FIG. 4.

DNase I footprint of E. coli crude extracts containing YrzC on the ytlI promoter region. The 241-bp PCR fragment representing the coding strand of the ytlI promoter region (positions −130 to +111) was 5′-end labeled and incubated in separate reactions without protein (lane 1), in the presence of 20 μg, 30 μg, or 40 μg of crude extracts without YrzC (lanes 2, 3, and 4), or in the presence of 10 μg (lane 5), 20 μg (lane 6), 30 μg (lane 7), or 40 μg (lane 8) of the E. coli crude extracts containing YrzC and subjected to DNase I digestion. Lane 9, G+A sequencing ladder. The position of the protected region (positions −54 to −21) is marked by a vertical bar. Numbers indicate the distance from the transcription initiation site of the ytlI operon. The −10 and −35 boxes are indicated by brackets.