1QS3

NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 30 
  • Selection Criteria: structures with the lowest energy 

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This is version 1.3 of the entry. See complete history

Literature

NMR solution conformation of an antitoxic analogue of alpha-conotoxin GI: identification of a common nicotinic acetylcholine receptor alpha 1-subunit binding surface for small ligands and alpha-conotoxins.

Mok, K.H.Han, K.H.

(1999) Biochemistry 38: 11895-11904


  • PubMed Abstract: 
  • The three-dimensional solution conformation of an 11-residue antitoxic analogue of alpha-conotoxin GI, des-Glu1-[Cys3Ala]-des-Cys13-conotoxin GI (CANPACGRHYS-NH(2), designated "GI-15" henceforth), has been determined using two-dimensional (1)H NMR sp ...

    The three-dimensional solution conformation of an 11-residue antitoxic analogue of alpha-conotoxin GI, des-Glu1-[Cys3Ala]-des-Cys13-conotoxin GI (CANPACGRHYS-NH(2), designated "GI-15" henceforth), has been determined using two-dimensional (1)H NMR spectroscopy. The disulfide loop region (1C-6C) and the C-terminal tail (8R-11S) are connected by a flexible hinge formed near 7G, and the pairwise backbone rmsds for the former and the latter are 0.58 and 0.65 A, respectively. Superpositioning GI-15 with the structure of alpha-conotoxin GI shows that the two share an essentially identical fold in the common first disulfide loop region (1C-6C). However, the absence of the second disulfide loop in GI-15 results in segmental motion of the C-terminal half, causing the key receptor subtype selectivity residue 8R (Arg9 in alpha-conotoxin GI) to lose its native spatial orientation. The combined features of structural equivalence in the disulfide loop and a mobile C-terminal tail appear to be responsible for the activity of GI-15 as a competitive antagonist against native toxin. Electrostatic surface potential comparisons of the first disulfide region of GI-15 with other alpha-conotoxins or receptor-bound states of acetylcholine and d-tubocurarine show a common protruding surface that may serve as the minimal binding determinant for the neuromuscular acetylcholine receptor alpha 1-subunit. On the basis of the original "Conus toxin macrosite model" [Olivera, B. M., Rivier, J., Scott, J. K., Hillyard, D. R., and Cruz, L. J. (1991) J. Biol. Chem. 266, 1923-1936], we propose a revised binding model which incorporates these results.


    Organizational Affiliation

    Biomolecular Structure Research Unit, Korea Research Institute of Bioscience and Biotechnology, Taejon, Republic of Korea.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DES-GLU1-[CYS3ALA]-DES-CYS13-ALPHA CONOTOXIN GI
A
12Conus geographusMutation(s): 0 
Find proteins for P01519 (Conus geographus)
Go to UniProtKB:  P01519
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 Calculated: 100 
  • Conformers Submitted: 30 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1QS3 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 1999-06-25 
  • Released Date: 1999-10-06 
  • Deposition Author(s): Mok, K.H., Han, K.-H.

Revision History 

  • Version 1.0: 1999-10-06
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2014-03-12
    Type: Database references