Engineering Living Biosensors using the Hemeprotein Transcription Factor CooA

Abstract

Biosensors are devices that detect the presence of a biological compound. Currently biosensors have applications in food safety, medical diagnosis, and environmental monitoring. The lifetime of use is limited in the current models, so we looked to examine archetypes found in nature to improve the field of biosensors. Bacteria utilize gas sensor proteins to detect changes in their environment to modulate their metabolism. Iron containing transcription factors are responsible for sensing/binding O2, CO, and NO to initiate a biological response. CooA is a heme‐containing transcription factor from the photosynthetic bacterium Rhodospirillum Rubrum. CooA is a homo‐dimer and acts as a carbon monoxide (CO) sensor. CooA senses the abundance of CO in the environment and in response activates the transcription of genes involved in CO metabolism. The goal of this project is to engineer cells capable of sensing CO to induce the expression of Red Fluorescent Protein (mRFP). We designed a CO sensing transcription system based on R. Rubrum for use in E. coli using a single expression plasmid encoding CooA and mRFP transformed into the E. coli strain BL21 DE3. The expression of mRFP will be induced by CooA activity in vivo and quantified using fluorescence spectroscopy. The long‐term goal is to use this template to design and optimize CooA into detecting other chemical signals using a hydrid computational and experimental approach. The outcome is to develop a family of biosensors to detect and respond to specific chemical signals. Using living biosensors, we can expand the uses of these devices to serve as environmental watchdogs monitoring pollution in lakes, streams, and other bodies of water.Support or Funding InformationNSF STC CCC Grant: 1548297, Genentech Foundation MS Dissertation ScholarshipThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.