HAAO

3-hydroxyanthranilate 3,4-dioxygenase (EC 1.13.11.6) is an enzyme encoded by the HAAO gene that catalyzes the chemical reaction

3-hydroxyanthranilate + O₂ ${\displaystyle \rightleftharpoons }$ 2-amino-3-carboxymuconate semialdehyde

3-hydroxyanthranilic acid dioxygenase
Identifiers
Aliases	3hydroanth_dOaseIPR0103293-hydroxyanthranilate 3,4-dioxygenase3-hydroxyanthranilate oxygenase3-hydroxyanthranilic oxygenase3-hydroxyanthranilate:oxygen 3,4-oxidoreductase (decyclizing)3-hydroxyanthranilic acid oxygenase
External IDs	GeneCards: ; OMA:- orthologs
Orthologs Species Human Mouse Entrez n/a n/a Ensembl n/a n/a UniProt n a n/a RefSeq (mRNA) n/a n/a RefSeq (protein) n/a n/a Location (UCSC) n/a n/a PubMed search n/a n/a
Wikidata
View/Edit Human

3-hydroxyanthranilate 3,4-dioxygenase
3-hydroxyanthranilate 3,4-dioxygenase monomer, Human
Identifiers
EC no.	1.13.11.6
CAS no.	9029-50-9
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are 3-hydroxyanthranilate and O₂, whereas its product is 2-amino-3-carboxymuconate semialdehyde.

This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O₂ as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O₂.

The systematic name of this enzyme class is 3-hydroxyanthranilate:oxygen 3,4-oxidoreductase (decyclizing). Other names in common use include 3-hydroxyanthranilate oxygenase, 3-hydroxyanthranilic acid oxygenase, 3-hydroxyanthranilic oxygenase, 3-hydroxyanthranilic acid oxidase and 3HAO. This enzyme participates in tryptophan metabolism. It employs one cofactor, iron.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 1YFU, 1YFW, 1YFX, 1YFY, 1ZVF, and 2QNK.h