pBAD/AraC promoter

In our system and measurements we have been using the pBAD/AraC promoter ([http://partsregistry.org/Part:BBa_I0500 BBa_I0500]). This promoter is functioning in our circuit as a jammer for the LasR autoinducing loop. It is also used to induce the cI autoinducing loops during the measurements. That is why, in our opinion, characterizing this promoter in a way that would show us the activity rate not only depending on concentration of arabinose, but also in a dynamic way - over time - is crucial. The measurements were done as described in protocol.

Below you will find four figures representing the results of our measurements.

Figure 1a. Cells carrying a pSB1C3 plasmid with pBAD/AraC-GFP-DT construct, induced at time=0h.

Figure 1b. Wild type cells, induced at time=0h.

Figure 2a. Cells carrying a pSB1C3 plasmid with pBAD/AraC-GFP-DT construct, induced at time=0h.

Figure 2b. Wild type cells, induced at time=0h.

The pBAD/AraC promoter exhibits a dynamic response in a range of arabinose concentrations. Both the speed of activation and its strength are higher with higher concentrations of the inducing molecule. Because of that this promoter is a good choice for constructs producing transcription factors that induce other measured promoters. It is also a good choice for a promoter used in a jammer construct, as its response is predictable and can be very strong.