Lux Operon (under pBAD)
This page described the lux operon from Vibrio fischeri. To relieve LuxR control we placed Lux C, D, A, B, E under the pBad promoter. A more complete description can be found on the Cambridge iGEM 2010 website.
This Bacterial lux operons encodes five enzymes involved in the light-generating pathway. LuxA and LuxB encode the two subunits of the bacterial luciferase, while the products of LuxC, LuxD and LuxE synthesise the substrate for the light emitting reaction, tetradecanal. The exact function of LuxG is unknown, and it appears to be non-essential for light emission, but its presence increases light output.
In nature, the lux genes appear to be repressed by the nucleoid protein, H-NS, and occur under quorum sensing control. We removed the natural quorum sensing control to facilitate use of the part in biosensors under different regulatory inputs.
As of October 2010 we believe this is the first and only BioBrick to emit light in normal E. coli strains without the addition of any external substrate.
Measured by the Cambridge iGEM team 2010
Chassis: Device has been shown to work in Top 10 (Invitrogen), BW25113 DELTA H-NS::kan and H-NS mutant JM 230 H-NS -205::tn10.br>
Plasmids: Device has been shown to work on pSB1C3
Additional Characterization by the Penn iGEM team 2015
Penn iGEM 2015 used this part to make the sender cells in light-mediated cell communication. The lux operon BioBrick on PSB1C3 was transformed it into NEB 10-beta competent cells (since it is a commonly used E. coli strain in iGEM) and an H-NS mutant E. coli strain (since the protein has been shown to reduce lux gene expression). THe luminescent signal of the two sender strains was compared over time to determine what luminescent output trend would be best for inducing our light-sensitive receiver. Furthermore, using a calibrated conversion system designed by the team, Penn IGEM was about to convert the output from relative lights units (a measure typically used to calculate bioluminescent signals) to an absolute measure in uW/cm^2. Using the absolute units will assist in making characterization of bioluminescent parts such as BBa_K325909 more consistent across luminometer devices and across projects. For more information, please follow this link.
Figure 1 - E.coli cells (Invitrogen TOP 10) transformed with BBa K325909 in a 96 well plate.
: J. Slock, (1995) Transformation Experiments Using Bioluminescence Genes of Vibrio fischeri,The American Biology Teacher, 57, 225-227.
: E.A. Meighen (1988) Enzymes and genes from the lux operons of bioluminescent bacteria, Annual Reviews in Microbiology 42, 151-176.
E.A. Meighen, (1994) Genetics of bacterial bioluminescence, Annual Reviews of Genetics