Caffeine synthase

Caffeine synthase
Identifiers
EC number	2.1.1.160
CAS number	155215-94-4
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

Caffeine synthase is a methyltransferase enzyme involved in the caffeine biosynthesis pathway. It is expressed in tea species, coffee species, and cocoa species. The enzyme catalyses the following reactions:^[1]

• S-adenosyl-L-methionine + theobromine $\rightleftharpoons$ S-adenosyl-L-homocysteine + caffeine + H⁺
• S-adenosyl-L-methionine + paraxanthine $\rightleftharpoons$ S-adenosyl-L-homocysteine + caffeine + H⁺
• 7-methylxanthine + S-adenosyl-L-methionine $\rightleftharpoons$ S-adenosyl-L-homocysteine + H⁺ + theobromine

Caffeine synthase is expressed in the Camellia species irrawadiensis, ptilophylla, and sinensis;^[2] the Coffea species arabica,^[3][4] and canephora;^[5] and in Theobroma cacao.^[6]

References

1. Kato M, Mizuno K, Fujimura T, Iwama M, Irie M, Crozier A, Ashihara H (June 1999). "Purification and characterization of caffeine synthase from tea leaves". Plant Physiol. 120 (2): 579–86. doi:10.1104/pp.120.2.579. PMC 59297. PMID 10364410.
2. Kato M, Mizuno K, Crozier A, Fujimura T, Ashihara H (August 2000). "Caffeine synthase gene from tea leaves". Nature. 406 (6799): 956–7. doi:10.1038/35023072. PMID 10984041.
3. Mizuno K, Okuda A, Kato M, Yoneyama N, Tanaka H, Ashihara H, Fujimura T (January 2003). "Isolation of a new dual-functional caffeine synthase gene encoding an enzyme for the conversion of 7-methylxanthine to caffeine from coffee (Coffea arabica L.)". FEBS Lett. 534 (1-3): 75–81. doi:10.1016/S0014-5793(02)03781-X. PMID 12527364.
4. Uefuji H, Ogita S, Yamaguchi Y, Koizumi N, Sano H (May 2003). "Molecular cloning and functional characterization of three distinct N-methyltransferases involved in the caffeine biosynthetic pathway in coffee plants". Plant Physiol. 132 (1): 372–80. doi:10.1104/pp.102.019679. PMC 166982. PMID 12746542.
5. McCarthy AA, Biget L, Lin C, Petiard V, Tanksley SD, McCarthy JG (April 2007). "Cloning, expression, crystallization and preliminary X-ray analysis of the XMT and DXMT N-methyltransferases from Coffea canephora (robusta)". Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 63 (Pt 4): 304–7. doi:10.1107/S1744309107009268. PMC 2330209. PMID 17401201.
6. Yoneyama N, Morimoto H, Ye CX, Ashihara H, Mizuno K, Kato M (February 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. doi:10.1007/s00438-005-0070-z. PMID 16333668.