(4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin

Three steps

• anthranilateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-phenylalanine + O2 = (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tyrosine
  2. Transport of L-Kynurenine
  3. L-kynurenine + H2O = anthranilate + L-alanine + H(+)

  Catalysed by PAH, SLC7A8, KYNUextracellular space, cytosol

• CHEBI:16633Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. L-selenocysteine selenide-lyase (L-alanine-forming)

  Catalysed by TPH1, TPH2, SLC7A5, SCLYextracellular space, cytosol

• Met-tRNA(Met)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-Methionine:tRNAMet ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, MARS1extracellular space, cytosol

• (S)-lactateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-phenylalanine + O2 = (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tyrosine
  2. (S)-lactate + L-phenylalanine = N-[(S)-lactoyl]-L-phenylalanine + H2O
  3. (S)-lactate + L-phenylalanine = N-[(S)-lactoyl]-L-phenylalanine + H2O

  Catalysed by PAH, CNDP2

• 4-methylsulfanyl-2-oxobutanoateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. glyoxylate + L-methionine = 4-methylsulfanyl-2-oxobutanoate + glycine

  Catalysed by TPH1, TPH2, SLC7A5, AADATextracellular space, cytosol

• 2-oxobutanoateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of threonine and tryptophan (cytosol to extracellular)
  3. L-threonine ammonia-lyase (2-oxobutanoate-forming)

  Catalysed by TPH1, TPH2, SLC7A5, SDS and 1 moreextracellular space, cytosol

• 2-oxoglutaramateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glutamine and tryptophan (cytosol to extracellular)
  3. L-Glutamine:pyruvate aminotransferase

  Catalysed by TPH1, TPH2, SLC7A5, KYAT1extracellular space, cytosolOne of 4 routes

• enol-phenylpyruvateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-phenylalanine + O2 = (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tyrosine
  2. Phenylalanine Transaminase, Mitochondrial
  3. 3-phenylpyruvate = enol-phenylpyruvate

  Catalysed by PAH, GOT2, TAT, MIFmitochondrial matrix

• CHEBI:16856Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. gamma-L-glutamyl-L-cysteine:glycine ligase (ADP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, GSSextracellular space, cytosolOne of 2 routes

• glyoxylic acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. glycine:oxygen oxidoreductase (deaminating)

  Catalysed by TPH1, TPH2, SLC7A5, DAOextracellular space, cytosol, peroxisome

• N-acetyl-L-aspartateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. L-tryptophan(out) + L-aspartate(in) = L-tryptophan(in) + L-aspartate(out)
  3. acetyl-CoA:L-aspartate N-acetyltransferase

  Catalysed by TPH1, TPH2, SLC7A13, NAT8Linner side of the membrane, outer side of the membrane, mitochondrial matrixOne of 2 routes

• oxalic acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. Transport of L-Tryptophan by Atb0 Transporter
  3. transport of chloride and oxalate (cytosol to extracellular)

  Catalysed by TPH1, TPH2, SLC6A14, SLC26A6extracellular space, cytosol

• L-glutamic 5-semialdehydeReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of ornithine and tryptophan (cytosol to extracellular)
  3. L-Ornithine:2-oxo-acid aminotransferase

  Catalysed by TPH1, TPH2, SLC7A6, OATextracellular space, cytosol, mitochondrial matrix

• (S)-1-pyrroline-5-carboxylateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of proline and tryptophan (cytosol to extracellular)
  3. L-proline:(acceptor) oxidoreductase

  Catalysed by TPH1, TPH2, ABCA1, SLC7A5 and 1 moreextracellular space, cytosolOne of 2 routes

• agmatineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of arginine and tryptophan (cytosol to extracellular)
  3. L-arginine carboxy-lyase (agmatine-forming)

  Catalysed by TPH1, TPH2, SLC7A6extracellular space, cytosol, mitochondrial matrix

• AH2Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. Mo-molybdopterin + L-cysteine + AH2 = thio-Mo-molybdopterin + L-alanine + A + H2O

  Catalysed by TPH1, TPH2, SLC7A5, MOCOSextracellular space, cytosolOne of 4 routes

• 5-aminolevulinic acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. succinyl-CoA:glycine C-succinyltransferase (decarboxylating)

  Catalysed by TPH1, TPH2, SLC7A5, ALAS1 and 2 moreextracellular space, cytosol, mitochondrial matrix

• Ala-tRNA(Ala)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. L-Alanine:tRNA(Ala) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, AARS1extracellular space, cytosol

• glycine betaineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. Transport of L-Tryptophan by Atb0 Transporter
  3. transport of betaine and chloride (cytosol to extracellular)

  Catalysed by TPH1, TPH2, SLC6A14, SLC6A12extracellular space, cytosolOne of 3 routes

• trans-urocanateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of histidine and tryptophan (cytosol to extracellular)
  3. L-histidine ammonia-lyase (urocanate-forming)

  Catalysed by TPH1, TPH2, SLC7A6, HALextracellular space, cytosolOne of 2 routes

• urateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(out) + a dicarboxylate(in) = (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(in) + a dicarboxylate(out)
  3. urate(out) + a dicarboxylate(in) = urate(in) + a dicarboxylate(out)

  Catalysed by TPH1, TPH2, SLC22A6, SLC22A8inner side of the membrane, outer side of the membraneOne of 2 routes

• 4-methyl-2-oxopentanoateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of leucine and tryptophan (cytosol to extracellular)
  3. L-Leucine:2-oxoglutarate aminotransferase

  Catalysed by TPH1, TPH2, SLC7A5, BCAT2extracellular space, cytosol, mitochondrial matrixOne of 4 routes

• CHEBI:17927Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of arginine and tryptophan (cytosol to extracellular)
  3. Transport by Y+Lat-2 into Extracellular Space

  Catalysed by TPH1, TPH2, SLC7A6, SLC3A2extracellular space, cytosol

• indole-3-acetaldehydeReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. L-tryptophan decarboxy-lyase
  3. Tryptamine:oxygen oxidoreductase(deaminating)

  Catalysed by TPH1, TPH2, DDC, AOC1 and 2 morecytosolOne of 2 routes

• CHEBI:18095Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. Transport of Hydroxy-Proline

  Catalysed by TPH1, TPH2, SLC7A5, SLC1A4extracellular space, cytosolOne of 5 routes

• N-carbamoyl-beta-alanineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. Transport of L-Tryptophan by Atb0 Transporter
  3. Transport of 3-Ureidopropionate

  Catalysed by TPH1, TPH2, SLC6A14extracellular space, cytosolOne of 2 routes

• N(1)-(5-phospho-D-ribosyl)glycinamideReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. 5-Phospho-D-ribosylamine:glycine ligase (ADP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, GARTextracellular space, cytosol

• 2-formamido-N(1)-(5-phospho-D-ribosyl)acetamidineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glutamine and tryptophan (cytosol to extracellular)
  3. 5'-Phosphoribosylformylglycinamide:L-glutamine amido-ligase (ADP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, PFASextracellular space, cytosol

• ophthalmateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. gamma-L-glutamyl-(2S)-2-aminobutanoate + glycine + ATP = ophthalmate + ADP + phosphate + H(+)

  Catalysed by TPH1, TPH2, SLC7A5, GSSextracellular space, cytosol

• 2-aminoisobutanoateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. 2-aminoisobutanoate(out) + L-alanine(in) = 2-aminoisobutanoate(in) + L-alanine(out)

  Catalysed by TPH1, TPH2, SLC7A5, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

• N-methyltryptamineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. L-tryptophan decarboxy-lyase
  3. S-Adenosyl-L-methionine:amine N-methyltransferase

  Catalysed by TPH1, TPH2, DDC, INMTcytosol

• 3-carboxy-4-methyl-5-propyl-2-furanpropanoateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(out) + a dicarboxylate(in) = (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(in) + a dicarboxylate(out)
  3. 3-carboxy-4-methyl-5-propyl-2-furanpropanoate(out) + a dicarboxylate(in) = 3-carboxy-4-methyl-5-propyl-2-furanpropanoate(in) + a dicarboxylate(out)

  Catalysed by TPH1, TPH2, SLC22A6, SLC22A8inner side of the membrane, outer side of the membraneOne of 2 routes

• L-sepiapterinReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(out) + a dicarboxylate(in) = (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin(in) + a dicarboxylate(out)
  3. L-sepiapterin(out) + a dicarboxylate(in) = L-sepiapterin(in) + a dicarboxylate(out)

  Catalysed by TPH1, TPH2, SLC22A6, SLC22A8inner side of the membrane, outer side of the membraneOne of 2 routes

• N(omega),N('omega)-dimethyl-L-arginineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. N(omega),N('omega)-dimethyl-L-arginine + glyoxylate = 5-(3,3'-dimethylguanidino)-2-oxopentanoate + glycine

  Catalysed by TPH1, TPH2, SLC7A5, AGXT2extracellular space, cytosolOne of 2 routes

• 5,6,7,8-tetrahydrofolic acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. 5,10-Methylenetetrahydrofolate:glycine hydroxymethyltransferase

  Catalysed by TPH1, TPH2, SLC7A5, SHMT1extracellular space, cytosolOne of 2 routes

• S-disulfanyl-L-cysteineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of cysteine and tryptophan (cytosol to extracellular)
  3. S-sulfanyl-L-cysteine + L-cysteine = S-disulfanyl-L-cysteine + L-alanine

  Catalysed by TPH1, TPH2, SLC7A5, CARS2extracellular space, cytosol

• CHEBI:240943Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. glycine N-acyltransferase (2-methylbutyryl-CoA)

  Catalysed by TPH1, TPH2, SLC7A5, GLYAT and 2 moreextracellular space, cytosol, mitochondrial matrixOne of 3 routes

• hypochlorous acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. Transport of L-Tryptophan by Atb0 Transporter
  3. Peroxidase

  Catalysed by TPH1, TPH2, SLC6A14, LPOextracellular space, cytosolOne of 4 routes

• potassium atomReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. Transport of L-Tryptophan by Atb0 Transporter
  3. transport of chloride (cytosol to extracellular)

  Catalysed by TPH1, TPH2, SLC6A14, SLC12A2 and 1 moreextracellular space, cytosolOne of 3 routes

• phenylacetylglycineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. phenylacetyl-CoA:glycine N-phenylacetyltransferase

  Catalysed by TPH1, TPH2, SLC7A5, GLYATextracellular space, cytosolOne of 3 routes

• (2-hydroxyphenyl)acetic acidReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-phenylalanine + O2 = (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tyrosine
  2. Phenylalanine Transaminase, Mitochondrial
  3. Phenylpyruvate:oxygen oxidoreductase (hydroxylating,decarboxylating)

  Catalysed by PAH, GOT2, TAT, HPDmitochondrial matrix, cytosol

• CHEBI:28666Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. LTD4 hydrolysis

  Catalysed by TPH1, TPH2, SLC7A5extracellular space, cytosol

• pyridoxine 5'-phosphateReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of alanine and tryptophan (cytosol to extracellular)
  3. L-selenocysteine selenide-lyase (L-alanine-forming)

  Catalysed by TPH1, TPH2, SLC7A5, SCLYextracellular space, cytosol

• N-acetyl-L-cysteineReach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of cysteine and tryptophan (cytosol to extracellular)
  3. N-acetylglutamate synthase (N-acetyl-L-cysteine)

  Catalysed by TPH1, TPH2, SLC7A5, NAGSextracellular space, cytosol, mitochondrial matrix

• K(+)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of cysteine and tryptophan (cytosol to extracellular)
  3. K(+)(in) + L-cysteine(out) + 3 Na(+)(out) + H(+)(out) = K(+)(out) + L-cysteine(in) + 3 Na(+)(in) + H(+)(in)

  Catalysed by TPH1, TPH2, SLC7A5, SLC1A1extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 4 routes

• Cys-tRNA(Cys)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of cysteine and tryptophan (cytosol to extracellular)
  3. L-Cysteine:tRNA(Cys) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, CARS1extracellular space, cytosol

• Gly-tRNA(Gly)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glycine and tryptophan (cytosol to extracellular)
  3. glycine:tRNA(Gly) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, GARS1extracellular space, cytosol

• Asp-tRNA(Asp)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. L-tryptophan(out) + L-aspartate(in) = L-tryptophan(in) + L-aspartate(out)
  3. L-Aspartate:tRNA(Asp) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A13, DARS1inner side of the membrane, outer side of the membrane, cytosol

• Ile-tRNA(Ile)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of isoleucine and tryptophan (cytosol to extracellular)
  3. L-Isoleucine:tRNA(Ile) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, IARS1extracellular space, cytosol

• Gln-tRNA(Gln)Reach from here →
  1. (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
  2. transport of glutamine and tryptophan (cytosol to extracellular)
  3. L-Glutamine:tRNA(Gln) ligase (AMP-forming)

  Catalysed by TPH1, TPH2, SLC7A5, QARS1extracellular space, cytosol