FoundationalConceptsNeuroscience

Several scientists at the time were already investigating the molecular
structure of DNA, and the results of the Hershey—Chase experiment
made the question of DNA’s structure all the more interesting. Among
those investigators were Rosalind Franklin (1920-1958) and Maurice
Wilkins (1916-2004) in London, Francis Crick (1916-2004) and
James Watson (born 1928) in Cambridge, England, and Linus Pauling
at Caltech in Pasadena, California. Within a year, in early 1953, Crick
and Watson proposed their famous double-helical structure for the
DNA molecule. They published their structure in a one-page paper
in the journal Nature in April 1953 and suggested that the genetic
material was composed of two long strands of DNA, deoxyribonucleic
acid. Each strand consists of a sequence of nucleotide bases, adenine
(A), thymine (T), guanine (G), and cytosine (C), joined by covalent
bonds to a very long backbone of sugar molecules (deoxyribose) and
phosphates (phosphorus-oxygen groups). The two strands wrap
around one another, forming a double helix, and are held together by
hydrogen bonds (dashed lines) between the nucleotides—adenine to
thymine, and guanine to cytosine.