Fig. 6.
The stabilization of an intermediate by IpdAB. (A) The UV-visible absorption spectra of 3.5 μM IpdABRHA1 E105AA (gray trace) titrated with up to 5 μM COCHEA-CoA (purple trace). The buffer was Hepes and 1 mM MgCl2, pH 7.5 (I = 0.01 M). (B) Increase in absorbance at 310 nm of the E105AA·COCHEA-CoA complex as a function of COCHEA-CoA concentration. The curve represents a fit of the quadratic binding equation to the data.