Figure 7.

Function of Aro mutants in Rad51 mediated strand exchange. (A) Schematic of the RAD51 DNA strand exchange assay. RAD51 coated φX174 circular ssDNA recombines with φX174 RFI linear dsDNA. This leads to formation of joint molecules followed by the nicked circular product, containing the ssDNA circular substrate and the complementary ssDNA strand, and the displaced ssDNA strand. (B) Reactions containing indicated amounts of wild-type or Aro mutant forms of RPA were assembled (0 min) and incubated at 37° for 60 min. Positions of starting DNA (linear duplex), initially formed joint molecule intermediates and completely exchanged nicked circular product are indicated. Some denatured ssDNA (bottom of gel) was present in the starting DNA (0-min points).