Team:BNU-China/kill

Kill Switch

A kill switch is designed to control “Prometheus” and to reduce biological pollution.

The difficulty is how to trigger the suicide progress spontaneously at a certain time. In the medium, the bacteria are easily controlled by adding or removing regulatory factors. However, after pouring E. coli into soil, it is hard for us to control. The suicide progress needs to be activated spontaneously. Moreover, the kill switch is supposed to be “off” for a certain time in the soil, so the bacteria will gain enough time to perform its function.

Considering the problems, toxin protein MazF is the best candidate to kill the “Prometheus” as well as to restrict the bacterial number under reasonable level.

Background

MazEF is a toxin-antitoxin module composed of mazE and mazF locating on the chromosome of E. Coli and other pathogens (Hanna et al, 2005). The expression product of mazF is a stable toxin, while that of mazE is a labile antitoxin of MazF (Hazan et al, 2004; Schusteret al., 2013). MazF is a sequence-specific mRNA endoribonuclease that initiates a programmed cell death pathway in response to various stresses. The mazEF-mediated death pathway can act as a defense mechanism that prevents the spread of bacterial phage infection, allowing bacterial populations to behave like multicellular organisms.

We also designed kill switch to control the death of E. Coli.

Design:

Fig 1. Stable State

Fig 2. Killing State

The Story of E.coli Prometheus

BNU-China