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  Domain Name: ACT_AAAH-PDT-like
ACT domain of the nonheme iron-dependent, aromatic amino acid hydroxylases (AAAH). ACT domain of the nonheme iron-dependent, aromatic amino acid hydroxylases (AAAH): Phenylalanine hydroxylases (PAH), tyrosine hydroxylases (TH) and tryptophan hydroxylases (TPH), both peripheral (TPH1) and neuronal (TPH2) enzymes. This family of enzymes shares a common catalytic mechanism, in which dioxygen is used by an active site containing a single, reduced iron atom to hydroxylate an unactivated aromatic substrate, concomitant with a two-electron oxidation of tetrahydropterin (BH4) cofactor to its quinonoid dihydropterin form. Eukaryotic AAAHs have an N-terminal ACT (regulatory) domain, a middle catalytic domain and a C-terminal domain which is responsible for the oligomeric state of the enzyme forming a domain-swapped tetrameric coiled-coil. The PAH, TH, and TPH enzymes contain highly conserved catalytic domains but distinct N-terminal ACT domains and differ in their mechanisms of regulation. One commonality is that all three eukaryotic enzymes appear to be regulated, in part, by the phosphorylation of serine residues N-terminal of the ACT domain. Also included in this CD are the C-terminal ACT domains of the bifunctional chorismate mutase-prephenate dehydratase (CM-PDT) enzyme and the prephenate dehydratase (PDT) enzyme found in plants, fungi, bacteria, and archaea. The P-protein of Escherichia coli (CM-PDT) catalyzes the conversion of chorismate to prephenate and then the decarboxylation and dehydration to form phenylpyruvate. These are the first two steps in the biosynthesis of L-Phe and L-Tyr via the shikimate pathway in microorganisms and plants. The E. coli P-protein (CM-PDT) has three domains with an N-terminal domain with chorismate mutase activity, a middle domain with prephenate dehydratase activity, and an ACT regulatory C-terminal domain. The prephenate dehydratase enzyme has a PDT and ACT domain. The ACT domain is essential to bring about the negative allosteric regulation by L-Phe binding. L-Phe binds with positive cooperativity; with this binding, there is a shift in the protein to less active tetrameric and higher oligomeric forms from a more active dimeric form. Members of this CD belong to the superfamily of ACT regulatory domains.
No pairwise interactions are available for this conserved domain.

Total Mutations Found: 8
Total Disease Mutations Found: 8
This domain occurred 4 times on human genes (9 proteins).


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Range on the Protein:  

   Protein ID            Protein Position

Domain Position:  

Feature Name:Total Found:
putative amino acid bindi

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Please Cite: Peterson, T.A., Adadey, A., Santana-Cruz ,I., Sun, Y., Winder A, Kann, M.G., (2010) DMDM: Domain Mapping of Disease Mutations. Bioinformatics 26 (19), 2458-2459.

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