Comparison of crossing segment juxtaposition angles in supercoiled,
braided, and catenated DNA. (A) We define the angle of juxtaposed
crossing segments (θ) for braids in
Fig. 1C and
analogously for supercoiled and catenated DNA. The angular distribution
between juxtaposed segments of DNA in simulated 3.5-kb (+) supercoiled
(σ =+0.05, green circles) and (–) supercoiled (σ =
–0.05, red circles) DNA under no force is plotted along with the angular
distribution between juxtaposed segments of DNA in simulated left-handed
(σbr = –0.05, green triangles) and right-handed
(σbr = +0.05, red triangles) braids of 3.5-kb nicked DNAs
held under 1 pN of tension. For comparison, the distribution of crossing
angles between randomly juxtaposed segments is shown (dashed black line). The
vertical solid black line is at θ = 57°. (B) The angular
distribution between juxtaposed segments of DNA in simulated DNA catenanes
with σcat = 0.045 (red squares), 0.036 (red triangles), 0.024
(red circles), and 0.012 (green circles). The distribution of crossing angles
between randomly juxtaposed segments is shown (dashed black line). The
vertical solid black line corresponds to θ = 57°.