Figure 5. CDA-C1 is catalytically active.
a) A schematic diagram explaining the C domain activity assay. b) HPLC traces and c) mass spectra of reaction assays show that product epoxyl-hexanoyl-serinyl-PCP1 is formed only when wild type CDA-C1 (blue) is present in the reaction mixture. Reactions with CDA-C1 harboring the active-site mutation H157A (red) do not lead to product formation. Expected mass of epoxyl-hexanoyl-serinyl-PCP1 is 12618.3 Da. Expected and observed masses for other carrier protein states are listed in Table S2.