FIGURE 5.

IF3, not RRF/EF-G, stays on subunits after the subunit formation by three factors. W-ribosomes (0.07 μM) were dissociated into subunits by 1 μM RRF, 1 μM EF-G, 0.36 mM GTP, and 4.5 μM IF3 in conventional buffer R, then sedimented through a 15%–30% sucrose gradient. Fractions were taken from the bottom of the sucrose gradient (10 drops per fraction, 24 fractions), and IF3, EF-G, and RRF were detected by Western blotting. Positions of 30S, 50S, and 70S are indicated. St (standard), purified IF3, EF-G, and RRF as controls.