Accepted name: bisdemethoxycurcumin synthase
Reaction: 2 4-coumaroyl-CoA + malonyl-CoA + H2O = 3 CoA + bisdemethoxycurcumin + 2 CO2
Glossary: bisdemethoxycurcumin = (1E,6E)-5-hydroxy-1,7-bis(4-hydroxyphenyl)hepta-1,4,6-trien-3-one
Other name(s): CUS; curcuminoid synthase (ambiguous)
Systematic name: 4-coumaroyl-CoA:malonyl-CoA 4-coumaryltransferase (bisdemethoxycurcumin-forming)
Comments: A polyketide synthase characterized from the plant Oryza sativa (rice) that catalyses the formation of the C6-C7-C6 diarylheptanoid scaffold of bisdemethoxycurcumin. Unlike the process in the plant Curcuma longa (turmeric), where the conversion is carried out via a diketide intermediate by two different enzymes (EC, phenylpropanoylacetyl-CoA synthase and EC, curcumin synthase), the diketide intermediate formed by this enzyme remains within the enzyme’s cavity and is not released to the environment.
1.  Morita, H., Wanibuchi, K., Nii, H., Kato, R., Sugio, S. and Abe, I. Structural basis for the one-pot formation of the diarylheptanoid scaffold by curcuminoid synthase from Oryza sativa. Proc. Natl. Acad. Sci. USA 107 (2010) 19778–19783. [PMID: 21041675]
[EC created 2013]
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]