Figure 7. Mei5-Sae3 lacks DNA single-strand annealing activity.

(A) The radiolabeled OL83 and unlabeled OL83-c oligonucleotides (0.83 μM nucleotides) were incubated in the absence of protein (A, panel I) or in the presence of Rad52 (0.34 μM, A, panel II) or Mei5-Sae3 (0.34 μM, A, panel III) at 37°C for the indicated times. (B) The same oligonucleotide substrates (0.83 μM nucleotides) were incubated in the presence of RPA (0.12 μM, B, panel I) and either Rad52 (0.34 μM, B, panel II) or Mei5-Sae3 (0.34 μM, B, panel III) at 37°C for the indicated times. For both (A) and (B), the samples were quenched with excess OL83-c and deproteinized by treatment with SDS (0.5% final), Proteinase K (0.5 mg/mL) for 15 min at 37°C. The reaction mixtures were resolved in 12 % non-denaturing TAE polyacrylamide gels. The gels were dried and subjected to phosphorimaging analysis. The position of the ssDNA (ss) and annealed dsDNA (ds) product are indicated on the right in (panels I–III). The results in panels I–III were quantified with ImageQuant (GE Healthcare) and plotted (panel IV).