This situation varies in unusual conformations of DNA within the cell (see below), but the major and minor grooves are always named to reflect the differences in size that would be seen if the DNA is twisted back into the ordinary B form.Isemeji ipileIn a DNA double helix, each type of nucleobase on one strand normally interacts with just one type of nucleobase on the other strand.. 
These structures are stabilized by hydrogen bonding between the edges of the Bses and Chelation of a metal ion in the centre of each four-base unit.. 