Device

Part:BBa_K1886002

Designed by: Lejian Jiang   Group: iGEM16_ZJU-China   (2016-10-06)


AHL,DPD double-cycled oscillation

Two molecules of luxR binds with AHL (catalyzed by luxI), and this compound will promote the activity of pluxR. pluxR controls the expression of gene aiiA and luxS, Gene aiiA encodes the enzyme which degrades AHLs. And gene luxS produces DPD. Therefore, we could realize an AHL-DPD double-cycled oscillation, and the phase difference is half a cycle.


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BglII site found at 1821
    Illegal BamHI site found at 4352
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 3256
    Illegal AgeI site found at 4450
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI.rc site found at 1101
    Illegal BsaI.rc site found at 1970
    Illegal BsaI.rc site found at 3073
    Illegal BsaI.rc site found at 4114


Characterization

BACKGROUND

Overview

The difference between the part for single-cycled oscillation and the part for double-cycled oscillation is that pluxR and LuxS are added, which enable the connection difference of the expression of AHL and DPD. The expression quantity of DPD and aiiA will increase due to the accumulation of AHL, while the increased connection of aiiA will hold up the expression of AHL in return. In that way, the peak value of these two substance is staggered.

Principle

The ZJU-modified synchronized oscillator design is based on elements of the quorum sensing machineries in Vibrio fischeri and Bacillus Thurigensis. We placed the luxI (from V. fischeri), aiiA (from B. Thurigensis) and DPD which is another auto inducer widely existing in Gram-negative bacteria and Gram-positive bacteria under the control of three identical copies of the luxI promoter. The LuxI synthase enzymatically produces an acyl-homoserine lactone (AHL), which is a small molecule that can diffuse across the cell membrane and mediates intercellular coupling. It binds intracellularly to the constitutively produced LuxR, and the LuxR–AHL complex is a transcriptional activator for the luxI promoter. The expression of the auto inducer DPD increases. AiiA negatively regulates the promoter by catalysing the degradation of AHL. This network architecture, whereby an activator activates its own protease or repressor, is similar to the motif used in other synthetic oscillator designs and forms the core regulatory module for many circadian clock networks. Furthermore, theoretical work has shown how the introduction of an autoinducer in similar designs can potentially lead to synchronized oscillations over a population of cells. These two auto inducers can trigger different promoters when their expression quantity reaches a certain value, which means different circuits will be triggered, then different downstream proteins will be expressed. Therefore the execution of different signal during different time is realized.

RESULTS


Gel electrophoretic analysis


Fig.1 Fig.1 Gel electrophoretic analyses of PCR products




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