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Part:BBa_K3883029
Inhibitory effect of lacI on Ptrc
This part contains the trc promoter and the regulator gene lacI. By connecting the sfGFP gene downstream, the inhibitory effect of lacI on Ptrc is verified.
Usage and Biology
lacI, 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.
![](/wiki/images/4/48/LacI_can_regulate_downstream_expression_of_Ptrc.png)
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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