Figure 1.

Camphor degradation in Pseudomonas putida NCIMB 10007: In the first step camphor (1) is hydroxylated by the P450_Cam-monooxygenase (Unger et al. 1986) followed by an oxidation by the 5-exo-alkohol dehydrogenase (Koga et al. 1989) yielding the corresponding diketocamphane (3). (+)-1 is degraded by the 2,5-dicetocamphane 1,2-monooxygenase (a), while (-)-1 requires the 3,6-diketocamphane 1,6-monooxygenase (b). Both resulting lactones are unstable and lead to spontaneous formation of the 2-oxo-Δ3-4,5,5-trimethylcylopentenylacetic acid, which is further converted to a coenzyme A derivative (4), which is again a substrate for a third involved BVMO (2-oxo-Δ3-4,5,5-trimethylcylopentenylacetic acid monooxygenase, often designated as MO2) (Ougham et al. 1983).