Difference between revisions of "Part:BBa K3332039"
 
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===Usage and Biology===
 
===Usage and Biology===
 
The tetR protein is used to inhibit pLtetO-1. It is part of the circuit designed to prevent engineered bacteria in the detection instrument from escaping.
 
The tetR protein is used to inhibit pLtetO-1. It is part of the circuit designed to prevent engineered bacteria in the detection instrument from escaping.
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<table><tr><th>[[File:T--XMU-CHINA--circuit--circuit.png|thumb|600px|'''Fig 1.''' Kill switch of the detection part]]</th><th></table>
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<html>
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In this circuit, LacI can repress pTrc-2 promoter and pTrc-2 derivative promoter ，while tetR can repress pLtetO-1 promoter. When ATc exits, it combines with tetR, so that pLtetO-1 promoter can’t be repressed. Then LacI which is controlled by pLtetO-1 can repress the pTrc-2 promoter and pTrc-2 derivative promoter. As a result, mf-lon and MazF can’t be expressed.  
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    <figure>
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        <img src="https://2020.igem.org/wiki/images/5/56/T--XMU-China--XMU-China_2020-deadman-2.png" width="60%" style="float:center">
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        <figcaption>
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        <p style="font-size:1rem">
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        </p>
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        </figcaption>
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    </figure>
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</html>
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'''Fig 1.''' Kill switch of the detection part.
  
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As a kind of bacterial toxin, the expression of MazF often lead to the death of bacteria. So there comes the conclusion that as long as the engineered ''E.coli'' are cultured in the environment with ATc, it won’t be killed by the mazF, but when the ''E.coli'' escape from our detection instrument, the effect can be reversed. That is to say, the ''E.coli'' will be killed by MazF. In the same way, we can see that in the presence of IPTG, MazF can be expressed and kill the''E.coli''.
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pTrc-2 promoter is used to express mf-lon and MazF in the absence of ATc so as to inhibit the growth of ''E.coli''. It is part of the circut designed to prevent engineered ''E.coli'' in the detection instrument from escaping.
  
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In this circuit, LacI can repress pTrc-2 promoter and pTrc-2 derivative promoter ，while tetR can repress pLtetO-1 promoter. When ATc exits, it combines with tetR, so that pLtetO-1 promoter can’t be repressed. Then LacI which is controlled by pLtetO-1 can repress pTrc-2 promoter and pTrc-2 derivative promoter. As a result, mf-lon and mazF can’t be expressed.
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As a kind of bacterial toxin, the expression of mazF often leads to the death of bacteria. So there comes the conclusion that the engineered ''E.coli'' won’t be killed by mazF as long as it is cultured in the environment with ATc. Therefore, when the ''E.coli'' escapes from our detection instrument, the effects can be reversed. That is to say, the ''E.coli'' will be killed by mazF. In the same way, we can see that mazF can be expressed and kill the ''E.coli'' in the presence of IPTG, MazF can be expressed and kill the ''E.coli''.
 
===Sequence and Features===
 
===Sequence and Features===
 
<partinfo>BBa_K3332039 SequenceAndFeatures</partinfo>
 
<partinfo>BBa_K3332039 SequenceAndFeatures</partinfo>
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<partinfo>BBa_K3332039 parameters</partinfo>
 
<partinfo>BBa_K3332039 parameters</partinfo>
 
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===Reference===
 
===Reference===
 
[1] Chan CT, Lee JW, Cameron DE, Bashor CJ, Collins JJ. &apos;Deadman&apos; and &apos;Passcode&apos; microbial kill switches for bacterial containment. Nat Chem Biol. 2016;12(2):82-86. doi:10.1038/nchembio.1979
 
[1] Chan CT, Lee JW, Cameron DE, Bashor CJ, Collins JJ. &apos;Deadman&apos; and &apos;Passcode&apos; microbial kill switches for bacterial containment. Nat Chem Biol. 2016;12(2):82-86. doi:10.1038/nchembio.1979

Latest revision as of 19:03, 27 October 2020


tetR

The tetR protein is able to repress pLtetO-1 promoter in the absence of ATc.

Usage and Biology

The tetR protein is used to inhibit pLtetO-1. It is part of the circuit designed to prevent engineered bacteria in the detection instrument from escaping.

Fig 1. Kill switch of the detection part.

pTrc-2 promoter is used to express mf-lon and MazF in the absence of ATc so as to inhibit the growth of E.coli. It is part of the circut designed to prevent engineered E.coli in the detection instrument from escaping.

In this circuit, LacI can repress pTrc-2 promoter and pTrc-2 derivative promoter ，while tetR can repress pLtetO-1 promoter. When ATc exits, it combines with tetR, so that pLtetO-1 promoter can’t be repressed. Then LacI which is controlled by pLtetO-1 can repress pTrc-2 promoter and pTrc-2 derivative promoter. As a result, mf-lon and mazF can’t be expressed.

As a kind of bacterial toxin, the expression of mazF often leads to the death of bacteria. So there comes the conclusion that the engineered E.coli won’t be killed by mazF as long as it is cultured in the environment with ATc. Therefore, when the E.coli escapes from our detection instrument, the effects can be reversed. That is to say, the E.coli will be killed by mazF. In the same way, we can see that mazF can be expressed and kill the E.coli in the presence of IPTG, MazF can be expressed and kill the E.coli.

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


Reference

[1] Chan CT, Lee JW, Cameron DE, Bashor CJ, Collins JJ. 'Deadman' and 'Passcode' microbial kill switches for bacterial containment. Nat Chem Biol. 2016;12(2):82-86. doi:10.1038/nchembio.1979