Why DNA has 2 different sizes grooves?

Answer 1

As the DNA strands wind around each other, they leave gaps between each set of phosphate backbones, revealing the sides of the bases inside. There are two of these grooves twisting around the surface of the double helix: one groove, the major groove, is 22 Ã… wide and the other, the minor groove, is 12 Ã… wide. The narrowness of the minor groove means that the edges of the bases are more accessible in the major groove. As a result, proteins like that can bind to specific sequences in double-stranded DNA usually make contacts to the sides of the bases exposed in the major groove. This situation varies in unusual conformations of DNA within the cell , 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.

Answer 2

DNA has two different size grooves, the major groove and the minor groove, due to the structural arrangement of the double helix. The major groove is wider and allows for better access to the nucleotide bases, making it important for protein binding and gene regulation. The minor groove is narrower and plays a role in DNA-protein interactions by providing a specific interface for proteins to recognize the sequence of DNA.