MXMT2_COFAR
ID MXMT2_COFAR Reviewed; 384 AA.
AC Q84PP7; A0A096VHZ2; Q8H0G0;
DT 03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2003, sequence version 1.
DT 03-AUG-2022, entry version 46.
DE RecName: Full=Monomethylxanthine methyltransferase 2 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
DE Short=CaMXMT2 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
DE EC=2.1.1.159 {ECO:0000269|PubMed:12527364, ECO:0000269|PubMed:12746542};
DE AltName: Full=7-methylxanthine N-methyltransferase 2 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
DE AltName: Full=Theobromine synthase 2 {ECO:0000303|PubMed:12527364};
DE AltName: Full=Theobromine synthase 3;
GN Name=MXMT2 {ECO:0000303|PubMed:12746542, ECO:0000303|PubMed:25249475};
GN Synonyms=CTS2 {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, AND PATHWAY.
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 [2]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY,
RP BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, AND PATHWAY.
RC TISSUE=Fruit;
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 [3]
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 [4]
RP BIOPHYSICOCHEMICAL PROPERTIES.
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 [5]
RP FUNCTION, AND REVIEW ON CAFFEINE BIOSYNTHESIS.
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 with a lower
CC activity of paraxanthine to caffeine (PubMed:12746542, PubMed:12527364,
CC PubMed:18068204). Does not have 1-N-methylation activity
CC (PubMed:12527364). {ECO:0000269|PubMed:12527364,
CC ECO:0000269|PubMed:12746542, 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:12527364, ECO:0000269|PubMed:12746542};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:24605;
CC Evidence={ECO:0000269|PubMed:12527364, 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=171 uM for 7-methylxanthine {ECO:0000269|PubMed:12527364,
CC ECO:0000269|PubMed:12860386};
CC KM=251 uM for 7-methylxanthine {ECO:0000269|PubMed:12746542};
CC KM=738 uM for paraxanthine {ECO:0000269|PubMed:12746542};
CC KM=14 uM for S-adenosyl-L-methionine {ECO:0000269|PubMed:12746542};
CC pH dependence:
CC Optimum pH is 8. {ECO:0000269|PubMed:12527364,
CC ECO:0000269|PubMed:12860386};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000269|PubMed:12527364,
CC ECO:0000269|PubMed:12746542}.
CC -!- TISSUE SPECIFICITY: Expressed, at low levels, in young leaves, floral
CC buds and immature fruits (grains), but not in old leaves and mature
CC fruits (PubMed:12746542, PubMed:25249475). Highly expressed in
CC developing endosperm and flower buds (PubMed:12527364). Detected in
CC young leaves (PubMed:12527364, PubMed:25249475).
CC {ECO:0000269|PubMed:12527364, ECO:0000269|PubMed:12746542,
CC ECO:0000269|PubMed:25249475}.
CC -!- SIMILARITY: Belongs to the methyltransferase superfamily. Type-7
CC methyltransferase family. {ECO:0000305}.
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DR EMBL; AB054841; BAC43757.1; -; mRNA.
DR EMBL; AB084126; BAC75664.1; -; mRNA.
DR EMBL; JX978512; AFV60440.1; -; Genomic_DNA.
DR EMBL; JX978520; AFV60448.1; -; mRNA.
DR AlphaFoldDB; Q84PP7; -.
DR SMR; Q84PP7; -.
DR KEGG; ag:BAC75664; -.
DR BRENDA; 2.1.1.159; 1559.
DR SABIO-RK; Q84PP7; -.
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..384
FT /note="Monomethylxanthine methyltransferase 2"
FT /id="PRO_0000408305"
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 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 333
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 368
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 343
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT CONFLICT 5
FT /note="E -> A (in Ref. 1; BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 11
FT /note="E -> G (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 22
FT /note="A -> S (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 34
FT /note="F -> V (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 52
FT /note="K -> N (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 153
FT /note="L -> I (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 159
FT /note="V -> F (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 176
FT /note="G -> S (in Ref. 3; AFV60440/AFV60448 and 1;
FT BAC43757)"
FT /evidence="ECO:0000305"
FT CONFLICT 384
FT /note="V -> M (in Ref. 1; BAC43757)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 384 AA; 43472 MW; DC8FC623081280A1 CRC64;
MELQEVLHMN EGEGDTSYAK NASYNLALAK VKPFLEQCIR ELLRANLPNI NKCIKVADLG
CASGPNTLLT VRDIVQSIDK VGQEEKNELE RPTIQIFLND LFQNDFNSVF KLLPSFYRKL
EKENGRKIGS CLISAMPGSF YGRLFPEESM HFLHSCYSVH WLSQVPSGLV IELGIGANKG
SIYSSKASRP PVQKAYLDQF TKDFTTFLRI HSKELFSRGR MLLTCICKVD EYDEPNPLDL
LDMAINDLIV EGHLEEEKLA SFNLPFFTPS AEEVKCIVEE EGSFEILYLE TFKAHYDAGF
SIDDDYPVRS HFQVYGDEHI KAEYVASLIR SVYEPILASH FGEAIMPDLF HRLAKHAAKV
LHLGKGCYNN LIISLAKKPE KSDV
