Fig. 3.

Knot tightening by supercoiling also occurs in the case of longer chains of around (A) 3 kb and (B) 6 kb. A clear shift is observed in the distribution of the length of the knotted portion. Interestingly the peak of the distribution is situated in both cases around 220 nm (650 bp), showing that, for the observed molecular lengths, the knot tightening effect is largely independent from the chain size. The snapshots show typical configurations with the localized knotted domain indicated in green.