Cloning, sequencing, and phylogenetic analysis of complementary DNA of novel cytochrome P-450 CYP1A in Japanese eel (Anguilla japonica).
Complementary DNA of cytochrome P-450 CYP1A, in addition to CYP1A1, has been isolated from Japanese eel (Anguilla japonica) liver treated with 3-methylcholanthrene. The cDNA contained a 5' untranslated region of 66 bp, an open reading frame of 1554 bp coding for 517 amino acids and a stop codon, and a 3' untranslated region of 1166 bp. The predicted molecular weight of the Japanese eel CYP1A was approximately 58.5 kDa. The nucleotide sequence exhibited identities with the reported CYP1A1 sequences of 77% for Japanese eel, 75% for rainbow trout, 72% for scup, plaice, and butterfly fish, and 71% for toadfish. The deduced amino acid sequence exhibited identities with the reported CYP1A1 sequences of 78% for Japanese eel, 77% for rainbow trout, 75% for scup, 74% for toadfish, 73% for plaice, and 72% for butterfly fish. The novel eel CYP1A obtained had less similarity to the other teleost CYP1A1 proteins (72%-78%) than that of the eel CYP1A1 (74%-80%). When compared with mammalian CYP proteins, the novel eel CYP1A was more similar to the CYP1A1 proteins (54%-56%) than to the CYP1A2 proteins (50%-53%). The phylogenetic tree of the teleost CYP1A genes constructed using the maximum likelihood method suggested that the novel eel CYP1A is ubiquitous among the Anguilliformes.