FIG. 5.

(A) Identification of the core RNA polymerase subunits in the eluted fractions of biotin-streptavidin pull-down assays with the dps promoter at 48 (lanes a) and 72 (lanes b) hours under glucose-depleted conditions. The eluates were probed with M. tuberculosis β′ antibody and M. smegmatis α antibodies. In both cases, lanes S contain the purified holo-RNA polymerase as a standard. (B) Identification of new ECF family sigma factors σ^H and σ^F associated with the dps promoter by promoter-specific biotin-streptavidin pull-down assays. The eluted fractions, E1 and E2, were treated with antibodies against M. tuberculosis σ^H and σ^F, respectively. (C) Western blot with σ^A antibody done to check the sensitivity of the dps promoter with holo-RNA polymerase containing σ^A. Lane 1, pure σ^A; lanes 2 to 4, pull-down fractions with the 1.6-kb rel promoter (lane 2), the 2-kb acetamidase gene promoter (lane 3), and the 1-kb dps promoter (lane 4).