Figure 3.

The levels of protein import into atToc159-A864R chloroplasts are increased compared with wild-type chloroplasts. (A) Isolated chloroplasts from WT, WT:ppi2, and A864R:ppi2 plants were incubated with in vitro–translated [³⁵S]preSSu under import conditions for the times indicated. The graph presents quantification of triplicate experiments from import of preSSu at the 5-min and 20-min time points. (B) Chloroplasts from preSSu 20-min import reactions in A were treated with 100 μg/ml thermolysin on ice for 30 min to discriminate between bound and fully imported protein. (C) Effect of GTPγS on protein import into WT:ppi2 and A864R:ppi2 chloroplasts. Chloroplasts were incubated under standard import conditions for 20 min in the presence of GTP or GTPγS. The graph presents quantification of preSSu import from triplicate experiments. The position of preSSu and imported mature SSu are indicated at the left of each panel. IVT, 10% of in vitro–translated [³⁵S]preSSu added to each import reaction. Dashed lines indicate that the figures were generated from different regions of the same SDS-PAGE gel using samples from the same experiment.