Part:BBa_K1679014

RNA thermometer (FourU) +mRFP

This is a device containing a RBS (BBa_K115002) and a RFP coding sequence (BBa_E0010) on the pSB1C3, which can be easily transformed into E.coli. RNA Thermometers(RNAT) are temperature-sensing RNA sequences in 5’UTR of their mRNAs. At low temperature, RNAT folds into structure, blocking access of ribosome; At high temperature, RNAT switch from off to open conformation, increasing the efficiency of translation initiation. When the temperature rises above 37°C, this RNA terminator would turn on and RFP would be expressed in theory.

Usage and Biology

TUDelft-2008 has modified 3 kinds of RNAT: ROSE(BBa_K115001), FourU(BBa_ K115002), PrfA(BBa_K115003). We constructed each RNAT under the control of 3 different constitutive promoters:BBa_J23101, BBa_J23106, BBa_J23119 and use RFP as a reporter. After construction, the 9 circuits were transformed into DH5α. According to the results of TUDelft-2008, the temperature threshold is 37℃ for FourU and PfrA, 42℃ for ROSE. Thus, we set the culture temperature to 28℃, 37℃ and 42℃ on solid LB medium while 28℃, 35℃, 37℃, 40℃, and 42℃ in liquid LB medium.

For one temperature, we spotted one strain on 3 different plates, each plate contains 9 different strains. After 48 hours, as we can see in the photo: this RNA thermometer worked best under all these promoters and show great switch activity when be used cooperatively with J23101 and J23109.

After 36 h culturing in solid LB medium , when some replicates had changed color, we calculated the Fluorescence(excitation wavelength-584 nm and emission wavelength-607 nm) and OD(600).This part works well in solid LB medium also.

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
  INCOMPATIBLE WITH RFC[25]

  Illegal AgeI site found at 613
  Illegal AgeI site found at 725
  
• 1000
  COMPATIBLE WITH RFC[1000]