4-hydroxyphenylpyruvate dioxygenase activity
Definition
Target type: molecularfunction
Catalysis of the reaction: 4-hydroxyphenylpyruvate + O2 = homogentisate + CO2. [EC:1.13.11.27]
4-hydroxyphenylpyruvate dioxygenase (HPPD) catalyzes the conversion of 4-hydroxyphenylpyruvate (HPP) to homogentisate, a key step in the tyrosine catabolic pathway. This reaction involves the oxidative decarboxylation of HPP, with molecular oxygen serving as the oxidant. The enzyme utilizes a non-heme iron atom in its active site, which is essential for the catalytic process. The mechanism involves the coordination of HPP to the iron center, followed by the activation of molecular oxygen. The iron atom then facilitates the removal of a hydrogen atom from the substrate, leading to the formation of a radical intermediate. Subsequently, the radical undergoes decarboxylation, and the resulting carbon monoxide is released. The final step involves the addition of oxygen to the substrate, yielding homogentisate. HPPD is a crucial enzyme in the biosynthesis of tyrosine, a vital amino acid involved in various cellular processes. Its activity is tightly regulated to ensure proper tyrosine metabolism and prevent the accumulation of toxic intermediates.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| 4-hydroxyphenylpyruvate dioxygenase | A 4-hydroxyphenylpyruvate dioxygenase that is encoded in the genome of Arabidopsis thaliana. [OMA:P93836, PRO:DNx] | Arabidopsis thaliana (thale cress) |
| 4-hydroxyphenylpyruvate dioxygenase | A 4-hydroxyphenylpyruvate dioxygenase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P32754] | Homo sapiens (human) |
Compounds (8)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| pinocembrin | pinocembrin : A dihydroxyflavanone in which the two hydroxy groups are located at positions 5 and 7. A natural product found in Piper sarmentosum and Cryptocarya chartacea. | (2S)-flavan-4-one; dihydroxyflavanone | antineoplastic agent; antioxidant; metabolite; neuroprotective agent; vasodilator agent |
| sulcotrione | sulcotrione : An aromatic ketone that is cyclohexane-1,3-dione substituted by a 2-chloro-4-(methylsulfonyl)benzoyl group at position 2. sulcotrione: a bleaching herbicide | aromatic ketone; beta-triketone; cyclohexanones; sulfone | carotenoid biosynthesis inhibitor; environmental contaminant; herbicide; xenobiotic |
| nitisinone | (trifluoromethyl)benzenes; C-nitro compound; cyclohexanones; mesotrione | EC 1.13.11.27 (4-hydroxyphenylpyruvate dioxygenase) inhibitor | |
| mesotrione | mesotrione : An aromatic ketone that is cyclohexa-1,3-dione in which one of the hydrogens at position 2 is substituted by a 4-(methanesulfonyl)-2-nitrobenzoyl group. mesotrione: brandname is after the Callistemon (MYRTACEAE) plant it was found in; structure in first source | aromatic ketone; beta-triketone; C-nitro compound; sulfone | carotenoid biosynthesis inhibitor; EC 1.13.11.27 (4-hydroxyphenylpyruvate dioxygenase) inhibitor; environmental contaminant; herbicide; xenobiotic |
| (+)-usnic acid | usnic acid | ||
| leptospermone | leptospermone: a beta-triketone phloroglucinol derivative and constituent of essential oil extracted from Leptospermum scoparium (manuka oil); structure in first source | ||
| topramezone | topramezone : An aromatic ketone that is phenyl 1H-pyrazol-4-yl ketone in which the pyrazolyl group is substituted at positions 1 and 5 by methyl and hydroxy groups, respectively, and in which the phenyl group is substituted at positions 2, 3, and 4 by methyl, 4,5-dihydro-1,2-oxazol-3-yl, and methylsulfonyl groups, respectively. A potent inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD) that is rapily metabolised by corn to non-active substances, it is used as a herbicide for the treatment of broadleaf weeds. topramezone: corn herbicide, an inhibitor of 4-hydroxyphenylpyruvate dioxygenase; structure in first source | ||
| tembotrione | tembotrione : An aromatic ketone that is 2-benzoylcyclohexane-1,3-dione in which the phenyl group is substituted at positions 2, 3, and 4 by chlorine, (2,2,2-trifluoroethoxy)methyl, and methylsulfonyl groups, respectively. It is a post-emergence herbicide used (particularly in conjunction with the herbicide safener cyprosulfamide) for the control of a wide range of broad-leaved and grassy weeds in corn and other crops. | aromatic ketone; beta-triketone; cyclic ketone; ether; monochlorobenzenes; organofluorine compound; sulfone | agrochemical; carotenoid biosynthesis inhibitor; EC 1.13.11.27 (4-hydroxyphenylpyruvate dioxygenase) inhibitor; herbicide |