ROBERT HOLLEY was a biochemist of international renown who shared the 1968 Nobel Prize for medicine and physiology for his pioneering work on the chemistry of the genetic code.
Not only an outstanding scientist, Holley was a warm and generous mentor who regarded the younger members of his laboratory as an extended family. A gentle and modest man, he nevertheless greatly influenced others by his intellectual integrity, strength of character and dedication to science. Until the onset of his illness last year, he continued not only to direct research but also to conduct his own experiments with a quiet but determined enthusiasm for scientific discovery.
A native of Urbana, Illinois, Holley studied chemistry at the University of Illinois and earned his doctorate in organic chemistry at Cornell University in Ithaca, New York. He became an assistant professor of organic chemistry in 1948 at Cornell's Agricultural Station in Geneva, NY. In 1957, he joined the Department of Agriculture's Plant, Soil and Nutrition Laboratory at Cornell. He was appointed a professor of biochemistry at Cornell University in 1962; in 1964 he became professor of biochemistry and molecular biology at Cornell, and was the department's chairman from 1965 to 1966.
At the time he shared the Nobel Prize in 1968 with Marshall Nirenberg of the National Heart Institute in Bethesda, Maryland, and Har Gobind Khorana of the University of Wisconsin in Madison, Holley was a visiting Fellow at the Salk Institute for Biological Studies in La Jolla, California. The three men conducted research independently on different aspects of the genetic code that collectively explained how the genetic information stored in the DNA of a cell could be translated and used to make proteins, the building blocks of cells. Holley's seminal contribution, the result of nine years' work beginning in 1956, was to determine the structure of alanine transfer RNA.
This was the first time the sequence of a nucleic acid had been determined and from this sequence the first structure of a gene could be deduced. The work required the painstaking purification of small amounts of the RNA from more than 300lb of baker's yeast and the development of new sequencing methods for RNA. This accomplishment was like trying for years to solve a large jigsaw puzzle without knowing, until the successful conclusion, that all the pieces came from the same set.
Upon joining the Salk Institute as a resident Fellow in 1968 Holley turned his attention to a completely new problem - the regulation of cell growth and how abnormalities in this process cause cancer. This research led to the discovery of growth factors that stimulate or inhibit the growth of mammalian cells. These molecules are important in normal processes such as wound healing, as well as diseases such as cancer. His most recent work concerned factors that influence the timing of cell division, a critical element of growth control.
Besides the Nobel Prize, Holley received more than a dozen other prestigious awards and honours. These included the Lasker Award for Basic Medical Research, an American Cancer Society Research Professorship, and appointment to the National Academy of Sciences. Characteristically, however, he said in his Nobel address: 'Without minimising the pleasure of receiving awards and prizes, I think it is true that the greatest satisfaction for a scientist comes from carrying a major piece of research to a successful conclusion.'
In addition to his lifelong love of science, Holley was also a nature-lover and gifted sculptor, often working on pieces in his study at the Salk Institute high on the cliffs overlooking the Pacific Ocean. He displayed the same creativity with his art as he did with his science, excelling in both. He epitomised the best in science - always willing to share his time and ideas with others and to lead by example.