Figure 5.

2-Bromopalmitic acid and palmitic acid compete for the same TrwD binding site. TrwD ATPase rates (2 μm) were measured as described under “Experimental procedures” at increasing concentrations of palmitic acid (dark circles), 2-bromopalmitic acid (white circles), and mixtures of both fatty acids consisting of a fixed concentration of palmitic acid (500 μm) and increasing concentrations of 2-bromopalmitate (dark triangles). In the latter case, the protein sample was first incubated with palmitic acid for 5 min, and then 2-bromopalmitic acid was added at the indicated concentrations. Data were fitted to a sigmoidal Hill equation for inhibition (error bars indicate S.D.).