FIG 7.

Stability of the Lon substrate proteins in LVS and its protease-deficient mutants. Each pEDL17 derivative containing the coding region of clpX (A), FTL578 (B), FTL663 (C), or FTL1957 (D) behind a tetracycline-inducible promoter was transformed in LVS (WT), ST1118 (ΔclpP), or ST1120 (Δlon). A cell lysate of each resulting strain was prepared from the culture grown in the absence (−) or presence (+) of the inducer. The recombinant protein from the episomal copy of each target gene was detected by immunoblotting as described in Materials and Methods. The protein encoded by endogenous (chromosomal) FTL1017 was detected with an antiserum as a loading control.