Inhibition of PrtA and PrtS by protease inhibitors. The inhibited activities of the purified proteases are expressed as a percentage of the uninhibited activity. Symbols: ⧫, PrtA treated with EDTA; •, PrtS treated with EDTA; ▵, PrtA treated with 1,10-phenantroline; □, PrtS treated with 1,10-phenanthroline.