Part:BBa_K1897015

LuxR + LuxI

This part is made by 3A ligation (see: https://parts.igem.org/Help:Assembly/3A_Assembly) of LuxR BBa_K1897008 and LuxI BBa_K1897009. Both LuxR and LuxI are derived from Vibrio fischeri.

Usage and Biology

This quorum sensing system was derived from Vibrio fischeri, and involves the regulatory LuxR and the autoinducer producing LuxI. Originally in Vibrio fischeri, the Lux operon can be transcribed from from the left (operonL) or right (operonR). Transcription of operonR, which consists of LuxICDABE, occurs only in the presence of N-(3-oxo-hexanoyl)-homoserine lactone (AHL), which is an autoinducer produced by LuxI (Shaldel and Baldwin, 1991). This also produces light due to the production of LuxCDABE (Shaldel and Baldwin, 1991). Transcription of operonL leads to the production of LuxR, which negatively regulates it's own transcription (Shaldel and Baldwin, 1991).

As the cell membrane is permeable to AHL, it diffuses out of the cell down a concentration gradient when there is low cell density (Fuqua et al., 1994). In high cell densities, it is able to accumulate within the cell to turn on the transcrption of genes under the control of pLuxR (see: BBa_R0062) or pLuxL (see: BBa_R0063) (Fuqua et al., 1994).This is due to rising amounts of AHL, which results in LuxR-AHL complexes begin to form, and LuxR undergoes a conformational change (likely to form a dimer) that leads to the activation of the Lux operon (Choi and Greenberg, 1992; Trott, 2000).

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 7
  Illegal NheI site found at 30
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 1852
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal AgeI site found at 50
  Illegal AgeI site found at 1065
  
• 1000
  COMPATIBLE WITH RFC[1000]