FIG. 5.

Effect of NtcA and 2-OG on permanganate footprinting in promoters of the hetC and devB genes. The DNA fragments of the genomic regions of hetC (the fragment with the mutated −10 box in the lane marked with *; see the text for details) (A) and devB (B) genes were incubated, as indicated, with purified NtcA (188 and 130 nM, respectively) without or with 2-OG (0.6 mM) and then with purified RNAP holoenzyme (100 nM plus 390 nM SigA and 60 nM plus 110 nM SigA, respectively) and further incubated before potassium permanganate treatment (see Materials and Methods for details). Arrows point to the reactive T's (the noncoding strand of hetC and the coding strand of devB were subjected to primer extention). The −10 promoter element and the tsp (+1) are indicated in the corresponding sequence ladder.