Figure 1. Enzymatic activities of PRAC and HyPRE from different pathogens.

Optimal reaction conditions consisted of 10 µg of the enzyme and 20 mM of substrate in specific buffers during 30 min at 37°C. (A) Percent of L- or D-Pro racemization in NaOAc, pH 6; (B) Percent of OH-L-Pro or OH-D-Pro epimerization in TE, pH 8. P. aeruginosa (SC) and B. cenocepacia (CT) recombinant proteins whose sequences lack one of the two Cys catalytic residues do not display any PRAC or HyPRE activities.