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)
Summary for 1SXM
| Entry DOI | 10.2210/pdb1sxm/pdb |
| Descriptor | NOXIUSTOXIN (1 entity in total) |
| Functional Keywords | toxin |
| Biological source | Centruroides noxius (Mexican scorpion) |
| Cellular location | Secreted: P08815 |
| Total number of polymer chains | 1 |
| Total formula weight | 4207.00 |
| Authors | Dauplais, M.,Gilquin, B.,Possani, L.D.,Gurrola-Briones, G.,Roumestand, C.,Menez, A. (deposition date: 1995-09-07, release date: 1996-01-29, Last modification date: 2024-11-13) |
| Primary citation | Dauplais, M.,Gilquin, B.,Possani, L.D.,Gurrola-Briones, G.,Roumestand, C.,Menez, A. Determination of the three-dimensional solution structure of noxiustoxin: analysis of structural differences with related short-chain scorpion toxins. Biochemistry, 34:16563-16573, 1995 Cited by PubMed Abstract: 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. PubMed: 8527429DOI: 10.1021/bi00051a004 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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