Our project is centered around creating a working toggle switch that flips between two different states when presented with certain chemicals. We started with a simple switch that utilizes two inhibitor proteins, LacI and TetR, which bind to sites on the pLac and pTet promoters, respectively. When bound to these promoters transcription is not able to proceed; any genes downstream of the promoter are effectively off. However, certain chemicals (IPTG in the case of LacI) will prevent these inhibitor proteins from binding to their respective promoters, allowing transcription of genes to continue constituively. Our design places a fluorescent and inhibitor gene downstream of one of these promoters, as shown in the diagram below. If these parts work as intended, then side 1, when running, should turn off side 2, and vice versa. By adding the chemicals IPTG or ATc, we can turn off the inhibitor proteins of one side, allowing the other side to become dominant.
"
