Structure and organization of the cardiotoxin genes in Naja naja sputatrix1

Autor: Lachumanan, Ramkumar, Armugam, Arunmozhiarasi, Tan, Chee-Hong, Jeyaseelan, Kandiah
Zdroj: FEBS Letters; August 1998, Vol. 433 Issue: 1-2 p119-124, 6p
Abstrakt: We report the genomic structure, organization and the presence of multiple isoforms of the gene encoding cardiotoxins (CTX) of Naja naja sputatrix. The cardiotoxin gene consists of six CTX isoforms, each (2.2 kb) having three exons and two introns. Two possible transcription initiation sites as well as consensus TATA boxes and transcription factor binding motifs, AP‐2, NFIL‐6/C/EBP, NF‐κB and PuF have been identified in the 5′‐region of the gene. The CTX gene isoforms show nucleotide variations at specific segmentsin exon 2 and exon 3, which correspond to the functional domains in the three‐finger loop structure of the cardiotoxin molecule. The diverse functions of cardiotoxins together with our findings suggest that the cardiotoxin gene isoforms may have evolved under adaptive pressure through a positive Darwinian selection process.
Databáze: Supplemental Index