Fig. 2.

In vitro degradation of PerR by LonA. (A) Mass spectra of untreated (Upper) and H₂O₂-treated (Lower) PerR. The original molecular mass of the PerR monomer is 16,292 Da, and single oxidation increases it to 16,308 Da; this increase corresponds to the molecular mass of single oxygen (16 Da). All purification steps were performed in aerobic conditions. (B) Both untreated (Upper) and H₂O₂-treated (Lower) PerR are degraded by B. subtilis LonA in the presence of an ATP-regenerating system; however, PerR was not detectably degraded by E. coli Lon in vitro.