Fig. 3.
IPTG-dependent complementation of the ΔrasP mutation in AmyE-producing cells containing pHTK315-rasP. ΔrasP mutant bacteria overproducing AmyE and carrying either pHTK315-rasP or the empty vector pHTK315 were grown for 16 h in MBU with 2.5 µg/ml chloramphenicol. Next rasP expression in cells containing pHTK315-rasP, where rasP is transcribed from the IPTG-dependent Pspac promoter, was induced for 4 h by the addition of IPTG to different end concentrations as indicated. ΔrasP mutant bacteria carrying the empty vector pHTK315 were also treated with IPTG as a negative control. Proteins in the growth medium were precipitated with TCA and separated by LDS-PAGE. Protein bands were visualized with the SimplyBlue SafeStain. The AmyE band is indicated with an arrow, and the molecular weights of marker proteins are indicated on the left of the gel (in kDa)