SOMT2_PAPSO
ID SOMT2_PAPSO Reviewed; 356 AA.
AC I3PLQ6; I3V6A8;
DT 03-JUL-2019, integrated into UniProtKB/Swiss-Prot.
DT 05-SEP-2012, sequence version 1.
DT 03-AUG-2022, entry version 38.
DE RecName: Full=Scoulerine-9-O-methyltransferase 2 {ECO:0000303|PubMed:22535422};
DE Short=PsSOMT2 {ECO:0000303|PubMed:22535422};
DE EC=2.1.1.117 {ECO:0000269|PubMed:22535422};
DE AltName: Full=3-O-acetyl-4'-O-demethylpapaveroxine 4'-O-methyltransferase OMT2 {ECO:0000305};
DE EC=2.1.1.352 {ECO:0000269|PubMed:27378283, ECO:0000269|PubMed:29723437};
DE AltName: Full=O-methyltransferase 2 {ECO:0000303|PubMed:22653730};
GN Name=SOMT2 {ECO:0000303|PubMed:22535422};
GN Synonyms=OMT2 {ECO:0000303|PubMed:29723437},
GN PSMT2 {ECO:0000303|PubMed:22653730};
OS Papaver somniferum (Opium poppy).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; Ranunculales; Papaveraceae; Papaveroideae;
OC Papaver.
OX NCBI_TaxID=3469;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY,
RP BIOPHYSICOCHEMICAL PROPERTIES, AND TISSUE SPECIFICITY.
RX PubMed=22535422; DOI=10.1104/pp.112.194886;
RA Dang T.T., Facchini P.J.;
RT "Characterization of three O-methyltransferases involved in noscapine
RT biosynthesis in opium poppy.";
RL Plant Physiol. 159:618-631(2012).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND TISSUE SPECIFICITY.
RX PubMed=22653730; DOI=10.1126/science.1220757;
RA Winzer T., Gazda V., He Z., Kaminski F., Kern M., Larson T.R., Li Y.,
RA Meade F., Teodor R., Vaistij F.E., Walker C., Bowser T.A., Graham I.A.;
RT "A Papaver somniferum 10-gene cluster for synthesis of the anticancer
RT alkaloid noscapine.";
RL Science 336:1704-1708(2012).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, ACTIVE SITE,
RP SUBUNIT, MUTAGENESIS OF HIS-263, AND POLYMORPHISM.
RC STRAIN=cv. Bea's Choice;
RX PubMed=29723437; DOI=10.1111/tpj.13947;
RA Park M.R., Chen X., Lang D.E., Ng K.K.S., Facchini P.J.;
RT "Heterodimeric O-methyltransferases involved in the biosynthesis of
RT noscapine in opium poppy.";
RL Plant J. 95:252-267(2018).
RN [4]
RP FUNCTION, CATALYTIC ACTIVITY, AND SUBUNIT.
RX PubMed=27378283; DOI=10.1038/ncomms12137;
RA Li Y., Smolke C.D.;
RT "Engineering biosynthesis of the anticancer alkaloid noscapine in yeast.";
RL Nat. Commun. 7:12137-12137(2016).
RN [5]
RP FUNCTION.
RX PubMed=29610307; DOI=10.1073/pnas.1721469115;
RA Li Y., Li S., Thodey K., Trenchard I., Cravens A., Smolke C.D.;
RT "Complete biosynthesis of noscapine and halogenated alkaloids in yeast.";
RL Proc. Natl. Acad. Sci. U.S.A. 115:E3922-E3931(2018).
CC -!- FUNCTION: Methyltransferase involved in the biosynthesis of the
CC benzylisoquinoline alkaloid noscapine (PubMed:22535422,
CC PubMed:29723437, PubMed:27378283, PubMed:29610307). Catalyzes the
CC conversion of (S)-scoulerine to (S)-tetrahydrocolumbamine
CC (PubMed:22535422). The heterodimers SOMT2-SOMT3 and SOMT2-6OMT convert
CC 3-O-acetyl-4'-O-demethylpapaveroxine to 3-O-acetylpapaveroxine, where
CC SOMT2 is the catalytic subunit (PubMed:29723437, PubMed:27378283).
CC {ECO:0000269|PubMed:22535422, ECO:0000269|PubMed:27378283,
CC ECO:0000269|PubMed:29610307, ECO:0000269|PubMed:29723437}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(S)-scoulerine + S-adenosyl-L-methionine = (S)-
CC tetrahydrocolumbamine + H(+) + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:23808, ChEBI:CHEBI:15378, ChEBI:CHEBI:17129,
CC ChEBI:CHEBI:17772, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789;
CC EC=2.1.1.117; Evidence={ECO:0000269|PubMed:22535422};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:23809;
CC Evidence={ECO:0000305|PubMed:22535422};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(S)-S-adenosyl-L-methionine + 3-O-acetyl-4'-O-
CC demethylpapaveroxine = 3-O-acetylpapaveroxine + H(+) + S-adenosyl-L-
CC homocysteine; Xref=Rhea:RHEA:57396, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:141643, ChEBI:CHEBI:141645,
CC ChEBI:CHEBI:142094; EC=2.1.1.352;
CC Evidence={ECO:0000269|PubMed:29723437};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:57397;
CC Evidence={ECO:0000305|PubMed:29723437};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=73.3 uM for (S)-scoulerine {ECO:0000269|PubMed:22535422};
CC KM=69.6 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:22535422};
CC Vmax=145.8 nmol/min/mg enzyme with (S)-scoulerine as substrate
CC {ECO:0000269|PubMed:22535422};
CC Vmax=134 nmol/min/mg enzyme with S-adenosyl-L-methionine as substrate
CC {ECO:0000269|PubMed:22535422};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000305}.
CC -!- SUBUNIT: Homodimer (PubMed:29723437). Forms heterodimers with SOMT3 and
CC 6OMT (PubMed:29723437, PubMed:27378283). The heterodimers SOMT2-SOMT3
CC and SOMT2-6OMT possess 3-O-acetyl-4'-O-demethylpapaveroxine 4'-O-
CC methyltransferase activity, where SOMT2 is the catalytic subunit
CC (PubMed:29723437, PubMed:27378283). Homodimer does not possess 3-O-
CC acetyl-4'-O-demethylpapaveroxine 4'-O-methyltransferase activity
CC (PubMed:29723437). {ECO:0000269|PubMed:27378283,
CC ECO:0000269|PubMed:29723437}.
CC -!- TISSUE SPECIFICITY: Highly expressed in capsules (PubMed:22653730).
CC Expressed is stems (PubMed:22653730, PubMed:22535422). Expressed at low
CC levels in roots (PubMed:22535422). {ECO:0000269|PubMed:22535422,
CC ECO:0000269|PubMed:22653730}.
CC -!- POLYMORPHISM: A single amino acid substitution of Ser-122 in cultivar
CC Bea's Choice (AC I3PLQ6) to Tyr-122 in cultivar Marianne (AC
CC A0A2S1WBY6) abolishes the 3-O-acetyl-4'-O-demethylpapaveroxine 4'-O-
CC methyltransferase activity. {ECO:0000269|PubMed:29723437}.
CC -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC superfamily. Cation-independent O-methyltransferase family. COMT
CC subfamily. {ECO:0000305}.
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DR EMBL; JN185324; AFK73710.1; -; mRNA.
DR EMBL; JQ659000; AFB74612.1; -; Genomic_DNA.
DR EMBL; MH029292; AWJ64116.1; -; mRNA.
DR AlphaFoldDB; I3PLQ6; -.
DR SMR; I3PLQ6; -.
DR EnsemblPlants; RZC84732; RZC84732; C5167_047513.
DR Gramene; RZC84732; RZC84732; C5167_047513.
DR BRENDA; 2.1.1.352; 4515.
DR GO; GO:0030777; F:(S)-scoulerine 9-O-methyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0008171; F:O-methyltransferase activity; IEA:InterPro.
DR GO; GO:0046983; F:protein dimerization activity; IEA:InterPro.
DR GO; GO:0009820; P:alkaloid metabolic 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 1: Evidence at protein level;
KW Alkaloid metabolism; Methyltransferase; S-adenosyl-L-methionine;
KW Transferase.
FT CHAIN 1..356
FT /note="Scoulerine-9-O-methyltransferase 2"
FT /id="PRO_0000447592"
FT ACT_SITE 263
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020,
FT ECO:0000305|PubMed:29723437"
FT BINDING 173
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 176
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 177
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 202
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:I3V6A7"
FT BINDING 225
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT BINDING 245..246
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:I3V6A7"
FT BINDING 259
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:I3V6A7"
FT BINDING 260..264
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT MUTAGEN 263
FT /note="H->A,N: Loss of enzymatic activity."
FT /evidence="ECO:0000269|PubMed:29723437"
SQ SEQUENCE 356 AA; 39087 MW; 2B10D19711DC74FC CRC64;
MEIHLESQEQ EMKYQSQIWN QICGTVDTSV LRCAIQLGIF DAIHNSGKPM ITLTELSSIV
SSPSSSSIEP CNLYRLVRYL SQMDLISIGE CLNEATVSLT GTSKLLLRNQ EKSLIDWVLA
ISCEMMVVVW HELSSSVSTP ADEPPIFQKV HGKNALELAG EFPEWNDLIN NAMTSDTSVT
KPALIQGCGK ILNGVTSLID VGGGHGATMA YIVEAFPHIK GAVIDLPHVV EAAPERPGVE
FISGDIFKSI SNADAVLLKY VLHNWEDTEC VNLLKRCKEA VPADKGKVII MDLVIDDDDN
SILTQAKLSL DLTVMNHGGG RERTKEDWRN LIEMSGFSRH EIIPISAMPS IIVAYP
