Khorana, the Nobel laureate we forgot

Dr Har Gobind Khorana, who died November 9 in Massachusetts, was the first person of Indian origin since Independence to receive the Nobel Prize. If you have crammed the contents of a high school science textbook, Dr Khorana’s name might fleet in and out of memory, along with the acronym RNA.

RNA stands for Ribonucleic Acid, one of three macromolecules (apart from DNA – Deoxyribonucleic Acid – and proteins) that are the essence of all known forms of life. The components of nucleic acids are nucleotides, and their precise sequence enables RNA to encode genetic information. The microbiology we take for granted today was the subject of intense debate and speculation in 1968. Dr Khorana’s distinction shines bright in that climate.

1.    In the late 1960s Dr Khorana demonstrated how nucleotides in nucleic acids, which bear the cell’s genetic code, control how the cell synthesizes proteins. RNA is composed of four chemical bases –adenine, cytosine, uracil and guanine – represented by A, C, U and G. Khorana and two other biochemists, Marshall W Nirenberg and Robert W Folley, who worked independently on RNA, showed that these chemical bases combine to form three-letter "words" that represent amino-acids, the components from which proteins are constructed. They were awarded the Nobel Prize in Physiology and Medicine in 1968. It was the first Nobel honor for a person of Indian origin since Independence. Although Dr Khorana became a naturalized citizen of the United States in 1966, the land of his birth celebrated his achievement.

In 1972, Dr Khorana constructed the first artificial gene and followed that achievement by getting one to function inside the cell of a bacterium. These discoveries were central to the rapid advances genetic engineering to follow. His lab has since turned out several distinguished scientists, among them Nobel laureates Michael Smith, winner of the 1993 Nobel Prize in Chemistry.

1.    Khorana was born in Raipur in Punjab (now in Pakistan) in 1922 to what, in the great scientist’s own words, was “practically the only literate family in the village.” Home-schooled by his father, a taxation official, he got a master’s degree in science from Punjab University in Lahore. In 1945 he moved to the University of Liverpool where he earned a doctoral degree, then to Zurich for postdoctoral studies, and thereon to Cambridge. After a stint in Vancouver, Canada he moved to the United States, beginning with the University of Wisconsin-Madison and eventually to the Massachusetts Institute of Technology (MIT) in 1970, where he was Alfred P Sloan Professor of Biology and Chemistry until his retirement in 2007. Esther Elizabeth Sibler, the Swiss national he married in 1952, brought stability and purpose to his life. She died in 2001. Of their three children, the eldest Julia Elizabeth, 58, and Dave Roy, 53, survive them. Daughter Emily Anne died in 1979.

Shy and unassuming, Khorana was known to be uncomfortable speaking on the phone. The story goes that he had to be tracked down after several calls and messages from the White House went unattended. That was 1987, and Khorana was being approached by the highest office in the United States to be informed that he had won the prestigious National Medal of Science. He was a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences.