The Watson-Crick Model of DNA
(1953)
Deoxyribonucleic
Acid (DNA) is a double-stranded,
helical
molecule. It consists of two sugar-phosphate
backbones
on the
outside, held together by hydrogen bonds between pairs
of
nitrogenous bases
on the inside. The bases are of four types (A, C,
G,
&
T): pairing always occurs between A &
T, and C & G.
James Watson (1928 - ) and Francis
Crick (1916-2004)
realized that these
pairing
rules meant that either strand contained all the information necessary to
make a
new copy of the entire molecule, and that the order of bases
might
provide
a "genetic code".
Watson and
Crick shared the Nobel
Prize
in
1962 for their discovery, along with Maurice Wilkins (1916-2004),
in whose lab Rosalind
Franklin (1920-1958) had
produced crystallographic evidence for a helical structure.
Crick went
on to do fundamental
work in molecular biology and neurobiology. Watson become
Director of
the Cold Spring Harbor Laboratory, and headed up the Human Genome
Project from the 1990s.