Accepted name: phenylpropanoylacetyl-CoA synthase
Reaction: (1) feruloyl-CoA + malonyl-CoA = feruloylacetyl-CoA + CO2 + CoA
(2) 4-coumaroyl-CoA + malonyl-CoA = (4-coumaroyl)acetyl-CoA + CO2 + CoA
Glossary: feruloylacetyl-CoA = feruloyl-diketide-CoA
(4-coumaroyl)acetyl-CoA = 4-coumaroyl-diketide-CoA
phenylpropanoylacetyl-CoA = phenylpropanoyl-diketide-CoA
Other name(s): phenylpropanoyl-diketide-CoA synthase; DCS
Systematic name: phenylpropanoyl-CoA:malonyl-CoA phenylpropanoyl-transferase (decarboxylating)
Comments: The enzyme has been characterized from the plant Curcuma longa (turmeric). It prefers feruloyl-CoA, and has no activity with cinnamoyl-CoA.
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]
[EC created 2013]
Accepted name: demethoxycurcumin synthase
Reaction: (1) 4-coumaroyl-CoA + feruloylacetyl-CoA + H2O = 2 CoA + demethoxycurcumin + CO2
(2) 4-coumaroyl-CoA + (4-coumaroyl)acetyl-CoA + H2O = 2 CoA + bisdemethoxycurcumin + CO2
Glossary: demethoxycurcumin = (1E,6E)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-1,4,6-trien-3-one
bisdemethoxycurcumin = (1E,6E)-5-hydroxy-1,7-bis(4-hydroxyphenyl)hepta-1,4,6-trien-3-one
feruloylacetyl-CoA = feruloyl-diketide-CoA
(4-coumaroyl)acetyl-CoA = 4-coumaroyl-diketide-CoA
Other name(s): CURS3
Systematic name: 4-coumaroyl-CoA:feruloylacetyl-CoA feruloyltransferase (demethoxycurcumin-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 (cf. EC, curcumin synthase), CURS3 can accept 4-coumaroyl-CoA equally well [1].
1.  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]
[EC created 2013]