Figure 6.

Interaction between FFA-1 and RPA. (A) Coimmunoprecipitation of FFA-1 and RPA. Western blot analysis of the proteins brought down from the cytosol by the Affi-gel protein A beads precoated with the indicated antibodies. Blots were probed with the rabbit anti–FFA-1C (top) and rabbit anti-RPA (bottom). (B) Mapping of the RPA interaction domain in FFA-1. The various GST–FFA-1 fusion proteins were incubated with the cytosol and then brought down by glutathione beads. The bound proteins were then subject to Western blot analysis with the purified rat anti-RPA antibody. (C) Interaction between GST-Xho and the purified Xenopus RPA in the presence or absence of DNase I. The proteins brought down by glutathione beads were analyzed by Western blot with the purified rat anti-RPA antibody. (D) Amount of RPA bound to GST-Stu/Xho. GST-Stu/Xho (500 nM) was incubated with 5 μl of cytosol in a 15-μl reaction and then brought down by glutathione beads. Indicated amounts (as percentages of cytosol) of the beads and supernatant fractions were analyzed by Western blot with the purified rat anti-RPA antibody.