Biology: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 | ||||||||
| |||||||||
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 three related reactions:[1][2]
- REDIRECT Template:Chemical reaction
The first is the final methylation step in the biosynthesis of caffeine from xanthosine via theobromine. The methyl group comes from the cofactor, S-adenosyl methionine (SAM), which becomes S-adenosyl-L-homocysteine (SAH).[3]
The second is the reaction which produces theobromine from 7-methylxanthine, a reaction also catalysed by theobromine synthase:[3]
- REDIRECT Template:Chemical reaction
Finally, the enyme also converts paraxanthine to caffeine:[2]
- REDIRECT Template:Chemical reaction
Caffeine synthase is expressed in the Camellia species irrawadiensis, ptilophylla, and sinensis;[4] the Coffea species arabica,[3][5] and canephora;[6] and in Theobroma cacao.[7]
References
- ↑ "Purification and characterization of caffeine synthase from tea leaves". Plant Physiol. 120 (2): 579–86. June 1999. doi:10.1104/pp.120.2.579. PMID 10364410.
- ↑ 2.0 2.1 Enzyme 2.1.1.160 at KEGG Pathway Database.
- ↑ 3.0 3.1 3.2 "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. May 2003. doi:10.1104/pp.102.019679. PMID 12746542.
- ↑ "Caffeine synthase gene from tea leaves". Nature 406 (6799): 956–7. August 2000. doi:10.1038/35023072. PMID 10984041. http://eprints.gla.ac.uk/126/1/Kato%2CM_2000pdf.pdf.
- ↑ "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. January 2003. doi:10.1016/S0014-5793(02)03781-X. PMID 12527364.
- ↑ "Cloning, expression, crystallization and preliminary X-ray analysis of the XMT and DXMT N-methyltransferases from Coffea canephora (robusta)". Acta Crystallographica Section F 63 (Pt 4): 304–7. April 2007. doi:10.1107/S1744309107009268. PMID 17401201.
- ↑ "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. February 2006. doi:10.1007/s00438-005-0070-z. PMID 16333668.
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