1era
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(New page: 200px<br /><applet load="1era" size="450" color="white" frame="true" align="right" spinBox="true" caption="1era" /> '''TERTIARY STRUCTURE OF ERABUTOXIN B IN AQUEOU...)
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Revision as of 12:07, 20 November 2007
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TERTIARY STRUCTURE OF ERABUTOXIN B IN AQUEOUS SOLUTION ELUCIDATED BY TWO-DIMENSIONAL NUCLEAR MAGNETIC RESONANCE
Overview
The three-dimensional structure of erabutoxin b, a short-chain neurotoxic, peptide purified from the venom of the sea snake Laticauda semifasciata, was determined in aqueous solution by two-dimensional proton nuclear, magnetic resonance and simulated annealing-based calculations. On the, basis of 883 assigned nuclear Overhauser effect (NOE) connectivities, 676, final distance constraints were derived and used together with 38 torsion, angle (phi, chi 1) constraints, four distance constraints derived from, disulfide bridges and 30 distance constraints derived from hydrogen bonds., A total of 14 converged structures were obtained from 50 runs of, calculations. The atomic root-mean-square difference about the mean, coordinate positions (excluding the residues 18 to 22) is 0.60 A for, backbone atoms (N, C alpha and C'). The protein consists of a core region, from which three finger-like loops emerge outwards. It includes a short, two-stranded antiparallel beta-sheet of residues 2 to 5 and 13 to 16, a, three-stranded antiparallel beta-sheet involving residues 23 to 30, 35 to, 41 and 50 to 56, and four disulfide bridges in the core region. Comparison, with two crystal structures of erabutoxin b at 1.4 A and 1.7 A resolution, indicated that the solution and the crystal structures were very similar, but less defined regions were observed at the localized region of the tip, of the central loop and the outside of the third loop in solution. Other, short-chain alpha-neurotoxins showed structural characteristics similar to, those of erabutoxin b.
About this Structure
1ERA is a Single protein structure of sequence from Laticauda semifasciata. Full crystallographic information is available from OCA.
Reference
Tertiary structure of erabutoxin b in aqueous solution as elucidated by two-dimensional nuclear magnetic resonance., Hatanaka H, Oka M, Kohda D, Tate S, Suda A, Tamiya N, Inagaki F, J Mol Biol. 1994 Jul 8;240(2):155-66. PMID:8027999
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