2ctx
From Proteopedia
(New page: 200px<br /><applet load="2ctx" size="450" color="white" frame="true" align="right" spinBox="true" caption="2ctx, resolution 2.4Å" /> '''THE REFINED CRYSTAL S...) |
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| - | [[Image:2ctx.jpg|left|200px]]<br /><applet load="2ctx" size=" | + | [[Image:2ctx.jpg|left|200px]]<br /><applet load="2ctx" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2ctx, resolution 2.4Å" /> | caption="2ctx, resolution 2.4Å" /> | ||
'''THE REFINED CRYSTAL STRUCTURE OF ALPHA-COBRATOXIN FROM NAJA NAJA SIAMENSIS AT 2.4-ANGSTROMS RESOLUTION'''<br /> | '''THE REFINED CRYSTAL STRUCTURE OF ALPHA-COBRATOXIN FROM NAJA NAJA SIAMENSIS AT 2.4-ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the "long" alpha-neurotoxin alpha-cobratoxin was | + | 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== | ==About this Structure== | ||
| - | 2CTX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Naja_naja Naja naja]. Full crystallographic information is available from [http:// | + | 2CTX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Naja_naja Naja naja]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CTX OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Lange, G.]] | [[Category: Lange, G.]] | ||
[[Category: Maelicke, A.]] | [[Category: Maelicke, A.]] | ||
| - | [[Category: Pal, G | + | [[Category: Pal, G P.]] |
[[Category: Saenger, W.]] | [[Category: Saenger, W.]] | ||
| - | [[Category: Wilson, K | + | [[Category: Wilson, K S.]] |
[[Category: neurotoxin]] | [[Category: neurotoxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:52:30 2008'' |
Revision as of 14:52, 21 February 2008
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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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