Reaction: feruloyl-CoA + feruloylacetyl-CoA + H2O = 2 CoA + curcumin + CO2
For diagram of reaction click here.
Glossary: curcumin = (1E,6E)-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one
feruloylacetyl-CoA = feruloyl-diketide-CoA
Other name(s): CURS; CURS1 (gene name); CURS2 (gene name); CURS3 (gene name)
Systematic name: feruloyl-CoA:feruloylacetyl-CoA feruloyltransferase (curcumin-forming)
Comments: A polyketide synthase from the plant Curcuma longa (turmeric). Three isoforms exist, CURS1, CURS2 and CURS3. While CURS1 and CURS2 prefer feruloyl-CoA as a starter substrate, CURS3 can accept 4-coumaroyl-CoA equally well  (see EC 126.96.36.199, demethoxycurcumin synthase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
1. Katsuyama, Y., Kita, T., Funa, N. and Horinouchi, S. Curcuminoid biosynthesis by two type III polyketide synthases in the herb Curcuma longa. J. Biol. Chem. 284 (2009) 11160-11170. [PMID: 19258320]
2. Katsuyama, Y., Kita, T. and Horinouchi, S. Identification and characterization of multiple curcumin synthases from the herb Curcuma longa. FEBS Lett 583 (2009) 2799-2803. [PMID: 19622354]
3. Katsuyama, Y., Miyazono, K., Tanokura, M., Ohnishi, Y. and Horinouchi, S. Structural and biochemical elucidation of mechanism for decarboxylative condensation of β-keto acid by curcumin synthase. J. Biol. Chem. 286 (2011) 6659-6668. [PMID: 21148316]