Genomic structure of a potassium channel toxin from Heteractis magnifica 1
1997; Wiley; Volume: 418; Issue: 1-2 Linguagem: Inglês
10.1016/s0014-5793(97)01365-3
ISSN1873-3468
AutoresG. Gendeh, Max C.M Chung, Kandiah Jeyaseelan,
Tópico(s)Marine Invertebrate Physiology and Ecology
ResumoWe provide information on the gene encoding the K + channel toxin, HmK, of the sea anemone Heteractis magnifica . A series of DNA amplifications by PCR, which included the amplification of the 5′‐untranslated region of the gene, showed that an intron of 402 nucleotides separated the sequence that encodes the matured toxin from the signal peptide sequence. A second 264 nucleotide intron interrupted the 5′‐untranslated region of the previously reported HmK cDNA. Two possible transcription‐initiation sites were identified by primer extension analysis. Corresponding TATA‐box consensus sequences, characteristic of a promoter region, were also located from PCR products of uncloned libraries of adaptor‐ligated genomic DNA fragments. The coding region for matured HmK is intronless. The same is also true for other sea anemone toxins reported thus far. More notably, a similar intron‐exon organization is present in other ion channel‐blocking toxins from scorpions implying that molecules having similar functions share a similar organization at the genomic level suggesting a common path of evolution.
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