Part:BBa_K2510020
T7 - O-P22c2 - O-HKcI promoter
This promoter is a dually repressible promoter.
Usage and Biology
This dually repressible promoter allows for the creation of a logic-gate, specifically a NOR-Gate. Indeed, gene expression will occur only when the two repressor are either expressed but non-functioning or absent from the system altogether. To design such a promoter, we combined insulated promoter that had been previously tested to form repressible promoter to create new dually repressible promoters that can be used to form a logic gate. The promoter was tested both in vivo and in a cell-free environment using repressors that were caged with a photoswitchable fluorescent protein.
In vivoTesting
Promoters were tested in vivo in 3 different strains of E. coli. The results show that the system is not as efficient as it could be, and insularity of promoter elements is still a long way off.
Figure 5: Data obtained from flow cytometry experiments. The number showed is the mean of medians for 3 different experiments.
Cell-free testing
This synthetic operator was part of the library that we used to test the activity of repressors caged with Dronpa
Figure 1 : the experiment conducted with the repressors caged with Dronpa
Figure 2 : An over view of the results of the cell-free experiment. Each
promoter was tested with its cognate repressors. Our results show that in 90% of our
constructs caging the repressors with Dronpa has increased the repression strength.
We have also obtained a wide linear range of repression strength-indicated by the red
slope-.
Figure 3: detailed Results of the cell-free experiment. Each promoter was
tested with its cognate repressors. Top: Testing with TetR caged with
either wt-Dronpa (BBa_K2510108) or a mutated version(BBa_K2510109)Middle:
Testing with P22c2 caged with either wt-Dronpa (BBa_K2510112) or a mutated
version(BBa_K2510113).Bottom: Testing with HKcI caged with either wt-
Dronpa (BBa_K2510110) or a mutated version(BBa_K2510111)
Figure 4: the wtDronpa has a better control of HKC1 and C2P22 repressors while the mutDronpa has a better control of TetR repressors
Sequence and Features
| None |