FIG 5.

Electrophoretic mobility shift assay of purified S. marcescens PhoP with the phoP or arn promoter fragment. DNA fragments (0.1 μg) of the phoP promoter (431 bp), arn promoter (342 bp), or negative-control DNA (424 bp) obtained by PCR were incubated with the indicated concentrations (0, 0.5, 1, and 2 μM) of the PhoP protein. After protein-DNA complex formation, the fragments were resolved on a 5% nondenaturing polyacrylamide gel. Arrows, protein-DNA complex. Lane MW, size markers; lanes 1 to 4, phoP promoter with PhoP; lanes 8 to 11, arn promoter with PhoP; lanes 5 to 7, negative-control DNA with PhoP.