Figure 3. Effects of temperature on short RecA filaments.

(A–B) Time traces of polymerization and de-polymerization of RecA nucleoprotein filament on another 595 bp dsDNA tether in 1 µM RecA 1 mM ATP, 1x ATP regeneration system, 50 mM KCl, 10 mM MgCl₂, pH 7.4, at 37°C (A) first then 24°C (B) next. Different colors indicate data at different forces. The results revealed stable RecA nucleoprotein filament at 37°C and unstable RecA nucleoprotein filament at 24°C at low force, consistent with results obtained on large λ-DNA (Figure 2A–B).