DNA

The **DNA double helix** is the canonical three-dimensional structure of deoxyribonucleic acid. It consists of two long polynucleotide chains coiled around a common axis in a right-handed spiral, forming a shape similar to a twisted ladder or spiral staircase[1][2][4]. Each strand has a backbone made up of alternating sugar (deoxyribose) and phosphate groups; attached to each sugar is one of four nitrogenous bases—adenine (A), thymine (T), guanine (G), or cytosine (C)[1][2][6]. The two strands are antiparallel, meaning they run in opposite directions with respect to their 5’ and 3’ ends[1][4]. Base pairing occurs via hydrogen bonds between complementary bases—A pairs with T via two hydrogen bonds, G pairs with C via three hydrogen bonds—which holds the two strands together[1][2]. The double helix has major and minor grooves along its length; these structural features are important for protein-DNA interactions such as those involved in gene regulation[5]. The double-helical structure allows for accurate replication during cell division and serves as the template for transcription into RNA during protein synthesis[2][6]. While many drugs interact with DNA by binding within its grooves or intercalating between base pairs—especially chemotherapeutics—the "DNA double helix" itself is not considered a therapeutic target like an enzyme or receptor. Rather, it is the fundamental molecule encoding genetic information. **Note:** "DNA double helix" refers specifically to the structural conformation of nucleic acids rather than an individual molecular target such as an enzyme, receptor, transporter, etc. Therefore: > The entry "DNA double helix" is not considered a therapeutic target per se but rather describes the physical structure adopted by deoxyribonucleic acid molecules. Drugs may interact with this structure nonspecifically but do not 'target' it in the same sense as proteins like receptors or enzymes. If you require structured data about specific proteins that bind to or modify DNA—for example topoisomerases ("Topoisomerase I"), polymerases ("DNA polymerase"), histones ("Histone H3")—those would be appropriate targets under your conventions.

Other names

Deoxyribonucleic acidDNA duplexB-DNA (for the most common form)Double-stranded DNA

Intercalation between base pairs disrupting replication/transcription Alkylation or crosslinking of strands inhibiting function and causing cell death