FIG 2.

YvmB represses pulcherriminic acid biosynthesis by binding to the promoter of yvmC-cypX. (A) Effects of yvmB deletion (DW2 ΔyvmB) and overexpression (DW2/pHY-yvmB) on pulcherriminic acid production. (B) Gene transcription variations in yvmB deletion and overexpression strains. (C) Binding of the YvmB protein to the promoter regions of yvmC and yvmA. Gel shifts of the labeled P2-yvmC (87 bp) and P1-yvmA (91 bp) probes by the YvmB protein are shown. The concentrations of YvmB in lanes 1 to 8 were 0, 1, 2, 5, 0, 1, 2, and 5 ng/μl, respectively. Twenty nanograms of the P2-yvmC (lanes 1 to 4) or P1-yvmA (lanes 5 to 8) probe was added to each lane. The nonspecific competitor poly(dI-dC) was added to the EMSA binding buffer. (D) Expression-level comparisons of PyvmC-amyL and PyvmA-amyL transcriptional fusions. The amyL gene on the chromosome was deleted in DW2 ΔyvmB for the construction of DW2 ΔyvmB ΔamyL. pHY-PyvmC-amyL was transformed into DW2 ΔamyL and DW2 ΔyvmB ΔamyL to construct DW2 ΔamyL/pHY-PyvmC-amyL and DW2 ΔyvmB ΔamyL/pHY-PyvmC-amyL. pHY-PyvmA-amyL was transformed into DW2 ΔamyL and DW2 ΔyvmB ΔamyL to construct DW2 ΔamyL/pHY-PyvmA-amyL and DW2 ΔyvmB ΔamyL/pHY-PyvmA-amyL.