IUBMB Enzyme Nomenclature


Accepted name: indole 2,3-dioxygenase

Reaction: indole + O2 = 2-formylaminobenzaldehyde

Other name(s): indole oxidase; indoleamine 2,3-dioxygenase (ambiguous); indole:O2 oxidoreductase ; indole-oxygen 2,3-oxidoreductase (decyclizing); IDO (ambiguous); indole:oxygen 2,3-oxidoreductase (decyclizing)

Systematic name: indole:oxygen 2,3-oxidoreductase (ring-opening)

Comments: Enzymes from the plants Tecoma stans, Jasminum grandiflorum and Zea mays are flavoproteins containing copper. They are part of enzyme systems that form either anthranil (2,1-benzoisoxazole) (Tecoma stans), anthranilate (Jasminum grandiflorum) or both (Zea mays) as the final product. A second enzyme from Tecoma stans is not a flavoprotein, does not require copper, and is part of a system that forms anthranilate as the final product.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37256-57-8


1. Divakar, N.G., Subramanian, V., Sugumaran, M. and Vaidyanathan, C.S. Indole oxygenase from the leaves of Jasminum grandiflorum. Plant Sci. Lett. 15 (1979) 177-181.

2. Chauhan, Y.S., Rathore, V.S., Garg, G.K. and Bhargava, A. Detection of an indole oxidizing system in maize leaves. Biochem. Biophys. Res. Commun. 83 (1978) 1237-1245. [PMID: 697856]

3. Nair, P.M. and Vaidyanathan, C.S. An indole oxidase isolated from the leaves of Tecoma stans. Biochim. Biophys. Acta 81 (1964) 496-506.

4. Kunapuli, S.P. and Vaidyanathan, C.S. Purification and characterization of a new indole oxygenase from the leaves of Tecoma stans L. Plant Physiol. 71 (1983) 19-23. [PMID: 16662784]

[EC created 1972, modified 1986]

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