The coiling of a covalently closed circular duplex DNA molecule upon itself so that it crosses its own axis. A supercoil is also referred to as a superhelix. The B form of DNA is a right-handed double helix. Winding of the DNA duplex in the same direction as that of the turns of the double helix is called positive supercoiling. Twisting of a duplex DNA molecule in a direction opposite to the turns of the strands of the double helix is called negative supercoiling. See DNA gyrase, replisome.
Subjects: Medicine and Health — Genetics and Genomics.