ID 6OMT_PAPSO Reviewed; 346 AA.
AC Q6WUC1; Q7XB09;
DT 16-APR-2014, integrated into UniProtKB/Swiss-Prot.
DT 05-JUL-2004, sequence version 1.
DT 27-MAR-2024, entry version 62.
DE RecName: Full=(RS)-norcoclaurine 6-O-methyltransferase {ECO:0000303|PubMed:12946416};
DE Short=Ps6OMT {ECO:0000303|PubMed:12946416};
DE EC=2.1.1.128 {ECO:0000269|PubMed:14675446};
GN Name=6OMT {ECO:0000303|PubMed:12946416};
GN Synonyms=PSOMT2 {ECO:0000303|PubMed:14675446};
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], TISSUE SPECIFICITY, DEVELOPMENTAL STAGE, AND
RP INDUCTION BY ELICITOR AND WOUNDING.
RC STRAIN=cv. Marianne;
RX PubMed=12946416; DOI=10.1016/s0031-9422(03)00292-9;
RA Facchini P.J., Park S.U.;
RT "Developmental and inducible accumulation of gene transcripts involved in
RT alkaloid biosynthesis in opium poppy.";
RL Phytochemistry 64:177-186(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA], TISSUE SPECIFICITY, SUBUNIT, FUNCTION,
RP CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=14675446; DOI=10.1046/j.1365-313x.2003.01928.x;
RA Ounaroon A., Decker G., Schmidt J., Lottspeich F., Kutchan T.M.;
RT "(R,S)-Reticuline 7-O-methyltransferase and (R,S)-norcoclaurine 6-O-
RT methyltransferase of Papaver somniferum - cDNA cloning and characterization
RT of methyl transfer enzymes of alkaloid biosynthesis in opium poppy.";
RL Plant J. 36:808-819(2003).
RN [3]
RP TISSUE SPECIFICITY, AND DEVELOPMENTAL STAGE.
RX PubMed=16813579; DOI=10.1111/j.1365-313x.2006.02801.x;
RA Samanani N., Alcantara J., Bourgault R., Zulak K.G., Facchini P.J.;
RT "The role of phloem sieve elements and laticifers in the biosynthesis and
RT accumulation of alkaloids in opium poppy.";
RL Plant J. 47:547-563(2006).
RN [4]
RP TISSUE SPECIFICITY.
RX PubMed=21037103; DOI=10.1105/tpc.110.077958;
RA Lee E.J., Facchini P.;
RT "Norcoclaurine synthase is a member of the pathogenesis-related 10/Bet v1
RT protein family.";
RL Plant Cell 22:3489-3503(2010).
RN [5]
RP FUNCTION.
RX PubMed=22725256; DOI=10.1111/j.1365-313x.2012.05084.x;
RA Desgagne-Penix I., Facchini P.J.;
RT "Systematic silencing of benzylisoquinoline alkaloid biosynthetic genes
RT reveals the major route to papaverine in opium poppy.";
RL Plant J. 72:331-344(2012).
RN [6]
RP FUNCTION.
RX PubMed=23738019; DOI=10.1371/journal.pone.0065622;
RA Pathak S., Lakhwani D., Gupta P., Mishra B.K., Shukla S., Asif M.H.,
RA Trivedi P.K.;
RT "Comparative transcriptome analysis using high papaverine mutant of Papaver
RT somniferum reveals pathway and uncharacterized steps of papaverine
RT biosynthesis.";
RL PLoS ONE 8:E65622-E65622(2013).
RN [7]
RP 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 [8]
RP ACTIVE SITE, AND SUBUNIT.
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).
CC -!- FUNCTION: Involved in the biosynthesis of (S)-coclaurine, the common
CC precursor of all benzylisoquinoline alkaloids such as morphine,
CC sanguinarine, codeine or papaverine. Catalyzes the transfer of a methyl
CC group to norcoclaurine to form coclaurine. Methylates (R,S)-
CC norcoclaurine, (R)-norprotosinomenine, (S)-norprotosinomenine and
CC (R,S)-isoorientaline. {ECO:0000269|PubMed:14675446,
CC ECO:0000269|PubMed:22725256, ECO:0000269|PubMed:23738019}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=norcoclaurine + S-adenosyl-L-methionine = coclaurine + H(+) +
CC S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:19941, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:58481, ChEBI:CHEBI:58482,
CC ChEBI:CHEBI:59789; EC=2.1.1.128;
CC Evidence={ECO:0000269|PubMed:14675446};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:19942;
CC Evidence={ECO:0000305|PubMed:14675446};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=10 uM for (R,S)-norcoclaurine {ECO:0000269|PubMed:14675446};
CC KM=5 uM for (R)-norprotosinomenine {ECO:0000269|PubMed:14675446};
CC KM=5 uM for (S)-norprotosinomenine {ECO:0000269|PubMed:14675446};
CC KM=29 uM for (R,S)-isoorientaline {ECO:0000269|PubMed:14675446};
CC KM=100 uM for S-adenosyl-L-methionine with (R,S)-norcoclaurine as
CC substrate {ECO:0000269|PubMed:14675446};
CC KM=200 uM for S-adenosyl-L-methionine with (R)-norprotosinomenine as
CC substrate {ECO:0000269|PubMed:14675446};
CC KM=260 uM for S-adenosyl-L-methionine with (S)-norprotosinomenine as
CC substrate {ECO:0000269|PubMed:14675446};
CC KM=280 uM for S-adenosyl-L-methionine with (R,S)-isoorientaline as
CC substrate {ECO:0000269|PubMed:14675446};
CC Note=kcat is 0.08 sec(-1) with (R,S)-norcoclaurine as substrate. kcat
CC is 0.02 sec(-1) with (R)-norprotosinomenine as substrate. kcat is
CC 0.02 sec(-1) with (S)-norprotosinomenine as substrate. kcat is 0.03
CC sec(-1) with (R,S)-isoorientaline as substrate.;
CC pH dependence:
CC Optimum pH is 6.0-9.0. {ECO:0000269|PubMed:14675446};
CC Temperature dependence:
CC Optimum temperature is 37-41 degrees Celsius.
CC {ECO:0000269|PubMed:14675446};
CC -!- PATHWAY: Alkaloid biosynthesis; (S)-reticuline biosynthesis; (S)-
CC reticuline from (S)-norcoclaurine: step 1/4. {ECO:0000305}.
CC -!- SUBUNIT: Homodimer (PubMed:14675446, PubMed:29723437). Forms
CC heterodimer with SOMT2 (PubMed:27378283, PubMed:29723437). The
CC heterodimer SOMT2-6OMT possesses 3-O-acetyl-4'-O-demethylpapaveroxine
CC 4'-O-methyltransferase activity, where SOMT2 is the catalytic subunit
CC (PubMed:27378283, PubMed:29723437). {ECO:0000269|PubMed:14675446,
CC ECO:0000269|PubMed:27378283, ECO:0000269|PubMed:29723437}.
CC -!- TISSUE SPECIFICITY: Expressed in buds, stems, leaves and roots, and at
CC lower levels in capsules (PubMed:12946416, PubMed:14675446,
CC PubMed:16813579). Localized to sieve elements of the phloem adjacent or
CC proximal to laticifers (PubMed:16813579, PubMed:21037103).
CC {ECO:0000269|PubMed:12946416, ECO:0000269|PubMed:14675446,
CC ECO:0000269|PubMed:16813579, ECO:0000269|PubMed:21037103}.
CC -!- DEVELOPMENTAL STAGE: Increases rapidly between 1 and 4 days after seed
CC germination. {ECO:0000269|PubMed:12946416,
CC ECO:0000269|PubMed:16813579}.
CC -!- INDUCTION: Up-regulated upon fungal elicitor treatment or wounding.
CC {ECO:0000269|PubMed:12946416}.
CC -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC superfamily. Cation-independent O-methyltransferase family.
CC {ECO:0000305}.
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DR EMBL; AY268894; AAQ01669.1; -; mRNA.
DR EMBL; AY217335; AAP45315.1; -; mRNA.
DR AlphaFoldDB; Q6WUC1; -.
DR SMR; Q6WUC1; -.
DR BRENDA; 2.1.1.128; 4515.
DR SABIO-RK; Q6WUC1; -.
DR UniPathway; UPA00306; UER00441.
DR PRO; PR:Q6WUC1; -.
DR GO; GO:0030786; F:(RS)-norcoclaurine 6-O-methyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0042802; F:identical protein binding; IDA:UniProtKB.
DR GO; GO:0008171; F:O-methyltransferase activity; IDA:UniProtKB.
DR GO; GO:0046983; F:protein dimerization activity; IEA:InterPro.
DR GO; GO:0009821; P:alkaloid biosynthetic process; IDA:UniProtKB.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR CDD; cd02440; AdoMet_MTases; 1.
DR Gene3D; 3.40.50.150; Vaccinia Virus protein VP39; 1.
DR Gene3D; 1.10.10.10; Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain; 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:SF327; ACETYLSEROTONIN O-METHYLTRANSFERASE; 1.
DR PANTHER; PTHR11746; O-METHYLTRANSFERASE; 1.
DR Pfam; PF08100; Dimerisation; 1.
DR Pfam; PF00891; Methyltransf_2; 1.
DR PIRSF; PIRSF005739; O-mtase; 1.
DR SUPFAM; SSF53335; S-adenosyl-L-methionine-dependent methyltransferases; 1.
DR SUPFAM; SSF46785; Winged helix' DNA-binding domain; 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..346
FT /note="(RS)-norcoclaurine 6-O-methyltransferase"
FT /id="PRO_0000428643"
FT ACT_SITE 253
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020,
FT ECO:0000305|PubMed:29723437"
FT BINDING 162
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 165
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 166
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 192
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 215
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01020"
FT BINDING 235..236
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 249
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 250..254
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT BINDING 302
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:Q5C9L7"
FT CONFLICT 150
FT /note="V -> E (in Ref. 1; AAP45315)"
FT /evidence="ECO:0000305"
FT CONFLICT 274
FT /note="G -> V (in Ref. 1; AAP45315)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 346 AA; 38511 MW; 4E12399B79773F73 CRC64;
METVSKIDQQ NQAKIWKQIY GFAESLVLKC AVQLEIAETL HNNVKPMSLS ELASKLPVAQ
PVNEDRLFRI MRYLVHMELF KIDATTQKYS LAPPAKYLLR GWEKSMVDSI LCINDKDFLA
PWHHLGDGLT GNCDAFEKAL GKSIWVYMSV NPEKNQLFNA AMACDTRLVT SALANECKSI
FSDGISTLVD VGGGTGTAVK AISKAFPDIK CTIYDLPHVI ADSPEIPNIT KISGDMFKSI
PSADAIFMKC ILHDWNDDEC IQILKRCKEA LPKGGKVIIV DVVIDMDSTH PYAKIRLTLD
LDMMLNTGGK ERTKEEWKTL FDAAGFASHK VTQISAVQSV IEAYPY
//
