Part:BBa_K3332036

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