Red recombination of symmetrically resected dsDNA substrates. (A) Schematic representation of linear PSSP dsDNA substrates showing the distance (in nt) to two phosphothioate bonds that were symmetrically positioned from each 5' end. Additionally, phosphates were present at both 5'ends (black stars). Below the PSSP30 substrate is illustrated after Redα digestion exposing 30 nt ssDNA tails at each end; (B) Recombination efficiencies of the PSSP substrates. Either Redα, Redβ and Redγ (blue line, left ordinate) or only Redβ (red line, right ordinate) were expressed. In the second case (only Redβ) the dsDNA substrates were heat denatured prior to electroporation.