Difference between revisions of "Part:BBa K3190601"

Revision as of 17:23, 16 October 2019

pGAL1-BI-I: BI-I CDS under inducible promoter

The coding sequence of BAX Inhibitor-I anti-toxin under the control of inducible promoter 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 survives only unless it is present in the medium with inducer.

Usage and Biology

The Biobrick XXXX we seek to improve is the BI-1 coding sequence as it was submitted by the iGEM team NAU_CHINA 2017. They used it as part of their kill switch system and even submitted a composite part consisting of TEF1 constitutive promoter, the BI-1 coding sequence, and the yeast CYC1 terminator.

Our improvement lays in the addition of the pGAL1 promoter in front of the BI-1 sequence. This improvement is necessary to contain the yeast in a defined environment (, in our case the gum matrix). The GAL1 promoter allows transcription of BI-1 only in the presence of galactose. A yeast strain that expresses BI-1 under control of this promoter and Bax constitutively will therefor only able to survive if enough galactose is present. If a yeast cell escapes its defined environment, the supply of this sugar will likely drop, BI-1 expression is interrupted, which will shift the toxin anti-toxin equilibrium in favor of Bax.

We claim that 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.

Figure legend: Overview of the toxin/anti-toxin biosafety device.

Sequence and Features