FIG. 4.

Sensitivity of TnMK to endogenously produced or exogenously added EtpM-ColV fusion. (A) CFU of TnMK/pEtpM167-ColV grown on an LB-AMP plate supplemented with glucose (Glc +) or arabinose (Ara +) without (pcvi −) or with (pcvi +) coexpression of ColV immunity protein. (B) Crude extracts containing ColV (lanes 1 and 3) or ColV and EtpM-ColV (lanes 2 and 4) were resolved on 0.1% sodium dodecyl sulfate-20% polyacrylamide gels. The gels were then incubated for 30 min in a 50% methanol-10% acetic acid solution, washed twice with 250 ml of sterile water, and placed onto LB plates. Soft agar containing the wild-type MC4100A strain (lanes 1 and 2) or the sdaC mutant (lanes 3 and 4) was poured on the top, and the petri dishes were incubated overnight at 37°C. The migration positions of ColV and EtpM-ColV are indicated.