Fig 4. TriMV requires eIF4A helicase activity for its translation.

A) Relative luciferase activity in wheat germ extract of the TriMV 5’ UTR and m7GpppG-capped control polyadenylated mRNAs with increasing concentrations of the eIF4A-inhibiting drug hippuristanol, suspended in 5% DMSO and added to the translation reaction. The luciferase activities were standardized to the measured luciferase activities of each mRNA with no hippuristanol added. At the 0 μM concentration of hippuristanol, equal volume of 5% DMSO alone also was added to the reaction. B) Translation inhibition by 10 μM hippuristanol can be reversed by adding 15 μM recombinant wheat eIF4A protein.