Biosafety
We take biosafety seriously as prevention of unintentional exposure to pathogens and toxins.
After rigorous identification, we can declare that: the safety issues in our project will not post any hazard toward environment and human body. Because every organisms and part we use are from model organisms which have been fully understood.But we still need prevention to any possibility of accidently leaking.
In order to prevent potential biohazard, we have designed a self-destroying system. The K117000 gene is a biobrick registered by 2008 The NTU @ iGEM https://2008.igem.org/Team:NTU-Singapore. This lysis gene encodes for the lysis protein in colicin-producing strains of bacteria. Once activated, it causes the host cell to lyze. It also removes the immunity protein out of colicin, and hence, activates the endonuclease activity of the colicin. http://parts.igem.org/Part:BBa_K117000.
We use the lysis gene for destructing bacteria. The destruction is designed to be activated after a period of time. The postponement of destruction is achieved by the transcriptional model as well.
This is the gene circuit of self-destroying system. The PKEK coding sequence can be substituted by any other target gene. As a result, this system can be applied by many other iGEM team.
K117000 coding region precedes a repressible promoter http://parts.igem.org/Part:BBa_R0011, which is a highly registered biobrick. The lysis gene is efficiently inhibited by LacI protein originally. Once the uptake of fatty acid occurred, the pLacI promoter will be activated, causing the expression of K117000. The dynamic response of K117000 gene is delayed comparing to the activation of target gene (PKEK) due to the latency incurred by the additional components in the system. As a result, the plasmid containing bacteria will die after the target protein expresses for a while. This prediction of circuit property can be supported by the article, “Parameter Estimation For Two Synthetic Gene Networks: A Case Study”.
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