Altman, Sidney (1939-2022), a Canadian-born American molecular biologist, discovered important properties of a complex molecule called ribonucleic acid (RNA). RNA assists in constructing enzymes (types of protein), a process crucial to the workings of the living cell. Altman discovered that RNA also worked as a catalyst of the cell’s chemical processes. A catalyst is a substance that speeds up a reaction without itself being altered. Altman’s discovery clarified several problems in biology about the origins of life. Altman was awarded the Nobel Prize in chemistry in 1989, and shared the prize with Thomas Cech who worked independently in the same field. See Cech, Thomas Robert; Cell ( The genetic code).
Biologists had long been puzzled about which came first—enzymes, or RNA and deoxyribonucleic acid (DNA). The problem was that enzymes could not be produced without the direction of DNA and RNA; but DNA and RNA could not do their job without enzymes as catalysts to speed up their reactions. Now it appears that RNA is also a catalyst for the building of the proteins essential to life.
Altman had been trying to discover the composition of a catalyst, ribonuclease P. A series of experiments by Altman and other scientists showed that ribonuclease P itself contained RNA. The experiments also revealed that in a certain one-celled organism, called Tetrahymena, RNA could be produced without the aid of an enzyme. This discovery was made by Cech. Finally, Altman’s team discovered that the RNA part of ribonuclease P could act as a catalyst by itself.
Altman was born in Montreal, Quebec, Canada, on May 7, 1939. He graduated from Massachusetts Institute of Technology (MIT) in the United States. He then went to Columbia University and to the University of Colorado, where he gained his Ph.D. in molecular biology. He then spent two years at Harvard University, studying viral DNA. Altman worked with Francis Crick at the Medical Research Council Molecular Biology Laboratory in Cambridge, England. After leaving Cambridge, he joined the faculty of Yale University in 1971. He acquired American citizenship in 1984. Altman died on April 5, 2022.
See also Crick, Francis H. C.
