DNA

Part:BBa_K2377009

Designed by: Tuoyu Zhou   Group: iGEM17_Lanzhou   (2017-10-23)


zrap ribB

Improved target: BBa_K1755301

Improved form:

We replaced a sensor element（Copper-Responsive Two-Component System BBa_K190017）for the Zinc-Responsive Two-Component regulatory system (contains σ54 promoter).

Mechanism of changed sensor The mechanism of Zinc sensor is related to a intrinsic signaling pathway in Ecoli. Which is known that many sensing proteins ZraS immobilized on the membrane of cell. And when Zn2+ show up in periplasmic space, the ions will combine with ZraS and trigger it autophosphorylation. (ZraS*) The phosphorylation signal will transmit from ZraS* to ZraR, then ZraR* come to ZraR(HydG) binding site[1] that will make σ54promoter start downstream transcription. (ZraS* ,ZraR* means activated condition.)

800px-Lanzhou_Parts_2.png

So, we substitute Zinc-Responsive Two-Component regulatory system for the copper one in BBa_K1755301. Successfully construct a new heavy metal sensor.

Function of improved new part Improved new part is BBa_K2377009, which can detect the concentration of Zn2+ and transform it into electric signal.

The downstream protein ribB (3,4-dihydroxy-2-butanone 4-phosphate synthase ,ribB) could catalyze the conversion of D-ribulose 5-phosphate formate to 3,4-dihydroxy-2-butanone 4-phosphate. This step is part of the biosynthesis pathway of riboflavin, an electron carrier in microfunction circuit (MFC).

So when the whole gene circuit works, it will result in a consequence that once the concentration of Zn2+ in environment increased, more riboflavin will be produced to impact the voltage of MFC.

Through this new part we realized monitoring heavy metal Zn2+ automatically, quantitatively and efficiently.

The figure below shows the comparison of the part BBa_K1755301 (left) with the new improved part BBa_K2377009 (right), the riboflavin concentration versus heavy metal ion concentration.

800px-Lanzhou_Parts_1.png

And this is the improve target biobrick designed by 2015 LZU-China iGEM team

https://parts.igem.org/Part:BBa_K1755301

https://parts.igem.org/Part:BBa_K1755303


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 625
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 515
    Illegal AgeI site found at 557
  • 1000
    COMPATIBLE WITH RFC[1000]


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