1IDH image
Entry Detail
PDB ID:
1IDH
Keywords:
Title:
THE NMR SOLUTION STRUCTURE OF THE COMPLEX FORMED BETWEEN ALPHA-BUNGAROTOXIN AND AN 18MER COGNATE PEPTIDE
Biological Source:
PDB Version:
Deposition Date:
2001-04-04
Release Date:
2001-04-25
Method Details:
Experimental Method:
Conformers Calculated:
300
Conformers Submitted:
20
Selection Criteria:
The submitted conformer models are the 20 structures with the lowest energy from 120 acceptable structures which were from 300 total calculated structures and had no restraint violations. The best representative conformer is the lowest potential energy structure of the ensemble.
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:ALPHA-BUNGAROTOXIN
Chain IDs:A
Chain Length:74
Number of Molecules:1
Biological Source:Bungarus multicinctus
Polymer Type:polypeptide(L)
Description:ACETYLCHOLINE RECEPTOR PROTEIN, ALPHA CHAIN
Chain IDs:B
Chain Length:19
Number of Molecules:1
Biological Source:Torpedo californica
Ligand Molecules
Primary Citation
The solution structure of the complex formed between alpha-bungarotoxin and an 18-mer cognate peptide derived from the alpha 1 subunit of the nicotinic acetylcholine receptor from Torpedo californica.
J.Biol.Chem. 276 22930 22940 (2001)
PMID: 11312275 DOI: 10.1074/jbc.M102300200

Abstact

The region encompassing residues 181-98 on the alpha1 subunit of the muscle-type nicotinic acetylcholine receptor forms a major determinant for the binding of alpha-neurotoxins. We have prepared an (15)N-enriched 18-amino acid peptide corresponding to the sequence in this region to facilitate structural elucidation by multidimensional NMR. Our aim was to determine the structural basis for the high affinity, stoichiometric complex formed between this cognate peptide and alpha-bungarotoxin, a long alpha-neurotoxin. Resonances in the complex were assigned through heteronuclear and homonuclear NMR experiments, and the resulting interproton distance constraints were used to generate ensemble structures of the complex. Thr(8), Pro(10), Lys(38), Val(39), Val(40), and Pro(69) in alpha-bungarotoxin and Tyr(189), Tyr(190), Thr(191), Cys(192), Asp(195), and Thr(196) in the peptide participate in major intermolecular contacts. A comparison of the free and bound alpha-bungarotoxin structures reveals significant conformational rearrangements in flexible regions of alpha-bungarotoxin, mainly loops I, II, and the C-terminal tail. Furthermore, several of the calculated structures suggest that cation-pi interactions may be involved in binding. The root mean square deviation of the polypeptide backbone in the complex is 2.07 A. This structure provides, to date, the highest resolution description of the contacts between a prototypic alpha-neurotoxin and its cognate recognition sequence.

Legend

Protein

Chemical

Disease

Primary Citation of related structures