Device

Part:BBa_K2936019

Designed by: Weng Jiaqi   Group: iGEM19_ZJUT-China   (2019-10-10)


pBAD-lacZ alpha-pFrmR-AraC-CAT

The AraC protein would binds to AraBAD promoter, inhibiting its expression. At this time, only CAT gene is expressed in the pathway, then the culture added with TMB will turns blue. And when the pFrmR turn off, without repressor protein the AraBAD promoter activate, the LacZɑ expresses and the culture with ONPG would turns orange.Those parts form a bidirectional switch determined by formaldehyde concentration.

Short description

A bilateral switching element.

Description

We chosen the pFrmR, an engineered formaldehyde-inducible promoter, to expresses the genes when the concentration of CHOH in the environment reach a certain level. However, when testing the sensitive concentration of the FrmR promoter, we found that for the system cultured overnight, there was no obvious difference in the presence of with or without formaldehyde. That is to say, the promoter leakage was relatively serious. To control the genes to start or stop being expressed, we need a regulatory system. In consideration of the lactose operon has been used in light-dependent controlled lysis groups, Ara Operon is used in our pathways. The AraC protein would binds to AraBAD promoter, inhibiting its expression. At this time, only CAT gene is expressed in the pathway, then the culture added with TMB will turns blue. And when the pFrmR turn off, without repressor protein the AraBAD promoter activate, the LacZ alpha expresses and the culture with ONPG would turns orange.

Source

Escherichia coli and Parageobacillus.

Design consideration

The pBAD-LacZ alpha is the reverse complementary chain.

Future improvement


In order to solve the leak of pFrmR and achieve the ideal expression effect, our color reaction indicator system together with formaldehyde degradation group designed the amplification system to connect luxI to our group and put the gene expressing the enzyme of color reaction on PUC18. Sequence and Features


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal PstI site found at 3178
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal PstI site found at 3178
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 120
    Illegal BamHI site found at 182
    Illegal BamHI site found at 2421
    Illegal XhoI site found at 3214
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal PstI site found at 3178
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal PstI site found at 3178
  • 1000
    COMPATIBLE WITH RFC[1000]


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