Q9FRX6 · AS1_ANTMA
- ProteinAureusidin synthase
- GeneAS1
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids562 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Involved in the biosynthesis of aurones, plant flavonoids that provide yellow coloration to flowers. Can use tetrahydroxychalcone (THC), pentahydroxychalcone (PHC), THC 4'-glucoside and PHC 4'-glucoside as substrates, but not 2'-hydroxychalcone, 4-hydroxychalcone, PHC 3-glucoside, 2',6'-dihydroxy-4,4'-dimethoxychalcone, naringenin, eriodictyol and 4,4',6-trihydroxyaurone. Can also produce bracteatin from PHC.
Catalytic activity
- 2',4,4',6'-tetrahydroxychalcone 4'-O-beta-D-glucoside + O2 = aureusidin 6-O-beta-glucoside + H2O
Cofactor
Note: Binds 2 copper ions per subunit.
Activity regulation
H2O2 activates the 3-hydroxylation and oxidative cyclization of tetrahydroxychalcone but inhibits reaction with pentahydroxychalcone. Inhibited by phenylthiourea.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
4.3 μM | 2',4,4',6'-tetrahydroxychalcone | |||||
3.9 μM | 2',4,4',6'-tetrahydroxychalcone 4'-glucoside | |||||
2.5 μM | isoliquiritigenin | |||||
15.7 μM | 2',3,4,4',6'-pentahydroxychalcone | |||||
8.1 μM | 2',3,4,4',6'-pentahydroxychalcone 4'-glucoside | |||||
14.7 μM | butein |
pH Dependence
Optimum pH is 5.4 for the reaction with tetrahydroxychalcone and 5.0 - 7.0 for the reaction with pentahydroxychalcone.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 147 | Cu cation A (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 168 | Cu cation A (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 177 | Cu cation A (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 301 | Cu cation B (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 305 | Cu cation B (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 335 | Cu cation B (UniProtKB | ChEBI) | ||||
Sequence: H |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | vacuolar lumen | |
Molecular Function | aureusidin synthase activity | |
Molecular Function | butein:oxygen oxidoreductase activity | |
Molecular Function | catechol oxidase activity | |
Molecular Function | copper ion binding | |
Molecular Function | sulfuretin synthase activity | |
Biological Process | pigment biosynthetic process |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameAureusidin synthase
- EC number
- Short namesAmAS1
Gene names
Organism names
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > asterids > lamiids > Lamiales > Plantaginaceae > Antirrhineae > Antirrhinum
Accessions
- Primary accessionQ9FRX6
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 50 | Loss of vacuolar targeting. | ||||
Sequence: L → F | ||||||
Mutagenesis | 52 | Loss of vacuolar targeting. | ||||
Sequence: Y → P |
PTM/Processing
Features
Showing features for chain, disulfide bond, cross-link.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000418416 | 1-562 | Aureusidin synthase | |||
Sequence: MFKNPNIRYHKLSSKSNDNDQESSHRCKHILLFIITLFLLIVGLYIANSLAYARFASTSTGPIAAPDVTKCGQPDLPPGTAPINCCPPIPAKIIDFELPPPSTTMRVRRAAHLVDDAYIAKFKKAVELMRALPEDDPRSFKQQANVHCAYCAGAYNQAGFTNLKLQIHRSWLFFPFHRYYIYFFERILGKLINDTTFALPFWNYDSPGGMTIPSMFIDTNSSLYDSLRDSNHQPPTIVDLNYAFSDSDNTTTPEEQMIINLKIVYRQMVSSAKTPQLFFGRPYRRGDQEFPGVGSIELVPHGMIHLWTGSENTPYGENMGAFYSTARDPIFFAHHSNVDRMWSIWKTLGGPRRTDLTDPDFLDASFVFYDENAEMVRVKVRDCLDEKKLGYVYQDVEIPWLNTRPTPKVSPSLLKKFHRTNTANPRQVFPAILDRVLKVIVTRPKKTRSRKEKDELEEILVIEGIELERDHGHVKFDVYINADEDDLAVISPENAEFAGSFVSLWHKPIKGKRTKTQLLTLSICDILEDLDADEDDYVLVTLVPRNAGDAIKIHNVKIELDG | ||||||
Disulfide bond | 71↔86 | |||||
Sequence: CGQPDLPPGTAPINCC | ||||||
Disulfide bond | 85↔148 | |||||
Sequence: CCPPIPAKIIDFELPPPSTTMRVRRAAHLVDDAYIAKFKKAVELMRALPEDDPRSFKQQANVHC | ||||||
Cross-link | 151↔168 | 2'-(S-cysteinyl)-histidine (Cys-His) | ||||
Sequence: CAGAYNQAGFTNLKLQIH |
Post-translational modification
Glycosylated.
Contains probably N- and C-terminal propeptides.
Keywords
- PTM
Expression
Tissue specificity
Expressed in petals. Not detected in stems and leaves.
Interaction
Subunit
Monomer.
Structure
Sequence
- Sequence statusComplete
- Length562
- Mass (Da)64,044
- Last updated2001-03-01 v1
- Checksum660C2D72C3C054E3
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AB044884 EMBL· GenBank· DDBJ | BAB20048.1 EMBL· GenBank· DDBJ | mRNA | ||
EF650014 EMBL· GenBank· DDBJ | ABR57233.1 EMBL· GenBank· DDBJ | mRNA |