The long range goal of this project is to study structure-function relationships in cytochromes P450 and related proteins using x-ray crystallography, molecular biology, and biochemistry. The focus will be on redox complexes formed between protein electron donors and acceptors in various P450 systems with an emphasis on three bacterial systems: P450cam, P450cin, and P450BM3. In addition to the traditional tools of crystallography, spectroscopy, protein engineering, and enzymology high field NMR will be employed to study protein-protein interactions.