Part:BBa_K4385011
Lead sensor
The lead sensor is composed of lead-inducible promoter and GFP. When there is no lead ion in the environment, PbrR protein is expressed in the presence of Pbr constitutive promoter and binds to its downstream inducible promoter Pbc to repress GFP expression; when lead ion reaches a certain concentration in the environment, PbrR protein chelates lead ion so that it cannot bind to the inducible promoter Pbc and downstream GFP can be expressed and the engineered bacteria can see green fluorescence.
Usage and Biology
cI, from Escherichia coli str.K-12, is a regulator gene in lac operon, located near the promoter lac P and encodes Lac repressor. Lac repressor proteins assemble into active tetramers that bind specifically to the manipulation site (O) in the lac operon and inhibit RNA polymerase recruitment, thereby inhibiting gene transcription. Ptrc, a heterozygous promoter constructed from Trp promoter and Lac promoter, is a strong promoter and can be inhibited by lac repressor. These two are used as part of our dynamic regulatory system.
Characterization
To verify the inhibitory effect of lacI on Ptrc, two genetic circuits were constructed (Fig1). The trends of fluorescence intensity were measured at the indicated time. As shown in the Fig1, the fluorescence of the experimental group was suppressed and stabilized at a low value, while that of the control group increased with time. It demonstrated that Ptrc is normally a strong constitutive promoter, while the Lac repressor encoded by lacI has a significant inhibitor on Ptrc. Sequence and Features
- 10INCOMPATIBLE WITH RFC[10]Illegal PstI site found at 462
- 12INCOMPATIBLE WITH RFC[12]Illegal PstI site found at 462
- 21COMPATIBLE WITH RFC[21]
- 23INCOMPATIBLE WITH RFC[23]Illegal PstI site found at 462
- 25INCOMPATIBLE WITH RFC[25]Illegal PstI site found at 462
- 1000INCOMPATIBLE WITH RFC[1000]Illegal BsaI site found at 253
Illegal BsaI.rc site found at 1394
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