Figure 4
Local force destabilization following a double-strand DNA break (DSB). (A) Schematic representation of a randomly cross-linked (RCL) polymer, where N c random connectors (red) are initially added to the linear backbone (green) of a Rouse chain. A DSB is induced between monomers m 50 and m 51, modeled by removing the spring connectors between them and all random connectors to these monomers. (B) Mean maximal distance 〈Max(d(m 50, m 51))〉 for both the unbroken loci (blue) and DSB (orange) simulations, where the shaded are the STD. The black rectangle indicates the value obtained for N c = 130 matching L c (eq. 3) measurements reported in ref. 2, where we obtain 0.37 μm for the unbroken and 0.86 μm for DSB simulation. (C) The mean radius of gyration (MRG), 〈R g 〉, obtained from simulations of 100 monomer RCL polymer (blue) and after DSB between monomers 50 and 51 (orange). Three sample polymer realizations are shown for N c = 10, 50, and 150. For N c = 130 we obtain 〈R g 〉 = 0.15 μm for both cases. (D) The mean first encounter time (MFET) 〈τ E 〉 for m 50 and m 51 plotted with respected to N c for both the unbroken (blue) and DSB (orange) simulations. The MFET is displayed on a semi-log axes, where before DSB we obtained 〈τ E 〉 = 1 s and 2.8 s following DSB and the removal of 5 random connectors on average.
