Fig. 3: Experimental construction of the layered feedback control in E. coli.
From: Layered feedback control overcomes performance trade-off in synthetic biomolecular networks
a The four genetic constructs designed for experimental construction of the open loop, the cis feedback, the trans feedback, and the layered feedback. b Part-characterization of the combinatorial promoter PRhl/LacO on its activation function. The signal output of PRhl/LacO upon Rhl induction, compared with the constitutive promoter Pcon and the Rhl-inducible promoter PRhl, performing in an RhlR integrated JS006 strain. c Part-characterization of sRNA regulator AS with its paired attenuator Att and its orthogonal attenuator Att(M). d Part-characterization of the combinatorial promoter PRhl/LacO on its repression function, tested with its repressor LacI and a mutated repressor LacI(M). LacI(M) was built off LacI, with the LacO binding site deleted. e RBS screening results for the expression of CinR to enable activation cascade. The RBS in Clone D8 was chosen to proceed with the following stages of construction. f RBS screening result for the expression of LacI to facilitate the trans feedback. The plot shows that the selected clone confirmed the functionality of the negative feedback without over-repression. All data are presented as mean value +/− standard deviation of n samples, n = number of biological replicates.
