Part:BBa_K3161003
Pc-RBS-PbrR-W
PbrR protein expressed under the control of weak Anderson promoter J23117
Usage and Biology
Aim of experiment
PbrR is a lead-binding protein in the form of dimer. In the presence of lead ions, Pb2+ binds to the PbrR protein dimer, resulting in a conformational change that causes lead sensitive promoters to begin transcription. In order to design biosensor that can detect different concentration of lead threshold, we designed a series of parts expressing PbrR protein under the control of different strength constitutive promoter, including strong promoter J23100, medium promoter J23106 and weak promoter J23117.
Results
PbrR-W (K3161003) was expressed under the control of weak Anderson promoter J23117. We measured the protein expression of three kinds of PbrR, and the results were as follows As can be seen from figure 6, PbrR protein expressed under different strengths of constitutive promoters J23100(S), J23106 (M) and J23117 (W). The order of expression intensity is S>M>W. This also explains why biosensors constructed in S, M and W have different tolerance to lead. As shown in figure 2, biosensors containing PbrR-S were more resistant to Pb2+, while biosensors composed of PbrR-M (K3161002) or PbrR-W(K3161003) were less resistant to high concentrations of lead (5ppm and 10ppm), indicating that PbrR expression played a role in the adsorption of lead by cells.
Fig1. PbrR protein expression under different strength of Anderson promoters in SDS-PAGE. S, strong Anderson promoter J23100, M, medium promoter, J23106, W, weak promoter J23117.
Fig2. Effect of PbrR protein expression under the control of different strength of promoters on bacteria resistance to lead. S, strong Anderson promoter J23100, M, medium promoter, J23106, W, weak promoter J23117.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 7
Illegal NheI site found at 30 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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