Figure 4.

Peptidyl-tRNA hydrolase prevents the inhibition of β-gal caused by the AGAAGA codons. (A) In vitro transcription–translation reactions, supplemented with Pth (3 µg/50 µg reaction), were primed with AGAAGA lacZ constructs as described in Figure 1 legend. (C) Absolute radioactivity levels indicated as electronic density values (pixels) from each construct were quantified as indicated in ‘Materials and Methods’ section and plotted against the AGAAGA codon position. (B) In vitro reactions, supplemented with Pth (3 µg/50 µl reaction), were directed with the +7 AGA lacZ construct and the AGAAGAUAA minigenes as in Figure 2 legend. The mobility of β-galactosidase (β-gal) and β-lactamase (β-lac) is indicated. (D) β-gal absolute radioactivity levels from the reporter gene indicated as electronic density values (pixels) were plotted against minigene length.