EC - Tyrosine 3-monooxygenase

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IntEnz Enzyme Nomenclature


Accepted name:
tyrosine 3-monooxygenase
Other names:
L-tyrosine hydroxylase
tyrosine 3-hydroxylase
tyrosine hydroxylase
Systematic name:
L-tyrosine,tetrahydrobiopterin:oxygen oxidoreductase (3-hydroxylating)




The active centre contains mononuclear iron(II). The enzyme is activated by phosphorylation, catalysed by EC, [aceteyl-CoA caboxylase]kinase. The 4a-hydroxytetrahydrobiopterin formed can dehydrate to 6,7-dihydrobiopterin, both spontaneously and by the action of EC, 4a-hydroxytetrahydrobiopterin dehydratase. The 6,7-dihydrobiopterin can be enzymically reduced back to tetrahydrobiopterin, by EC (6,7-dihydropteridine reductase), or slowly rearranges into the more stable compound 7,8-dihydrobiopterin.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00316
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004511
CAS Registry Number: 9036-22-0
UniProtKB/Swiss-Prot: (18) [show] [UniProt]


  1. El Mestikawy, S., Glowinski, J. and Hamon, M.
    Tyrosine hydroxylase activation in depolarized dopaminergic terminals -involvement of Ca2+-dependent phosphorylation.
    Nature (Lond.) 302 : 830-832 (1983). [PMID: 6133218]
  2. Ikeda, M., Levitt, M. and Udenfriend, S.
    Phenylalanine as substrate and inhibitor of tyrosine hydroxylase.
    Arch. Biochem. Biophys. 120 : 420-427 (1967). [PMID: 6033458]
  3. Nagatsu, T., Levitt, M. and Udenfriend, S.
    Tyrosine hydroxylase. The initial step in norepinephrine biosynthesis.
    J. Biol. Chem. 239 : 2910-2917 (1964). [PMID: 14216443]
  4. Pigeon, D., Drissi-Daoudi, R., Gros, F. and Thibault, J.
    Copurification of tyrosine-hydroxylase from rat pheochromocytoma, with a protein-kinase activity.
    C.R. Acad. Sci. Paris, Ser. 3, 302 : 435-438 (1986). [PMID: 2872947]
  5. Goodwill, K.E., Sabatier, C., Marks, C., Raag, R., Fitzpatrick, P.F. and Stevens, R.C.
    Crystal structure of tyrosine hydroxylase at 2.3 Å and its implications for inherited neurodegenerative diseases.
    Nat. Struct. Biol. 4 : 578-585 (1997). [PMID: 9228951]

[EC created 1972, modified 2003, modified 2019]