Cloning and sequence analysis of the cDNA encoding a snake neurotoxin precursor.

A recombinant plasmid has been constructed containing a sequence of 186 nucleotides encoding a potent neurotoxin found in the venom of the sea-snake Laticauda semifasciata and designated as erabutoxin a. This sequence is flanked, in the upstream region, by a sequence of 60 nucleotides encoding a hydrophobic peptide fragment presumably involved in the secretion process of the neurotoxin. The sequence coding for the toxin ends with a termination codon which is followed by a 3'-untranslated sequence of approximately 240 nucleotides (excluding the poly(A) tract).