Integrated Sensor-Executor Proteins and Molecular Switches

Abstract

Our goal is to design integrated molecular sensing and executing devices based on modular protein engineering. These integrated devices can then easily be used for the construction of complex systems. We fuse sensing proteins, which provide nano-mechanical movements or dimerization upon an external signal, to executing proteins, which depend in their activity on the nano-mechanical change in the sensing part.
To elucidate the possibilities of such a system we used the calcium-ion sensor Calmodulin and the light sensor system PhyA-Fhy1. To test execution we used the split enzymes DHFR or beta-lactamase or the fluorescent proteins CFP and YFP, which can form a FRET pair. Sensors and executors were geneticlly fused and tesetd in E. coli for activity. So far we could demonstrate Ca2+ dependent growth of E. coli with the DHFR[1]-Calmodulin-DHFR[2] construct.