Homogenate dioxygenase
Homogentisate 1,2-dioxygenase | ||
---|---|---|
Properties of human protein | ||
Mass / length primary structure | 445 AS ; 50 kDa | |
Secondary to quaternary structure | Homohexamer | |
Cofactor | Fe 2+ | |
Identifier | ||
Gene names | HGD ; AKU | |
External IDs | ||
Enzyme classification | ||
EC, category | 1.13.11.5 , dioxygenase | |
Response type | oxidation | |
Substrate | Homogenate + O 2 | |
Products | 4-maleyl acetoacetate | |
Occurrence | ||
Homology family | Homogenate dioxygenase | |
Parent taxon | Creature |
Homogentisate dioxygenase (HGD) is the name for the enzyme that splits homogentisate to 4-maleyl acetoacetate. This reaction step is important for the breakdown of the amino acid tyrosine in the metabolism of all living things. A deficiency in homogentisate dioxygenase leads to alkaptonuria , a metabolic disease , and the cause is always a mutation in the gene that contains the genetic code for the HGD enzyme.
biosynthesis
The greatest amounts of homogentisate dioxygenase are produced in the tissues of the prostate , small and large intestines , kidneys and liver . In humans , the gene coding for the enzyme is located on chromosome 3 , gene locus q21-q23, and comprises 54,100 base pairs with 14 exons . After transcription , a 1,713 base long mRNA is produced and the final protein counts 445 amino acids after translation .
Catalyzed reaction
The reaction enabled by HGD is the iron (II) -dependent ring opening of the homogenate molecule, with the simultaneous transfer of two oxygen atoms. So the enzyme acts as a dioxygenase . There are no similarities to any other enzyme with iron as a cofactor .