2crs
CARDIOTOXIN III FROM TAIWAN COBRA (NAJA NAJA ATRA) DETERMINATION OF STRUCTURE IN SOLUTION AND COMPARISON WITH SHORT NEUROTOXINS
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OverviewOverview
The structure in solution of cardiotoxin III, a membrane toxin purified, from the venom of the Taiwan cobra, Naja naja atra, is reported., Sequence-specific assignment of 1H-NMR lines was completed and the NMR, data show the presence of a triple and a double-stranded antiparallel, beta-sheet. Many NOE cross peaks identified in NOESY spectra were applied, as distance constraints based on a hybrid distance geometry/dynamical, simulated annealing technique; 20 structures were found within a single, family. The average value of atomic RMS differences between the 20, structures and their geometric mean is 0.087 nm for the backbone atoms and, 0.152 nm for all heavy atoms; they are 0.055 nm and 0.12 nm, respectively, for the segments of secondary structure. In these selected structures the, backbone of the polypeptide chain folds such that five strands emerge from, a globular head. Three major loops link these strands to form a double and, a triple-stranded antiparallel beta-sheet. Comparison of the structures of, the toxin in solution with the X-ray crystal structure of its homologous, protein, cardiotoxin V4II from Naja mossambica mossambica, showed good, agreement between the structures except at segments of the turns. As the, functions of short neurotoxins and cardiotoxins are distinct, despite, their similar secondary structural patterns and tertiary folding, a, comparative analysis has been carried out between cardiotoxin III and, short neurotoxins of known structures. We discuss their structural, features in order to clarify relationships between their structure and, function.
About this StructureAbout this Structure
2CRS is a Single protein structure of sequence from Naja atra. Full crystallographic information is available from OCA.
ReferenceReference
Cardiotoxin III from the Taiwan cobra (Naja naja atra). Determination of structure in solution and comparison with short neurotoxins., Bhaskaran R, Huang CC, Chang DK, Yu C, J Mol Biol. 1994 Jan 28;235(4):1291-301. PMID:8308891
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