1IJC

Solution Structure of Bucandin, a Neurotoxin from the Venom of the Malayan Krait

DOI: 10.2210/pdb1IJC/pdb
BMRB: 5097

Classification: TOXIN
Organism(s): Bungarus candidus
Mutation(s): No

Deposited: 2001-04-25 Released: 2001-12-21
Deposition Author(s): Torres, A.M., Kini, R.M., Nirthanan, S., Kuchel, P.W.

Experimental Data Snapshot

Method: SOLUTION NMR
Conformers Calculated: 6000
Conformers Submitted: 20
Selection Criteria: structures with the lowest energy

wwPDB Validation 3D Report Full Report

This is version 1.2 of the entry. See complete history.

Literature

NMR structure of bucandin, a neurotoxin from the venom of the Malayan krait (Bungarus candidus).

Torres, A.M., Kini, R.M., Selvanayagam, N., Kuchel, P.W.

(2001) Biochem J 360: 539-548

PubMed: 11736642 Search on PubMedSearch on PubMed Central
DOI: 10.1042/0264-6021:3600539
Primary Citation of Related Structures:
1IJC

PubMed Abstract:

A high-resolution solution structure of bucandin, a neurotoxin from Malayan krait (Bungarus candidus), was determined by (1)H-NMR spectroscopy and molecular dynamics. The average backbone root-mean-square deviation for the 20 calculated structures and the mean structure is 0.47 A (1 A=0.1 nm) for all residues and 0.24 A for the well-defined region that spans residues 23-58. Secondary-structural elements include two antiparallel beta-sheets characterized by two and four strands. According to recent X-ray analysis, bucandin adopts a typical three-finger loop motif and yet it has some peculiar characteristics that set it apart from other common alpha-neurotoxins. The presence of a fourth strand in the second antiparallel beta-sheet had not been observed before in three-finger toxins, and this feature was well represented in the NMR structure. Although the overall fold of the NMR structure is similar to that of the X-ray crystal structure, there are significant differences between the two structures that have implications for the pharmacological action of the toxin. These include the extent of the beta-sheets, the conformation of the region spanning residues 42-49 and the orientation of some side chains. In comparison with the X-ray structure, the NMR structure shows that the hydrophobic side chains of Trp(27) and Trp(36) are stacked together and are orientated towards the tip of the middle loop. The NMR study also showed that the two-stranded beta-sheet incorporated in the first loop, as defined by residues 1-22, and the C-terminus from Asn(59), is probably flexible relative to the rest of the molecule. On the basis of the dispositions of the hydrophobic and hydrophilic side chains, the structure of bucandin is clearly different from those of cytotoxins.

Related Citations:

The atomic resolution structure of bucandin, a novel toxin isolated from the Malayan krait, determined by direct methods
Kuhn, P., Deacon, A.M., Comoso, S., Rajaseger, G., Kini, R.M., Uson, I., Kolatkar, P.R.
(2000) Acta Crystallogr D Biol Crystallogr 56: 1401

Organizational Affiliation:

Department of Biochemistry, University of Sydney, N.S.W. Australia 2006.

Macromolecules

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
bucandin	A	63	Bungarus candidus	Mutation(s): 0
UniProt
Find proteins for P81782 (Bungarus candidus) Explore P81782 Go to UniProtKB: P81782
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Reference Sequence