ID   COMT2_POPTM             Reviewed;         364 AA.
AC   Q41086;
DT   11-APR-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Caffeic acid 3-O-methyltransferase 2;
DE            Short=CAOMT-2;
DE            Short=COMT-2;
DE            EC=2.1.1.68;
DE   AltName: Full=S-adenosysl-L-methionine:caffeic acid 3-O-methyltransferase 2;
GN   Name=OMT2;
OS   Populus tremuloides (Quaking aspen).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; fabids; Malpighiales; Salicaceae; Saliceae; Populus.
OX   NCBI_TaxID=3693;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Hu W.-J., Chiang V.L.C.;
RT   "Nucleotide sequence of an additional member of bispecific caffeic acid/5-
RT   hydroxyferulic acid O-methyltransferase gene family in Populus
RT   tremuloides.";
RL   (er) Plant Gene Register PGR97-035(1997).
CC   -!- FUNCTION: Catalyzes the conversion of caffeic acid to ferulic acid and
CC       of 5-hydroxyferulic acid to sinapic acid. The resulting products may
CC       subsequently be converted to the corresponding alcohols that are
CC       incorporated into lignins.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(E)-caffeate + S-adenosyl-L-methionine = (E)-ferulate + H(+) +
CC         S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:20225, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:29749, ChEBI:CHEBI:57770, ChEBI:CHEBI:57856,
CC         ChEBI:CHEBI:59789; EC=2.1.1.68;
CC   -!- PATHWAY: Aromatic compound metabolism; phenylpropanoid biosynthesis.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
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; U50522; AAB68049.1; -; Genomic_DNA.
DR   PIR; T09780; T09780.
DR   AlphaFoldDB; Q41086; -.
DR   SMR; Q41086; -.
DR   UniPathway; UPA00711; -.
DR   GO; GO:0047763; F:caffeate O-methyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046983; F:protein dimerization activity; IEA:InterPro.
DR   GO; GO:0009809; P:lignin biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
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   3: Inferred from homology;
KW   Lignin biosynthesis; Methyltransferase; S-adenosyl-L-methionine;
KW   Transferase.
FT   CHAIN           1..364
FT                   /note="Caffeic acid 3-O-methyltransferase 2"
FT                   /id="PRO_0000063210"
FT   REGION          161..179
FT                   /note="Substrate binding"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        268
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         129..135
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         207
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         230
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         250
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         251
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT   BINDING         264
FT                   /ligand="S-adenosyl-L-methionine"
FT                   /ligand_id="ChEBI:CHEBI:59789"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
SQ   SEQUENCE   364 AA;  39658 MW;  078C0DE060C1B65F CRC64;
     MGSTGETQMS PAQILDEEAN FALQLISSSV LPMVLKTAIE LDLLEIMAKA GPGALLPPSD
     IASHLPTKNP NAPVMLDRIL RLLASYSILI CSLRDLPDGK VERLYGLASV CKFLTRNEDG
     VSVSPLCLMN QDKVLMESWY HLKDAILEGG IPFNKAYGMT AFEYHGTDPR FNKVFNKGMS
     VHSKMAMKKI LETYKGFEGL ASLVDVGGGT GAVVSTIVSK YPSIKGINFD LPHVIADAPA
     FPGVENVGGD MFVSVPKADA VFMKWICHDW SDEHCLTFLK NCYDALPENG KVILVECILP
     VAPDTSLATK GVMHVDVIML AHNPGGKERT DREFESLARG AGFKGFEVMC CAFNTHVIEF
     RKKA