title: Genomic organization of three neurotoxins active on small conductance Ca2+-activated potassium channels from the scorpion Buthus martensi Karsch.
abstract: According to the known primary sequences of three neurotoxins active on small conductance Ca2+-activated potassium channels from the scorpion Buthus martensi Karsch, their corresponding cDNAs were cloned and sequenced using 3'- and 5'-RACE. All of them encoded a signal peptide composed of 28 residues and a mature toxin of 29, 28 and 33 residues, respectively. Their cDNA deduced sequences were totally consistent with those determined, and the C-terminal amidation of one neurotoxin was confirmed. The genomic DNAs of these three toxins were also amplified by PCR, cloned and sequenced. They all consisted of two exons disrupted by a small single intron. All of these introns were inserted within the signal peptide at the same -10 position upstream from the mature toxin, consisting of 94, 78 and 87 bp, respectively.
authors.affiliation: State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, PR China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Wu
authors.forename: L
authors.initials: L
authors.lastname: Dai
authors.forename: Z D
authors.initials: ZD
authors.lastname: Lan
authors.forename: C W
authors.initials: CW
authors.lastname: Chi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005091:Exons; D007438:Introns; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity; D016133:Polymerase Chain Reaction; D015221:Potassium Channels / Q000009:adverse effects*; D021382:Protein Sorting Signals / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000633:toxicity; D012604:Scorpion Venoms / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity; D012605:Scorpions / Q000235:genetics*
chemical_list: C106377:BmP01 toxin; C106379:BmP03 toxin; C106380:BmP05 toxin; D018076:DNA, Complementary; D009498:Neurotoxins; D015221:Potassium Channels; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D012604:Scorpion Venoms