Fig. 3. Coimmunoprecipitation of DmUba2 and DmUbc9. Immunoprecipitates were prepared from embryo lysates using the antibodies indicated (see Materials and Methods) and analyzed by immunoblotting using (A) DmUba2-specific antibodies or (B) DmUbc9-specific antibodies. The immunoprecipitation using anti-myc antibodies serves as a negative control. The dark band at 20 kDa in (B) is presumably an allotypic form of rabbit IgG light chain in the anti-DmUbc9 antibodies that is recognized by the HRP-conjugated goat anti-rabbit-IgG.