Abstract: Disclosed are methods and compositions for effecting bacterial expression of eukaryotic cytochrome P450 enzymes and fusion proteins comprising a eukaryotic P450 domain fused to a reductase enzyme domain in a biologically active form. Certain embodiments involve the expression of eukaryotic cytochrome P450.sub.17.alpha. -hydroxylase which is expressed in large amounts in an E. coli host in a biologically active form without the need for coexpression or admixture of a cytochrome P450 reductase. Methods and compositions are also disclosed for the construction of cytochrome P450 enzyme hybrids or fusion proteins, incorporating the N-terminal 9 amino acids from bovine 17.alpha.-hydroxylase, which will enable many eukaryotic cytochrome P450 enzymes or fusion proteins to be expressed in bacteria.

Abstract: Disclosed are methods and compositions for effecting bacterial expression of eukaryotic cytochrome P450 enzymes in a biologically active form. Particular embodiments involve the expression of eukaryotic cythochrome P450.sub.17.alpha. -hydroxylase which is expressed in large amounts in an E. coli host in a biologically active form without the need for coexpression or admixture of a cytochrome P450 reductase. Techniques are disclosed for effecting improved bacterial expression which are proposed to be useful in connection with all eukaryotic cytochrome P450 enzymes which one may desire to express in bacterial hosts such as E. coli and others.