FIG 1.

PhoP regulates genes involved in phosphate metabolism. (a) PhoP-binding motifs were identified in phosphate-related genes. (b) EMSA results indicating His-PhoP interactions with the predicted motifs. The DNA probes containing the predicted motifs were incubated with 1 μM protein and a 200-fold excess of nonspecific competitor DNA (sperm DNA). (c) EMSA results showing interactions between His-PhoP and the PHO box or mutant PHO box in the phoS2 gene. (d) Transcription profiles of phoPR and PhoP-regulated genes in response to phosphate downshift. (e) Transcription profiles of phoPR and PhoP-regulated genes in response to overexpression of phoP gene.