Fig. 5. Insertion of Toc34 and variants into chloroplasts outer envelope membrane. (A) [³H]-Leucine-labelled Toc34 (upper, left), (2-230)Toc34 (lower, left), Toc34C++ (upper, right) and (2-230)Toc34C++ (lower, right) were incubated with chloroplasts as described and shown in the legend for Fig. 2. Binding and insertion was quantified as for Fig. 3. The binding of Toc34 was set to 100% and the numbers in brackets indicate the s.e.m. The models indicate the orientation of the proteins and the location of the C-terminus. The results represent an average of at least three independent experiments. (B) Insertion of [³H]-leucine-labelled (lane 1-3) and [³⁵S]-methionine-labelled (lanes 4-6) (2-230)Toc34 (upper panel) and (2-230)Toc34C++ (lower panel) into chloroplasts (lanes 2, 3, 5 and 6) was performed as described in Fig. 2 and followed by thermolysin treatment (Thr, lanes 3 and 6). In lanes 1 and 4, 10% of the translation product is shown.