Fig. 2.

T7 promoter library. (A) Synthetic overlapping oligos was annealed together and assembled into the AvrII and XbaI digested pETM6-eGFP vector backbone. Box region shows the overlapping region and sequence flanked by AvrII and XbaI is the core of the degenerate T7 promoter and lactose-repressor binding site. Strategically designed unique restriction enzyme sites are flanking the promoter, 5′UTR and terminator region to facilitate the insertion of regulatory element libraries. (B) Promoter strength screened by green fluorescence protein. (C) DAN sequence of representative promoters. (D) Statistical distribution of promoter strength across the engineered promoter library.