Immunoprecipitations of SecB complexes A. Precipitation was performed with antibody directed against SecB, followed by immunoblotting using antibody against the His tag on the λ repressor fragments. B. Precipitating antibody was directed against the His tag, immunoblotting utilized the anti-SecB antibody. C. Precipitation was carried out with antibody against LamB, anti-SecB was used for immunoblotting. In all gels, samples were as follows: lanes 1–4 – whole cell lysates prior to immunoprecipitation, lanes 5–8 – immunoprecipitated material; lanes 1 and 5 – N102LT/prlA4, lanes 2 and 6 – LA57-N102LT/prlA4, lanes 3 and 7 – N102LT/prlA+, lanes 4 and 8 – LA57-N102LT/prlA+, lane 9 in gel B – purified SecB.