- L-tyrosine + O2 <=> H2O + L-dopaquinone
- 2 L-dopa + O2 <=> 2 H2O + 2 L-dopaquinone
- Found in a broad variety of bacteria, fungi, plants, insects,
crustaceans, and mammals, which is involved in the synthesis of
betalains and melanin.
- The enzyme, which is activated upon binding molecular oxygen,
can catalyze both a monophenolase reaction cycle or a diphenolase
- During the monophenolase cycle, one of the bound oxygen atoms is
transferred to a monophenol (such as L-tyrosine), generating an
O-diphenol intermediate, which is subsequently oxidized to an
o-quinone and released, along with a water molecule.
- The enzyme remains in an inactive deoxy state, and is restored to the
active oxy state by the binding of a new oxygen molecule.
- During the diphenolase cycle the enzyme binds an external diphenol
molecule (such as L-dopa) and oxidizes it to an O-quinone that is
released along with a water molecule, leaving the enzyme in the
intermediate met state.
- The enzyme then binds a second diphenol molecule and repeats the
process, ending in a deoxy state.
- The second reaction is identical to that catalyzed by the related
enzyme catechol oxidase (EC 220.127.116.11).
- However, the latter can not catalyze the hydroxylation or
monooxygenation of monophenols.
- Formerly EC 18.104.22.168.
|PRIAM enzyme-specific profiles||22.214.171.124|
|KEGG Ligand Database for Enzyme Nomenclature||126.96.36.199|
|IUBMB Enzyme Nomenclature||188.8.131.52|
|MEDLINE||Find literature relating to 184.108.40.206|
|Rhea expert-curated reactions||220.127.116.11|
|Q00024, PPO1_AGABI; ||Q3ZPT5, PPO1_SPOLT; ||O42713, PPO2_AGABI; |
|Q9V521, PPO2_DROME; ||C7FF04, PPO3_AGABI; ||Q8I1F6, PPO3_DROER; |
|Q9W1V6, PPO3_DROME; ||C0HJM0, PPO3_SARAR; ||C7FF05, PPO4_AGABI; |
|Q27451, PRP1_BOMMO; ||O44249, PRP1_MANSE; ||P85046, PRP1_SIMDA; |
|Q27452, PRP2_BOMMO; ||Q6UEH6, PRP2_GALME; ||Q25519, PRP2_MANSE; |
|Q8J130, TYRO_ASPFU; ||Q00234, TYRO_ASPOR; ||Q8MIU0, TYRO_BOVIN; |
|P54834, TYRO_CANLF; ||P55024, TYRO_CHICK; ||Q08410, TYRO_COTJA; |
|P55033, TYRO_FELCA; ||Q9BDE0, TYRO_GORGO; ||P14679, TYRO_HUMAN; |
|P11344, TYRO_MOUSE; ||P00440, TYRO_NEUCR; ||P55025, TYRO_ORYLA; |
|Q0MVP0, TYRO_PELLE; ||Q04604, TYRO_PELNI; ||P55026, TYRO_PELSI; |
|A7BHQ9, TYRO_PHONA; ||Q92396, TYRO_PODAS; ||P33180, TYRO_RHIML; |
|P07524, TYRO_STRAT; ||P06845, TYRO_STRGA; ||P55022, TYRO_STRGB; |
|P55023, TYRO_STRLN; ||B8NM74, USTQ_ASPFN; |