Team:Imperial College London/M2/Genetic
From 2009.igem.org
Contents |
M2 Genetic Circuit
Video
Genetic circuit
Elaboration
This genetic circuit consists of two parts. The first part deals with the production of colanic acid, while the second part deals with the production of trehalose. Colanic acid is being used to encapsulate our drug protein, protecting it from the harsh acidic environment of our gut. Trehalose will ensure the stability of the colanic acid coat.
Genes RcsB, YgiV and Rfal control the production of colanic acid. RcsB is concerned with the production of colanic acid, YgiV increases the production of colanic acid and Rfal ligates colanic acid produced, to the outer membrane of E. coli.
Genes OtsA and OtsB are involved in the production of trehalose.
Encapsulation is auto-induced when the concentration of glucose decreases below threshold. Initially, glucose concentration is high and this represses the CRP promoter. No transcription occurs and encapsulation does not occur. As E. coli grows, it consumes glucose, resulting in a decrease in glucose concentration until the threshold is reached. At this point, glucose will no longer be able to repress the CRP promoter. Colanic acid and trehalose would be produced.