) containing conotoxin isolated from the venom of the marine cone snail Conus geographus. This 17-residue polypeptide, which contains five gamma-carboxyglutamic acid residues, is a N-methyl-d-asparta ...

    Conantokin G is a gamma-carboxyglutamic acid- (Gla-) containing conotoxin isolated from the venom of the marine cone snail Conus geographus. This 17-residue polypeptide, which contains five gamma-carboxyglutamic acid residues, is a N-methyl-d-aspartate- (NMDA-) type glutamate receptor antagonist. To investigate the role of gamma-carboxyglutamic acid in the calcium-induced structural transition of conantokin G, we determined the three-dimensional structure of the conantokin G/Ca2+ complex by two-dimensional 1H NMR spectroscopy and compared it to the high-resolution structure of conantokin G in the absence of metal ions [Rigby et al. (1997) Biochemistry 36, 6906]. Complete resonance assignments were made by two dimensional 1H NMR spectroscopy at pH 5.6 in the presence of saturating amounts of Ca2+. Distance geometry and simulated annealing methods were used to derive 23 convergent structures from a set of 302 interproton distance restraints and two torsion angle measurements. A high-resolution structure, with the backbone root mean square deviation to the geometric average of the 23 structures of 0.6 +/- 0.1 A, contains a linear alpha-helix from Gla 3 to Lys 15. Gla residues 3, 7, 10, and 14 are aligned in a linear array on one face of the helix. A genetic algorithm was applied to determine the calcium positions in conantokin G, and the conantokin G/Ca2+ complex refined by molecular simulation. Upon binding of Ca2+ to gamma-carboxyglutamic acid, conantokin G undergoes a conformational transition from a distorted curvilinear 310 helix to a linear alpha-helix. Occupancy of the metal binding sites, defined by gamma-carboxyglutamic acids, results in formation of a calcium-carboxylate network that linearizes the helix and exposes the hydrophobic amino acids on the opposite face of the helix.


    Organizational Affiliation

    Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CONANTOXIN G
A
18Conus geographusN/A
Find proteins for P07231 (Conus geographus)
Go to UniProtKB:  P07231
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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CGU
Query on CGU
A
L-PEPTIDE LINKINGC6 H9 N O6GLU
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 25 
  • Conformers Submitted: 
  • Selection Criteria: LOWEST ENERGY 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-04-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance