1sxm
From Proteopedia
(New page: 200px<br /><applet load="1sxm" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sxm" /> '''SCORPION TOXIN (NOXIUSTOXIN) WITH HIGH AFFIN...) |
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| - | [[Image:1sxm.gif|left|200px]]<br /><applet load="1sxm" size=" | + | [[Image:1sxm.gif|left|200px]]<br /><applet load="1sxm" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1sxm" /> | caption="1sxm" /> | ||
'''SCORPION TOXIN (NOXIUSTOXIN) WITH HIGH AFFINITY FOR VOLTAGE DEPENDENT POTASSIUM CHANNEL AND LOW AFFINITY FOR CALCIUM DEPENDENT POTASSIUM CHANNEL (NMR AT 20 DEGREES, PH3.5, 39 STRUCTURES)'''<br /> | '''SCORPION TOXIN (NOXIUSTOXIN) WITH HIGH AFFINITY FOR VOLTAGE DEPENDENT POTASSIUM CHANNEL AND LOW AFFINITY FOR CALCIUM DEPENDENT POTASSIUM CHANNEL (NMR AT 20 DEGREES, PH3.5, 39 STRUCTURES)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The 3D structure of noxiustoxin, the first identified scorpion toxin | + | The 3D structure of noxiustoxin, the first identified scorpion toxin acting on K+ channels, has been elucidated by NMR and molecular modeling. Thirty-nine solution structures were calculated using 572 distance and 42 dihedral restraints. The average atomic rms deviation between the refined structures and the mean structure is 0.75 A for the backbone atoms. Noxiustoxin adopts a alpha/beta scaffold constituted of a three-stranded beta-sheet (residues 2-3, 25-30, 33-38) linked to a helix (residues 10-20) through two disulfide bridges. A comparison between the 3D structure of noxiustoxin and those of other structurally and functionally related scorpion toxins (charybdotoxin, PO5-NH2, kaliotoxin) revealed a bending capacity of the helix and a variability in the relative orientations between the helix and the beta-sheet. These two features highlight the plasticity of the alpha/beta scaffold and offer a structural explanation for the capacity of the fold to accommodate an additional alanine residue in the Gly-x-Cys pattern of a previously proposed consensus sequence [Bontems et al. (1991) Science 254, 1521-1523]. Our structural data also emphasize the possibility that the beta-sheet of NTX is implicated in the capacity of NTX to recognize voltage-dependent K+ channels. |
==About this Structure== | ==About this Structure== | ||
| - | 1SXM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_noxius Centruroides noxius] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1SXM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Centruroides_noxius Centruroides noxius] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SXM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gurrola-Briones, G.]] | [[Category: Gurrola-Briones, G.]] | ||
[[Category: Menez, A.]] | [[Category: Menez, A.]] | ||
| - | [[Category: Possani, L | + | [[Category: Possani, L D.]] |
[[Category: Roumestand, C.]] | [[Category: Roumestand, C.]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:06:50 2008'' |
Revision as of 13:06, 21 February 2008
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SCORPION TOXIN (NOXIUSTOXIN) WITH HIGH AFFINITY FOR VOLTAGE DEPENDENT POTASSIUM CHANNEL AND LOW AFFINITY FOR CALCIUM DEPENDENT POTASSIUM CHANNEL (NMR AT 20 DEGREES, PH3.5, 39 STRUCTURES)
Overview
The 3D structure of noxiustoxin, the first identified scorpion toxin acting on K+ channels, has been elucidated by NMR and molecular modeling. Thirty-nine solution structures were calculated using 572 distance and 42 dihedral restraints. The average atomic rms deviation between the refined structures and the mean structure is 0.75 A for the backbone atoms. Noxiustoxin adopts a alpha/beta scaffold constituted of a three-stranded beta-sheet (residues 2-3, 25-30, 33-38) linked to a helix (residues 10-20) through two disulfide bridges. A comparison between the 3D structure of noxiustoxin and those of other structurally and functionally related scorpion toxins (charybdotoxin, PO5-NH2, kaliotoxin) revealed a bending capacity of the helix and a variability in the relative orientations between the helix and the beta-sheet. These two features highlight the plasticity of the alpha/beta scaffold and offer a structural explanation for the capacity of the fold to accommodate an additional alanine residue in the Gly-x-Cys pattern of a previously proposed consensus sequence [Bontems et al. (1991) Science 254, 1521-1523]. Our structural data also emphasize the possibility that the beta-sheet of NTX is implicated in the capacity of NTX to recognize voltage-dependent K+ channels.
About this Structure
1SXM is a Single protein structure of sequence from Centruroides noxius with as ligand. Full crystallographic information is available from OCA.
Reference
Determination of the three-dimensional solution structure of noxiustoxin: analysis of structural differences with related short-chain scorpion toxins., Dauplais M, Gilquin B, Possani LD, Gurrola-Briones G, Roumestand C, Menez A, Biochemistry. 1995 Dec 26;34(51):16563-73. PMID:8527429
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