2ctx
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ctx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ctx OCA], [http://www.ebi.ac.uk/pdbsum/2ctx PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2ctx RCSB]</span> | ||
}} | }} | ||
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[[Category: neurotoxin]] | [[Category: neurotoxin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 02:26:22 2008'' |
Revision as of 23:26, 30 March 2008
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| , resolution 2.4Å | |||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
THE REFINED CRYSTAL STRUCTURE OF ALPHA-COBRATOXIN FROM NAJA NAJA SIAMENSIS AT 2.4-ANGSTROMS RESOLUTION
Overview
The crystal structure of the "long" alpha-neurotoxin alpha-cobratoxin was refined to an R-factor of 19.5% using 3271 x-ray data to 2.4-A resolution. The polypeptide chain forms three loops, I, II, III, knotted together by four disulfide bridges, with the most prominent, loop II, containing another disulfide close to its lower tip. Loop I is stabilized by one beta-turn and two beta-sheet hydrogen bonds; loop II by eight beta-sheet hydrogen bonds, with the tip folded into two distorted right-handed helical turns stabilized by two alpha-helical and two beta-turn hydrogen bonds; and loop III by hydrophobic interactions and one beta-turn. Loop II and one strand of loop III form an antiparallel triple-pleated beta-sheet, and tight anchoring of the Asn63 side chain fixes the tail segment. In the crystal lattice, the alpha-cobratoxin molecules dimerize by beta-sheet formation between strands 53 and 57 of symmetry-related molecules. Because such interactions are found also in a cardiotoxin and alpha-bungarotoxin, this could be of importance for interaction with acetylcholine receptor.
About this Structure
2CTX is a Single protein structure of sequence from Naja naja. Full crystallographic information is available from OCA.
Reference
The refined crystal structure of alpha-cobratoxin from Naja naja siamensis at 2.4-A resolution., Betzel C, Lange G, Pal GP, Wilson KS, Maelicke A, Saenger W, J Biol Chem. 1991 Nov 15;266(32):21530-6. PMID:1939183
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