FIG. 1.

Growth inhibition by LolA(I93C/F140C). (A and B) E. coli MY201 (wild type) (A) and MY202 (cpx::spc) (B) cells harboring either pSW77, which encodes wild-type LolA (open circles), or pSWIF, which encodes LolA(I93C/F140C) (closed circles), were grown to the early logarithmic phase of growth (OD₆₆₀ = 0.2), and then the expression of FLAG-tagged LolA proteins was induced for 3 h by the addition of various concentrations of arabinose. Cellular growth was then measured as OD₆₆₀. (C and D) Cell lysates were prepared from MY201 (C) and MY202 (D) cells and examined by SDS-PAGE and Western blotting with anti-FLAG peptide antibodies. The amounts of cell lysates examined for LolA(I93C/F140C) were five times higher than those examined for wild-type LolA because the mutant protein was unstable and expressed at a low level.