v5.1.0.3
Cicer data from the Legume Information System
Type | Homologous_superfamily |
Description | Hydroxylation of the aromatic amino acids phenylalanine, tyrosine and tryptophan 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-terminal oligomerization motif. The eukaryotic enzymes are all homotetramers [, ].Three-dimensional structures have been determined for the three types of enzymes. 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 listed below:Phenylalanine-4-hydroxylase ( ) (PAH). Catalyzes the conversion of 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 limiting step in catecholamine biosynthesis: the conversion of tyrosine to 3,4-dihydroxy-L-phenylalanine. Tryptophan 5-hydroxylase ( ) (TRH). Catalyzes the rate-limiting step 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. |
Short Name | Aro-AA_hydroxylase_C_sf |