Difference between revisions of "Part:BBa K3332036"
 
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<partinfo>BBa_K3332036 short</partinfo>
 
<partinfo>BBa_K3332036 short</partinfo>
  
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The ribosome binding sites which has suitable strength for the kill switch in detection part.We use it to favor TetR expression in the absence of aTc.
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The ribosome binding site which has suitable strength for the kill switch in detection part.  
  
 
===Usage and Biology===
 
===Usage and Biology===
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RBS1 is used to favor TetR expression in the absence of aTc. It is part of the circuit designed to prevent engineered bacteria in the detection instrument from escaping. Its strength fits the design of this monostable switch.
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RBS1 is used to favor tetR expression. It is part of the circut designed to prevent engineered ''E.coli'' in the detection instrument from escaping. Its strength fits the design of this monostable switch.
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In this circuit, LacI can repress ptrc-2 promoter and ptrc-2 derived promoter while the LacI can repress the pLtetO-1 promoter. When the aTc exits, it can combine tetR, so that the pLtetO-1 promoter can’t be repressed. Then the LacI which is controlled by the pLtetO-1 can repress the ptrc-2 promoter and ptrc-2 derived promoter. As a result, mf-lon and mazF can’t be expressed. As a kind of bacterial toxin, mazF can cause the bacteria death. 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 bacteria escape from our testing instrument, the effect can be reversed, that is to say, the bacteria will be killed by the mazF. In the same way, we can conclude that in the presence of IPTG, MazF can be expressed to cause bacterial death.
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<table><tr><th>[[File:Circuit.tif|thumb|720px|Fig.1 Circuit.]]</th><th></table>
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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 can combine 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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As a kind of bacterial toxin, MazF can cause the death of bacteria. So there comes the conclusion that as long as the engineered ''E.coli'' is 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 the mazF. In the same way, we can conclude that in the presence of IPTG, mazF can be expressed to cause the death of bacteria.
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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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'''Fig 1.''' Kill switch of the detection part.
  
 
===Sequence and Features===
 
===Sequence and Features===

Latest revision as of 18:29, 27 October 2020


RBS1

The ribosome binding site which has suitable strength for the kill switch in detection part.

Usage and Biology

RBS1 is used to favor tetR expression. It is part of the circut designed to prevent engineered E.coli in the detection instrument from escaping. Its strength fits the design of this monostable switch.

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 can combine 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.

As a kind of bacterial toxin, MazF can cause the death of bacteria. So there comes the conclusion that as long as the engineered E.coli is 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 the mazF. In the same way, we can conclude that in the presence of IPTG, mazF can be expressed to cause the death of bacteria.

Fig 1. Kill switch of the detection part.

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