|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
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."