Expression, purification and crystallization of a plant type III polyketide synthase that produces diarylheptanoids

Curcuminoid synthase (CUS) from Oryza sativa is a plant-specific type III polyketide synthase that catalyzes the one-pot formation of bisdemethoxycurcumin by the condensation of two molecules of 4-coumaroyl-CoA and one molecule of malonyl-CoA. Recombinant CUS was expressed in Escherichia coli and crystallized by the sitting-drop vapour-diffusion method. The crystals belonged to space group P2(1), with unit-cell parameters a=72.7, b=97.2, c=126.2 A, alpha=gamma=90.0, beta=103.7 degrees. A diffraction data set was collected in-house to 2.5 A resolution.