'Deadman' and 'Passcode' Microbial Kill Switches for Bacterial Containment

Overview

Journal Nat Chem Biol

Specialties Biochemistry
Biology
Chemistry

Date 2015 Dec 8

PMID 26641934

Citations 127

Authors

Clement T Y Chan

Jeong Wook Lee

D Ewen Cameron

Caleb J Bashor

James J Collins

Affiliations

Soon will be listed here.

Abstract

Biocontainment systems that couple environmental sensing with circuit-based control of cell viability could be used to prevent escape of genetically modified microbes into the environment. Here we present two engineered safeguard systems known as the 'Deadman' and 'Passcode' kill switches. The Deadman kill switch uses unbalanced reciprocal transcriptional repression to couple a specific input signal with cell survival. The Passcode kill switch uses a similar two-layered transcription design and incorporates hybrid LacI-GalR family transcription factors to provide diverse and complex environmental inputs to control circuit function. These synthetic gene circuits efficiently kill Escherichia coli and can be readily reprogrammed to change their environmental inputs, regulatory architecture and killing mechanism.

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