Free for academic non-profit institutions. Other users need a Commercial license

Aliases for TDO2 Gene

Aliases for TDO2 Gene

  • Tryptophan 2,3-Dioxygenase 2 3
  • TRPO 3 4 6
  • Tryptamin 2,3-Dioxygenase 3 4
  • Tryptophan Oxygenase 3 4
  • Tryptophan Pyrrolase 3 4
  • Tryptophanase 3 4

External Ids for TDO2 Gene

Summaries for TDO2 Gene

Entrez Gene Summary for TDO2 Gene

  • This gene encodes a heme enzyme that plays a critical role in tryptophan metabolism by catalyzing the first and rate-limiting step of the kynurenine pathway. Increased activity of the encoded protein and subsequent kynurenine production may also play a role in cancer through the suppression of antitumor immune responses, and single nucleotide polymorphisms in this gene may be associated with autism. [provided by RefSeq, Feb 2012]

GeneCards Summary for TDO2 Gene

TDO2 (Tryptophan 2,3-Dioxygenase) is a Protein Coding gene. Diseases associated with TDO2 include pellagra and haemophilus influenzae. Among its related pathways are Metabolism and Metabolism. GO annotations related to this gene include heme binding and amino acid binding.

UniProtKB/Swiss-Prot for TDO2 Gene

  • Incorporates oxygen into the indole moiety of tryptophan. Has a broad specificity towards tryptamine and derivatives including D- and L-tryptophan, 5-hydroxytryptophan and serotonin (By similarity).

Gene Wiki entry for TDO2 Gene

No data available for Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for TDO2 Gene

Genomics for TDO2 Gene

Genomic Location for TDO2 Gene

155,854,738 bp from pter
155,920,406 bp from pter
65,669 bases
Plus strand

Genomic View for TDO2 Gene

UCSC Golden Path with GeneCards custom track
Cytogenetic band:
Genomic Location for TDO2 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for TDO2 Gene

Proteins for TDO2 Gene

  • Protein details for TDO2 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Tryptophan 2,3-dioxygenase
    Protein Accession:
    Secondary Accessions:
    • A8K053

    Protein attributes for TDO2 Gene

    406 amino acids
    Molecular mass:
    47872 Da
    Name=heme; Xref=ChEBI:CHEBI:30413; Note=Binds 2 heme groups per tetramer.;
    Quaternary structure:
    • Homotetramer.

    Three dimensional structures from OCA and Proteopedia for TDO2 Gene

neXtProt entry for TDO2 Gene

Proteomics data for TDO2 Gene at MOPED

Post-translational modifications for TDO2 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

Other Protein References for TDO2 Gene

ENSEMBL proteins:
Reactome Protein details:
REFSEQ proteins:

Domains for TDO2 Gene

Protein Domains for TDO2 Gene


Suggested Antigen Peptide Sequences for TDO2 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the tryptophan 2,3-dioxygenase family.:
    • P48775
genes like me logo Genes that share domains with TDO2: view

No data available for Gene Families for TDO2 Gene

Function for TDO2 Gene

Molecular function for TDO2 Gene

GENATLAS Biochemistry: tryptophan 2-3 dioxygenase
UniProtKB/Swiss-Prot CatalyticActivity: L-tryptophan + O(2) = N-formyl-L-kynurenine.
UniProtKB/Swiss-Prot Function: Incorporates oxygen into the indole moiety of tryptophan. Has a broad specificity towards tryptamine and derivatives including D- and L-tryptophan, 5-hydroxytryptophan and serotonin (By similarity).

Enzyme Numbers (IUBMB) for TDO2 Gene

Gene Ontology (GO) - Molecular Function for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0004833 tryptophan 2,3-dioxygenase activity TAS --
GO:0005515 protein binding IPI 16189514
GO:0016597 amino acid binding IEA --
GO:0019825 oxygen binding IEA --
GO:0020037 heme binding IBA --
genes like me logo Genes that share ontologies with TDO2: view
genes like me logo Genes that share phenotypes with TDO2: view

Animal Models for TDO2 Gene

MGI Knock Outs for TDO2:

No data available for miRNA , Transcription Factor Targeting and HOMER Transcription for TDO2 Gene

Localization for TDO2 Gene

Subcellular locations from

Jensen Localization Image for TDO2 Gene COMPARTMENTS Subcellular localization image for TDO2 gene
Compartment Confidence
cytosol 4
nucleus 2
peroxisome 2
endoplasmic reticulum 1
extracellular 1
mitochondrion 1
plasma membrane 1

Gene Ontology (GO) - Cellular Components for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005829 cytosol TAS --
genes like me logo Genes that share ontologies with TDO2: view

No data available for Subcellular locations from UniProtKB/Swiss-Prot for TDO2 Gene

Pathways for TDO2 Gene

genes like me logo Genes that share pathways with TDO2: view

UniProtKB/Swiss-Prot P48775-T23O_HUMAN

  • Pathway: Amino-acid degradation; L-tryptophan degradation via kynurenine pathway; L-kynurenine from L-tryptophan: step 1/2.

Gene Ontology (GO) - Biological Process for TDO2 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0006568 tryptophan metabolic process --
GO:0006569 tryptophan catabolic process TAS --
GO:0019441 tryptophan catabolic process to kynurenine IEA --
GO:0019442 tryptophan catabolic process to acetyl-CoA IBA --
GO:0034641 cellular nitrogen compound metabolic process TAS --
genes like me logo Genes that share ontologies with TDO2: view

Compounds for TDO2 Gene

(3) Tocris Compounds for TDO2 Gene

Compound Action Cas Number
680C91 Potent and selective inhibitor of tryptophan 2,3-dioxygenase [163239-22-3]
Febuxostat Xanthine oxidase inhibitor [144060-53-7]
MDL 72527 Polyamine oxidase (PAO) inhibitor [93565-01-6]

(5) HMDB Compounds for TDO2 Gene

Compound Synonyms Cas Number PubMed IDs
  • (protoporphyrinato)iron
  • (-)-tryptophan
  • 3-(N-formylanthraniloyl)-Alanine
  • Oxygen
  • Bextra

(3) Drugbank Compounds for TDO2 Gene

Compound Synonyms Cas Number Type Actions PubMed IDs
  • (-)-Tryptophan
73-22-3 enzyme substrate
Nalidixic Acid
389-08-2 enzyme inhibitor
  • Tolmetin Sodium
26171-23-3 enzyme inhibitor

(29) Novoseek inferred chemical compound relationships for TDO2 Gene

Compound -log(P) Hits PubMed IDs
indoleamine 88 14
kynurenine 85.8 11
l-tryptophan 84.1 18
indole 81.8 15
n-formylkynurenine 81.4 4
genes like me logo Genes that share compounds with TDO2: view

Transcripts for TDO2 Gene

mRNA/cDNA for TDO2 Gene

Unigene Clusters for TDO2 Gene

Tryptophan 2,3-dioxygenase:
Representative Sequences:

Alternative Splicing Database (ASD) splice patterns (SP) for TDO2 Gene

ExUns: 1a · 1b ^ 2 ^ 3a · 3b ^ 4a · 4b · 4c ^ 5a · 5b · 5c ^ 6 ^ 7 ^ 8 ^ 9 ^ 10 ^ 11 ^ 12 ^ 13
SP1: - -
SP2: - -
SP3: -
SP4: - - -
SP5: - - - -

Relevant External Links for TDO2 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for TDO2 Gene

mRNA expression in normal human tissues for TDO2 Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

mRNA differential expression in normal tissues according to GTEx for TDO2 Gene

This gene is overexpressed in Liver (49.4).

Integrated Proteomics: protein expression from ProteomicsDB, PaxDb, and MOPED for TDO2 Gene

SOURCE GeneReport for Unigene cluster for TDO2 Gene Hs.183671

genes like me logo Genes that share expressions with TDO2: view

No data available for mRNA Expression by UniProt/SwissProt for TDO2 Gene

Orthologs for TDO2 Gene

This gene was present in the common ancestor of animals.

Orthologs for TDO2 Gene

Organism Taxonomy Gene Similarity Type Details
(Pan troglodytes)
Mammalia TDO2 35
  • 99.59 (n)
  • 99.75 (a)
TDO2 36
  • 100 (a)
(Bos Taurus)
Mammalia TDO2 35
  • 86.78 (n)
  • 91.87 (a)
TDO2 36
  • 92 (a)
(Canis familiaris)
Mammalia TDO2 35
  • 91.87 (n)
  • 94.33 (a)
TDO2 36
  • 94 (a)
(Mus musculus)
Mammalia Tdo2 35
  • 83.58 (n)
  • 88.67 (a)
Tdo2 16
Tdo2 36
  • 89 (a)
(Monodelphis domestica)
Mammalia TDO2 36
  • 90 (a)
(Ornithorhynchus anatinus)
Mammalia -- 36
  • 89 (a)
-- 36
  • 85 (a)
(Rattus norvegicus)
Mammalia Tdo2 35
  • 83.99 (n)
  • 88.67 (a)
(Gallus gallus)
Aves TDO2 35
  • 78.33 (n)
  • 83.74 (a)
(Anolis carolinensis)
Reptilia TDO2 36
  • 83 (a)
African clawed frog
(Xenopus laevis)
Amphibia Xl.30711 35
tropical clawed frog
(Silurana tropicalis)
Amphibia tdo2 35
  • 75.78 (n)
  • 82.51 (a)
(Danio rerio)
Actinopterygii tdo2a 36
  • 75 (a)
tdo2b 35
  • 67.57 (n)
  • 75.31 (a)
tdo2b 36
  • 75 (a)
wufi30d08 35
African malaria mosquito
(Anopheles gambiae)
Insecta T23O_ANOGA 35
  • 55.64 (n)
  • 54.17 (a)
fruit fly
(Drosophila melanogaster)
Insecta v 35
  • 60.11 (n)
  • 58.49 (a)
v 36
  • 57 (a)
v 37
  • 56 (a)
(Caenorhabditis elegans)
Secernentea C28H8.11 35
  • 56.28 (n)
  • 53.27 (a)
tdo-2 36
  • 51 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 36
  • 47 (a)
-- 36
  • 41 (a)
Species with no ortholog for TDO2:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • rice (Oryza sativa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)

Evolution for TDO2 Gene

Gene Tree for TDO2 (if available)
Gene Tree for TDO2 (if available)

Paralogs for TDO2 Gene

No data available for Paralogs for TDO2 Gene

Variants for TDO2 Gene

Sequence variations from dbSNP and Humsavar for TDO2 Gene

SNP ID Clin Chr 04 pos Sequence Context AA Info Type MAF
rs1399043 -- 155,906,292(-) AAGAA(C/T)AGAAG intron-variant
rs1399049 -- 155,917,702(-) TTTTC(A/G)TGAGC intron-variant
rs2048652 -- 155,906,439(-) GAATC(C/T)AATTA intron-variant
rs2137778 -- 155,905,014(-) TTTAT(C/G)AACTT intron-variant
rs2271537 -- 155,908,671(-) GAAAA(G/T)TATAT intron-variant

Structural Variations from Database of Genomic Variants (DGV) for TDO2 Gene

Variant ID Type Subtype PubMed ID
nsv830121 CNV Gain 17160897

Relevant External Links for TDO2 Gene

HapMap Linkage Disequilibrium report
Human Gene Mutation Database (HGMD)

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for TDO2 Gene

Disorders for TDO2 Gene

(2) University of Copenhagen DISEASES for TDO2 Gene

(3) Novoseek inferred disease relationships for TDO2 Gene

Disease -log(P) Hits PubMed IDs
alcoholism 23 1
schizophrenia 17.7 7
psychiatric disorder 13.6 3

Relevant External Links for TDO2

Genetic Association Database (GAD)
Human Genome Epidemiology (HuGE) Navigator
genes like me logo Genes that share disorders with TDO2: view

No data available for UniProtKB/Swiss-Prot for TDO2 Gene

Publications for TDO2 Gene

  1. Sequence of human tryptophan 2,3-dioxygenase (TDO2): presence of a glucocorticoid response-like element composed of a GTT repeat and an intronic CCCCT repeat. (PMID: 8666386) Comings D.E. … Forest G.L. (Genomics 1995) 3 4 23
  2. Exon and intron variants in the human tryptophan 2,3-dioxygenase gene: potential association with Tourette syndrome, substance abuse and other disorders. (PMID: 8873217) Comings D.E. … MacMurray J.P. (Pharmacogenetics 1996) 23 48
  3. Human tryptophan oxygenase localized to 4q31: possible implications for alcoholism and other behavioral disorders. (PMID: 2004780) Comings D.E. … Donlon T. (Genomics 1991) 3 23
  4. Association of tryptophan 2,3 dioxygenase gene polymorphism with autism. (PMID: 14755447) Nabi R. … Huq A.H. (Am. J. Med. Genet. B Neuropsychiatr. Genet. 2004) 3 23
  5. Antimicrobial and immunoregulatory properties of human tryptophan 2,3-dioxygenase. (PMID: 19637229) Schmidt S.K. … DAoubener W. (Eur. J. Immunol. 2009) 3 23

Products for TDO2 Gene

Sources for TDO2 Gene

Back to Top