Gel mobility shift assays with His-NrrA and the promoter regions of the glgP1 and hetR genes. A, digoxigenin-labeled probe P1272 (50 pm) including the glgP1 promoter region was mixed with His-NrrA in the amounts indicated above each lane, and then the mixtures were subjected to electrophoresis. Nonlabeled fragments of P1272 (lanes 5 and 6), PhetR2 (lanes 7 and 8), and P1272D (lanes 9 and 10) were added at a final concentration of 0.5 nm (lanes 5, 7, and 9) or 1.5 nm (lanes 6, 8, and 10). B, binding of His-NrrA to probe PhetR1 (50 pm) was examined. His-NrrA was added in the amount indicated above each lane. Nonlabeled fragments of PhetR1 (lanes 3 and 4) and PhetR1D (lanes 5 and 6) were added at a final concentration of 5 nm (lanes 3 and 5) and 15 nm (lanes 4 and 6). Filled arrows, complexes of His-NrrA and P1272 or PhetR1; open arrows, probe alone; gray arrow, a nonspecific fragment amplified by PCR.