Born: 7 May 1939, Montreal, Canada
Affiliation at the time of the award: Yale University, New Haven, CT, USA
Prize motivation: "for their discovery of catalytic properties of RNA"
Prize share: 1/2
Enzymes are substances that speed up the chemical processes in organisms' cells without being consumed. It was long thought that all enzymes were proteins. Sidney Altman and Thomas Cech demonstrated that RNA can also function as an enzyme. In 1978, Sidney Altman studied an enzyme taken from the E. coli bacteria that has the ability to cleave RNA. This enzyme was a combination of a protein and RNA. He discovered that the enzyme lost its ability to cleave if the RNA was removed from the protein. Later, he also succeeded in proving that RNA alone had the same ability to cleave as the enzyme.