Part:BBa_K819008

Lux Operon under T7 promoter

Lux operon genes (from BBa_K325909) and related RBS are placed under T7 promoter (from BBa_I712074 ). Cells transformed with this part can produce blue luminescence while no exogenous substrate is needed.

When introducing synthetic DNA into a cell, it is desirable that the encoded processes be functionally distinct from host processes. Phage polymerases are a means to control orthogonal transcription and are one of the most used tools in genetic engineering. Specifically, T7 RNA polymerase (RNAP) has been shown to function in a variety of hosts, including Gram-negative and -positive bacteria, plant chloroplasts and mammalian cells. An advantage of T7 polymerase is that its promoters are tightly inactive in the absence of the polymerase, thus reducing the load on the cell when uninduced.

Therefore, T7 promoter separates sensing/circuitry functions from pathways/actuation. It is encoded in genetically distinct regions while linked with other circuits by providing the output for the circuits that drive the expression of phage polymerases. Luxbrick under T7 promoter is very modular, because it is transcribed by T7 polymerase, which can be placed under any other promoter, forming a interface between luxbrick and other systems. Also, when transformed into BL21 cells, it can be induced with IPTG to reach a high expression level.

Usage and Biology

To note that the incubating temperature should be no higher than 30^oC, or the heavy Lux complex can easily aggregate. Optimum incubating conditions provided by Peking iGEM 2012: 250 rpm, 22oC, good ventilation after induction(final concentration of IPTG: round 0.5 mM). BL21 cells harboring T7-lux operon induced with IPTG at 0.5 mM is shown in the photo

Sequence and Features

Assembly Compatibility:

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

  Illegal NheI site found at 3014
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 2012
  Illegal XhoI site found at 2842
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI site found at 4401
  Illegal BsaI.rc site found at 1410
  Illegal SapI.rc site found at 4726