Part:BBa_K1212024
J23106+TBS2+GFP
A mid-range strength promoter from the Anderson Family, J23106, with TALe binding site 2, corresponding to TAL repressor 8, controls the expression of GFP.
The data below shows the behavior of this part in the context of a cotransformation between pBAD+RS2+TAL 8 in pSB3K3 (low copy number) and this part in pSB1A2 (high copy number). See BBa_K1212012 for further characterization of pBAD+RS2+TAL 8.
See our wiki's data page for more information.
The data show clear repression of the reporter under conditions of maximal induction of the RiboTALe transcription factor (10mM theophylline and 1% arabinose), indicating that gene expression is repressible by the synthetic transcription factor. In other words, the once constitutive promoters are now repressor-controlled by the RiboTALe device. The data also show that the promoters maintain, qualitatively, their relative strengths. The value listed under each promoter is it's relative promoter strength as listed in the Registry of Standard Biological Parts. The fold-decrease in fluorescence achieved by maximum induction of the RiboTALe was 56.8, 21.7, 3.99, and 1.38 for J23100, J23101, J23105, and J23109, respectively. (See parts K1212021, K1212022, K1212023 and K1212025 respectively for more information about these other promoters)
These data show greater repression at greater levels of theophylline induction (0-10mM), for all promoter constructs with 0.1% arabinose. The data indicate that the repression activity of the RiboTALe device is sensitive to the level of theophylline added. A RiboTALe transcription factor may be used to reliably modulate the expression of genes of interest by means of the riboswitch ligand.
As seen in the graph above, J23106 construct showed fluorescence levels barely above those of the theoretically much weaker promoter J23109. There are many possible reasons why this result may have occurred, such as mutations in the sequence, environmental variables that differ between labs or the addition of the TAL binding site altering promoter strength.
When both of the inducers concentrations, arabinose (0-1%) and theophylline (0-10mM), are varied, a 3D surface of the system response can be obtained. The plot above shows the system responses of the constructs containing J23105, J23106 and J23109 as their parent promoters (K1212023, K1212024 and K1212025 respectively). See our wiki for the interactive KO3D plot (made possible thanks to the 2011 UC Davis iGEM team).
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 7
Illegal NheI site found at 30 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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