Fig. 4: Comparison of the active site topologies in the crystal structures and the activities of various PECPS mutants.

a Wild type PECPS. b MsCHS. c CUS. d PECPS F340W. e PECPS A210E. f PECPS N199L. g PECPS N199F. h HPLC chromatograms of the products obtained from the enzymatic reactions of wild type PECPS and its mutants using 4-hydroxyphenylpropionyl-CoA and malonyl-CoA as substrates. Chromatograms were recorded at 295 nm. i Relative activities for the formation of tetrahydrobisdemethoxycurcumin (1) between wild type PECPS and its mutants. Activities are percentages of tetrahydrobisdemethoxycurcumin (1) production relative to that of wild type PECPS. Data represent the mean ± SD (n = 3). PDB ID: a 7FFA. b 3ALE. c 1CGK. d 7FFI. e 7FFC. f 7FFH. g 7FFG.