Figure 3.

traR and traM are not significantly regulated at the level of transcription. Native expression of traR and traM was assessed utilizing lacZ transcriptional or translational fusions integrated into pAoF64/95. The translational fusions disrupt the target genes; the transcriptional fusion leaves an intact copy of the gene upstream of lacZ. Cells were subcultured into AB minimal medium with mannitol (light gray) or mannopine (dark gray) and grown to an approximate OD ₆₀₀ of 0.4 to 0.6. Cells were incubated, then harvested and assayed for β‐galactosidase activity as described in Experimental Procedures. n = 3 and error bars represent standard deviation. Expression of traR in both the presence and absence of TraM was assessed in strain NTL4 harboring pL6480ptraR::lacZ, a recombinant vector encoding traR translationally fused to lacZ, and either (b) pSRKGm (n = 2, standard deviation) or (c) pSRKGm::traM (n = 2, standard deviation). Cells were grown in ABM with increasing concentrations of IPTG to induce increasing amounts of TraM and assessed for expression of TraR as measured by β‐galactosidase activity as described in Experimental Procedures