XMT1_COFAR
ID XMT1_COFAR Reviewed; 372 AA.
AC Q9AVK0; A0A096VI00;
DT 03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2001, sequence version 1.
DT 03-AUG-2022, entry version 59.
DE RecName: Full=7-methylxanthosine synthase 1 {ECO:0000303|PubMed:12860386};
DE Short=CmXRS1 {ECO:0000303|PubMed:12860386};
DE EC=2.1.1.158 {ECO:0000269|PubMed:12746542, ECO:0000269|PubMed:12860386};
DE AltName: Full=Methyltransferase-like 3 {ECO:0000303|PubMed:11108716};
DE Short=CaMTL3 {ECO:0000303|PubMed:11108716};
DE AltName: Full=Xanthosine methyltransferase 1 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
DE Short=CaXMT1 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
GN Name=XMT1 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
GN Synonyms=CS1 {ECO:0000303|PubMed:12527364},
GN MTL3 {ECO:0000303|PubMed:11108716}, XRS1 {ECO:0000303|PubMed:12860386};
OS Coffea arabica (Arabian coffee).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC asterids; lamiids; Gentianales; Rubiaceae; Ixoroideae; Gardenieae complex;
OC Bertiereae - Coffeeae clade; Coffeeae; Coffea.
OX NCBI_TaxID=13443;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], AND TISSUE SPECIFICITY.
RC STRAIN=cv. Caturra;
RX PubMed=11108716; DOI=10.1074/jbc.m009480200;
RA Ogawa M., Herai Y., Koizumi N., Kusano T., Sano H.;
RT "7-Methylxanthine methyltransferase of coffee plants. Gene isolation and
RT enzymatic properties.";
RL J. Biol. Chem. 276:8213-8218(2001).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA].
RX PubMed=12527364; DOI=10.1016/s0014-5793(02)03781-x;
RA Mizuno K., Okuda A., Kato M., Yoneyama N., Tanaka H., Ashihara H.,
RA Fujimura T.;
RT "Isolation of a new dual-functional caffeine synthase gene encoding an
RT enzyme for the conversion of 7-methylxanthine to caffeine from coffee
RT (Coffea arabica L.).";
RL FEBS Lett. 534:75-81(2003).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC STRAIN=cv. Catuai; TISSUE=Leaf;
RA Kretschmar J.A., Baumann T.W.;
RT "N-methyltransferases in the genus Coffea.";
RL Submitted (MAR-2002) to the EMBL/GenBank/DDBJ databases.
RN [4]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY,
RP BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, AND PATHWAY.
RX PubMed=12746542; DOI=10.1104/pp.102.019679;
RA Uefuji H., Ogita S., Yamaguchi Y., Koizumi N., Sano H.;
RT "Molecular cloning and functional characterization of three distinct N-
RT methyltransferases involved in the caffeine biosynthetic pathway in coffee
RT plants.";
RL Plant Physiol. 132:372-380(2003).
RN [5]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA], TISSUE SPECIFICITY, GENE FAMILY,
RP AND NOMENCLATURE.
RC STRAIN=cv. Caturra, and cv. ET39;
RX PubMed=25249475; DOI=10.1007/s00425-014-2170-7;
RA Perrois C., Strickler S.R., Mathieu G., Lepelley M., Bedon L., Michaux S.,
RA Husson J., Mueller L., Privat I.;
RT "Differential regulation of caffeine metabolism in Coffea arabica (Arabica)
RT and Coffea canephora (Robusta).";
RL Planta 241:179-191(2015).
RN [6]
RP FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, TISSUE
RP SPECIFICITY, AND PATHWAY.
RX PubMed=12860386; DOI=10.1016/s0014-5793(03)00670-7;
RA Mizuno K., Kato M., Irino F., Yoneyama N., Fujimura T., Ashihara H.;
RT "The first committed step reaction of caffeine biosynthesis: 7-
RT methylxanthosine synthase is closely homologous to caffeine synthases in
RT coffee (Coffea arabica L.).";
RL FEBS Lett. 547:56-60(2003).
RN [7]
RP FUNCTION, REVIEW ON CAFFEINE BIOSYNTHESIS, AND BIOTECHNOLOGY.
RX PubMed=18068204; DOI=10.1016/j.phytochem.2007.10.029;
RA Ashihara H., Sano H., Crozier A.;
RT "Caffeine and related purine alkaloids: biosynthesis, catabolism, function
RT and genetic engineering.";
RL Phytochemistry 69:841-856(2008).
RN [8]
RP FUNCTION, AND BIOTECHNOLOGY.
RX PubMed=25133732; DOI=10.1371/journal.pone.0105368;
RA Jin L., Bhuiya M.W., Li M., Liu X., Han J., Deng W., Wang M., Yu O.,
RA Zhang Z.;
RT "Metabolic engineering of Saccharomyces cerevisiae for caffeine and
RT theobromine production.";
RL PLoS ONE 9:e105368-e105368(2014).
CC -!- FUNCTION: Involved in the biosynthesis of caffeine (PubMed:18068204,
CC PubMed:25133732). Specific for xanthosine and could not use xanthosine
CC 5'-monophosphate (XMP) as substrate. Catalyzes the 7-N-methylation
CC activity of xanthosine, but does not have 1-N- or 3-N-methylation
CC activity (PubMed:18068204). {ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386, ECO:0000269|PubMed:25133732,
CC ECO:0000303|PubMed:18068204}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=S-adenosyl-L-methionine + xanthosine = 7-methylxanthosine + S-
CC adenosyl-L-homocysteine; Xref=Rhea:RHEA:15025, ChEBI:CHEBI:18107,
CC ChEBI:CHEBI:49310, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789;
CC EC=2.1.1.158; Evidence={ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:15026;
CC Evidence={ECO:0000269|PubMed:12746542, ECO:0000269|PubMed:12860386};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:Q9FLN8};
CC Note=Binds 1 Mg(2+) ion per subunit. {ECO:0000250|UniProtKB:Q9FLN8};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=73.7 uM for xanthosine {ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386};
CC KM=13 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386};
CC Vmax=11.8 pmol/sec/mg enzyme toward xanthosine
CC {ECO:0000269|PubMed:12746542, ECO:0000269|PubMed:12860386};
CC pH dependence:
CC Optimum pH is 7.0. {ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:12860386}.
CC -!- TISSUE SPECIFICITY: Expressed in stems, young leaves, floral buds,
CC developing endosperm and immature fruits (grains) (PubMed:25249475).
CC Detected in roots and old leaves, but not in mature fruits
CC (PubMed:25249475). {ECO:0000269|PubMed:11108716,
CC ECO:0000269|PubMed:12746542, ECO:0000269|PubMed:12860386,
CC ECO:0000269|PubMed:25249475}.
CC -!- BIOTECHNOLOGY: Saccharomyces cerevisiae (Yeast) expressing Coffea
CC arabica (coffee) xanthosine methyltransferase (CaXMT1) and Camellia
CC sinensis (tea) caffeine synthase (TCS1) accumulates caffeine.
CC {ECO:0000269|PubMed:25133732}.
CC -!- BIOTECHNOLOGY: Tobacco plants (Nicotiana tabacum cv. Xanthi) expressing
CC CaXMT1, CaMXMT1 and CaDXMT1 accumulate caffeine and become less
CC appetant and toxic for caterpillars cutworms (Spodoptera litura).
CC Caffeine also stimulates endogenous defense mechanisms against other
CC pathogens (e.g. tobacco mosaic virus and Pseudomonas syringae) by
CC triggering the expression of defense-related genes.
CC {ECO:0000269|PubMed:18068204}.
CC -!- SIMILARITY: Belongs to the methyltransferase superfamily. Type-7
CC methyltransferase family. {ECO:0000305}.
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DR EMBL; AB048793; BAB39215.1; -; mRNA.
DR EMBL; AB034699; BAC43755.1; -; mRNA.
DR EMBL; AF494412; AAM18502.1; -; mRNA.
DR EMBL; JX978514; AFV60442.1; -; Genomic_DNA.
DR EMBL; JX978521; AFV60449.1; -; mRNA.
DR AlphaFoldDB; Q9AVK0; -.
DR SMR; Q9AVK0; -.
DR KEGG; ag:BAB39215; -.
DR BRENDA; 2.1.1.158; 1559.
DR SABIO-RK; Q9AVK0; -.
DR Proteomes; UP000515148; Genome assembly.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008168; F:methyltransferase activity; IEA:UniProtKB-KW.
DR GO; GO:0009820; P:alkaloid metabolic process; IEA:UniProtKB-KW.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR Gene3D; 1.10.1200.270; -; 1.
DR Gene3D; 3.40.50.150; -; 1.
DR InterPro; IPR005299; MeTrfase_7.
DR InterPro; IPR042086; MeTrfase_capping.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR PANTHER; PTHR31009; PTHR31009; 1.
DR Pfam; PF03492; Methyltransf_7; 1.
DR SUPFAM; SSF53335; SSF53335; 1.
PE 1: Evidence at protein level;
KW Alkaloid metabolism; Magnesium; Metal-binding; Methyltransferase;
KW Reference proteome; S-adenosyl-L-methionine; Transferase.
FT CHAIN 1..372
FT /note="7-methylxanthosine synthase 1"
FT /id="PRO_0000408302"
FT BINDING 18
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 18
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 21..25
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 61..62
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 61
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 62
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A0A6C0WW36"
FT BINDING 67
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 99..102
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 140..142
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 157..159
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 158..162
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 179
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 261
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 263
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 264
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 316
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 321
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 356
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT SITE 155
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 267
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 331
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT CONFLICT 8
FT /note="R -> Q (in Ref. 5; AFV60442/AFV60449)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 372 AA; 41842 MW; 1C9D2D53263828D2 CRC64;
MELQEVLRMN GGEGDTSYAK NSAYNQLVLA KVKPVLEQCV RELLRANLPN INKCIKVADL
GCASGPNTLL TVRDIVQSID KVGQEKKNEL ERPTIQIFLN DLFPNDFNSV FKLLPSFYRK
LEKENGRKIG SCLIGAMPGS FYSRLFPEES MHFLHSCYCL QWLSQVPSGL VTELGISTNK
GSIYSSKASR LPVQKAYLDQ FTKDFTTFLR IHSEELFSHG RMLLTCICKG VELDARNAID
LLEMAINDLV VEGHLEEEKL DSFNLPVYIP SAEEVKCIVE EEGSFEILYL ETFKVLYDAG
FSIDDEHIKA EYVASSVRAV YEPILASHFG EAIIPDIFHR FAKHAAKVLP LGKGFYNNLI
ISLAKKPEKS DV
