Double Helix

In molecular biology, the double helix is the structure formed by double-stranded molecules of nucleic acids such as DNA. The double-helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The DAN double-helix biopolymer of nucleic acids is held together by nucleotides which base pair together. In B-DNA, the most common double-helical structure found in nature, the double helix is right-handed with about 10–10.5 base pairs per turn. The double-helix structure of DNA contains a major groove and minor groove. In B-DNA the major groove is wider than the minor groove. Given the difference in widths of the major groove and minor groove, many proteins which bind to B-DNA do so through the wider major groove. The double helix structure of DNA was first proposed by James Watson and Francis Crick, based on the work of Rosalind Franklin, Raymond Gosling, Maurice Wilkins, and others. The term "double helix" entered popular culture with the 1968 publication of Watson's The Double Helix: A Personal Account of the Discovery of the Structure of DNA.