CHOMT_MEDSA
ID CHOMT_MEDSA Reviewed; 372 AA.
AC P93324;
DT 01-MAR-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1997, sequence version 1.
DT 03-AUG-2022, entry version 102.
DE RecName: Full=Isoliquiritigenin 2'-O-methyltransferase;
DE Short=MsCHMT;
DE EC=2.1.1.154 {ECO:0000269|PubMed:1731632, ECO:0000269|PubMed:9055445};
DE AltName: Full=Chalcone O-methyltransferase;
DE Short=ChOMT;
DE AltName: Full=Licodione 2'-O-methyltransferase;
DE Short=MsLMT;
DE EC=2.1.1.65 {ECO:0000269|PubMed:9055445};
OS Medicago sativa (Alfalfa).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; fabids; Fabales; Fabaceae; Papilionoideae; 50 kb inversion clade;
OC NPAAA clade; Hologalegina; IRL clade; Trifolieae; Medicago.
OX NCBI_TaxID=3879;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 2-31, TISSUE SPECIFICITY,
RP DEVELOPMENTAL STAGE, AND INDUCTION.
RC STRAIN=cv. Apollo;
RX PubMed=8281189; DOI=10.1046/j.1365-313x.1993.04060971.x;
RA Maxwell C.A., Harrison M.J., Dixon R.A.;
RT "Molecular characterization and expression of alfalfa isoliquiritigenin 2'-
RT O-methyltransferase, an enzyme specifically involved in the biosynthesis of
RT an inducer of Rhizobium meliloti nodulation genes.";
RL Plant J. 4:971-981(1993).
RN [2]
RP FUNCTION, CATALYTIC ACTIVITY, ACTIVITY REGULATION, BIOPHYSICOCHEMICAL
RP PROPERTIES, SUBUNIT, AND TISSUE SPECIFICITY.
RC STRAIN=cv. Apollo;
RX PubMed=1731632; DOI=10.1016/0003-9861(92)90379-b;
RA Maxwell C.A., Edwards R., Dixon R.A.;
RT "Identification, purification, and characterization of S-adenosyl-L-
RT methionine: isoliquiritigenin 2'-O-methyltransferase from alfalfa (Medicago
RT sativa L.).";
RL Arch. Biochem. Biophys. 293:158-166(1992).
RN [3]
RP FUNCTION, CATALYTIC ACTIVITY, AND TISSUE SPECIFICITY.
RC STRAIN=cv. Moapa;
RX PubMed=9055445; DOI=10.1016/s0031-9422(96)00670-x;
RA Ichimura M., Furuno T., Takahashi T., Dixon R.A., Ayabe S.;
RT "Enzymic O-methylation of isoliquiritigenin and licodione in alfalfa and
RT licorice cultures.";
RL Phytochemistry 44:991-995(1997).
RN [4]
RP X-RAY CRYSTALLOGRAPHY (1.82 ANGSTROMS) IN COMPLEX WITH SUBSTRATES, SUBUNIT,
RP SUBSTRATE-BINDING, AND ACTIVE SITE.
RC STRAIN=cv. Apollo;
RX PubMed=11224575; DOI=10.1038/85029;
RA Zubieta C., He X.-Z., Dixon R.A., Noel J.P.;
RT "Structures of two natural product methyltransferases reveal the basis for
RT substrate specificity in plant O-methyltransferases.";
RL Nat. Struct. Biol. 8:271-279(2001).
CC -!- FUNCTION: Methylates the 2'-hydroxyl of isoliquiritigenin and
CC licodione. Does not methylate narigenin chalcone, caffeic acid or
CC daidzein. Involved in the root nodulation initiation by promoting the
CC biosynthesis of nod-inducing molecules. {ECO:0000269|PubMed:1731632,
CC ECO:0000269|PubMed:9055445}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=isoliquiritigenin + S-adenosyl-L-methionine = 2'-O-
CC methylisoliquiritigenin + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:21608, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC ChEBI:CHEBI:77948, ChEBI:CHEBI:519567; EC=2.1.1.154;
CC Evidence={ECO:0000269|PubMed:1731632, ECO:0000269|PubMed:9055445};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=licodione + S-adenosyl-L-methionine = 2'-O-methyllicodione +
CC H(+) + S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:18521,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC ChEBI:CHEBI:77642, ChEBI:CHEBI:77711; EC=2.1.1.65;
CC Evidence={ECO:0000269|PubMed:9055445};
CC -!- ACTIVITY REGULATION: Inhibited by 1 mM Co(2+), Cu(2+), Zn(2+) or
CC Fe(2+). Non-competitively inhibited by S-adenosyl-L-homocysteine.
CC Competitively inhibited by 2'-O-methylisoliquiritigenin.
CC {ECO:0000269|PubMed:1731632}.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=2.2 uM for isoliquiritigenin {ECO:0000269|PubMed:1731632};
CC KM=17.7 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:1731632};
CC pH dependence:
CC Optimum pH is 9.0. {ECO:0000269|PubMed:1731632};
CC -!- SUBUNIT: Monomer (PubMed:1731632). Homodimer (PubMed:11224575).
CC {ECO:0000269|PubMed:11224575, ECO:0000269|PubMed:1731632}.
CC -!- TISSUE SPECIFICITY: Roots (at protein level). Expressed mainly in
CC roots, and to a lesser extent in root nodules. In the roots, expression
CC is not detected in the root tip or the cells immediately behind the
CC tip, but is detected in tissues starting 1.5-2.0 mm distal to the root
CC tip. Detected in the epidermal and cortical cells of 2 day old roots,
CC with lower levels in vascular tissue. {ECO:0000269|PubMed:1731632,
CC ECO:0000269|PubMed:8281189, ECO:0000269|PubMed:9055445}.
CC -!- DEVELOPMENTAL STAGE: Levels are highest one week after planting.
CC {ECO:0000269|PubMed:8281189}.
CC -!- INDUCTION: By fungal elicitor. {ECO:0000269|PubMed:8281189}.
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; L10211; AAB48059.1; -; mRNA.
DR PIR; T09617; T09617.
DR PDB; 1FP1; X-ray; 1.82 A; D=1-372.
DR PDB; 1FPQ; X-ray; 2.00 A; A=1-372.
DR PDBsum; 1FP1; -.
DR PDBsum; 1FPQ; -.
DR AlphaFoldDB; P93324; -.
DR SMR; P93324; -.
DR KEGG; ag:AAB48059; -.
DR BRENDA; 2.1.1.154; 3078.
DR SABIO-RK; P93324; -.
DR EvolutionaryTrace; P93324; -.
DR GO; GO:0033802; F:isoliquiritigenin 2'-O-methyltransferase activity; IDA:UniProtKB.
DR GO; GO:0030751; F:licodione 2'-O-methyltransferase activity; IDA:UniProtKB.
DR GO; GO:0046983; F:protein dimerization activity; IEA:InterPro.
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 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Methyltransferase;
KW S-adenosyl-L-methionine; Transferase.
FT INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000269|PubMed:8281189"
FT CHAIN 2..372
FT /note="Isoliquiritigenin 2'-O-methyltransferase"
FT /id="PRO_0000204439"
FT ACT_SITE 278
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020,
FT ECO:0000269|PubMed:11224575"
FT BINDING 217
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT BINDING 240
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT BINDING 260
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT BINDING 261
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT BINDING 274
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT HELIX 21..33
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 36..46
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 49..54
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 65..69
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 74..76
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 81..94
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 97..104
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 110..116
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 120..123
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 134..139
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 142..148
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 151..156
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 179..203
FT /evidence="ECO:0007829|PDB:1FP1"
FT TURN 206..209
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 211..216
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 222..230
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 235..240
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 242..245
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 254..258
FT /evidence="ECO:0007829|PDB:1FP1"
FT TURN 261..263
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 268..276
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 277..279
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 282..295
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 296..309
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 317..333
FT /evidence="ECO:0007829|PDB:1FP1"
FT HELIX 340..349
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 353..361
FT /evidence="ECO:0007829|PDB:1FP1"
FT TURN 362..364
FT /evidence="ECO:0007829|PDB:1FP1"
FT STRAND 365..371
FT /evidence="ECO:0007829|PDB:1FP1"
SQ SEQUENCE 372 AA; 41138 MW; 3ADC2D65E33F240E CRC64;
MGNSYITKED NQISATSEQT EDSACLSAMV LTTNLVYPAV LNAAIDLNLF EIIAKATPPG
AFMSPSEIAS KLPASTQHSD LPNRLDRMLR LLASYSVLTS TTRTIEDGGA ERVYGLSMVG
KYLVPDESRG YLASFTTFLC YPALLQVWMN FKEAVVDEDI DLFKNVHGVT KYEFMGKDKK
MNQIFNKSMV DVCATEMKRM LEIYTGFEGI STLVDVGGGS GRNLELIISK YPLIKGINFD
LPQVIENAPP LSGIEHVGGD MFASVPQGDA MILKAVCHNW SDEKCIEFLS NCHKALSPNG
KVIIVEFILP EEPNTSEESK LVSTLDNLMF ITVGGRERTE KQYEKLSKLS GFSKFQVACR
AFNSLGVMEF YK
