Deduced amino acid sequence of heme binding region of chicken cholesterol side chain cleavage cytochrome P450.

The primary structure of the carboxy terminal 296 amino acids of chicken cholesterol side chain cleavage cytochrome P450 (P450scc) was deduced from a partial cDNA clone isolated from a chicken ovarian cDNA library. The sequence contained putative steroid binding and heme binding regions. Comparison of this sequence with the corresponding sequences of three mammalian forms of P450scc shows greater than 50% homology. The heme binding region of the avian P450scc shows 76% homology with the heme binding regions of rat and human P450scc and 81% homology with that of bovine P450scc.