FIG. 6.

Ribosomal protein S9 requires the context of the ribosomal 40S subunit to bind to the HCV IRES. (A and B) UV cross-linking of native S9 as a constituent of 40S subunits (A, lanes 2 and 3; B, lane 2) and (B) UV cross-linking of recombinant S9 (B, lane 3) to [³²P]UTP-labeled HCV nt 40-372 RNA (A, lanes 1 and 2; B, lanes 1 to 3), nt 118 to 372 RNA (A, lane 3) or nt 118-372(Δ229-238) RNA (panel A, lane 4). Samples were treated with RNases after irradiation, and proteins were resolved by gel electrophoresis. The position of S9 is indicated to the right of both panels. (C) Effect of recombinant S9 added with dicistronic cyclin-CSFV IRES-NS′ mRNA at the indicated molar ratios to translation reaction mixtures on CSFV IRES-mediated NS′ translation.