Cloned (Comment) | Organism |
---|---|
gene AS1, DNA and amino acid sequence determination and analyis | Antirrhinum majus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
vacuole | - |
Antirrhinum majus | 5773 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cu2+ | a copper-containing enzyme | Neurospora crassa | |
Cu2+ | a copper-containing enzyme | Antirrhinum majus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 2',3,4,4',6'-pentahydroxychalcone + O2 | Antirrhinum majus | - |
bracteatin + 2 H2O | - |
? | |
2',4',6',4-tetrahydroxychalcone + O2 | Neurospora crassa | - |
aureusidin + H2O | - |
? | |
2',4',6',4-tetrahydroxychalcone + O2 | Antirrhinum majus | - |
aureusidin + H2O | - |
? | |
additional information | Antirrhinum majus | substrate specificity allows elucidation of a likely mechanism of aurone formation from 2,4,6,4-tetrahydroxychalcone or PHC involving both tyrosinase and catechol oxidase activities of the Antirrhinum majus PPO, pathway overview. Starting with THC, tyrosinase and catechol oxidase activity, EC 1.14.18.1, result in 3-hydroxylation and formation of the corresponding o-quinone. Whether aureusidine synthase PPO carries out the 3-hydroxylation reaction in vivo, or whether a cytochrome P450 chalcone 3-hydroxylase is also involved is not definitively established. Aureusidine synthase likely forms the same quinone from 2',3,4,4',6'-pentahydroxychalcone without the need for the 3-hydroxylation step. The resulting quinone is predicted to undergo a 2-step non-enzyme mediated rearrangement to form aureusidin | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Antirrhinum majus | Q9FRX6 | - |
- |
Neurospora crassa | - |
- |
- |
Purification (Comment) | Organism |
---|---|
native enzyme to homogeneity from yellow snapdragon flower buds | Antirrhinum majus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
flower | - |
Antirrhinum majus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 2',3,4,4',6'-pentahydroxychalcone + O2 | - |
Antirrhinum majus | bracteatin + 2 H2O | - |
? | |
2',4',6',4-tetrahydroxychalcone + O2 | - |
Neurospora crassa | aureusidin + H2O | - |
? | |
2',4',6',4-tetrahydroxychalcone + O2 | - |
Antirrhinum majus | aureusidin + H2O | - |
? | |
additional information | substrate specificity allows elucidation of a likely mechanism of aurone formation from 2,4,6,4-tetrahydroxychalcone or PHC involving both tyrosinase and catechol oxidase activities of the Antirrhinum majus PPO, pathway overview. Starting with THC, tyrosinase and catechol oxidase activity, EC 1.14.18.1, result in 3-hydroxylation and formation of the corresponding o-quinone. Whether aureusidine synthase PPO carries out the 3-hydroxylation reaction in vivo, or whether a cytochrome P450 chalcone 3-hydroxylase is also involved is not definitively established. Aureusidine synthase likely forms the same quinone from 2',3,4,4',6'-pentahydroxychalcone without the need for the 3-hydroxylation step. The resulting quinone is predicted to undergo a 2-step non-enzyme mediated rearrangement to form aureusidin | Antirrhinum majus | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
AS1 | - |
Antirrhinum majus |
aureusidin synthase | - |
Neurospora crassa |
aureusidin synthase | - |
Antirrhinum majus |
aurone synthase | - |
Antirrhinum majus |
More | cf. EC 1.14.18.1 | Neurospora crassa |
More | cf. EC 1.14.18.1 | Antirrhinum majus |
General Information | Comment | Organism |
---|---|---|
metabolism | substrate specificity allows elucidation of a likely mechanism of aurone formation from 2,4,6,4-tetrahydroxychalcone or PHC involving both tyrosinase and catechol oxidase activities of the Antirrhinum majus PPO, pathway overview. Starting with THC, tyrosinase and catechol oxidase activity, EC 1.14.18.1, result in 3-hydroxylation and formation of the corresponding o-quinone. Whether aureusidine synthase PPO carries out the 3-hydroxylation reaction in vivo, or whether a cytochrome P450 chalcone 3-hydroxylase is also involved is not definitively established. Aureusidine synthase likely forms the same quinone from 2',3,4,4',6'-pentahydroxychalcone without the need for the 3-hydroxylation step. The resulting quinone is predicted to undergo a 2-step non-enzyme mediated rearrangement to form aureusidine | Antirrhinum majus |
physiological function | PPOs have a role in postharvest browning, secondary reactions of PPO-generated o-quinones with cellular nucleophiles leading to the familiar discoloration of fresh products and plant materials. Aurones (aureusidin and bracteatin) are formed from 2,4,6,4-tetrahydroxychalcone or 2,4,6,3,4-pentahydroxychalcone upon incubation with extracts of yellow snapdragon flowers through activity of aureusidin (or aurone) synthase | Antirrhinum majus |