FIG. 2.

Gel retardation of the operator-promoter region of dcuB by DcuR. The results of gel retardation analysis of DcuR (A and B) and acetylphosphate-treated DcuR (C) with the −327 to +24 (A) and −517 to −318 (B and C) fragments of the dcuB promoter-operator region are shown. Similar gel retardation studies with −517 to +24, −432 to −318, and −432 to −371 dcuB operator-promoter fragments were performed (data not shown), and the results are summarized in Fig. 1A. The mobility positions of the free DNA and various DcuR-DNA complexes are indicated. For DcuR-P, the concentrations given are for the protein at the beginning of the phosphorylation reaction. The final concentrations of DcuR-P are likely to be lower due to precipitation induced by the acetylphosphate treatment.