Figure 7.

Effect of a GTP analog on the import of a preSSU early import intermediate in intact or protease-treated chloroplasts. Intact chloroplasts or chloroplasts treated with 10 μg/mL thermolysin were incubated with in vitro-synthesized [³⁵S]preSSU in a standard import reaction containing apyrase or 25 μm ATP as indicated (Import inter.). The chloroplasts were re-isolated and resuspended in import buffer containing 1 mm ATP and 1 mm GTPγS as indicated and incubated at 26°C for 10 min (Chase). The chloroplasts were re-isolated and analyzed by SDS-PAGE and phosphor imager analysis.