Difference between revisions of "Part:BBa K819008"

Revision as of 12:57, 26 September 2012

Lux Operon under T7 promoter

Lux operon genes (from BBa_K325909) and related RBS are placed under T7 promoter. 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. They are encoded in genetically distinct regions and linked by having the output of the circuits 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

BL21 cells harboring T7-lux operon induced with IPTG at 5*10^-5M is shown in the photo
The best temperature for cells to glow is 30^oC rather than 37^oC, which was discovered by Peking iGEM 2012.