IUBMB Enzyme Nomenclature


Accepted name: carbazole 1,9a-dioxygenase

Reaction: 9H-carbazole + NAD(P)H + H+ + O2 = 2'-aminobiphenyl-2,3-diol + NAD(P)+

Other name(s): CARDO

Systematic name: 9H-carbazole,NAD(P)H:oxygen oxidoreductase (2,3-hydroxylating)

Comments: This enzyme catalyses the first reaction in the pathway of carbazole degradation. The enzyme attacks at the 1 and 9a positions of carbazle, resulting in the formation of a highly unstable hemiaminal intermediate that undergoes a spontaneous cleavage and rearomatization, resulting in 2'-aminobiphenyl-2,3-diol. In most bacteria the enzyme is a complex composed of a terminal oxygenase, a ferredoxin, and a ferredoxin reductase. The terminal oxygenase component contains a nonheme iron centre and a Rieske [2Fe-2S] iron-sulfur cluster.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Nam, J.W., Nojiri, H., Noguchi, H., Uchimura, H., Yoshida, T., Habe, H., Yamane, H. and Omori, T. Purification and characterization of carbazole 1,9a-dioxygenase, a three-component dioxygenase system of Pseudomonas resinovorans strain CA10. Appl. Environ. Microbiol. 68 (2002) 5882-5890. [PMID: 12450807]

2. Gai, Z., Wang, X., Liu, X., Tai, C., Tang, H., He, X., Wu, G., Deng, Z. and Xu, P. The genes coding for the conversion of carbazole to catechol are flanked by IS6100 elements in Sphingomonas sp. strain XLDN2-5. PLoS One 5 (2010) e10018. [PMID: 20368802]

[EC created 2010]

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