Fig 3.

SecA residues 2 to 11 are involved in SecA dimerization in vivo. Lysates from UV-treated (+) cells expressing pBpa-containing SecA (A) and pBpa-containing SecA and SecA-c-myc (B) were analyzed via Western blotting and probed with antibodies specific to His tag (A) and to c-myc tag (B). The corresponding nontreated (−) cells are also shown. The amount of sample proteins loaded for panel B is 3 times higher than that for panel A. To reduce the interference from the monomer bands, the gels in panel B were run longer to allow the monomer to migrate out of the gel (same in Fig. 4B). Cross-linked SecA dimer bands are indicated with asterisks. Lanes M, protein molecular mass markers, with molecular masses shown on the left.