Part:BBa_K4144006

This part is designed to constitutively express XylR, a repressor suppressing promoter Pxyl

This part is designed to constitutively express XylR a repressor from genome of Bacillus subtilis to suppress the transcription of promoter Pxyl. By overexpressing such protein, we can reduce the leakage of Pxyl in BBa_K4144007, which makes it more precise to be regulated. Without this part BBa_K4144007, Promoter Pxyl will constitutively express the downstream proteins. The figure 1.1 shows that E. coli DH5α containing Pxyl-opPet8p-sfGFP without exogenous expression of XylR Repressor Generator, can display green fluorescence radiated by UV. However, when inserted with such generator, the strain remains non-fluorescent until induced.

Consideration

Bacillus subtilis have endogenous XylR and Pxyl. However, we found that with such endugenous repressive regulator, promoter Pxyl is inevitable to leak. So we overexpressed it in our engineered bacteria. If other teams find that their designed xylose-induced promoter with low affinity of RNA polymerase, it could be need to use our part to overexpress XylR.

Reference

[1]iGEM20_FCB-UANL https://parts.igem.org/Part:BBa_K3498008
[2]iGEM19_Jiangnan-China  https://parts.igem.org/Part:BBa_K2985006

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]