Reviewed, UniProtKB/Swiss-Prot O24529 (7OMT8_MEDSA)

Names and origin

Protein names	Recommended name:     Isoflavone-7-O-methyltransferase 8     EC=2.1.1.150 Alternative name(s):     Isoflavone-O-methyltransferase 8     7-IOMT-8
Organism	Medicago sativa (Alfalfa)
Taxonomic identifier	3879 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids I › Fabales › Fabaceae › Papilionoideae › Trifolieae › Medicago

Protein attributes

Sequence length	352 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Transfers a methyl group to 7-hydroxyls of the isoflavones daidzein, genistein and 6,7,4'-trihydroxyisoflavone. Can also methylate (+)6a-hydroxymaackiain with lower efficiency.
Catalytic activity	S-adenosyl-L-methionine + a 7-hydroxyisoflavone = S-adenosyl-L-homocysteine + a 7-methoxyisoflavone.
Pathway	Phytoalexin biosynthesis; medicarpin biosynthesis.
Subunit structure	Homodimer. Ref.3
Sequence similarities	Belongs to the methyltransferase superfamily. Type 2 family. COMT subfamily.

Ontologies

Keywords
Molecular function	Methyltransferase Transferase
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Molecular function	isoflavone 7-O-methyltransferase activity Inferred from electronic annotation. Source: EC protein dimerization activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 352

352

Isoflavone-7-O-methyltransferase 8

PRO_0000204437

Regions

Region

118 – 127

10

Substrate binding

Sites

Active site

257

1

Proton acceptor

Binding site

196

1

S-adenosyl-L-methionine; via carbonyl oxygen

Binding site

219

1

S-adenosyl-L-methionine

Binding site

239

1

S-adenosyl-L-methionine

Binding site

240

1

S-adenosyl-L-methionine; via amide nitrogen

Binding site

253

1

S-adenosyl-L-methionine

Secondary structure

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352

Helix Strand Turn

Details...

Helix

12 – 24

13

Helix

27 – 38

12

Helix

41 – 48

8

Helix

54 – 61

8

Helix

65 – 67

3

Helix

68 – 80

13

Beta strand

83 – 96

14

Helix

98 – 101

4

Beta strand

107 – 109

3

Helix

112 – 118

7

Helix

121 – 125

5

Helix

126 – 129

4

Helix

130 – 134

5

Helix

141 – 146

6

Helix

150 – 156

7

Helix

158 – 170

13

Helix

172 – 180

9

Helix

183 – 186

4

Beta strand

190 – 195

6

Helix

201 – 209

9

Beta strand

214 – 219

6

Helix

221 – 224

4

Beta strand

233 – 237

5

Turn

240 – 242

3

Beta strand

248 – 254

7

Helix

256 – 258

3

Helix

261 – 275

15

Helix

277 – 279

3

Beta strand

283 – 288

6

Turn

293 – 295

3

Helix

298 – 310

13

Helix

311 – 314

4

Helix

321 – 330

10

Beta strand

335 – 342

8

Beta strand

345 – 351

7

Sequences

	Sequence		Length	Mass (Da)
	O24529-1 [UniParc]. Last modified January 1, 1998. Version 1. Checksum: 31B95228986C1296	FASTA	352	39,604
	10 20 30 40 50 60 MASSINGRKP SEIFKAQALL YKHIYAFIDS MSLKWAVEMN IPNIIQNHGK PISLSNLVSI 70 80 90 100 110 120 LQVPSSKIGN VRRLMRYLAH NGFFEIITKE EESYALTVAS ELLVRGSDLC LAPMVECVLD 130 140 150 160 170 180 PTLSGSYHEL KKWIYEEDLT LFGVTLGSGF WDFLDKNPEY NTSFNDAMAS DSKLINLALR 190 200 210 220 230 240 DCDFVFDGLE SIVDVGGGTG TTAKIICETF PKLKCIVFDR PQVVENLSGS NNLTYVGGDM 250 260 270 280 290 300 FTSIPNADAV LLKYILHNWT DKDCLRILKK CKEAVTNDGK RGKVTIIDMV IDKKKDENQV 310 320 330 340 350 TQIKLLMDVN MACLNGKERN EEEWKKLFIE AGFQHYKISP LTGFLSLIEI YP

References

[1]	"Stress responses in alfalfa (Medicago sativa L). XXII. cDNA cloning and characterization of an elicitor-inducible isoflavone 7-O-methyltransferase." He X.-Z., Reddy J.T., Dixon R.A. Plant Mol. Biol. 36:43-54(1998) [PubMed: 9484461] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Affinity chromatography, substrate/product specificity, and amino acid sequence analysis of an isoflavone O-methyltransferase from alfalfa (Medicago sativa L.)." He X.-Z., Dixon R.A. Arch. Biochem. Biophys. 336:121-129(1996) [PubMed: 8951042] [Abstract] Cited for: PROTEIN SEQUENCE OF 23-31; 77-105 AND 327-337, CHARACTERIZATION.
[3]	"Structures of two natural product methyltransferases reveal the basis for substrate specificity in plant O-methyltransferases." Zubieta C., He X.-Z., Dixon R.A., Noel J.P. Nat. Struct. Biol. 8:271-279(2001) [PubMed: 11224575] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.4 ANGSTROMS) IN COMPLEX WITH SUBSTRATES, SUBUNIT.

Cross-references

Sequence databases

EMBLGenBankDDBJ

U97125 mRNA. Translation: AAC49928.1.

PIR

T09707.

3D structure databases

PDBMSD

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1FP2	X-ray	1.40	A	1-352	[»]
1FPX	X-ray	1.65	A	1-352	[»]

ModBase

Search...

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

7OMT8_MEDSA

Accession

Primary (citable) accession number: O24529

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 1, 2004
Last sequence update:	January 1, 1998
Last modified:	November 25, 2008
This is version 62 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)