Fig 8.

Acetoacetyl-CoA increases the affinity of ArpR for the regulatory region of arsA. EMSA was performed using an arsA DNA fragment in the absence or presence of different amounts of acetoacetyl-CoA. The labeled DNA fragment containing the regulatory region of arsA was incubated with increasing concentrations of MBP-ArpR (0, 0.1, and 8.0 μM) and 0, 1, 4, 8, or 12 mM acetoacetyl-CoA. As a negative control, a 225-bp fragment containing the regulatory region of rpoS was included in each DNA binding reaction mix. (B) EMSA with MBP as a negative control.