Nobel Laureate in Chemistry, 1989

Sidney Altman was born in Montreal in 1939, the second son of poor immigrants. "The two events that sparked my early interest in science", he recalls, "were the appearance of the A-bomb and a book about the periodic table of the elements that I was given when I was 13".

By the time he reached high school, Altman was able to choose, "without any practical encumbrances", the subjects that he wanted to pursue in college: an unexpected series of events led him to study physics at the Massachusetts Institute of Technology, where he "experienced four years of over-stimulation among brilliant, arrogant and zany peers and outstanding teachers", and where he obtained the B.S. in Physics in 1960. During his final semester at MIT, he took a short introductory course in molecular biology, which familiarized him with nucleic acids and molecular genetics.

After having left Columbia he decided to enroll as a graduate student in biophysics at the University of Colorado Medical Center, where he started "to enjoy molecular biology in a productive manner", working with Leonard Lerman.

Two years later he became a member of the group led by Sydney Brenner and Francis Crick at the Medical Research Council Laboratory of Molecular Biology in Cambridge, England, which "turned out to be scientific heaven". Here he started the work that led to the discovery of RNase P and the enzymatic properties of the RNA subunit of that enzyme. The discovery of the first radiochemically pure precursor to a RNA molecule enabled him in 1971 to get a job as an assistant professor at Yale University, where he subsequently became Professor in 1980, Chairman of his department from 1983 - 1985 and Dean of Yale College fom 1985-1989, when he returned to the post of Professor on a full time basis.

In 1989 he was awarded the Nobel Prize, together with Thomas Cech, "for their discovery of catalytic properties of RNA".

Altman’s discovery concerns fundamental aspects of the molecular basis of life: a catalyst is a molecule which can facilitate a chemical reaction without being consumed or changed. Virtually all chemical reactions taking place in a living cell require catalysts, which are also called enzymes.

Until the results of Altman and Cech became known, all enzymes were considered to be proteins, whose specific properties and functions are determined by hereditary characters, or genes, composed of deoxyribonucleic acid, better known as DNA.

During the 1970s, Altman studied how the genetic code of the DNA was transcribed into RNA. This process requires, apart from the actual transcription, a shearing and splicing of the RNA molecules, because the DNA strands contain regions which are not essential for making proteins, and the excess codes are also transcribed into the RNA molecules.

Before the RNA can be further used by the cell, these extra pieces of nucleic acid have to be removed and the useful pieces rejoined. As all chemical reactions in a cell, this RNA shearing and splicing requires enzymes. It was during the search for the enzymatic proteins of these reactions that he made his surprising discovery - the enzymes were not proteins but nucleic acids!

The discovery of catalytic RNA has altered the central dogma of the biosciences. Moreover, it has already had a profound influence on our understanding of how life on earth began and developed. We know that the flow of genetic information from DNA to protein requires enzymes and other proteins. So which was the first biomolecule - DNA or protein? The discovery of catalytic RNA may solve this "chicken and egg" problem. It is very likely that the RNA molecules were the first biomolecules to contain both the genetic information and play a role as biocatalysts.

Catalytic RNA also provides gene technology with a new tool, with potential to create a new defence against infections. In 1997 Altman experimented a method to fight antibiotic resistance, inserting artifical genes in bacteria, in order to make them highly sensitive to two widely used antibiotics, ampicillin and chloramphenicol.

Besides the Nobel Prize Altman received several awards, among which the National Institutes of Health Medical Award.

He is married since 1972 to Ann Korner, who he defines "my colleague, mentor and friend in every respect", and has two children, Daniel, born in 1974 and Leah, born in 1977.