Reviewed, UniProtKB/Swiss-Prot Q7SIC2 (QDOI_ASPJA)

Names and origin

Protein names	Recommended name:     Quercetin 2,3-dioxygenase     EC=1.13.11.24 Alternative name(s):     2,3QD     Quercetinase     Flavonol 2,4-dioxygenase
Organism	Aspergillus japonicus
Taxonomic identifier	34381 [NCBI]
Taxonomic lineage	Eukaryota › Fungi › Dikarya › Ascomycota › Pezizomycotina › Eurotiomycetes › Eurotiomycetidae › Eurotiales › Trichocomaceae › mitosporic Trichocomaceae › Aspergillus

Protein attributes

Sequence length	350 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Performs the first step in the degradation of the flavonoid quercetin by a dioxygenase reaction. The enzyme catalyzes the cleavage of the O-heteroaromatic ring of the flavonol quercetin yielding the depside 2-protocatechuoyl-phloroglucinol carboxylic acid and carbon monoxide. This involves the remarkable dioxygenolytic cleavage of two carbon-carbon bonds.
Catalytic activity	Quercetin + O(2) = 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate + CO + H(+).
Cofactor	Binds 1 copper ion per subunit.
Enzyme regulation	Inhibited by diethyldithiocarbamate and kojic acid.
Pathway	Flavonoid metabolism; quercetin degradation.
Subunit structure	Homodimer.
Post-translational modification	The N-linked glycan at Asn-191 consists of Man(5)-GlcNAc(2).

Ontologies

Keywords
Domain	Repeat
Ligand	Copper Metal-binding
Molecular function	Dioxygenase Oxidoreductase
PTM	Glycoprotein
Technical term	3D-structure
Gene Ontology (GO)
Biological process	oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	copper ion binding Inferred from electronic annotation. Source: UniProtKB-KW quercetin 2,3-dioxygenase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 350

350

Quercetin 2,3-dioxygenase

PRO_0000097134

Regions

Region

1 – 145

145

Cupin 1

Region

146 – 205

60

Linker

Region

206 – 350

145

Cupin 2

Sites

Metal binding

66

1

Copper

Metal binding

68

1

Copper

Metal binding

73

1

Copper

Metal binding

112

1

Copper

Binding site

66

1

Substrate

Binding site

73

1

Substrate

Amino acid modifications

Glycosylation

90

1

N-linked (GlcNAc...)

Glycosylation

109

1

N-linked (GlcNAc...)

Glycosylation

142

1

N-linked (GlcNAc...)

Glycosylation

191

1

N-linked (GlcNAc...)

Glycosylation

248

1

N-linked (GlcNAc...)

Experimental info

Mutagenesis

73

1

E → Q: 1000-fold decrease in activity

Secondary structure

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350

Helix Strand Turn

Details...

Beta strand

5 – 9

5

Beta strand

17 – 19

3

Beta strand

28 – 30

3

Beta strand

33 – 39

7

Helix

41 – 44

4

Beta strand

49 – 55

7

Beta strand

72 – 87

16

Beta strand

94 – 99

6

Beta strand

103 – 106

4

Beta strand

111 – 116

6

Beta strand

121 – 129

9

Turn

130 – 133

4

Helix

134 – 139

6

Beta strand

140 – 142

3

Helix

173 – 175

3

Beta strand

193 – 197

5

Beta strand

200 – 203

4

Beta strand

215 – 217

3

Beta strand

224 – 227

4

Beta strand

233 – 239

7

Helix

241 – 244

4

Helix

245 – 247

3

Beta strand

249 – 256

8

Beta strand

274 – 281

8

Beta strand

283 – 287

5

Beta strand

293 – 295

3

Beta strand

300 – 303

4

Beta strand

309 – 329

21

Helix

330 – 336

7

Beta strand

338 – 341

4

Sequences

	Sequence		Length	Mass (Da)
	Q7SIC2-1 [UniParc]. Last modified December 15, 2003. Version 1. Checksum: 7F33C372D0DFA5D9	FASTA	350	37,935
	10 20 30 40 50 60 DTSSLIVEDA PDHVRPYVIR HYSHARAVTV DTQLYRFYVT GPSSGYAFTL MGTNAPHSDA 70 80 90 100 110 120 LGVLPHIHQK HYENFYCNKG SFQLWAQSGN ETQQTRVLSS GDYGSVPRNV THTFQIQDPD 130 140 150 160 170 180 TEMTGVIVPG GFEDLFYYLG TNATDTTHTP YIPSSSDSSS TTGPDSSTIS TLQSFDVYAE 190 200 210 220 230 240 LSFTPRTDTV NGTAPANTVW HTGANALAST AGDPYFIANG WGPKYLNSQY GYQIVAPFVT 250 260 270 280 290 300 ATQAQDTNYT LSTISMSTTP STVTVPTWSF PGACAFQVQE GRVVVQIGDY AATELGSGDV 310 320 330 340 350 AFIPGGVEFK YYSEAYFSKV LFVSSGSDGL DQNLVNGGEE WSSVSFPADW

References

[1]	"Functional analysis of the copper-dependent quercetin 2,3-dioxygenase. 1. Ligand-induced coordination changes probed by X-ray crystallography: inhibition, ordering effect, and mechanistic insights." Steiner R.A., Kooter I.M., Dijkstra B.W. Biochemistry 41:7955-7962(2002) [PubMed: 12069585] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) IN COMPLEX WITH DIETHYLDITHIOCARBAMATE AND KOJIC ACID.
[2]	"Anaerobic enzyme.substrate structures provide insight into the reaction mechanism of the copper-dependent quercetin 2,3-dioxygenase." Steiner R.A., Kalk K.H., Dijkstra B.W. Proc. Natl. Acad. Sci. U.S.A. 99:16625-16630(2002) [PubMed: 12486225] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.75 ANGSTROMS) IN COMPLEX WITH KAEMPFEROL AND QUERCETIN.
[3]	"Crystal structure of the copper-containing quercetin 2,3-dioxygenase from Aspergillus japonicus." Fusetti F., Schroeter K.H., Steiner R.A., van Noort P.I., Pijning T., Rozeboom H.J., Kalk K.H., Egmond M.R., Dijkstra B.W. Structure 10:259-268(2002) [PubMed: 11839311] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS), MUTAGENESIS OF GLU-73.

Cross-references

3D structure databases

PDBMSD

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1GQG	X-ray	1.70	A/B/C/D	1-350	[»]
1GQH	X-ray	2.15	A/B/C/D	1-350	[»]
1H1I	X-ray	1.75	A/B/C/D	1-350	[»]
1H1M	X-ray	1.90	A/B/C/D	1-350	[»]
1JUH	X-ray	1.60	A/B/C/D	1-350	[»]

ModBase

Search...

Family and domain databases

InterPro

IPR014710. RmlC-like_jellyroll.
[Graphical view]

Gene3D

G3DSA:2.60.120.10. RmlC-like_jellyroll. 2 hits.

ProtoNet

Search...

Entry information

Entry name

QDOI_ASPJA

Accession

Primary (citable) accession number: Q7SIC2
Secondary accession number(s): Q7SIE5, Q7SIE7

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 29, 2005
Last sequence update:	December 15, 2003
Last modified:	November 4, 2008
This is version 26 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

FPAP (Fungal Proteome Annotation Project)