Biological Modules

Input

For the input, it was needed to use a signal that can easily represents an “ON and OFF” switch. The use of lights to represent the inputs was our first idea: a blue and a red light.

Blue light system
YF1 is the fusion of LOV protein and an histidine kinase. With no light, YF1 can phosphorylate FixJ and the phosphorylated FixJ activates the PfixK2 promoter. In presence of a 480 nm wavelength light, YF1 can no longer phosphorylate FixJ and there is no activation of the PfixK2 promoter.

Red light system
It is a chimeric receptor. CpH8 is the fusion of Cph1 photoreceptor and EnvZ histidine kinase. With no light, Cph8 is phosphylated and can activate the ompC promoter. In presence of a 660 nm wavelength light, cph8 is no longer phosphoryalated and can not activate the ompC promoter.