Topologies of synthetic gene circuit for optimal fold change activation in bacterial biosensors

Abstract

Biological regulatory networks in nature comprise feedforward and feedback loops allowing cells to perform sophisticated tasks such as DNA repair, cell division, and apoptosis. During the past decades, network motifs have been introduced into living cells to scale–up the computational complexity of synthetic gene circuits. For example, mutual inhibition was the first network that has been implemented in Escherichia coli cells to create a bistable switch. Recently, an incoherent feedforward loop and integral feedback controller have been applied to achieve robust adaptation in Escherichia coli cells.