FIG. 1.
Anhydrotetracycline-inducible expression of Myc-tagged M. tuberculosis σ factors. (A) Structure of the plasmids used for expression of σ factors. OriE, replication origin in E. coli; OriM, pAL5000 mycobacterial replication determinant; Hyg, hygromycin resistance gene; TetR, Tn10 Tet repressor; pUV15-tetOrm, strong TetR-controlled mycobacterial promoter. (B) Time-dependent induction of Myc-tagged σA in M. bovis BCG-Russia. Samples were collected at 2, 4, 6, 8, 12, and 24 h after addition of 50 ng/ml anhydrotetracycline to the growth medium. Protein extracts were prepared and used for immunoblotting with the Myc 9E10 antibody. Lane C contained recombinant Myc-tagged σA.