RNA

Part:BBa_K2787030

Designed by: Weiyi Tang   Group: iGEM18_ShanghaiTech   (2018-10-09)
Revision as of 23:48, 17 October 2018 by Shihaoer (Talk | contribs)


pT181 Attenuator target sequence with improved repressive efficiency

An improved version of pT181 sense target with its length shortened from 287bp to 201bp and its repressive efficiency improved from 84%for BBa_ to 98%. The part achieve such efficiency through forming secondary structures that can interact with the pT181 antisense and hinder the transcription of downstream genes. With the absence of pT181 antisense, nevertheless, the expression is basically unaffected.

Usage and Biology

ShanghaiTech2018-pT181-1.png

A schematic representation of the pT181 attenuator in action

ShanghaiTech2018-pT181-2.png

A schematic representation of the experimental group plasmid. This has the basic pT181 attenuator Antisense under control of a constitutive promoter, as well as a GFP gene downstream of the pT181 attenuator sense target under the control of a constitutive promoter.

ShanghaiTech2018-pT181-3.png

A schematic representation of the positive control plasmid with the GFP gene downstream of the pT181 attenuator sense target under the control of a constitutive promoter, without a pT181 attenuator Antisense on it.

ShanghaiTech2018-pT181-4.png

400x image of positive control under fluorescence microscope.

ShanghaiTech2018-pT181-5.png

400x image of experimental group under fluorescence microscope

ShanghaiTech2018-pT181-6.png

Characterization of pT181 attenuator in DH5-α E.coli cells. OD600 monitored over time for cell lines incorporating the pT181 attenuator in the absence or presence of the pT181 antisense. The result shows that the pT181 antisense is not harmful to the E.coli, which provides convenience for test for fluorescence as we do not need to normalize the OD600.

ShanghaiTech2018-pT181-7.png

Fluorescence monitored over time for cell lines incorporating the pT181 system with pT181 antisense. It shows that the GFP can be expressed in the pT181-attenuator, and the expression level increases gradually.

ShanghaiTech2018-pT181-8.png

Fluorescence monitored over time for cell lines incorporating the pT181 system without pT181 antisense. It matches the curve of how GFP’s expression increases without being repressed, which establishes foundation for measure the repression effect of pT181-attenuator.

ShanghaiTech2018-pT181-9.png

The combination of the two figures above. We could see the sharp difference in the fluorescence between the two curves. This proves our pT181 could repress the expression of GFP as expected, which means our part C is able to produce repression effect as anticipated. This shows that the controller in our Three-Node Feedback Loop is constructed successfully.

ShanghaiTech2018-pT181-10.png

Characterization of pT181 attenuator in DH5-α E.coli cells. endpoint fluorescence (18 hours) for cell lines in the absence or presence of Pt181. The data shows that our Pt181 attenuator could repress the target gene for 98%.

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


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