FIG. 6.

Polymerase reconstituted with σ^Δ608-613 or σ^Δ604-613 is defective for MotA-dependent transcription at P_uvsX. AsiA (23 pmol) and the indicated σ⁷⁰ (1.3 pmol) were incubated for 10 min at 37°C in 2.5 μl of incubation buffer I. The mixture was placed on ice, and then 0.5 pmol of core polymerase in 2.89 μl of incubation buffer II was added. Transcription was initiated by adding an aliquot (2.16 μl) of the resulting solution to 2.35 μl of DNA buffer containing 0.02 pmol of linearized pDKT90 DNA with or without 1.9 pmol of MotA. (A) The ³²P-labeled P_uvsX RNA obtained after a set of single-round transcription reactions; (B) quantitation of the results from three independent reactions. For each σ⁷⁰, the values shown for +AsiA, +MotA, and +AsiA/MotA were normalized relative to a value of 1 for that polymerase alone.