Fig. 2

Design and characterisation of the biological AND gate. a Design and logic output of Hrp-based AND gate. The AND gate comprises HrpS and HrpR transcription factors that are unregulated under the control of pBAD and pRHAB promoters, respectively. In the presence of both inputs HrpRS jointly bind and induce conformational change in the pHrpL promoter, thereby enabling DNA transcription and the expression of GFP reporter. b Steady state profile of the AND gate for various concentrations of arabinose (input A) and rhamnose (input B). c Digital performance of AND gate at steady state. d Characterisation of the Hrp-based AND gate in both high and low copy plasmids. The input devices generating HrpRS transcription factors and pHrL-GFP reporter module are placed in plasmids of different copy numbers to study the effect of plasmid copy on precision control and tuning of Hrp-based AND gate. Error bars represent the standard deviation of three independent experiments