FIG 4.
The β′CTD stabilizes the ω in M. tuberculosis core. (A) Structure of M. tuberculosis RNAP core with the magnified view showing the β′ C-terminal domain (aa 1271 to 1316, β′ CTD, green), ω subunit (magenta), and ω loop region (aa 65 to 89, blue) (PDB 5UH8). (B) SDS-PAGE of the purified M. tuberculosis core and coreΔβ′CTD. (C) In vitro abortive transcription of purified M. tuberculosis core or coreΔβ′CTD at Rv1494p. Activities of M. tuberculosis coreΔβ′CTD (200 nM) with addition of purified ωHis (200, 400, or 800 nM, respectively) were tested. RbpA and σA were added in each reaction. A representative transcription result from two independent tests is shown in each panel. Quantifications of transcripts from two independent tests are shown in each bottom section. Mtb, M. tuberculosis.