Q9FRX6 (AS1_ANTMA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Aureusidin synthase
Short name=AmAS1
EC=1.21.3.6

Gene names

Name:

AS1

Organism

Antirrhinum majus (Garden snapdragon)

Taxonomic identifier

4151 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › asterids › lamiids › Lamiales › Plantaginaceae › Antirrhineae › Antirrhinum

Protein attributes

Sequence length	562 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

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. Ref.1 Ref.6
Catalytic activity	2',4,4',6'-tetrahydroxychalcone 4'-O-beta-glucoside + O2 = aureusidin 6-O-beta-glucoside + H2O. Ref.1 Ref.3 2 2',3,4,4',6'-pentahydroxychalcone 4'-O-beta-glucoside + O2 = 2 aureusidin 6-O-beta-glucoside + 2 H2O. Ref.1 Ref.3 2',3,4,4',6'-pentahydroxychalcone 4'-O-beta-glucoside + O2 = bracteatin 6-O-beta-glucoside + H2O. Ref.1 Ref.3
Cofactor	Binds 2 copper ions per subunit. Ref.1
Enzyme regulation	H2O2 activates the 3-hydroxylation and oxidative cyclization of tetrahydroxychalcone but inhibits reaction with pentahydroxychalcone. Inhibited by phenylthiourea. Ref.1 Ref.3
Subunit structure	Monomer. Ref.1
Subcellular location	Vacuole lumen Ref.4 Ref.6.
Tissue specificity	Expressed in petals. Not detected in stems and leaves. Ref.1
Domain	The N-terminal sequence (1-53) is sufficient for vacuolar targeting.
Post-translational modification	Glycosylated. Ref.1 Contains probably N- and C-terminal propeptides.
Sequence similarities	Belongs to the tyrosinase family.
Biophysicochemical properties	Kinetic parameters: KM=4.3 µM for 2',4,4',6'-tetrahydroxychalcone Ref.1 Ref.3 KM=3.9 µM for 2',4,4',6'-tetrahydroxychalcone 4'-glucoside KM=2.5 µM for isoliquiritigenin KM=15.7 µM for 2',3,4,4',6'-pentahydroxychalcone KM=8.1 µM for 2',3,4,4',6'-pentahydroxychalcone 4'-glucoside KM=14.7 µM for butein pH dependence: Optimum pH is 5.4 for the reaction with tetrahydroxychalcone and 5.0 - 7.0 for the reaction with pentahydroxychalcone.

Ontologies

Keywords
Cellular component	Vacuole
Ligand	Copper Metal-binding
Molecular function	Oxidoreductase
PTM	Disulfide bond Glycoprotein Thioether bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	pigment biosynthetic process Inferred from direct assay Ref.1. Source: UniProtKB
Cellular_component	vacuolar lumen Inferred from direct assay Ref.6. Source: UniProtKB
Molecular_function	aureusidin synthase activity Inferred from direct assay Ref.1. Source: UniProtKB catechol oxidase activity Inferred from electronic annotation. Source: InterPro copper ion binding Inferred from direct assay Ref.1. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 562	562	Aureusidin synthase		PRO_0000418416
Sites
	Metal binding	147	1	Copper A By similarity
	Metal binding	168	1	Copper A By similarity
	Metal binding	177	1	Copper A By similarity
	Metal binding	301	1	Copper B By similarity
	Metal binding	305	1	Copper B By similarity
	Metal binding	335	1	Copper B By similarity
Amino acid modifications
	Disulfide bond	71 ↔ 86		By similarity
	Disulfide bond	85 ↔ 148		By similarity
	Cross-link	151 ↔ 168		2'-(S-cysteinyl)-histidine (Cys-His) By similarity
Experimental info
	Mutagenesis	50	1	L → F: Loss of vacuolar targeting. Ref.4
	Mutagenesis	52	1	Y → P: Loss of vacuolar targeting. Ref.4

Sequences

	Sequence		Length	Mass (Da)
	Q9FRX6 [UniParc]. Last modified March 1, 2001. Version 1. Checksum: 660C2D72C3C054E3	FASTA	562	64,044
	10 20 30 40 50 60 MFKNPNIRYH KLSSKSNDND QESSHRCKHI LLFIITLFLL IVGLYIANSL AYARFASTST 70 80 90 100 110 120 GPIAAPDVTK CGQPDLPPGT APINCCPPIP AKIIDFELPP PSTTMRVRRA AHLVDDAYIA 130 140 150 160 170 180 KFKKAVELMR ALPEDDPRSF KQQANVHCAY CAGAYNQAGF TNLKLQIHRS WLFFPFHRYY 190 200 210 220 230 240 IYFFERILGK LINDTTFALP FWNYDSPGGM TIPSMFIDTN SSLYDSLRDS NHQPPTIVDL 250 260 270 280 290 300 NYAFSDSDNT TTPEEQMIIN LKIVYRQMVS SAKTPQLFFG RPYRRGDQEF PGVGSIELVP 310 320 330 340 350 360 HGMIHLWTGS ENTPYGENMG AFYSTARDPI FFAHHSNVDR MWSIWKTLGG PRRTDLTDPD 370 380 390 400 410 420 FLDASFVFYD ENAEMVRVKV RDCLDEKKLG YVYQDVEIPW LNTRPTPKVS PSLLKKFHRT 430 440 450 460 470 480 NTANPRQVFP AILDRVLKVI VTRPKKTRSR KEKDELEEIL VIEGIELERD HGHVKFDVYI 490 500 510 520 530 540 NADEDDLAVI SPENAEFAGS FVSLWHKPIK GKRTKTQLLT LSICDILEDL DADEDDYVLV 550 560 TLVPRNAGDA IKIHNVKIEL DG

References

[1]	"Aureusidin synthase: a polyphenol oxidase homolog responsible for flower coloration." Nakayama T., Yonekura-Sakakibara K., Sato T., Kikuchi S., Fukui Y., Fukuchi-Mizutani M., Ueda T., Nakao M., Tanaka Y., Kusumi T., Nishino T. Science 290:1163-1166(2000) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 93-121; 263-293 AND 389-400, FUNCTION, CATALYTIC ACTIVITY, SUBUNIT, GLYCOSYLATION, BIOPHYSICOCHEMICAL PROPERTIES, COFACTOR, ENZYME REGULATION, TISSUE SPECIFICITY.
[2]	"Genes involved in aurone biosynthesis." Wang C.-K., To K.-Y. Submitted (JUN-2007) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]	"Specificity analysis and mechanism of aurone synthesis catalyzed by aureusidin synthase, a polyphenol oxidase homolog responsible for flower coloration." Nakayama T., Sato T., Fukui Y., Yonekura-Sakakibara K., Hayashi H., Tanaka Y., Kusumi T., Nishino T. FEBS Lett. 499:107-111(2001) [PubMed] [Europe PMC] [Abstract] Cited for: CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, SUBSTRATE SPECIFICITY, ENZYME REGULATION.
[4]	"Localization of a flavonoid biosynthetic polyphenol oxidase in vacuoles." Ono E., Hatayama M., Isono Y., Sato T., Watanabe R., Yonekura-Sakakibara K., Fukuchi-Mizutani M., Tanaka Y., Kusumi T., Nishino T., Nakayama T. Plant J. 45:133-143(2006) [PubMed] [Europe PMC] [Abstract] Cited for: SUBCELLULAR LOCATION, MUTAGENESIS OF LEU-50 AND TYR-52.
[5]	"Homology modeling and dynamics study of aureusidin synthase--an important enzyme in aurone biosynthesis of snapdragon flower." Elumalai P., Liu H.L. Int. J. Biol. Macromol. 49:134-142(2011) [PubMed] [Europe PMC] [Abstract] Cited for: 3D-STRUCTURE MODELING.
[6]	"Yellow flowers generated by expression of the aurone biosynthetic pathway." Ono E., Fukuchi-Mizutani M., Nakamura N., Fukui Y., Yonekura-Sakakibara K., Yamaguchi M., Nakayama T., Tanaka T., Kusumi T., Tanaka Y. Proc. Natl. Acad. Sci. U.S.A. 103:11075-11080(2006) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, SUBCELLULAR LOCATION.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB044884 mRNA. Translation: BAB20048.1. EF650014 mRNA. Translation: ABR57233.1.
3D structure databases
HSSP	HSSP built from PDB template 1BT3 based on UniProtKB Q9ZP19.
ProteinModelPortal	Q9FRX6.
SMR	Q9FRX6. Positions 61-401.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	1.10.1280.10. 1 hit.
InterPro	IPR016213. Polyphenol_oxidase. IPR022740. Polyphenol_oxidase_C. IPR022739. Polyphenol_oxidase_cen. IPR002227. Tyrosinase. IPR008922. Unchr_di-copper_centre. [Graphical view]
Pfam	PF12142. PPO1_DWL. 1 hit. PF12143. PPO1_KFDV. 1 hit. PF00264. Tyrosinase. 1 hit. [Graphical view]
PIRSF	PIRSF000290. PPO_plant. 1 hit.
PRINTS	PR00092. TYROSINASE.
SUPFAM	SSF48056. Di-copper_centre. 1 hit.
PROSITE	PS00497. TYROSINASE_1. False negative. PS00498. TYROSINASE_2. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

AS1_ANTMA

Accession

Primary (citable) accession number: Q9FRX6

Entry history

Integrated into UniProtKB/Swiss-Prot:	September 5, 2012
Last sequence update:	March 1, 2001
Last modified:	April 3, 2013
This is version 54 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program