Adaptive evolution in the snake venom Kunitz/BPTI protein family.
Snake venoms are rich sources of serine proteinase inhibitors that are members of the Kunitz/BPTI (bovine pancreatic trypsin inhibitor) family. However, only a few of their gene sequences have been determined from snakes. We therefore cloned the cDNAs for the trypsin and chymotrypsin inhibitors from a Vipera ammodytes venom gland cDNA library. Phylogenetic analysis of these and other snake Kunitz/BPTI homologs shows the presence of three clusters, where sequences cluster by functional role. Analysis of the nucleotide sequences from the snake Kunitz/BPTI family shows that positive Darwinian selection was operating on the highly conserved BPTI fold, indicating that this family evolved by gene duplication and rapid diversification.
Zupunski
Vera
V
Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
Kordis
Dusan
D
Gubensek
Franc
F
D000595:Amino Acid Sequence; D000818:Animals; D007611:Aprotinin / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D015723:Gene Library; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D017819:Viperidae / Q000145:classification / Q000235:genetics*
D017931:DNA Primers; D018076:DNA, Complementary; D007611:Aprotinin