Figure 1.

The effect of C1 DNA on OmpR phosphorylation by acetyl phosphate. OmpR (7.5 μM) was phosphorylated in a buffer described in Materials and Methods with 25 mM acetyl phosphate in 300 μl for 120 min in the absence (A) or presence (B) of 15 μM C1 DNA, and the products were isolated on C4 reverse-phase HPLC as described (15). In A, 32% of the OmpR is phosphorylated compared with 94% in B. The percentage of the protein that is phosphorylated is determined by combining the areas of the two peaks (OmpR-P + OmpR). The area under each individual peak, representing the fraction of either OmpR-P or OmpR, is expressed as a percentage of the total protein.