Fig. 2.

Effect of rare codons in ORF1 on mCherry expression in ORF2 in E. coli strain BL21(DE3)pLysS. a BL21(DE3)pLysS harboring various plasmids were grown for 6 h in LB media after 0.5 mM IPTG induction. mCherry fluorescence of bacterial cells suspension was measured every hour using a Luminar fluorescence spectrometer. The fluorescence intensity is indicated as a fluorescence count value (unit = cnt) and normalized by OD₆₀₀. Data are representative of three independent experiments and values are expressed as mean ± SEM. b The recombinant E. coli suspension after 0.5 mM IPTG induction for 6 h. BL21(DE3)pLysS harboring different plasmids, 1. pET-RFP; 2. pO-RFP; 3. pOI-RFP; 4. pOII-RFP; 5. pOIII-RFP; 6. Control, BL21(DE3)pLysS harboring pET-21a with 0.5 mM IPTG induction. c Relationship of the genetic organization of recombinant plasmids and the expression level of the reporter gene mcherry