FIG. 2.

Effects of divalent cations on μ2 binding to poly(U)-Sepharose and poly(I-C)–Sepharose. Sepharose CL4B (Seph4B), poly(U)-Sepharose, and poly(I-C)–Sepharose were washed as for Fig. 1 RNA binding assays, except that 5 mM Mn²⁺ was substituted for with 5 mM Mg²⁺ or no divalent cation where indicated. Translated products (as for Fig. 1) were precleared with Sepharose CL4B and then incubated with the indicated beads as for Fig. 1 RNA binding assays, except that all incubations and washes contained the indicated divalent cation. Total translated product and triplicate samples (μ2) or single samples (luciferase [lucif]) bound to the indicated beads were resolved by SDS-PAGE and scanned with a Packard instant imager. The manufacturer’s software was used to select bands of the appropriate molecular weight for quantitation, and the percent of protein bound was calculated relative to total translated μ2 or luciferase (mean ± standard deviation).