This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:7-methylxanthine N3-methyltransferase. Other names in common use include monomethylxanthine methyltransferase, MXMT, CTS1, CTS2, and S-adenosyl-L-methionine:7-methylxanthine 3-N-methyltransferase.
Ogawa M, Herai Y, Koizumi N, Kusano T, Sano H (2001). "7-Methylxanthine methyltransferase of coffee plants. Gene isolation and enzymatic properties". J. Biol. Chem. 276 (11): 8213–8. PMID11108716. doi:10.1074/jbc.M009480200.
Yoneyama N, Morimoto H, Ye CX, Ashihara H, Mizuno K, Kato M (2006). "Substrate specificity of N-methyltransferase involved in purine alkaloids synthesis is dependent upon one amino acid residue of the enzyme". Mol. Genet. Genomics. 275 (2): 125–35. PMID16333668. doi:10.1007/s00438-005-0070-z.