FIG. 3.

In vitro translocation of pro-OmpA into IMVs prepared from secY mutants. IMVs were prepared from strains TW156 (secY⁺), GN5 (secY205), KC5 (secYΔ5), KC6 (secYΔ6), and KC7 (secYΔ7). They were incubated at 37°C (upper panel) or at 20°C (lower panel) for 5 min in the presence of SecA, SecB, ATP, the ATP regeneration system, and ³⁵S-labeled pro-OmpA. PMF was imposed or dissipated, as indicated. Extents of translocation (solid columns) and signal peptide cleavage (open columns) were assayed. Values represent percentages of radioactivities associated with translocated (solid columns) and processed (open columns) molecules after appropriate corrections for the distribution of methionine residues. The number above each pair of columns indicates the percentage of translocated component in the processed protein.