1not

THE 1.2 ANGSTROM STRUCTURE OF G1 ALPHA CONOTOXIN

spinqualitylabelsall models 1not, resolution 1.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1not is a 1 chain structure with sequence from Conge. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: NH2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [CA1A_CONGE] Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. The higher affinity site for alpha-conotoxin GI is the alpha/delta site on mouse muscle-derived BC3H-1 receptor, and the other site (alpha/gamma site) on nicotinic receptors from Torpedo californica electric organ. Publication Abstract from PubMed Predatory marine snails of the genus Conus paralyze their fish prey by injecting a potent toxin. The alpha-conotoxin GI is a 13-residue peptide isolated from venom of Conus geographus. It functions by blocking the postsynaptic nicotinic acetylcholine receptor. After crystallization in deionized water, the three-dimensional structure of the GI neurotoxin was determined to 1.2 A resolution by X-ray crystallography. This structure, which can be described as a triangular slab, shows overall similarities to those derived by NMR, CD, and predictive methods. The principal framework of the molecule is provided by two disulfide bonds, one linking Cys 2 and Cys 7 and the other Cys 3 and Cys 13. Opposite ends of the sequence are drawn together even further by hydrogen bonds between Glu 1 and Cys 13 and between Cys 2 and Ser 12. Since the C-terminus is amidated, only one negative charge is present (carboxylate of Glu 1), and this is not implicated in receptor binding. Two positively charged regions (the alpha-amino group of Glu 1 and the guanido group of Arg 9) are situated 15 A apart at the corners of the triangular face of the molecule. phi, psi angles characteristic of a 3(10) helix were observed for residues 5-7. For residues 8-11, these angles were consistent with either a type I beta-turn or a distorted 3(10) helix. Three-dimensional structure of the alpha-conotoxin GI at 1.2 A resolution.,Guddat LW, Martin JA, Shan L, Edmundson AB, Gray WR Biochemistry. 1996 Sep 3;35(35):11329-35. PMID:8784187 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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