Fig. 2: Stabilizing effect of DNA binding on the safety-belt dynamics based on all-atom MD simulations.

A Structural schematic highlighting functional regions of the condensin protein complex. The Ycg1 HEAT-repeat subunit is shown as an orange surface representation, and Brn1 kleisin is depicted in dark green. The linker region, absent from crystal structures and reconstructed, is shown in pale green. Specific Brn1 helices (α1-α4) are explicitly labeled for clarity. The C- and N-termini are indicated with red and blue dashed lines, respectively. Functional regions including the latch and buckle are distinctly highlighted, with symbolic representations for linker, latch, and PAR elements provided in the legend. B Residue-level RMSF comparison between the US and BS. Negatively charged residues exhibiting higher RMSF in the BS compared to the US are indicated with red circles. C Time-dependent contact numbers between the PAR and the rest of the protein complex in the US and BS during unbiased MD simulations. D Force profiles versus distance, derived from steered MD simulations. E Distance-dependent contact numbers from steered MD simulations. For the BS, contact numbers between PAR and DNA (purple), PAR and the remaining protein (green), and PAR and total remaining components (blue) are shown. For the US, the total contact number between the PAR and remaining components is shown in red. In (B–E), the shadow regions and error bars represent the mean  ± standard error of the mean (SEM) over n=3 independent MD simulations.