Rewiring the DNA Binding Domains of Bacterial Two-Component System Response Regulators

Two-component systems (TCSs) are the most ubiquitous sensing modality in biology, and the primary means by which bacteria sense environmental signals. However, most TCSs have unknown functions, and virtually no progress has been made in repurposing them as engineered sensors for medical, industrial, and scientific applications. The major limitations are that the bacteria containing them cannot be grown or genetically manipulated in the laboratory, TCSs are subject to complex and poorly understood genetic and environmental regulation, and there are no methods to adjust TCS sensitivity to desired levels.

My group has recently developed technologies to overcome these limitations. In this talk, I will describe the development of technologies for ‘mining’ TCSs from nature, identifying the inputs they sense, and recapitulating their natural function in non-native host bacteria. I will also describe new technologies to increase their often poor dynamic range hundreds of fold – to levels sufficient for robust in vivo sensing, and to rationally tune their sensitivities from the sub-micromolar to millimolar range, overcoming a long-standing challenge in biological sensor design. Finally, I will discuss early progress in using our engineered bacteria to diagnose and study inflammation in the colon, which is linked to pathogen infection, obesity, cancer, and other diseases.