FIG 5.

Growth of E. coli BL21(DE3) cells containing relevant pairs of toxic effector and immunity proteins. A growth curve (A, C, and E) and semiquantitative analysis of surviving bacteria at 2 h postinduction (B, D, and F) are shown for each set of toxic effector/immunity strain expression experiments. (A and B) E. coli BL21(DE3) containing the rhs1-CT–rhs1I T6SS effector/immunity cognate pair (pAL1234+pAL1282). (C and D) E. coli BL21(DE3) cells containing the rhs2-CT–rhs2I T6SS effector/immunity cognate pair (pAL1237+pAL1283). (E and F) E. coli BL21(DE3) cells containing the lysM-lysMI T6SS effector/immunity cognate pair (pAL1275+pAL1331). Cultures were grown for 1 h prior to the addition (designated by arrows in panels A, C, and E) of buffer (uninduced), 5 mM IPTG, 0.4% l-arabinose, or 5 mM IPTG and 0.4% l-arabinose and then grown for a further 7 h with optical density measurements taken every 1 h. Error bars represent standard errors of the means of three independent experiments performed in triplicate. Images are representative of three independent experiments.