Fig. 2. Single-promoter logic gates constructed in B. thetaiotaomicron.

a The AND gate is constructed by directing two repressors to the same operator. We refer to the genetic architecture of directing two or more TFs to a single operator as series-parallel (SE-PA). Bar charts show luciferase activity presented as luminescence per colony forming unit (CFU) (Methods). Each bar corresponds to the ligand condition shown below each bar (empty, no ligand; gray, IPTG; purple, D-ribose; gray and purple, IPTG and D-ribose). Strains harboring logic gates were grown in the presence of all combinations of both inducers (each at a final concentration of 10 mM) and assayed for luciferase activity (Methods). The fold change (presented as the high output state divided by the low output state) is given in Supplementary Fig. 5 for each set of input combinations.  b The NOR gate is constructed by directing two anti-repressors to the same operator. c The A NIMPLY B gate is constructed by directing an I⁺ and a R^A to the same promoter. d The B NIMPLY A gate is constructed by directing an I^A and a R⁺ to the same promoter. Source data are provided as a Source Data file. Data represent the average of n = 6 biological replicates. Error bars correspond to the SEM of these measurements.