supercoiling
Quick Summary
Supercoiling is a biological process where a DNA double helix undergoes additional twisting. This can happen in the same or opposite direction of the original helix's turns.1
In circular DNA, like that found in bacteria, supercoiling can be actively induced. This involves cutting one strand, twisting it around the other, and then resealing the molecule. Each full rotation adds a supercoiled turn, potentially causing the DNA to collapse into a compact ball. Enzymes called gyrases and topoisomerases manage this winding and unwinding.2
In eukaryotic linear chromosomes, DNA is tightly bound by proteins, allowing the sections between these points to supercoil. This supercoiling is crucial for compacting the extensive length of DNA to fit within the cell's nucleus.2
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