title: Molecular cloning and nucleotide sequence analysis of encoded anti-insect toxin BotIT2 from the scorpion Buthus occitanus tunetanus venom.
abstract: Numerous toxins from scorpion venoms are much more toxic to insects than to other animal classes, and possess high affinity to Na+ channels. Many of them active on insects were purified from the venom of Buthus occitanus tunetanus. Using amino acid sequences of BotIT2 and RACE-PCR amplification (Rapid amplification of cDNA ends) technique, we isolated, identified and sequenced the nucleotide sequence from the venom glands of the scorpion Buthus occitanus tunetanus. The cDNA encodes a precursor of an insect toxin of 60 amino acid residues. The deduced nucleotide sequence toxin was identical to the determined amino acid sequence of BotIT2. BotIT2 is more similar to the excitatory toxins in its mode of action and to the depressant toxins in its primary structure.
authors.affiliation: Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, BP 74, 1002 Tunis-Belvedère, Tunisia.
authors.forename: R
authors.initials: R
authors.lastname: Bel Haj Rhouma
authors.forename: H
authors.initials: H
authors.lastname: Dkhil
authors.forename: K
authors.initials: K
authors.lastname: Benkhadir
authors.forename: L
authors.initials: L
authors.lastname: Borchani
authors.forename: M
authors.initials: M
authors.lastname: El Ayeb
authors.forename: H
authors.initials: H
authors.lastname: Karoui
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics*; D015153:Blotting, Western; D003001:Cloning, Molecular / Q000379:methods*; D018076:DNA, Complementary / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression / Q000235:genetics; D007313:Insecta / Q000187:drug effects; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000009:adverse effects / Q000737:chemistry; D019105:Random Amplified Polymorphic DNA Technique; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D012604:Scorpion Venoms / Q000009:adverse effects / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012605:Scorpions; D015222:Sodium Channels / Q000187:drug effects; D013329:Structure-Activity Relationship; D014416:Tunisia
chemical_list: C102637:BotIT2 toxin; D018076:DNA, Complementary; D009498:Neurotoxins; D011993:Recombinant Fusion Proteins; D012604:Scorpion Venoms; D015222:Sodium Channels