FIG 1.

Regulation of target gene promoters by YjjQ and identification of a YjjQ DNA-binding motif. (A) The expression level of chromosomal promoter-lacZ reporter fusions was determined in the yjjQ⁺ strain background S4197 as well as in the yjjP-yjjQ-bglJ deletion strain T23 (ΔyjjQ). Further transformants of T23 (ΔyjjQ)-derived reporter strains with vector control plasmid pKESK22 (ctrl) and the yjjQ-containing plasmid pKEKD31 (+ YjjQ) were analyzed. Bacteria were grown to the mid-exponential phase (OD₆₀₀ of 0.5) in LB medium, which was supplemented with kanamycin and 1 mM IPTG in the case of transformants. The β-galactosidase activities of at least three biological replicates were determined. The following strains were used: T2047 and T1266 (P_flhDC), T2051 and T1541 (P_gfc), T2046 and T1268 (P_ompC), T2049 and T1533 (P_ybhL), T2050 and T1535 (P_ymiA), and T2048 and T1351 (P_yfiR). (B) Analysis of 150-bp DNA sequence encompassing the target promoters using MEME Suite (34) yielded a putative YjjQ DNA-binding motif. The individual sequences matching this motif in the target promoter fragments and their relative positions to the transcription start site are indicated at the bottom. At the gfc promoter, two sites were identified.