Team:INSA-Lyon/Project/Stage3/Theory/curli promoter
From 2010.igem.org
Curli Promoter
The Curli promoter is from the chassi E.Coli PHL1273. It is a kanamycin resistant chassi containing a plasmid with the full-length intergenic region between csgD and csgB genes (approximately 450 bp) including csgD and csgBA promoters. A gfp reporter gene is placed downstream the csgBA promoter (curli promoter), in order to quantify its activity. The promoter csgD is under the control of the protein ompR. This chassis is adherent but all the genes involving in adherence structure synthesis (csgA,B,E,F and G genes) are in the chromosomal DNA, not in the plasmid DNA.
The curli production involves two divergent operons:
![](https://static.igem.org/mediawiki/2010/a/af/Csg.jpg)
In addition, temperature and speed shaking conditions are also important in curli production. The precise mechanism of these regulations is still unknown, but some publications mention the Crl protein to be involved in the temperature regulation.
We have made some mesurments of fluorescence to verify the influence of the temperature, shaking speed and osmotic pressure. You can se the results here.
![](https://static.igem.org/mediawiki/2010/b/bc/Curligfp.png)
In conclusion, the csgD promoter is regulated by osmolarity, temperature and speed shaking. Consequently, the strong csgB promoter, called “curli promoter” is regulated by these three conditions. Each condition is necessary but not sufficient.