Cloning and structural analysis of alpha-latroinsectotoxin cDNA. Abundance of ankyrin-like repeats

Eur J Biochem. 1993 Apr 1;213(1):121-7. doi: 10.1111/j.1432-1033.1993.tb17741.x.


alpha-Latroinsectotoxin (alpha-LIT), purified from venom glands of the black widow spider Latrodectus mactans tredecimguttatus, is a presynaptic neurotoxin selective only for insects. A cDNA encoding the putative alpha-LIT precursor was isolated from a spider venom gland cDNA library. The cDNA contains a 4236-base-pair open reading frame corresponding to a 157826-Da protein composed of 1411 amino acids. The mature alpha-LIT, with molecular mass approximately 130 kDa, is probably derived from double processing in the N-terminal and C-terminal regions of the primary translation product. The structure region, extending over residues 464-1176, is composed almost entirely of ankyrin-like repeats which represent a motif also found in the alpha-latrotoxin (alpha-LTX), which has selective action on vertebrates. Total alignment of the alpha-LIT and alpha-LTX amino acid sequences reveals an overall similarity of 34.1%. Strong sequence divergence is observed in analogous cysteine-rich regions situated within the ankyrin-repeat domains of both alpha-LIT and alpha-LTX.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Ankyrins / genetics*
  • Base Sequence
  • Black Widow Spider
  • Cloning, Molecular
  • DNA
  • Molecular Sequence Data
  • Repetitive Sequences, Nucleic Acid*
  • Sequence Homology, Amino Acid
  • Spider Venoms / genetics*


  • Ankyrins
  • Spider Venoms
  • latroinsectotoxin
  • DNA

Associated data

  • GENBANK/L09679
  • GENBANK/L09680
  • GENBANK/L09681
  • GENBANK/L09682
  • GENBANK/L09683
  • GENBANK/X57950
  • GENBANK/X70999
  • GENBANK/X71000
  • GENBANK/X72862
  • GENBANK/Z14086