Figure 3.

Effect of the expression level of the fused proteins according to the identity of the second codon. The efficiency of cell-free protein synthesis was enhanced by switching the second codon of ompTss and heposs into AAA (A). In contrast, protein synthesis was repressed when the second codons (AAA) of ompAss and ompCss were mutated into NGG codons (AGG, TGG, GGG and CGG) (B). After 2 h incubation, 15 μl of the reaction samples were withdrawn from the reaction mixture, and the [¹⁴C]leucine-labeled radioactivity was measured as described in Materials and Methods.