Figure 1: Rad51 monomer binds three nucleotides and stable nucleation requires six monomers.
From: Srs2 prevents Rad51 filament formation by repetitive motion on DNA
(a) Schematic diagram of DNA constructs used in Rad51-binding experiment. Partially duplexed DNA of various poly-thymidine tail lengths (T10–T20) contain donor (Cy3) at 3′-end and acceptor (Cy5) at duplex junction. FRET value decreases upon Rad51 formation. (b) FRET values collected over 5,000 single molecules are built into a FRET histogram. DNA-only high FRET molecules (grey) transition to low FRET (orange) upon Rad51 formation. A complete shift to low FRET is observed in T18 and T20. (c) smFRET traces show up to three, four and five steps observed for T10, T13 and T15, respectively, reflecting monomer-binding steps. (d) TDP for each DNA built by collecting FRET values before (y axis) and after (x axis) transition from single molecules that show monomer-binding steps.
