CKTBS_CAMSB
ID CKTBS_CAMSB Reviewed; 370 AA.
AC A0A6C0WX00;
DT 10-FEB-2021, integrated into UniProtKB/Swiss-Prot.
DT 17-JUN-2020, sequence version 1.
DT 03-AUG-2022, entry version 9.
DE RecName: Full=3,7-dimethylxanthine N-methyltransferase CkTbS {ECO:0000303|PubMed:32193380};
DE EC=2.1.1.159 {ECO:0000269|PubMed:32193380};
DE AltName: Full=Theobromine synthase {ECO:0000303|PubMed:32193380};
DE Short=CkTbS {ECO:0000303|PubMed:32193380};
GN Name=TBS {ECO:0000303|PubMed:32193380};
OS Camellia sinensis var. assamica (Assam tea) (Thea assamica).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC asterids; Ericales; Theaceae; Camellia.
OX NCBI_TaxID=261999;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], X-RAY CRYSTALLOGRAPHY (2.49 ANGSTROMS),
RP FUNCTION, MUTAGENESIS OF HIS-226; THR-241 AND SER-270, CATALYTIC ACTIVITY,
RP PATHWAY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RC STRAIN=cv. Kucha;
RX PubMed=32193380; DOI=10.1038/s41467-020-15324-7;
RA Zhang Y.-H., Li Y.-F., Wang Y., Tan L., Cao Z.-Q., Xie C., Xie G.,
RA Gong H.-B., Sun W.-Y., Ouyang S.-H., Duan W.-J., Lu X., Ding K.,
RA Kurihara H., Hu D., Zhang Z.-M., Abe I., He R.-R.;
RT "Identification and characterization of N9-methyltransferase involved in
RT converting caffeine into non-stimulatory theacrine in tea.";
RL Nat. Commun. 11:1473-1473(2020).
CC -!- FUNCTION: Involved in the biosynthesis of caffeine in cv. Puer
CC (PubMed:32193380). Involved in the biosynthesis of theacrine in cv.
CC Kucha, a caffeine-like xanthine alkaloid with diverse beneficial
CC biological activities including anti-depressive, sedative, and hypnotic
CC activities, improving learning and memory, increasing exercise
CC activity, and preventing nonalcoholic fatty liver disease
CC (PubMed:32193380). Catalyzes the conversion of 7-methylxanthine (7mX)
CC to theobromine but not able to convert paraxanthine to caffeine
CC (PubMed:32193380). {ECO:0000269|PubMed:32193380}.
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:32193380};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:24605;
CC Evidence={ECO:0000269|PubMed:32193380};
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=162.20 uM for 1,3,7-trimethyluric acid
CC {ECO:0000269|PubMed:32193380};
CC Note=kcat is 0.00018 sec(-1) with 1,3,7-trimethyluric acid as
CC substrate. {ECO:0000269|PubMed:32193380};
CC -!- PATHWAY: Alkaloid biosynthesis. {ECO:0000250|UniProtKB:Q9FZN8}.
CC -!- MISCELLANEOUS: Caffeine is catabolized to produce theacrine in Camellia
CC sinensis var. assamica cv. Kucha, but not in cv. Puer.
CC {ECO:0000305|PubMed:32193380}.
CC -!- SIMILARITY: Belongs to the methyltransferase superfamily. Type-7
CC methyltransferase family. {ECO:0000305}.
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DR EMBL; MN163830; QIC50343.1; -; mRNA.
DR PDB; 6LYI; X-ray; 2.49 A; A/B=1-370.
DR PDBsum; 6LYI; -.
DR AlphaFoldDB; A0A6C0WX00; -.
DR SMR; A0A6C0WX00; -.
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 3D-structure; Alkaloid metabolism; Magnesium; Metal-binding;
KW Methyltransferase; S-adenosyl-L-methionine; Transferase.
FT CHAIN 1..370
FT /note="3,7-dimethylxanthine N-methyltransferase CkTbS"
FT /id="PRO_0000451782"
FT BINDING 24
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 24
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 27..31
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 66..67
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 66
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE69"
FT BINDING 67
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A0A6C0WW36"
FT BINDING 72
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000250|UniProtKB:A4GE70"
FT BINDING 102..105
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 264
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 266
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT BINDING 267
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250|UniProtKB:Q9FLN8"
FT SITE 154
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 226
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 270
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 318
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT SITE 333
FT /note="Involved in substrate discrimination"
FT /evidence="ECO:0000250|UniProtKB:Q9FZN8"
FT MUTAGEN 226
FT /note="H->R: Slight theacrine synthase activity which
FT mediates the conversion of 1,3,7-trimethyluric acid to
FT theacrine. Moderate theacrine synthase activity; when
FT associated with I-241 and C-270."
FT /evidence="ECO:0000269|PubMed:32193380"
FT MUTAGEN 241
FT /note="T->I: Slight theacrine synthase activity which
FT mediates the conversion of 1,3,7-trimethyluric acid to
FT theacrine. Moderate theacrine synthase activity; when
FT associated with R-226 and C-270."
FT /evidence="ECO:0000269|PubMed:32193380"
FT MUTAGEN 270
FT /note="S->C: Slight theacrine synthase activity which
FT mediates the conversion of 1,3,7-trimethyluric acid to
FT theacrine. Moderate theacrine synthase activity; when
FT associated with R-226 and I-241."
FT /evidence="ECO:0000269|PubMed:32193380"
FT STRAND 18..23
FT /evidence="ECO:0007829|PDB:6LYI"
FT TURN 24..26
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 29..46
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 48..51
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 55..66
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 73..91
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 97..103
FT /evidence="ECO:0007829|PDB:6LYI"
FT TURN 107..110
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 111..117
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 119..122
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 131..135
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 150..157
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 163..165
FT /evidence="ECO:0007829|PDB:6LYI"
FT TURN 177..180
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 190..214
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 215..226
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 229..232
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 236..254
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 260..263
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 275..284
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 285..298
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 308..331
FT /evidence="ECO:0007829|PDB:6LYI"
FT TURN 332..335
FT /evidence="ECO:0007829|PDB:6LYI"
FT HELIX 336..348
FT /evidence="ECO:0007829|PDB:6LYI"
FT TURN 349..353
FT /evidence="ECO:0007829|PDB:6LYI"
FT STRAND 358..367
FT /evidence="ECO:0007829|PDB:6LYI"
SQ SEQUENCE 370 AA; 41315 MW; FD4519B53271085A CRC64;
MELATMGKVN EVLFMNGGEG EISYAQNSSF TEKVASMAMP ALENAVETLF SKDFHLLPAL
NAADLGCAAG PNTFAVISMI KRMMEKKCRE LYCQTPELQV YLNDLFGNDF NTLFKGLSSE
VVGNKCEEVS CYVMGVPGSF HGRLFPRNSL HLVHSSYSVH WLTQAPKGLT SREGLALNKG
KIYISKTSPP AVKEAYLSQF HEDFTMFLNA RSQEVVPNGC MVLILHGRQS SDPSEMESCF
TWELLAIAIA ELVSQGLIDE DKLDTFNVPS YFPSLEEVKD IVERDGSFTI DHLEGFELDS
LEMQENDKWV RGDKFAKMVR AFTEPIISNQ FGHEIMDKLY DKFTHIVVSD LEAELPKTTS
IILVLSKIVG
