The (when stretched) two-meter-long DNA molecule in each human cell is continuously being unpacked and packed again to enable the expression of genetic information. When genes must be accessed for transcription, the DNA double helix unwinds and the strands separate from each other so that all the elements needed for gene expression can access the relevant DNA region. This process results in the accumulation of DNA supercoiling that needs to be resolved.
Click here for original story, DNA structure itself is involved in genome regulation
Source: Phys.org