Part:BBa_K3190601
pGAL1-BI-I: BI-I CDS under inducible promoter
The coding sequence of BAX Inhibitor-I (BI-1) anti-toxin under the control of inducible promoter GAL1 (Basic part BBa_K3190050) for the design of a kill switch system for a yeast wherein a BAX toxin is expressed under a constitutive promoter. This system ensures that the yeast will not survive if it escapes the medium containing the inducer.
Usage and Biology
Improvement of kill switch system
We seek to improve the BI-1 coding sequence (BBa_K2365518), which was submitted by the iGEM team NAU_CHINA 2017. They used it as part of their kill switch system and also submitted a composite part consisting of TEF1 constitutive promoter, the BI-1 coding sequence, and the yeast CYC1 terminator.
The kill switch proposed by team NAU China works by co-expressing the BAX gene (BBa_K2365048), which encodes the pro-apoptotic Bax protein, under a constitutive promoter, and BI-1 under the inducible GAL1 promoter. As long as galactose is present in the media, BI-1 will be expressed, inhibiting the Bax protein. Should the yeast cell escape the media or matrix, BAX will be expressed, causing apoptosis of the cell.
Figure 1: Overview of the kill switch.
Our improvement lays in the addition of the pGAL1 promoter in front of the BI-1 sequence. This improvement will allow us to control the expression of BI-1, as the GAL1 promoter allows transcription of BI-1 only in the presence of galactose.
this improvement is necessary to use this system as a kill switch and that the composite Biobrick that NAU-china 2017 themselves submitted is not able to allow apoptosis, since they had a TEF1 promoter controlling BI-1 which is not dependent the environmental galactose amount.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BamHI site found at 954
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal AgeI site found at 377
- 1000COMPATIBLE WITH RFC[1000]
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