ID   Q8OMT_MENPI             Reviewed;         366 AA.
AC   Q6VMW0;
DT   27-JUL-2011, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 62.
DE   RecName: Full=8-hydroxyquercetin 8-O-methyltransferase;
DE            EC=2.1.1.88;
DE   AltName: Full=Flavonol 8-O-methyltransferase;
GN   Name=OMT2;
OS   Mentha piperita (Peppermint) (Mentha aquatica x Mentha spicata).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Lamiales; Lamiaceae; Nepetoideae; Mentheae; Menthinae;
OC   Mentha.
OX   NCBI_TaxID=34256;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND CATALYTIC ACTIVITY.
RC   TISSUE=Leaf;
RX   PubMed=14697269; DOI=10.1016/j.phytochem.2003.10.005;
RA   Willits M.G., Giovanni M., Prata R.T., Kramer C.M., De Luca V.,
RA   Steffens J.C., Graser G.;
RT   "Bio-fermentation of modified flavonoids: an example of in vivo
RT   diversification of secondary metabolites.";
RL   Phytochemistry 65:31-41(2004).
CC   -!- FUNCTION: 8-O-methyltransferase active on various hydroxylated
CC       flavonoid substrates, including 7,8,3'4'-tetrahydroxy-flavone, 7,8,4'-
CC       trihydroxy-flavone and 8-hydroxy-flavone 7-methyl ether.
CC       {ECO:0000269|PubMed:14697269}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=3,3',4',5,7,8-hexahydroxyflavone + S-adenosyl-L-methionine =
CC         3,3',4',5,7-pentahydroxy-8-methoxyflavone + H(+) + S-adenosyl-L-
CC         homocysteine; Xref=Rhea:RHEA:16593, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:57856, ChEBI:CHEBI:58544, ChEBI:CHEBI:59789,
CC         ChEBI:CHEBI:77862; EC=2.1.1.88;
CC         Evidence={ECO:0000269|PubMed:14697269};
CC   -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC       superfamily. Cation-independent O-methyltransferase family. COMT
CC       subfamily. {ECO:0000255|PROSITE-ProRule:PRU01020}.
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DR   EMBL; AY337459; AAR09600.1; -; mRNA.
DR   AlphaFoldDB; Q6VMW0; -.
DR   SMR; Q6VMW0; -.
DR   BRENDA; 2.1.1.88; 3222.
DR   GO; GO:0030761; F:8-hydroxyquercitin 8-O-methyltransferase activity; IDA:UniProtKB.
DR   GO; GO:0008171; F:O-methyltransferase activity; IEA:InterPro.
DR   GO; GO:0046983; F:protein dimerization activity; IEA:InterPro.
DR   GO; GO:0009812; P:flavonoid metabolic process; IDA:UniProtKB.
DR   GO; GO:0032259; P:methylation; IDA:UniProtKB.
DR   Gene3D; 1.10.10.10; -; 1.
DR   Gene3D; 3.40.50.150; -; 1.
DR   InterPro; IPR016461; COMT-like.
DR   InterPro; IPR001077; O_MeTrfase_dom.
DR   InterPro; IPR012967; Plant_MeTrfase_dimerisation.
DR   InterPro; IPR029063; SAM-dependent_MTases_sf.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   InterPro; IPR036390; WH_DNA-bd_sf.
DR   PANTHER; PTHR11746; PTHR11746; 1.
DR   Pfam; PF08100; Dimerisation; 1.
DR   Pfam; PF00891; Methyltransf_2; 1.
DR   PIRSF; PIRSF005739; O-mtase; 1.
DR   SUPFAM; SSF46785; SSF46785; 1.
DR   SUPFAM; SSF53335; SSF53335; 1.
DR   PROSITE; PS51683; SAM_OMT_II; 1.
PE   1: Evidence at protein level;
KW   Methyltransferase; S-adenosyl-L-methionine; Transferase.
FT   CHAIN           1..366
FT                   /note="8-hydroxyquercetin 8-O-methyltransferase"
FT                   /id="PRO_0000412067"
FT   ACT_SITE        269
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         207..210
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         231..232
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         231
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         251..252
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         265
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
SQ   SEQUENCE   366 AA;  40849 MW;  E48B6B9F7FCCBBC9 CRC64;
     MALPNGISSK QELLEAQAHV WNHIYSYINS MSLKCAIQLG IPDAIHKHGN PITLSQLADA
     LNINKAKSHG LFRLMRILVH SGFFDKVKVK VKVEGEDEEE EEDAYSLTPA SRLLLRSEPL
     SVAPFALAMS DPVYTETWHH LSEWFRNDAV AAFDTKYGMT FPEYAVADDR LNVLFNEAMA
     CDAGFVNSIL TTECREIFDG LESMVDVGGG TGATAKGIAA AFPGMECTVL DLPNVVGGLK
     GSENLSFVSG DMFDFIPHAD AIFMKFILHD WNDEECVKIL KKCKEAISRS NNSCRKIILV
     EIVMEDEKET HEATETKLFF DMQMLAIITG KERSEKEWGK LFFDAGFTNY KITRVLGLRS
     VIEVFP