FIGURE 3.

Skp1 activation of AgtA. A, activity was measured based on the transfer of [³H] from UDP-[³H]Gal to 3.7 mm F-pNP by His₆AgtA-FL, in the presence of the indicated concentrations of non-substrate Skp1 isoforms. The curve was fitted by non-linear regression modeled as a single site binding interaction. Data are reported as representative mean ± S.D. B, fold-activation of AgtA-FL and AgtA-CAT activity toward FG-octyl, FGGn-pNP, or FGGn-Skp1 in the presence of the indicated concentration of unmodified Skp1. C, reactions were prepared as in A with the indicated concentrations of unmodified Skp1 and NaCl. Total activation levels of triplicate reactions relative to AgtA-FL alone are plotted.