Fig. 2.

SigR-dependent transcription activation of the hrdB gene encoding the major sigma factor in S. coelicolor.

A. The position of the SigR-dependent promoter p2 upstream of the hrdB coding region predicted from ChIP-chip and sequence pattern. The previously reported promoter p1 resides further upstream.

B. S1 nuclease mapping of hrdB transcripts from diamide-treated cells revealing two alternative transcripts.

C. Western blot analysis of HrdB protein. Crude extracts from cells treated with diamide (0.1 mM) for up to 120 min were analysed to quantify the amount of HrdB protein as described in Experimental procedures. For each lane, an aliquot of 1 µg protein extract plus 1 µg BSA in lysis buffer was analysed. Results from four independent experiments were quantified to estimate changes in the level of HrdB protein upon oxidative stress, presented with the average value ± standard deviations (SD).