FIG 5.
Effect of MTZ on formation of gel-retarded complexes with the porG promoter. EMSA was performed by using the indicated amounts of cell extracts (μg/ml), which were prepared following growth of H. pylori HP1061 or HP1061fur in medium supplemented with 10 μg/ml MTZ (+ MTZ) or with no MTZ (− MTZ). The cell extracts were incubated with a 32P-labeled DNA amplicon representing a portion of the porGDAB promoter from positions −89 to +25 depicted in Fig. 1. Samples were resolved by nondenaturing polyacrylamide gel electrophoresis, and the positions of the radioactive bands (C-1, C-2, and C-3) were detected by use of a PhosphorImager. Note the near absence of shifted complexes, particularly band C-3 in extracts from MTZ-grown bacteria.