doublehelical

Doublehelical refers to a structural motif found in certain biological macromolecules, particularly nucleic acids and synthetic polymers, where two helical strands are intertwined around a common axis. This configuration is most famously observed in the double helix structure of deoxyribonucleic acid (DNA), a fundamental component of genetic material in living organisms.

In DNA, two polynucleotide strands wind around each other to form a right-handed double helix, stabilized by hydrogen bonds between complementary nitrogenous bases (adenine with thymine, and cytosine with guanine). This arrangement allows for the efficient storage and transmission of genetic information while providing structural stability. The double-helical structure was first proposed by James Watson and Francis Crick in 1953, based on earlier work by Rosalind Franklin and Maurice Wilkins, which provided critical X-ray crystallography evidence.

Beyond DNA, doublehelical structures are also found in other biomolecules, such as certain types of RNA (e.g., double-stranded RNA viruses) and synthetic polymers designed to mimic biological helices. These structures play roles in molecular recognition, catalysis, and material science applications, including drug delivery systems and nanotechnology. The stability and programmability of doublehelical motifs make them a subject of ongoing research in biochemistry, structural biology, and materials engineering. Variations in helical pitch, strand composition, and bonding interactions allow for tailored properties in both natural and engineered systems.