1ctx is a 1 chain structure with sequence from Naja siamensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
Three-dimensional structure of the "long" neurotoxin from cobra venom.,Walkinshaw MD, Saenger W, Maelicke A Proc Natl Acad Sci U S A. 1980 May;77(5):2400-4. PMID:6930640[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Walkinshaw MD, Saenger W, Maelicke A. Three-dimensional structure of the "long" neurotoxin from cobra venom. Proc Natl Acad Sci U S A. 1980 May;77(5):2400-4. PMID:6930640