Part:BBa_K1541009

sfGFP under promoter P(Rhl) with riboregulator RR12

This riboregulated promoter construct contains the quorum sensing promoter BBa_I14017 which can be activated in presence of RhlR (BBa_C0171) and C4-HSL, the product of the enzyme RhlI (BBa_C0170), succeeded by the gene for sfGFP. However, the promoter BBa_I14017 by itself shows some leakiness. Together with the ribogegulator 12^[18] the leakiness could be reduced.

Figure 1 Improved signal-to-noise ratio and decreased basal GFP expression (leakiness) due to the use of a riboregulator in combination with a quorum-sensing module. The fluorescence per OD₆₀₀ is shown for the LuxR-system with a complete riboregulator over an inducer-range of 10^-13 M to 10^-5 M (dashed, light blue). An incomplete riboregulator without the trans-activator shows the expected reduced sensitivity towards the inducer (dark blue). As a reference, a system with a non-regulated RBS (BBa_B0034) is shown (light blue). Data points are mean values of triplicate measurements in 96-well microtiter plates 200 min after induction ± standard deviation. For the full data set and kinetics please [http://2014.igem.org/Team:ETH_Zurich/contact contact] us or visit the [http://2014.igem.org/Team:ETH_Zurich/data/raw raw data] page.

Figure 2 Confirmation of the improved signal-to-noise ratio and decreased basal GFP expression (leakiness) due to the use of a riboregulator without (w/o) EcoRI and XbaI restriction sites in combination with a quorum-sensing module. The fluorescence per OD₆₀₀ is shown for the LuxR-system with an unchanged riboregulator (dashed, light blue) and a regulator with a changed sequence due to EcoRI and XbaI restriction site removal (dashed, dark blue). The inducer range covers 10^-13 M to 10^-5 M. As a reference, a system with a non-regulated RBS (BBa_B0034) is shown (light blue). Data points are mean values of triplicate measurements in 96-well microtiter plates 200 min after induction ± standard deviation. For the full data set and kinetics please [http://2014.igem.org/Team:ETH_Zurich/contact contact] us or visit the [http://2014.igem.org/Team:ETH_Zurich/data/raw raw data] page.

Figure 3 Reduced basal GFP expression (leakiness) due to the use of a riboregulator in combination with a quorum-sensing module. The fluorescence per OD₆₀₀ is shown for the Rhl-system (pRhl (BBa_I14017) and RhlR (BBa_C0171)) with a riboregulator over an inducer-range of 10^-4 nM to 10⁴ nM (dashed, light green). A riboregulated Rhl-system with removed EcoRI and XbaI restriction sites shows the expected reduced basal GFP expression and a reduced sensitivity towards the inducer (black). As a reference, the Rhl-system without a riboregulator is shown (light green, non-regulated RBS (BBa_B0034)). Data points are mean values of triplicate measurements in 96-well microtiter plates 200 min after induction ± standard deviation. For the full data set and kinetics please [http://2014.igem.org/Team:ETH_Zurich/contact contact] us or visit the [http://2014.igem.org/Team:ETH_Zurich/data/raw raw data] page.