why is negative supercoiling important for replication
This super coiling accommodates the stress energy and the DNA becomes stable with 10.6 bp per coil. Generally the density of the super coils a DNA is one super coil per 200bp or per ~20 turns of the helix. Negative super coils help in stabilizing certain DNA structures i.e. Z-DNA, cruciform DNA, triplex DNA. It also helps in unwinding of the DNA during replication as replication bubble or during transcriptional initiation as transcriptional bubble.