MXMT1_COFAR
ID MXMT1_COFAR Reviewed; 378 AA.
AC Q9AVJ9; A0A096VHZ7; Q8H0G5; Q8RVM1;
DT 03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2001, sequence version 1.
DT 03-AUG-2022, entry version 61.
DE RecName: Full=Monomethylxanthine methyltransferase 1 {ECO:0000303|PubMed:25249475};
DE Short=CaMXMT1 {ECO:0000303|PubMed:25249475};
DE EC=2.1.1.159 {ECO:0000269|PubMed:11108716, ECO:0000269|PubMed:12746542};
DE AltName: Full=7-methylxanthine N-methyltransferase 1 {ECO:0000305};
DE AltName: Full=Theobromine synthase 1 {ECO:0000303|PubMed:12527364};
GN Name=MXMT1 {ECO:0000303|PubMed:25249475};
GN Synonyms=CTS1 {ECO:0000303|PubMed:12527364};
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], FUNCTION, CATALYTIC ACTIVITY,
RP BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, SUBCELLULAR LOCATION,
RP AND PATHWAY.
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].
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 [3]
RP NUCLEOTIDE SEQUENCE [MRNA], AND BIOPHYSICOCHEMICAL PROPERTIES.
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 [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, 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).
CC -!- FUNCTION: Involved in the biosynthesis of caffeine. Catalyzes the
CC conversion of 7-methylxanthine (7mX) to theobromine and of paraxanthine
CC to caffeine. Has a 5-fold preference for 7mX.
CC {ECO:0000269|PubMed:11108716, ECO:0000269|PubMed:12746542,
CC ECO:0000303|PubMed:18068204}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=7-methylxanthine + S-adenosyl-L-methionine = H(+) + S-
CC adenosyl-L-homocysteine + theobromine; Xref=Rhea:RHEA:24604,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:28946, ChEBI:CHEBI:48991,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789; EC=2.1.1.159;
CC Evidence={ECO:0000269|PubMed:11108716, ECO:0000269|PubMed:12746542};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:24605;
CC Evidence={ECO:0000269|PubMed:11108716, ECO:0000269|PubMed:12746542};
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=50 uM for 7-methylxanthine {ECO:0000269|PubMed:11108716};
CC KM=148 uM for 7-methylxanthine {ECO:0000269|PubMed:12746542};
CC KM=458 uM for paraxanthine {ECO:0000269|PubMed:12746542};
CC KM=11.9 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:11108716};
CC KM=12 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:12746542};
CC Vmax=7.14 pmol/min/ug enzyme toward 7-methylxanthine
CC {ECO:0000269|PubMed:11108716};
CC Vmax=7.94 pmol/min/ug enzyme toward S-adenosyl-L-methionine
CC {ECO:0000269|PubMed:11108716};
CC pH dependence:
CC Optimum pH is 7.5. {ECO:0000269|PubMed:11108716,
CC ECO:0000269|PubMed:12527364, ECO:0000269|PubMed:12746542};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000269|PubMed:11108716,
CC ECO:0000269|PubMed:12746542}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:11108716}.
CC -!- TISSUE SPECIFICITY: Expressed, at low levels, in stems, young leaves,
CC floral buds and immature fruits (grains), but not in roots, old leaves
CC and mature fruits. {ECO:0000269|PubMed:11108716,
CC ECO:0000269|PubMed:12746542, ECO:0000269|PubMed:25249475}.
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; AB048794; BAB39216.1; -; mRNA.
DR EMBL; AF494413; AAM18503.1; -; mRNA.
DR EMBL; AB034700; BAC43756.1; -; mRNA.
DR EMBL; AF494411; AAM18501.1; -; mRNA.
DR EMBL; JX978511; AFV60439.1; -; Genomic_DNA.
DR EMBL; JX978519; AFV60447.1; -; mRNA.
DR AlphaFoldDB; Q9AVJ9; -.
DR SMR; Q9AVJ9; -.
DR KEGG; ag:BAB39216; -.
DR BRENDA; 2.1.1.159; 1559.
DR BRENDA; 2.1.1.160; 1559.
DR SABIO-RK; Q9AVJ9; -.
DR Proteomes; UP000515148; Genome assembly.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
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; Cytoplasm; Magnesium; Metal-binding;
KW Methyltransferase; Reference proteome; S-adenosyl-L-methionine;
KW Transferase.
FT CHAIN 1..378
FT /note="Monomethylxanthine methyltransferase 1"
FT /id="PRO_0000408303"
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 60..61
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 60
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 61
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A0A6C0WW36"
FT BINDING 66
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 98..101
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 139..141
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 156..158
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 157..161
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 178
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 260
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 262
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 327
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 362
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT SITE 154
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 266
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 337
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT CONFLICT 11
FT /note="E -> G (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 22
FT /note="A -> S (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 34
FT /note="F -> V (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 52
FT /note="K -> N (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 153
FT /note="L -> I (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 159
FT /note="V -> F (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 176
FT /note="G -> S (in Ref. 2; AAM18503)"
FT /evidence="ECO:0000305"
FT CONFLICT 231
FT /note="E -> V (in Ref. 3; BAC43756)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 378 AA; 42747 MW; F36184F3D5243809 CRC64;
MELQEVLHMN EGEGDTSYAK NASYNLALAK VKPFLEQCIR ELLRANLPNI NKCIKVADLG
CASGPNTLLT VRDIVQSIDK VGQEEKNELE RPTIQIFLND LFQNDFNSVF KLLPSFYRKL
EKENGRKIGS CLISAMPGSF YGRLFPEESM HFLHSCYSVH WLSQVPSGLV IELGIGANKG
SIYSSKGCRP PVQKAYLDQF TKDFTTFLRI HSKELFSRGR MLLTCICKVD EFDEPNPLDL
LDMAINDLIV EGLLEEEKLD SFNIPFFTPS AEEVKCIVEE EGSCEILYLE TFKAHYDAAF
SIDDDYPVRS HEQIKAEYVA SLIRSVYEPI LASHFGEAIM PDLFHRLAKH AAKVLHMGKG
CYNNLIISLA KKPEKSDV
