Figure 2. Relationship between the number of AGG insertions and protein expression in different regulation systems.

(A) Constructs of rare codon devices with co-transcribed cognate tRNA^Arg (CCU) and the luciferase gene (green) with different numbers of AGG codons (cyan) under the T7 operon. (B) Regulation of luciferase expression using constructs shown in Fig. 2A. (C) Constructs of rare codon devices with the luciferase gene transcribed by the weak bla promoter. (D) Comparison between the real (cyan) and predicted (peach tint) results of luciferase expression regulated by the rare codon devices. Luciferase expression was predicted based on relative light units of luciferase with eight AGG codons and their ratios in Table 1.