Question

Lux

a) What does the signal detect/respond to?

b) When is the signal On/Off

c) Is the system inducible, repressible, or mixed?

d) Describe the systems response

Answer 1

a. The transfer of Lux gene resulting in light emission is detected by luminometers. The system can detect 1*102 cells in 60 minutes.

b. The signal is off when there is decrease in light, with the increase in light the signal becomes on.

c. The system is inducible.

d. The system encodes genes for self regulation and for the production of luminescent proteins. Operon produced luciferase produces bioluminescence. The Lux system consists of 5 genes, luxA, luxB, luxC, luxD, luxE. Depending on the combination of these genes, several different types of bioluminescent bioreporters can be constructed. On the molecular level, bioluminescence is enabled by a cascade of chemical reactions catalysed by enzymes encoded by the Lux operon. LuxA and LuxB genes encode alpha and beta subunits respectively, of the enzyme luciferase producing the light emitting species. The light emitting reaction catalysed by the LuxAB complex involves the oxidation of FMNH₂ and the conversion of a long chain fatty aldehyde to its cognate acid, with the emission of blue-green light.