FIG 1.
Overview of the clp operon. (A) Schematic representation of the clp operon. The two GATC sites subject to methylation by Dam are indicated by GATCdist and GATCprox. Note the absence of a papI homologue in the clp operon. (B) Comparison of the nucleotide sequences of the regulatory regions of the clp and pap operons. Identical nucleotides in clp and pap are shown as boxed regions. Lrp-binding site positions 1 to 6 in the pap sequence are indicated with underlines, and letters a to g with overlines indicate the positions of Lrp-binding sites in the clp sequence, as identified by DNase I footprint. The regions corresponding to the PapB binding sites and the CAP binding site are represented with dashed underlines, and the putative promoter regions (−10 and −35 sites) with underlines. Red letters indicate GATC sites. Blue and red arrows represent the boundaries of the distal and proximal fragments, respectively, used in Biacore experiments.