B. Trefz et al/PNAS 2014
DNA can get knotted naturally, and scientists have previously tied artificial loops into molecules of genetic material. Now, a team has created a computer simulation that shows how two knots on a strand of DNA can pass through each other without adding any additional snarls. One knot loosens while the other spreads along the curves of the first one and moves through it.
The way the knots pass through each other could play a role in sequencing DNA on nanopores once the strand sizes get bigger than 100,000 base pairs, the scientists report May 19 in the Proceedings of the National Academy of Sciences.