Team:Michigan/Project

Abstract

Recombinases can be used to create responsive, low background, boolean genetic circuit in biological systems. Further, it is theoretically possible to create complex control circuits using combinations of invertible DNA sequences. We utilized HbiF to augment an existing recombinase system in Escherichia coli that relied on FimE. A burst of induced, low level expression of one recombinase will invert the promoter flanked by the recombinase binding sites IRR and IRL, triggering a switch from strong expression of one to another set of proteins made downstream. Induced expression of the second recombinase will revert the promoter to its original orientation, triggering the original set of protein expression. The inversion will be sustained across cell divisions with little leaky protein expression and negligible performance degradation after repeated inversions. This is a heritable, binary memory system and can be used as a component in more complex systems.