Dioxygen reduction, via two-electrons with oxygenation in monoxygenase stoichiometry, has been inordinately advanced over the past ten years. The prokaryote-mitochondrial and the heme protein for "heme sulfur" protein and redoxin (reductase-effector) P450CAM has provided a fully equivalent model for the biosynthetic detoxification enzymes. During the current grant period, we propose to: 1) Complete the primary and tertiary structures of the first P450 "heme sulfur" monoxygenase protein, P450CAM. The heme protein, approximately 413 residues, has yielded 29 tryptic peptides; 7 carry the cystienyl residues essential to active site formation and catalysis. 2) We propose to identify which peptides carry in the primary structure, the essential positions' residues. 3) We shall map the heme pocket, to provide the tertiary structure with a 2.5 Angstrom units or better resolution. 4) P450 systems for linolool, et al., have been isolated. The redoxin-heme sulfur protein interactions were observed in homologous and heterologous recombination via both affinity constants and activity plus modulation of regulation. Additional P450 heme proteins, cloned into self-replicating DNA plasmids, have been introduced into hosts of known genetic constitution. The structure of these proteins determined by physical probe analysis and the requisites for P450 activity, and the primary reactions of oxygenation are being extended.