The present invention provides an enzymatic means for the biosynthetic production of caffeine. The present invention provides biosynthetic methods for production of caffeine comprising: providing guanine, a guanine deaminase, at least one methyl transferase, and a methyl donor contacting the guanine with the gtheuanine deaminase to produce xanthine contacting the xanthine with the methyl transferase and a methyl donor, under conditions wherein the xanthine is methylated, to produce a monomethylxanthine contacting the monomethylxanthine with the methyl transferase and a methyl donor, under conditions wherein the monomethylxanthine is methylated, to produce a dimethylxanthine and contacting the dimethylxanthine with the methyl transferase and a methyl donor, under conditions wherein the dimethylxanthine is methylated, to produce caffeine (i.e., 1,3,7-trimethylxanthine).
