The cytochrome P-450 heme-thiolate monooxygenases that hydroxylate monoterpene hydrocarbon groups are effective models for the cytochrome P-450 family. We have purified and characterized the three proteins from a P-450-dependent linalool 8-methyl hydroxylase in Pseudomonas putida (incognita) strain PpG777. The proteins resemble the camphor 5-exohydroxylase components in chemical and physical properties; however, they show neither immunological cross-reactivity nor catalytic activity in heterogenous recombination. These two systems provide an excellent model to probe more deeply the heme-thiolate reaction center, molecular domains of substrate specificity, redox-pair interactions, and the regulation of the reaction cycle.