Difference between revisions of "Part:BBa K1074011"

Revision as of 13:13, 26 September 2013

PsdpRI+RBS+SDP

We construct this gene circuit as our kill switch to kill the engineered Bacillus subtilis for the safety purpose.Killing is mediated by the exported toxic protein SdpC. Extracellular SdpC induces the synthesis of an immunity protein, SdpI, which protects toxin-producing cells from being killed. SdpI, a polytopic membrane protein, is encoded by a two-gene operon under sporulation control that contains the gene for an autorepressor, SdpR. The autorepressor binds to and blocks the promoter for the operon. Evidence indicates that SdpI is also a signal-transduction protein that responds to the SdpC toxin by sequestering the SdpR autorepressor at the membrane. Sequestration relieves repression and stimulates synthesis of immunity protein. The kill switch is based on a high-copy vector fused with promoter for operon sdpIR and coding sequence for protein SdpC. When SdpC toxins are sensed, they will be captured by Immunity Protein SdpI at the membrane, enabling SdpI to sequester SdpR. As a result, repression on promoter SdpIR is released and more SdpC will be produced. Trapped in this endless loop, the SdpC producing cells fails to cope with enormous toxin SdpC and doomed after eliminating their siblings. Eventually, the group of engineered Bacillus subtilis is destroyed instead of sporulating.

Sequence and Features