| Primary Identifier | IPR019774 | Type | Domain |
| Short Name | Aromatic-AA_hydroxylase_C |
| description | Hydroxylation of the aromatic amino acids phenylalanine, tyrosine andtryptophan is carried out by a family of non-heme iron and tetrahydrobiopterin(BH4) dependent enzymes: the aromatic amino acid hydroxylase []. Theseenzymes are structurally and functionally similar. The eukaryotic formsinclude a regulatory N-terminal domain, a catalytic domain and a C-terminaloligomerization motif. The eukaryotic enzymes are all homotetramers [, ].Three-dimensional structures have been determined for the three types ofenzymes. The iron atom is bound to three amino acid residues, two close histidine and a more distant acidic residue. This arrangement of ligands has been observed in a number of metalloproteins with divergent function [].Enzymes that belong to the aromatic amino acid hydroxylase family are listedbelow:Phenylalanine-4-hydroxylase () (PAH). Catalyzes the conversionof phenylalanine to tyrosine. In humans, deficiencies []of PAH are the cause of phenylketonuria, the most common inborn error of amino acid metabolism. In the bacteria Chromobacterium violaceum [], PAH is copper-dependent; it is iron-dependent in Pseudomonas aeruginosa [].Tyrosine 3-hydroxylase () (TYH). Catalyzes the rate limitingstep in catecholamine biosynthesis: the conversion of tyrosine to 3,4-dihydroxy-L-phenylalanine.Tryptophan 5-hydroxylase () (TRH). Catalyzes the rate-limitingstep in serotonin biosynthesis: the conversion of tryptophan to 3-hydroxy-anthranilate.This entry represents a domain containing the catalytic domain and the coiled-coil C-terminal oligomerization motif. |
