Reviewed, UniProtKB/Swiss-Prot Q9FK25 (OMT1_ARATH)

Names and origin

Protein names

Recommended name:
    Quercetin 3-O-methyltransferase 1
      Short name=AtOMT1
    EC=2.1.1.76
Alternative name(s):
    Flavonol 3-O-methyltransferase 1

Gene names

Name:	OMT1
Ordered Locus Names:	At5g54160
ORF Names:	K18G13.3

Organism

Arabidopsis thaliana (Mouse-ear cress) [Complete proteome]

Taxonomic identifier

3702 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids II › Brassicales › Brassicaceae › Arabidopsis

Protein attributes

Sequence length	363 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Methylates OH residues of flavonoid compounds. Substrate preference is quercetin > myricetin >> luteolin. Dihydroquercetin is not a substrate. Ref.6
Catalytic activity	S-adenosyl-L-methionine + 3,5,7,3',4'-pentahydroxyflavone = S-adenosyl-L-homocysteine + 3-methoxy-5,7,3',4'-tetrahydroxyflavone.
Enzyme regulation	Does not require magnesium. Completely inhibited by 5 mM of either NiSO4 or p-chloromercuribenzoate (pCMB). Ref.6
Pathway	Flavonoid metabolism; quercetin degradation.
Subunit structure	Monomer.
Sequence similarities	Belongs to the methyltransferase superfamily. Type 2 family. COMT subfamily.
Biophysicochemical properties	Kinetic parameters: KM=1.76 µM for quercetin KM=3.38 µM for myricetin Vmax=384.6 pmol/sec/mg enzyme with quercetin as substrate Vmax=227.3 pmol/sec/mg enzyme with myricetin as substrate pH dependence: Optimum pH is 7.5.

Ontologies

Keywords
Ligand	S-adenosyl-L-methionine
Molecular function	Methyltransferase Transferase
Technical term	3D-structure Complete proteome
Gene Ontology (GO)
Biological process	flavonol biosynthetic process Ref.6 Inferred from direct assay. Source: TAIR lignin biosynthetic process Inferred from mutant phenotype. Source: TAIR
Cellular component	cytoplasm Inferred from direct assay. Source: TAIR nucleus Inferred from direct assay. Source: TAIR plasma membrane Inferred from direct assay. Source: TAIR
Molecular function	caffeate O-methyltransferase activity Inferred from mutant phenotype. Source: TAIR myricetin 3'-O-methyltransferase activity Ref.6 Inferred from direct assay. Source: TAIR protein dimerization activity Inferred from electronic annotation. Source: InterPro quercetin 3-O-methyltransferase activity Ref.6 Inferred from direct assay. Source: TAIR
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
BRL1	Q9ZPS9	1	EBI-1633761,EBI-2292728
GRF6	P48349	1	EBI-1633761,EBI-1633785

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 363

363

Quercetin 3-O-methyltransferase 1

PRO_0000063217

Sites

Active site

267

1

Proton acceptor By similarity

Binding site

206

1

S-adenosyl-L-methionine; via carbonyl oxygen By similarity

Binding site

229

1

S-adenosyl-L-methionine By similarity

Binding site

249

1

S-adenosyl-L-methionine By similarity

Binding site

250

1

S-adenosyl-L-methionine; via amide nitrogen By similarity

Binding site

263

1

S-adenosyl-L-methionine By similarity

Experimental info

Sequence conflict

229

1

D → N in AAB96879. Ref.1

Sequence conflict

295

1

E → V in CAA81580. Ref.5

Sequence conflict

301

1

T → S in CAA81580. Ref.5

Sequence conflict

348

1

V → C in CAA81580. Ref.5

Secondary structure

1

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363

Helix Strand Turn

Details...

Beta strand

12 – 14

3

Helix

20 – 23

4

Turn

29 – 31

3

Helix

32 – 36

5

Turn

40 – 42

3

Helix

45 – 50

6

Helix

57 – 60

4

Beta strand

63 – 68

6

Helix

74 – 78

5

Helix

81 – 84

4

Beta strand

85 – 87

3

Beta strand

90 – 92

3

Beta strand

96 – 98

3

Beta strand

102 – 104

3

Turn

111 – 113

3

Beta strand

117 – 119

3

Helix

125 – 128

4

Beta strand

135 – 137

3

Helix

142 – 145

4

Helix

151 – 155

5

Helix

160 – 166

7

Helix

168 – 192

25

Beta strand

200 – 204

5

Beta strand

208 – 210

3

Turn

213 – 216

4

Beta strand

221 – 229

9

Turn

231 – 233

3

Beta strand

243 – 248

6

Beta strand

250 – 252

3

Beta strand

258 – 265

8

Turn

266 – 268

3

Helix

273 – 283

11

Beta strand

290 – 295

6

Helix

306 – 309

4

Helix

314 – 320

7

Beta strand

322 – 324

3

Helix

330 – 340

11

Beta strand

343 – 350

8

Beta strand

355 – 360

6

Sequences

	Sequence		Length	Mass (Da)
	Q9FK25-1 [UniParc]. Last modified March 1, 2001. Version 1. Checksum: B4380028D89C43DC	FASTA	363	39,618
	10 20 30 40 50 60 MGSTAETQLT PVQVTDDEAA LFAMQLASAS VLPMALKSAL ELDLLEIMAK NGSPMSPTEI 70 80 90 100 110 120 ASKLPTKNPE APVMLDRILR LLTSYSVLTC SNRKLSGDGV ERIYGLGPVC KYLTKNEDGV 130 140 150 160 170 180 SIAALCLMNQ DKVLMESWYH LKDAILDGGI PFNKAYGMSA FEYHGTDPRF NKVFNNGMSN 190 200 210 220 230 240 HSTITMKKIL ETYKGFEGLT SLVDVGGGIG ATLKMIVSKY PNLKGINFDL PHVIEDAPSH 250 260 270 280 290 300 PGIEHVGGDM FVSVPKGDAI FMKWICHDWS DEHCVKFLKN CYESLPEDGK VILAECILPE 310 320 330 340 350 360 TPDSSLSTKQ VVHVDCIMLA HNPGGKERTE KEFEALAKAS GFKGIKVVCD AFGVNLIELL KKL

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"An Arabidopsis gene encoding a putative 14-3-3-interacting protein, caffeic acid/5-hydroxyferulic acid O-methyltransferase." Zhang H., Wang J., Goodman H.M. Biochim. Biophys. Acta 1353:199-202(1997) [PubMed: 9349713] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: cv. C24. Tissue: Leaf.
[2]	"Structural analysis of Arabidopsis thaliana chromosome 5. VI. Sequence features of the regions of 1,367,185 bp covered by 19 physically assigned P1 and TAC clones." Kotani H., Nakamura Y., Sato S., Asamizu E., Kaneko T., Miyajima N., Tabata S. DNA Res. 5:203-216(1998) [PubMed: 9734815] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[3]	"Empirical analysis of transcriptional activity in the Arabidopsis genome." Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M., Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G., Liu S.X., Lam B., Sakano H., Wu T., Yu G. , Miranda M., Quach H.L., Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C., Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J., Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A., Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C., Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X., Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M., Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K., Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A., Ecker J.R. Science 302:842-846(2003) [PubMed: 14593172] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: cv. Columbia.
[4]	"Full-length cDNA from Arabidopsis thaliana." Brover V.V., Troukhan M.E., Alexandrov N.A., Lu Y.-P., Flavell R.B., Feldmann K.A. Submitted (MAR-2002) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[5]	"Further progress towards a catalogue of all Arabidopsis genes: analysis of a set of 5000 non-redundant ESTs." Cooke R., Raynal M., Laudie M., Grellet F., Delseny M., Morris P.-C., Guerrier D., Giraudat J., Quigley F., Clabault G., Li Y.-F., Mache R., Krivitzky M., Gy I.J.-J., Kreis M., Lecharny A., Parmentier Y., Marbach J. , Fleck J., Clement B., Philipps G., Herve C., Bardet C., Tremousaygue D., Lescure B., Lacomme C., Roby D., Jourjon M.-F., Chabrier P., Charpenteau J.-L., Desprez T., Amselem J., Chiapello H., Hoefte H. Plant J. 9:101-124(1996) [PubMed: 8580968] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 285-363. Strain: cv. Columbia. Tissue: Green siliques.
[6]	"Functional expression of an Arabidopsis cDNA clone encoding a flavonol 3'-O-methyltransferase and characterization of the gene product." Muzac I., Wang J., Anzellotti D., Zhang H., Ibrahim R.K. Arch. Biochem. Biophys. 375:385-388(2000) [PubMed: 10700397] [Abstract] Cited for: FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION.
[7]	"The three-dimensional structure of Arabidopsis thaliana O-methyltransferase predicted by homology-based modelling." Yang H., Ahn J.-H., Ibrahim R.K., Lee S., Lim Y. J. Mol. Graph. Model. 23:77-87(2004) [PubMed: 15331056] [Abstract] Cited for: 3D-STRUCTURE MODELING.

Cross-references

Sequence databases

EMBLGenBankDDBJ

U70424 mRNA. Translation: AAB96879.1.
AB013387 Genomic DNA. Translation: BAB11578.1.
AY062837 mRNA. Translation: AAL32915.1.
AY081565 mRNA. Translation: AAM10127.1.
AY087297 mRNA. Translation: AAM64849.1.
Z27062 mRNA. Translation: CAA81580.1.

IPI

IPI00542876.

RefSeq

NP_200227.1.

UniGene

At.47593

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1NII	model	-	A	1-363	[»]

SMR

Q9FK25. Positions 5-363.

ModBase

Search...

Protein-protein interaction databases

IntAct

Q9FK25. 1 interaction.

Proteomic databases

PRIDE

Q9FK25.

Genome annotation databases

GeneID

835504.

GenomeReviews

Gene locus AT5G54160 in contig BA000015_GR.

KEGG

ath:AT5G54160.

NMPDR

fig|3702.1.peg.27323.

Organism-specific databases

TAIR

At5g54160.

Phylogenomic databases

OMA

Q9FK25. MESWYYL.

Enzyme and pathway databases

BRENDA

2.1.1.76. 302.

Gene expression databases

ArrayExpress

Q9FK25.

GermOnline

AT5G54160. Arabidopsis thaliana.

Family and domain databases

InterPro

IPR016461. O-MeTrfase_COMT_euk.
IPR001077. O_MeTrfase_2.
IPR012967. Plant_MeTrfase_dimerisation.
IPR011991. Wing_hlx_DNA_bd.
[Graphical view]

Gene3D

G3DSA:1.10.10.10. Wing_hlx_DNA_bd. 1 hit.

Pfam

PF08100. Dimerisation. 1 hit.
PF00891. Methyltransf_2. 1 hit.
[Graphical view]

PIRSF

PIRSF005739. O-mtase. 1 hit.

ProtoNet

Search...

Entry information

Entry name

OMT1_ARATH

Accession

Primary (citable) accession number: Q9FK25
Secondary accession number(s): O49964, Q42170

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 19, 2002
Last sequence update:	March 1, 2001
Last modified:	June 16, 2009
This is version 67 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)