Figure 1.

Diagram of ectopic expression constructs. The four ectopic expression constructs characterized in this study are indicated. All have a linked antibiotic resistance cassette (Ab^R) to facilitate selection during integration into the genome by natural transformation. The gene encoding a transcription factor (lacIq or araC) and the promoter (P_tac or P_BAD) required for inducible gene regulation are indicated. The presence of a theophylline-dependent riboswitch is demarcated by a loop before the gene of interest (gene x). For details on how these constructs were assembled, see Fig. S1.