Fig. 4. Gel mobility shift assays of wt and mutant RPA.
Increasing amounts of wt or the indicated mutant RPA (0, 1, 2, 6, 25, 50, 100, 250, 500, 1000, 2000, 6000, 20000 or 60000 pg) were incubated with 2 fmols of radiolabeled (dT)17 (A) or (dT)40 (B). The reactions were then resolved on a 6% nondenaturing polyacrylamide gel. The first lane of each gel (−), is a negative control reaction containing no protein. The positions of RPA-DNA complexes (S, singly-liganded; M, multiply-liganded) and unbound oligonucleotide (F) are indicated. The asterisk indicates a binding reaction containing equimolar amounts of RPA and substrate.