PCS1_CAMPL
ID PCS1_CAMPL Reviewed; 365 AA.
AC Q2HXI6;
DT 10-FEB-2021, integrated into UniProtKB/Swiss-Prot.
DT 21-MAR-2006, sequence version 1.
DT 03-AUG-2022, entry version 36.
DE RecName: Full=7-methylxanthine methyltransferase PCS1 {ECO:0000303|PubMed:16333668};
DE Short=TCS1c {ECO:0000303|PubMed:26773541};
DE EC=2.1.1.159 {ECO:0000269|PubMed:16333668, ECO:0000269|PubMed:30303011};
DE AltName: Full=Theobromine synthase PCS1 {ECO:0000303|PubMed:16333668};
GN Name=PCS1 {ECO:0000303|PubMed:16333668};
GN Synonyms=TCS1C {ECO:0000303|PubMed:26773541};
OS Camellia ptilophylla (Cocoa tea).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC asterids; Ericales; Theaceae; Camellia.
OX NCBI_TaxID=319931;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, MUTAGENESIS OF HIS-221; SER-225 AND
RP GLU-232, CATALYTIC ACTIVITY, PATHWAY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=16333668; DOI=10.1007/s00438-005-0070-z;
RA Yoneyama N., Morimoto H., Ye C.-X., Ashihara H., Mizuno K., Kato M.;
RT "Substrate specificity of N-methyltransferase involved in purine alkaloids
RT synthesis is dependent upon one amino acid residue of the enzyme.";
RL Mol. Genet. Genomics 275:125-135(2006).
RN [2]
RP GENE FAMILY, AND NOMENCLATURE.
RX PubMed=26773541; DOI=10.1016/j.plaphy.2015.12.020;
RA Jin J.-Q., Yao M.-Z., Ma C.-L., Ma J.-Q., Chen L.;
RT "Natural allelic variations of TCS1 play a crucial role in caffeine
RT biosynthesis of tea plant and its related species.";
RL Plant Physiol. Biochem. 100:18-26(2016).
RN [3]
RP FUNCTION, AND CATALYTIC ACTIVITY.
RX PubMed=30303011; DOI=10.1021/acs.jafc.8b03433;
RA Jin J.Q., Chai Y.F., Liu Y.F., Zhang J., Yao M.Z., Chen L.;
RT "Hongyacha, a naturally caffeine-free tea plant from Fujian, China.";
RL J. Agric. Food Chem. 66:11311-11319(2018).
CC -!- FUNCTION: Involved in the biosynthesis of caffeine (PubMed:16333668,
CC PubMed:30303011). Catalyzes the conversion of 7-methylxanthine (7mX) to
CC theobromine, and, to some extent, the conversion of paraxanthine to
CC caffeine, but seems not able to convert theobromine to caffeine
CC (PubMed:16333668, PubMed:30303011). {ECO:0000269|PubMed:16333668,
CC ECO:0000269|PubMed:30303011}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=1,7-dimethylxanthine + S-adenosyl-L-methionine = caffeine +
CC H(+) + S-adenosyl-L-homocysteine; Xref=Rhea:RHEA:10280,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:25858, ChEBI:CHEBI:27732,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789;
CC Evidence={ECO:0000269|PubMed:16333668};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:10281;
CC Evidence={ECO:0000250|UniProtKB:Q2HXL9};
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:16333668, ECO:0000269|PubMed:30303011};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:24605;
CC Evidence={ECO:0000269|PubMed:16333668};
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=85 uM for 7-methylxanthine (in the presence of 50 uM S-adenosyl-L-
CC methionine) {ECO:0000269|PubMed:16333668};
CC pH dependence:
CC Optimum pH is 8.0-8.5. {ECO:0000269|PubMed:16333668};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000269|PubMed:16333668}.
CC -!- SIMILARITY: Belongs to the methyltransferase superfamily. Type-7
CC methyltransferase family. {ECO:0000305}.
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DR EMBL; AB207817; BAE79732.1; -; mRNA.
DR AlphaFoldDB; Q2HXI6; -.
DR SMR; Q2HXI6; -.
DR BRENDA; 2.1.1.160; 8605.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008168; F:methyltransferase activity; 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 Magnesium; Metal-binding; Methyltransferase; Transferase.
FT CHAIN 1..365
FT /note="7-methylxanthine methyltransferase PCS1"
FT /id="PRO_0000451790"
FT BINDING 19
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 19
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 22..26
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 97..100
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 134..136
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 151..153
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 152..156
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 173
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 259
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 262
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT SITE 149
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 221
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000269|PubMed:16333668"
FT SITE 265
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 313
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 328
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT MUTAGEN 221
FT /note="H->R: Normal theobromine synthase activity.
FT Increased caffeine synthase activity with paraxanthine as
FT substrate."
FT /evidence="ECO:0000269|PubMed:16333668"
FT MUTAGEN 225
FT /note="S->C: Normal theobromine synthase activity. Slighty
FT decreased caffeine synthase activity with paraxanthine as
FT substrate."
FT /evidence="ECO:0000269|PubMed:16333668"
FT MUTAGEN 232
FT /note="E->Q: Normal theobromine synthase activity. Slighty
FT decreased caffeine synthase activity with paraxanthine as
FT substrate."
FT /evidence="ECO:0000269|PubMed:16333668"
SQ SEQUENCE 365 AA; 40926 MW; 1F0DAE1242DEDE71 CRC64;
MGKVNEVLFM NRGEGEISYA QNSAFTQKVA SMAMPALENA VETLFSKDFH LLQALTAADL
GCAAGPNTFA VISTIKRMME KKCRELYCQT LELQVYLNDL FGNDFNTLFK GLSSQVVGNK
CEEVSCYVMG VPGSFHGRLF PRNSLHLVHS SYSVHWLTQA PKGLTSREGL ALNKGKIYIS
KTSPPVVKKA YLSQFHEDFT MFLNARSQEV VPNGCMVLIL HGRQSSDPSE MESCFTWELL
AIAIAELVSQ GLIDKDKLDT FNVPSYWPSL EEVKDIVERD GSFTIDHLEG FELDSLEMQE
DDKWVRGDKF AKMVRAFTEP IISNQFGQEI MDKLYDKFTH ILVSDLEAEL PKTTSIILVL
SKIVG
