FIG. 1.

Carbazole degradation by Car enzymes harbored by various carbazole degraders. The product of angular dioxygenation of carbazole shown in brackets is unstable and has not been detected directly. Enzyme (or protein) names: terminal oxygenase (CARDO-O), ferredoxin (CARDO-F), and reductase (CARDO-R) components of CARDO; meta-cleavage enzyme (CarBaBb); meta-cleavage compound hydrolase (CarC). ox. and red., oxidized and reduced states of the CARDO components, respectively. Compounds: I, carbazole; II, 2′-aminobiphenyl-2,3-diol; III, 2-hydroxy-6-oxo-6-(2′-aminobiphenyl)-hexa-2,4-dienoic acid; IV, anthranilic acid.