|From Proteins to DNA
In 1951, both Sir William Lawrence Bragg and Linus Pauling wanted to find the structure
of the master molecule of life, the gene. But both were focused on proteins.
The only strong evidence against protein genes and in favor of DNA was a little-appreciated
paper published in 1944 by Rockefeller Institute researcher Oswald Avery, who found that DNA, apparently by itself, could transfer new genetic traits between
Pneumococcus bacteria. For years no one paid much attention to Avery's work. "I knew the contention
that DNA was the hereditary material, but I didn't accept it," Pauling said about
his thinking in 1951. "I was so pleased with proteins, you know, that I thought that
proteins probably are the hereditary material rather than nucleic acids-but that of
course nucleic acids played a part. In whatever I wrote about nucleic acids, I mentioned
nucleoproteins, and I was thinking more of the protein than of the nucleic acids."
Click images to enlarge
Portrait of Oswald T. Avery. 1940s.
"Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal
Types: Induction of Transformation by a Desoxyribonucleic Acid Fraction Isolated from
Pneumococcus Type III." January 1944.
"Both Francis and I had no doubts that DNA was the gene. But most people did. And
again, you might say, 'Why didn't Avery get the Nobel Prize?' Because most people
didn't take him seriously. Because you could always argue that his observations were
limited to bacteria, or that [the transformation of Pneumococcus that he described
was caused by] a protein resistant to proteases and that the DNA was just scaffolding."