EC - Theobromine synthase

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IntEnz Enzyme Nomenclature


Accepted name:
theobromine synthase
Other names:
monomethylxanthine methyltransferase
S-adenosyl-L-methionine:7-methylxanthine 3-N-methyltransferase
Systematic name:
S-adenosyl-L-methionine:7-methylxanthine N3-methyltransferase



This is the third enzyme in the caffeine-biosynthesis pathway. This enzyme can also catalyse the conversion of paraxanthine into caffeine, although the paraxanthine pathway is considered to be a minor pathway for caffeine biosynthesis [2,3].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. Ogawa, M., Herai, Y., Koizumi, N., Kusano, T. and Sano, H.
    7-Methylxanthine methyltransferase of coffee plants. Gene isolation and enzymatic properties.
    J. Biol. Chem. 276 : 8213-8218 (2001). [PMID: 11108716]
  2. Uefuji, H., Ogita, S., Yamaguchi, Y., Koizumi, N. and Sano, H.
    Molecular cloning and functional characterization of three distinct N-methyltransferases involved in the caffeine biosynthetic pathway in coffee plants.
    Plant Physiol. 132 : 372-380 (2003). [PMID: 12746542]
  3. Yoneyama, N., Morimoto, H., Ye, C. X., Ashihara, H., Mizuno, K. and Kato, M.
    Substrate specificity of N-methyltransferase involved in purine alkaloids synthesis is dependent upon one amino acid residue of the enzyme.
    Mol. Genet. Genomics 275 : 125-135 (2006). [PMID: 16333668]

[EC created 2007]