Part:BBa_K3889100
SRTF1 expression cassette Bacillus subtilis
SRTF1 is expressed under a constitutive promoter SP126 (BBa_K3889010). In absence of progesterone it can bind to its binding site (BBa_K3889030) and repress transcription of the gene. Now as progesterone enters the system SRTF1 binds to progesterone leaving its binding site free for the transcription machinery to start working. This results in a progesterone inducible gene expression.
mcherry was linked with the help of P2A linker (BBa_K3889069)in order to coexpress it with SRTF1 and check protein expression
Usage and Biology
This part along with BBa_K3889101 and BBa_K3889102 was used in order to produce Ovastacin (BBa_K3889022) when progesterone in absent in the fallopian tube. The working of the system is shown below:
Results
In this graph, SRTF1 cassette (BBa_K3889100) and P22 Cassette(BBa_K3889101) were co-expressed in Bacillus subtilis 168 consisting of SRTF1 with mCherry reporter and P22 Cassette with Azurite reporter under various concentrations of progesterone.
Unexpectedly, the mCherry expression decreased at higher concentrations of progesterone. Further experimental evidence is needed to determine the cause. Additionally, the Azurite expression increased with progesterone levels signifying that p22 protein production increased. Hence, there is evidence to suggest that SRTF1 and SRTF1 DNA binding sites were interacting as expected and progesterone sensing is taking place in Bacillus subtilis.
Results Table:
| Progesterone Conc. (in nM) | Azurite | mCherry |
|---|---|---|
| 0 | 11374 | 297821 |
| 16.5 | 17101 | 281770 |
| 33 | 17275 | 287161 |
| 82.5 | 29714 | 249459 |
| 165 | 45536 | 153234 |
| 330 | 78069 | 117241 |
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
| None |