Team:PKU Beijing/Parts Characterization/BBa K228004


Parts > Parts Characterization > BBa_K228004

BBa K228004 - NahR( reverse) - salicylate promoter

Designed by Lin Min Group: iGEM09_PKU_Beijing (2009-09-18)
Input: Salicylate molecules
Output: GFP fluorescence

Part Main Page Transfer Function Growth Rate


This is a salicylate inducible promoter part constructed by Lin Min. The activator protein (NahR) gene is in the upstream but in an opposite direction of the regulated promoter. In the presence of salicylate, the promoter can be activated. If we place a generator on its downstream, the transcription of the coding sequence will be triggered by the salicylate-binding positive transcriptional activator protein which is encoded by NahR.

It is necessary to notice that there is no terminator downstream of the NahR coding sequence, but it has no effects on parts that are in the same direction as the pSal promoter. However, if coding gene is placed upstream of this part and in the same direction as NahR, it may cause unexpected expression.

For the purpose of characterization, we connected BBa_E0840 downstream of the salicylate promoter to make the composite part, BBa_K228850. This report system allowed us to test the salicylate inducible promoter indirectly via the fluorescence output of BBa_E0840, while the input is salicylate solution at a gradient of concentration.


Experiment*Characteristics*Value & Result*
Transfer Function Maximum Output

(Output tested in a time sequence)

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Hill coefficient

(Output tested in a time sequence)

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Switch Point

(Output tested in a time sequence)

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Demand Decrease on Growth Rate

(Input at a gradient of concentration)

The decrease level has significantly positive correlation with the input, the concentration of salicylate.

Measured by Haoqian Zhang & Chengzhe Tian, 2009


Because this part is from commonly used elements in bacteria. No safety problem can be arised by this part.


Chassis: Device has been shown to work in DH5α. Plasmids: Device has been shown to work on pSB1A2 and pSB1A3, pSB4K5 Devices: Device has been shown to work with BBa_K228013, BBa_K228227 - BBa_K228235, BBa_K228255 - BBa_K228263, BBa_K228851, BBa_K228852 - BBa_K228860, BBa_K228870 - BBa_K228878.