FIG 4.

Functional compatibility of each domain structure in the EHcV and HCV 5′ UTRs in terms of its IRES activity. (A) Schematic diagram of the bicistronic reporter transcripts including the chimeric 5′ UTRs. Domain I, II, or III of RL-HCV-FL was replaced with EHcV domain I (ESLI), II (ESLII), or III (ESLIII), respectively. Domains I, II, and III of RL-EHcV-FL were replaced with HCV domains I (HSLI), II (HSLII), and III (HSLIII), respectively. (B and C) The bicistronic reporter plasmids bearing the transcripts shown in panel A were transfected in triplicate into 293T cells. The resulting cells were harvested at 24 h posttransfection and subjected to a dual-luciferase assay. The ratio of FL to RL was normalized with the mean of that of RL-HCV-FL carrying WT HCV IRES. The statistical significance versus the cells transfected with RL-HCV-FL is indicated. *, P < 0.05; **, P < 0.01; n.s., not significant. The data are representative of the results of three independent experiments. The error bars indicate standard deviations.