A: Western blot analysis of ompATb expression in the porin mutant M. smegmatis ML16 (ΔmspA ΔmspC ΔmspD). Proteins of M. smegmatis ML16 were extracted with 1% SDS, separated on a 10% SDS-polyacrylamide gel, and transferred to a PVDF membrane. Upper panel: OmpATb was detected with an OmpATb-specific antiserum (Senaratne et al., 1998). Lanes: M, Pre-Stained Protein Ladder; 1, ML16/pMS2 (empty vector); 2, ML16/pML588; 3, ML16/pML003; 4, ML16/pML1450; 5, ML16/pML2334; 6, 50 ng rOmpATb73-326 purified from E. coli; 7, 25 ng rOmpATb73-326 purified from E. coli. Arrow denotes full-length OmpATb. Lower panel: M. smegmatis RNA polymerase (RNAP) was detected on the same blot with a monoclonal antibody.
B: Western blot analysis of ompATb expression in M. tuberculosis strains. Proteins were extracted, separated, blotted, and detected as described above. Lanes: M, Pre-Stained Protein Ladder; 1, wt M. tuberculosis H37Rv; 2, ?ompATb strain ML163 (?ompATb::loxP); 3, ML168 (ML163::ompATb); 4, ML163/pML588 (pimyc-ompATb); 5, ML163/pML763 (ompATb operon); 6, 20 ng rOmpATb73-326 purified from E. coli; 7, 40 ng rOmpATb73-326 purified from E. coli. Arrow denotes full-length OmpATb. Lower panel: M. tuberculosis RNAP was detected on the same blot with a monoclonal antibody.