1NOT

THE 1.2 ANGSTROM STRUCTURE OF G1 ALPHA CONOTOXIN

Summary for 1NOT

• Entry DOI: 10.2210/pdb1not/pdb
• Descriptor: GI ALPHA CONOTOXIN (2 entities in total)
• Functional Keywords: venom, disulphide loop, conotoxin, acetylcholine receptor
• Biological source: Conus geographus (geography cone)
• Cellular location: Secreted: P01519
• Total number of polymer chains: 1
• Total formula weight: 1442.65

Authors

Guddat, L.W.,Shan, L.,Martin, J.L.,Edmundson, A.B.,Gray, W.R. (deposition date: 1996-05-02, release date: 1996-12-07, Last modification date: 2024-11-20)

Primary citation

Guddat, L.W.,Martin, J.L.,Shan, L.,Edmundson, A.B.,Gray, W.R.
Three-dimensional structure of the alpha-conotoxin GI at 1.2 A resolution
Biochemistry, 35:11329-11335, 1996

PubMed Abstract: 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.

PubMed: 8784187
DOI: 10.1021/bi960820h

Experimental method

X-RAY DIFFRACTION (1.2 Å)