Structural Characteristics and Evolution of the Protobothrops elegans Pancreatic Phospholipase A₂ Gene in Contrast with Those of Protobothrops Genus Venom Phospholipase A₂ Genes

抄録

The nucleotide sequence of the gene encoding Protobothrops elegans (Crotalinae) pancreatic phospholipase A₂ (PLA₂), abbreviated PePancPLA₂, was determined by means of inverted PCR techniques. Since its deduced amino acid sequence contains a pancreatic loop and shows high similarity to that of Laticauda semifasciata (Elapinae) group IB pancreatic PLA₂, PePancPLA₂ is classified into group IB PLA₂. The nucleotide sequences of the PePancPLA₂ gene, the L. semifasciata group IB pancreatic PLA₂ gene, and the L. semifasciata group IA venom PLA₂ gene are similar to one another but greatly dissimilar to those of Protobothrops genus (Crotalinae) group II venom PLA₂ genes, suggesting that the Elapinae group IB PLA₂ gene and the group IA PLA₂ gene appeared after Elapinae was established, and that the Crotalinae group II venom PLA₂ genes came into existence before Elapinae and Crotalinae diverged. A phylogenetic analysis of their amino acid sequences confirms this.