Introduction

As previously described in the design of the switch, each half switch contains a nut site followed by a terminator, as well as an anti-terminator. The roles of these parts are to increase the stability of the current state and thereby also the robustness of the switch.

As the P_RM promoter is not very well repressed by the GogR/GtgR repressors, transcription is promoted even in their presence. If transcription was allowed to continue to the anti-repressor located on the inactive half of the switch, the switch could change state spontaneously. The terminator is placed in front of the anti-repressor to ensure that this does not happen. The anti-terminator of the active state is expressed, allowing continued transcription past the terminator.

The regulatory systems utilized in our switch can be divided into two:

• The Repressor - Anti-Repressor regulatory section
• The Terminator - Anti-Terminator regulatory section