Figure 5.

Decrease in TopA activity from acetyl phosphate mediated nonenzymatic lysine acetylation. (A) Western blot analysis of nonenzymatically acetylated TopA. Purified E. coli TopA (1 μg) was incubated with 2 and 5 mM acP at 37°C for 4 h. Acetylated TopA was visualized by western blot analysis with anti-acetyllysine antibody. TopA on the membrane was stained with Coomassie blue. (B) Following incubation with and without acetyl phosphate, serial dilutions of TopA (32, 16, 8, 4, 2 ng) were incubated with 150 ng negatively supercoiled plasmid DNA (S) at 37°C for 30 min to compare the relaxation activity.