FIG. 7.
Western blot (immunoblot) analysis of HemA[WT]-LacZ, HemA[AA]-LacZ, and HemA[KK]-LacZ expressed from F′ plasmids in E. coli protease mutants. Cultures were grown to an OD600 of 0.4 in minimal MOPS-glycerol medium with 2 μM ALA and kanamycin to maintain F′ plasmids. Samples were processed as described above for immunoblotting with anti-HemA MAb H17. All strains are E. coli. The arrows indicate the HemA-LacZ fusion protein as well as the native HemA protein encoded by the E. coli hemA gene. Lanes: a, TE7708 lon/F′ hemA1–416[WT]-lac [pr]; b, TE7714 lon/F′ hemA1–416[AA]-lac [pr]; c, TE7711 lon/F′ hemA1–416[KK]-lac [pr]; d, TE7706 clpP/F′ hemA1–416[WT]-lac [pr]; e, TE7712 clpP/F′ hemA1–416[AA]-lac [pr]; f, TE7709 clpP/F′ hemA1–416[KK]-lac [pr].