title: Building enhancers from the ground up: a synthetic biology approach.
abstract: A challenge of the synthetic biology approach is to use our understanding of a system to recreate a biological function with specific properties. We have applied this framework to bacterial enhancers, combining a driver, transcription factor binding sites, and a poised polymerase to create synthetic modular enhancers. Our findings suggest that enhancer-based transcriptional control depends critically and quantitatively on DNA looping, leading to complex regulatory effects when the enhancer cassettes contain additional transcription factor binding sites for TetR, a bacterial transcription factor. We show through a systematic interplay of experiment and thermodynamic modeling that the level of gene expression can be modulated to convert a variable inducer concentration input into discrete or step-like output expression levels. Finally, using a different DNA-binding protein (TraR), we show that the regulatory output is not a particular feature of the specific DNA-binding protein used for the enhancer but a general property of synthetic bacterial enhancers.
authors: Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
authors: Roee
authors: R
authors: Amit
authors: Hernan G
authors: HG
authors: Garcia
authors: Rob
authors: R
authors: Phillips
authors: Scott E
authors: SE
authors: Fraser
mesh_terms: D001419:Bacteria / Q000235:genetics; D004247:DNA / Q000737:chemistry; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000235:genetics; D011401:Promoter Regions, Genetic; D058615:Synthetic Biology / Q000379:methods*; D014158:Transcription, Genetic
chemical_list: D004247:DNA