Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

Official Name

indoleamine 2,3-dioxygenase

Name from literature

Indoleamine 2,3-dioxygenase

Pathway from literature

the kynurenine pathway of tryptophan metabolism/UV filter biosynthesis

Pathway from KEGG

Amino Acid Metabolism; Tryptophan metabolism; map00380


Rat (10116)

Genome localization

16q12.5[66029 ], 16q12.5[681319 ],


A protohemoprotein. Requires ascorbic acid and methylene blue for activity. This enzyme has broader substrate specificity than EC, tryptophan 2,3-dioxygenase [1]. It is induced in response to pathological conditions and host-defense mechanisms and its distribution in mammals is not confined to the liver [2]. While the enzyme is more active with D-tryptophan than L-tryptophan, its only known function to date is in the metabolism of L-tryptophan [2,6]. Superoxide radicals can replace O2 as oxygen donor [4,7].

Rate-limiting Description

"Heme oxygenase-1 (HO-1) is the rate limiting enzyme of heme catabolism whereas indoleamine 2,3 dioxygenase (IDO) catabolizes tryptophan through the kynurenine pathway." (16319139)

Gene ontology

Gene ontology

GO:0055114 (P) oxidation reduction [Q9ERD9 ];
GO:0020037 (F) heme binding [Q9ERD9 ];
GO:0005506 (F) iron ion binding [Q9ERD9 ];
GO:0033754 (F) indoleamine 2, 3-dioxygenase activity [Q9ERD9 ];




Entrez Gene

66029; 681319

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  Last Modified: 2009-03-24  
  Design by Zhao Min