THE ARTICLE published by Watson and Crick in 19531 was the landmark pointer to our contemporary model of DNA as a macromolecular structure. This lay on a well-worn path of biophysical analysis, reducing microscopic anatomy to the molecular level. It also helped inspire an enormous body of biochemical research that has defined DNA as the informational molecule, a discontinuity that has been labeled the Biological Revolution of the 20th Century. As a piece of structural analysis, the idea of the double helix includes the concepts (1) that DNA is a duplex structure, comprising two paired complementary strands, associated by secondary, noncovalent bonds; (2) that the strand pairs are coiled, forming a double helix; and (3) that these are antiparallel—the orientation of one strand being in the opposite polarity from the other.
The most novel features of DNA are associated with its duplicity, rather than its helicity. Linear polymers rarely
Lederberg J. What the Double Helix (1953) Has Meant for Basic Biomedical ScienceA Personal Commentary. JAMA. 1993;269(15):1981-1985. doi:10.1001/jama.1993.03500150093034