FIG. 3.

The TEV IRES directs internal initiation in vitro under competitive conditions. eIF4F/eIFiso4F-reduced wheat germ lysate was programmed with uncapped control (i.e., GUS-SL-Con₁₄₄-luc-A₅₀) or uncapped TEV IRES-containing (i.e., GUS-SL-TEV-luc-A₅₀) dicistronic constructs at the concentrations indicated below the histograms. Luciferase activity is reported as the average (from 2 μl of lysate) of three translation reactions with the standard deviation for each construct shown. The degree to which the presence of the TEV 5′ leader increased translation relative to the control (i.e., fold increase) is indicated below each pair of mRNAs for each concentration tested.