2018
- ▪T.H. Segall-Shapiro, E. D. Sontag, C. A. Voigt, "Engineered promoters enable constant gene expression at any copy number in bacteria", Nature Biotechnology, vol. 36, pp. 352-358, 2018. pdfsynthetic biology · systems biology · genetic circuits · gene copy number · incoherent feedforward loop · feedforward · IFFL
Abstract
This paper deals with the design of promoters that maintain constant levels of expression, whether they are carried at single copy in the genome or on high-copy plasmids. The design is based on an incoherent feedforward loop (iFFL) with a perfectly non-cooperative repression. The circuits are implemented in E. coli using Transcription Activator Like Effectors (TALEs). The resulting stabilized promoters generate near identical expression across different genome locations and plasmid backbones (pSC101, p15a, ColE1, pUC), and also provide robustness to strain mutations and growth media. Further, their strength is tunable and can be used to maintain constant ratios between proteins.