1CTX

THREE-DIMENSIONAL STRUCTURE OF THE-LONG-NEUROTOXIN FROM COBRA VENOM

Summary for 1CTX

• Entry DOI: 10.2210/pdb1ctx/pdb
• Descriptor: ALPHA-COBRATOXIN (1 entity in total)
• Functional Keywords: toxin
• Biological source: Naja siamensis
• Cellular location: Secreted : P01391
• Total number of polymer chains: 1
• Total formula weight: 7842.09

Authors

Saenger, W.,Walkinshaw, M.D. (deposition date: 1982-04-08, release date: 1982-05-26, Last modification date: 2024-10-23)

Primary citation

Walkinshaw, M.D.,Saenger, W.,Maelicke, A.
Three-dimensional structure of the "long" neurotoxin from cobra venom.
Proc.Natl.Acad.Sci.USA, 77:2400-2404, 1980

PubMed Abstract: The three-dimensional structure of alpha-cobra-toxin, the "long" neurotoxin from the venom of Naja naja siamensis, has been determined at 2.8-A resolution. Crystals grown as hexagonal needles have space group P6522 with unit cell parameters a = b = 74.59 A, c = 42.89 A; one molecule per asymmetric unit. Phases were determined with a single isomorphous derivative with HgI2 by using the anomalous scattering of the single-site HgI2 molecule to resolve the phase ambiguity. The polypeptide chain folds into three major loops and one tail emerging from a globular head. The protruding long central loop (residues 21-40) is flanked on either side by two shorter loops (residues 4-13 and 44-55); the tail piece (residues 63-71) hangs behind this loop. The molecular conformation is determined by four disulfides in the head and one at the tip of the long loop, by a triple-stranded beta-pleated sheet involving this loop, and by hydrophobic interactions stabilizing the other two loops. The structure of alpha-cobratoxin is compared to that described for the "short" erabutoxin b which shows similar arrangement of structurally and functionally invariant groups.

PubMed: 6930640
DOI: 10.1073/pnas.77.5.2400

Experimental method

X-RAY DIFFRACTION (2.8 Å)