Biopterin-dependent aromatic amino acid hydroxylase; a family of non-heme, iron(II)-dependent enzymes that includes prokaryotic and eukaryotic phenylalanine-4-hydroxylase (PheOH), eukaryotic tyrosine hydroxylase (TyrOH) and eukaryotic tryptophan hydroxylase (TrpOH). PheOH converts L-phenylalanine to L-tyrosine, an important step in phenylalanine catabolism and neurotransmitter biosynthesis, and is linked to a severe variant of phenylketonuria in humans. TyrOH and TrpOH are involved in the biosynthesis of catecholamine and serotonin, respectively. The eukaryotic enzymes are all homotetramers.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  20 QETSYIEDNCNQNGA-ISLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLDKRSLPALTNIIKIL 98
Cdd:TIGR01268   1 AEESYIADQVNENIAkTSLIFSLKEEAGALAETLKLFQAHDVNLTHIESRPSKTHPGEYEFFVEFDEASDRKLEGVIEHL 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  99 RHDIGATVHELSRDKKKDT--VPWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPR 176
Cdd:TIGR01268  81 RQKAEVTVNILSRDNKQNKdsVPWFPRKINDIDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAFNYKHGQPIPR 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1034579784 177 VEYMEEEKKTWGTVFKTLKSLYKTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:TIGR01268 161 VEYTDEEIATWRTVFNNLTVLYPTHACQEYNHIFPLLQQNCGFREDNIPQLEDVSQFLQ 219

phenylalanine-4-hydroxylase, tetrameric form; This model describes the larger, tetrameric form of phenylalanine-4-hydroxylase, as found in metazoans. The enzyme irreversibly converts phenylalanine to tryosine and is known to be the rate-limiting step in phenylalanine catabolism in some systems. It is closely related to metazoan tyrosine 3-monooxygenase and tryptophan 5-monoxygenase, and more distantly to monomeric phenylalanine-4-hydroxylases of some Gram-negative bacteria. The member of this family from Drosophila has been described as having both phenylalanine-4-hydroxylase and tryptophan 5-monoxygenase activity (. However, a Drosophila member of the tryptophan 5-monoxygenase clade has subsequently been discovered.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  20 QETSYIEDNCNQNGA-ISLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLDKRSLPALTNIIKIL 98
Cdd:TIGR01268   1 AEESYIADQVNENIAkTSLIFSLKEEAGALAETLKLFQAHDVNLTHIESRPSKTHPGEYEFFVEFDEASDRKLEGVIEHL 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  99 RHDIGATVHELSRDKKKDT--VPWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPR 176
Cdd:TIGR01268  81 RQKAEVTVNILSRDNKQNKdsVPWFPRKINDIDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAFNYKHGQPIPR 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1034579784 177 VEYMEEEKKTWGTVFKTLKSLYKTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:TIGR01268 161 VEYTDEEIATWRTVFNNLTVLYPTHACQEYNHIFPLLQQNCGFREDNIPQLEDVSQFLQ 219

Eukaryotic phenylalanine-4-hydroxylase (eu_PheOH); a member of the biopterin-dependent aromatic amino acid hydroxylase family of non-heme, iron(II)-dependent enzymes that also includes prokaryotic phenylalanine-4-hydroxylase (pro_PheOH), eukaryotic tyrosine hydroxylase (TyrOH) and eukaryotic tryptophan hydroxylase (TrpOH). PheOH catalyzes the first and rate-limiting step in the metabolism of the amino acid L-phenylalanine (L-Phe), the hydroxylation of L-Phe to L-tyrosine (L-Tyr). It uses (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as the physiological electron donor. The catalytic activity of the tetrameric enzyme is tightly regulated by the binding of L-Phe and BH4 as well as by phosphorylation. Mutations in the human enzyme are linked to a severe variant of phenylketonuria.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784 119 PWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPRVEYMEEEKKTWGTVFKTLKSLY 198
Cdd:cd03347     1 PWFPRTIQDLDRFANQILSYGAELDADHPGFKDPVYRARRKEFADIAYNYKHGQPIPRVEYTEEEKKTWGTVFRELKSLY 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1034579784 199 KTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:cd03347    81 PTHACYEYNHVFPLLEKNCGFSEDNIPQLEDVSNFLQ 117

prephenate dehydratase; Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1034579784  36 SLIFSLKEEV-GALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFF----THLDK-------RSLPALTNIIKIL 98
Cdd:PRK11898  198 SLVLTLPNNLpGALYKALSEFAWRGINLTRIESRPTKTGLGTYFFFidveGHIDDvlvaealKELEALGEDVKVL 272

phenylalanine-4-hydroxylase, tetrameric form; This model describes the larger, tetrameric form of phenylalanine-4-hydroxylase, as found in metazoans. The enzyme irreversibly converts phenylalanine to tryosine and is known to be the rate-limiting step in phenylalanine catabolism in some systems. It is closely related to metazoan tyrosine 3-monooxygenase and tryptophan 5-monoxygenase, and more distantly to monomeric phenylalanine-4-hydroxylases of some Gram-negative bacteria. The member of this family from Drosophila has been described as having both phenylalanine-4-hydroxylase and tryptophan 5-monoxygenase activity (. However, a Drosophila member of the tryptophan 5-monoxygenase clade has subsequently been discovered.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  20 QETSYIEDNCNQNGA-ISLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLDKRSLPALTNIIKIL 98
Cdd:TIGR01268   1 AEESYIADQVNENIAkTSLIFSLKEEAGALAETLKLFQAHDVNLTHIESRPSKTHPGEYEFFVEFDEASDRKLEGVIEHL 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  99 RHDIGATVHELSRDKKKDT--VPWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPR 176
Cdd:TIGR01268  81 RQKAEVTVNILSRDNKQNKdsVPWFPRKINDIDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAFNYKHGQPIPR 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1034579784 177 VEYMEEEKKTWGTVFKTLKSLYKTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:TIGR01268 161 VEYTDEEIATWRTVFNNLTVLYPTHACQEYNHIFPLLQQNCGFREDNIPQLEDVSQFLQ 219

Eukaryotic phenylalanine-4-hydroxylase (eu_PheOH); a member of the biopterin-dependent aromatic amino acid hydroxylase family of non-heme, iron(II)-dependent enzymes that also includes prokaryotic phenylalanine-4-hydroxylase (pro_PheOH), eukaryotic tyrosine hydroxylase (TyrOH) and eukaryotic tryptophan hydroxylase (TrpOH). PheOH catalyzes the first and rate-limiting step in the metabolism of the amino acid L-phenylalanine (L-Phe), the hydroxylation of L-Phe to L-tyrosine (L-Tyr). It uses (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) as the physiological electron donor. The catalytic activity of the tetrameric enzyme is tightly regulated by the binding of L-Phe and BH4 as well as by phosphorylation. Mutations in the human enzyme are linked to a severe variant of phenylketonuria.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784 119 PWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPRVEYMEEEKKTWGTVFKTLKSLY 198
Cdd:cd03347     1 PWFPRTIQDLDRFANQILSYGAELDADHPGFKDPVYRARRKEFADIAYNYKHGQPIPRVEYTEEEKKTWGTVFRELKSLY 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1034579784 199 KTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:cd03347    81 PTHACYEYNHVFPLLEKNCGFSEDNIPQLEDVSNFLQ 117

Eukaryotic tryptophan hydroxylase (TrpOH); a member of the biopterin-dependent aromatic amino acid hydroxylase family of non-heme, iron(II)-dependent enzymes that also includes prokaryotic and eukaryotic phenylalanine-4-hydroxylase (PheOH) and eukaryotic tyrosine hydroxylase (TyrOH). TrpOH oxidizes L-tryptophan to 5-hydroxy-L-tryptophan, the rate-limiting step in the biosynthesis of serotonin (5-hydroxytryptamine), a widely distributed hormone and neurotransmitter.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784 119 PWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPRVEYMEEEKKTWGTVFKTLKSLY 198
Cdd:cd03346     1 PWFPKKISDLDKCANRVLMYGSELDADHPGFKDNVYRKRRKYFADVAMNYKHGDPIPRVEYTEEEIKTWGTVYRELNRLY 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1034579784 199 KTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:cd03346    81 PTHACREYLKNLPLLEKHCGYREDNIPQLEDVSRFLK 117

tyrosine 3-monooxygenase, tetrameric; This model describes tyrosine 3-monooxygenase, a member of the family of tetrameric, biopterin-dependent aromatic amino acid hydroxylases found in metazoans. It is closely related to tetrameric phenylalanine-4-hydroxylase and tryptophan 5-monooxygenase, and more distantly related to the monomeric phenylalanine-4-hydroxylase found in some Gram-negative bacteria.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784  25 IEDNCNQNGAISLIFSLK-EEVGALAKVLRLFEENDVNLTHIESRPSRLKKD---EYEFFTHLDKrSLPALTNIIKILRH 100
Cdd:TIGR01269  28 THEQDSEAAMQNNQFYIRtKEISSLHRILKYIETFKLNLVHFETRPTRTLSNadvDYSCLITLEA-NEINMSLLIESLRG 106

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034579784 101 DiGATVHELSRDKKKDTVPWFPRTIQELDRFANQILSYGAELDADHPGFKDPVYRARRKQFADIAYNYRHGQPIPRVEYM 180
Cdd:TIGR01269 107 N-SFISGINLLNNQNVKEDWFPKHISELDKCQHLLTKFQPDLDTDHPGFHDKVYRQRREAIAEIAFQYKYGDPIPEVEYT 185

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1034579784 181 EEEKKTWGTVFKTLKSLYKTHACYEYNHIFPLLEKYCGFHEDNIPQLEDVSQFLQ 235
Cdd:TIGR01269 186 KEEIETWRLVFTTMKDLHASHACREYIDAFQLLEKYCNYNSESIPQLQTISEFLH 240

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. PAH catalyzes the hydroxylation of L-Phe to L-Tyr, the first step in the catabolic degradation of L-Phe; TH catalyses the hydroxylation of L-Tyr to 3,4-dihydroxyphenylalanine, the rate limiting step in the biosynthesis of catecholamines; and TPH catalyses the hydroxylation of L-Trp to 5-hydroxytryptophan, the rate limiting step in the biosynthesis of 5-hydroxytryptamine (serotonin) and the first reaction in the synthesis of melatonin. 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 (this CD) and differ in their mechanisms of regulation. One commonality is that all three eukaryotic enzymes are regulated in part by the phosphorylation of serine residues N-terminal of the ACT domain. Members of this CD belong to the superfamily of ACT regulatory domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1034579784  35 ISLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLDKRSlPALTNIIKILRHDiGATVHELS 110
Cdd:cd04904     1 TSLIFSLKEEVGALARALKLFEEFGVNLTHIESRPSRRNGSEYEFFVDCEVDR-GDLDQLISSLRRV-VADVNILS 74

Biopterin-dependent aromatic amino acid hydroxylase; a family of non-heme, iron(II)-dependent enzymes that includes prokaryotic and eukaryotic phenylalanine-4-hydroxylase (PheOH), eukaryotic tyrosine hydroxylase (TyrOH) and eukaryotic tryptophan hydroxylase (TrpOH). PheOH converts L-phenylalanine to L-tyrosine, an important step in phenylalanine catabolism and neurotransmitter biosynthesis, and is linked to a severe variant of phenylketonuria in humans. TyrOH and TrpOH are involved in the biosynthesis of catecholamine and serotonin, respectively. The eukaryotic enzymes are all homotetramers.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1034579784 175 PRVEYMEEEKKTWGTVFKTLKSLYKTHACYEYNHIFPLLekycGFHEDNIPQLEDVSQFLQ 235
Cdd:cd00361     1 PRVDYTEEEHATWRTLYRRLKKLLPTHACREYLEGLELL----GLPEDRIPQLEDVSEFLK 57

C-terminal ACT domain of the bifunctional chorismate mutase-prephenate dehydratase (CM-PDT) enzyme and the prephenate dehydratase (PDT) enzyme; The C-terminal ACT domain 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 E. coli (CM-PDT, PheA) 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.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1034579784  36 SLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFF 80
Cdd:cd04905     3 SIVFTLPNKPGALYDVLGVFAERGINLTKIESRPSKGGLWEYVFF 47

ACT domain; This family of domains generally have a regulatory role. ACT domains are linked to a wide range of metabolic enzymes that are regulated by amino acid concentration. Pairs of ACT domains bind specifically to a particular amino acid leading to regulation of the linked enzyme. The ACT domain is found in: D-3-phosphoglycerate dehydrogenase EC:1.1.1.95, which is inhibited by serine. Aspartokinase EC:2.7.2.4, which is regulated by lysine. Acetolactate synthase small regulatory subunit, which is inhibited by valine. Phenylalanine-4-hydroxylase EC:1.14.16.1, which is regulated by phenylalanine. Prephenate dehydrogenase EC:4.2.1.51. formyltetrahydrofolate deformylase EC:3.5.1.10, which is activated by methionine and inhibited by glycine. GTP pyrophosphokinase EC:2.7.6.5

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1034579784  35 ISLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLDKRSLPALTNIIKILRH 100
Cdd:pfam01842   1 TVLEVLVPDRPGLLARVLGALADRGINITSIEQGTSEDKGGIVFVVIVVDEEDLEEVLEALKKLEG 66

ACT domain of the nonheme iron-dependent aromatic amino acid hydroxylase, tyrosine hydroxylases (TH); ACT domain of the nonheme iron-dependent aromatic amino acid hydroxylase, tyrosine hydroxylases (TH). TH catalyses the hydroxylation of L-Tyr to 3,4-dihydroxyphenylalanine, the rate limiting step in the biosynthesis of catecholamines (dopamine, noradrenaline and adrenaline), functioning as hormones and neurotransmitters. The enzyme is not regulated by its amino acid substrate, but instead by phosphorylation at several serine residues located N-terminal of the ACT domain, and by feedback inhibition by catecholamines at the active site. Members of this CD belong to the superfamily of ACT regulatory domains.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1034579784  36 SLIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRLKKDEYEFFTHLD--KRSLPALTNIIK 96
Cdd:cd04930    43 TLLFSLKEGFSSLSRILKVFETFEAKIHHLESRPSRKEGGDLEVLVRCEvhRSDLLQLISSLR 105

ACT domains are commonly involved in specifically binding an amino acid or other small ligand leading to regulation of the enzyme; Members of this CD belong to the superfamily of ACT regulatory domains. Pairs of ACT domains are commonly involved in specifically binding an amino acid or other small ligand leading to regulation of the enzyme. The ACT domain has been detected in a number of diverse proteins; some of these proteins are involved in amino acid and purine biosynthesis, phenylalanine hydroxylation, regulation of bacterial metabolism and transcription, and many remain to be characterized. ACT domain-containing enzymes involved in amino acid and purine synthesis are in many cases allosteric enzymes with complex regulation enforced by the binding of ligands. The ACT domain is commonly involved in the binding of a small regulatory molecule, such as the amino acids L-Ser and L-Phe in the case of D-3-phosphoglycerate dehydrogenase and the bifunctional chorismate mutase-prephenate dehydratase enzyme (P-protein), respectively. Aspartokinases typically consist of two C-terminal ACT domains in a tandem repeat, but the second ACT domain is inserted within the first, resulting in, what is normally the terminal beta strand of ACT2, formed from a region N-terminal of ACT1. ACT domain repeats have been shown to have nonequivalent ligand-binding sites with complex regulatory patterns such as those seen in the bifunctional enzyme, aspartokinase-homoserine dehydrogenase (ThrA). In other enzymes, such as phenylalanine hydroxylases, the ACT domain appears to function as a flexible small module providing allosteric regulation via transmission of conformational changes, these conformational changes are not necessarily initiated by regulatory ligand binding at the ACT domain itself. ACT domains are present either singularly, N- or C-terminal, or in pairs present C-terminal or between two catalytic domains. Unique to cyanobacteria are four ACT domains C-terminal to an aspartokinase domain. A few proteins are composed almost entirely of ACT domain repeats as seen in the four ACT domain protein, the ACR protein, found in higher plants; and the two ACT domain protein, the glycine cleavage system transcriptional repressor (GcvR) protein, found in some bacteria. Also seen are single ACT domain proteins similar to the Streptococcus pneumoniae ACT domain protein (uncharacterized pdb structure 1ZPV) found in both bacteria and archaea. Purportedly, the ACT domain is an evolutionarily mobile ligand binding regulatory module that has been fused to different enzymes at various times.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1034579784  37 LIFSLKEEVGALAKVLRLFEENDVNLTHIESRPSRlKKDEYEFFTHLDKRslPALTNIIKILR 99
Cdd:cd02116     1 LTVSGPDRPGLLAKVLSVLAEAGINITSIEQRTSG-DGGEADIFIVVDGD--GDLEKLLEALE 60