FIG. 5.

DNase I footprinting analysis of the MntH-coding (A) and noncoding (B) strands of the mntH operator with MntR protein. The 311-bp DNA fragment comprising nt 4581 to 4271 of section 217, labeled on the MntH-coding strand with the fluorescence-labeled YFEP5C primer (A), and the 462-bp fragment encompassing nt 4303 to 4764 of section 217, labeled on the noncoding strand with the Cy5-labeled YFEP4C primer (B), were incubated without (row 1) or with (row 2) purified MntR protein as described in Materials and Methods. The nucleotide sequence obtained from the dideoxynucleotide sequencing reaction with the same end-labeled primer is given at the bottom of each panel; the protected region is expanded for clarity. (C) Nucleotide sequence of the mntH operator region with the translational start site. The boxed region indicates the nucleotides protected from DNase I by MntR. The area active in the in vivo Fur titration assay is shaded. Palindromic sequences are denoted by convergent arrows, with complementary bases shown in bold. Nucleotides are numbered according to E. coli genome section 217.