1TXA: SOLUTION NMR STRUCTURE OF TOXIN B, A LONG NEUROTOXIN FROM THE VENOM OF THE KING COBRA, MINIMIZED AVERAGE STRUCTURE

Citation:
Abstract
The solution structure of toxin b, a long neurotoxin (73 amino acids and 5 disulfides) from the venom of Ophiophagus hannah (king cobra), has been determined using 1H NMR and dynamical simulated annealing techniques. The structures were calculated using 485 distance constraints and 52 dihedral angle restraints. The 21 structures that were obtained satisfy the experimental restraints and possess good nonbonded contacts. Analysis of the converged structures revealed that the protein consists of a core region from which three finger-like loops extend outwards. The regular secondary structure in toxin b includes a double and a triple stranded antiparallel beta sheet. Comparison with the solution structures of other long neurotoxins reveals that although the structure of toxin b is similar to those of previously reported long neurotoxins, clear local structural differences are observed in regions proposed to be involved in binding to the acetylcholine receptor. A positively charged cluster is found in the C-terminal tail, in Loop III, and in the tip of Loop II. This cationic cluster could be crucial for the binding of the long neurotoxins to the acetylcholine receptor.
PDB ID: 1TXADownload
MMDB ID: 156846
PDB Deposition Date: 1996/7/20
Updated in MMDB: 2017/12
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 1TXA: monomeric; determined by author
Molecular Components in 1TXA
Label Count Molecule
Protein (1 molecule)
1
Toxin B
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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