Caffeate O-methyltransferase

In enzymology, a caffeate O-methyltransferase (EC 2.1.1.68) is an enzyme that catalyzes the chemical reaction

S-adenosyl-L-methionine + 3,4-dihydroxy-trans-cinnamate ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + 3-methoxy-4-hydroxy-trans-cinnamate

Thus, the two substrates of this enzyme are S-adenosyl methionine and 3,4-dihydroxy-trans-cinnamate (caffeic acid), whereas its two products are S-adenosylhomocysteine and 3-methoxy-4-hydroxy-trans-cinnamate (ferulic acid).

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:3,4-dihydroxy-trans-cinnamate 3-O-methyltransferase. Other names in common use include caffeate methyltransferase, caffeate 3-O-methyltransferase, and S-adenosyl-L-methionine:caffeic acid-O-methyltransferase. This enzyme participates in phenylpropanoid biosynthesis.

Structural studies[]

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1KYW and 1KYZ.

References[]

• Hahlbrock K; Schaller-Hekeler, B; Knobloch, KH; Wellman, E; Grisebach, H; Hahlbrock, K (1974). "Coordinated changes in enzyme activities of phenylpropanoid metabolism during the growth of soybean cell suspension cultures". Biochim. Biophys. Acta. 362 (3): 417–24. doi:10.1016/0304-4165(74)90137-8. PMID 4472044.
• Poulton JE, Butt VS (1975). "Purification and properties of S-adenosyl-L-methionine: caffeic acid O-methyltransferase from leaves of spinach beet (Beta vulgaris L)". Biochim. Biophys. Acta. 403 (2): 301–14. doi:10.1016/0005-2744(75)90060-1. PMID 241400.
• Shimada M, Kuroda H, Higuchi T (1973). "Evidence for the formation of methoxyl groups of ferulic and sinapic acid in Bambusa by the same O-methyltransferase". Phytochemistry. 12 (12): 2873–2875. doi:10.1016/0031-9422(73)80498-4.