Thomas Cech and Sidney Altman were awarded the 1989 Nobel Prize for Chemistry for their discoveries concerning RNA (ribonucleic acid), which overturned the notion that RNA is merely a genetic messenger – an intermediate in the synthesis of proteins from DNA. Prior to Cech’s research on RNA, most scientists thought that in living cells proteins called enzymes were the only catalysts − substances that accelerate chemical reactions without themselves being consumed or changed. Cech showed that some RNAs also act as enzymes, calling them “ribozymes.” This discovery had major implications for genetic engineering as well as for understanding how life arose. The Nobel Committee noted:
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.
- Kruger, K., Grabowski, P. J., Zaug, A. J., Sands, J., Gottschling, D. E. and Cech, T. R., “Self-splicing RNA: autoexcision and autocyclization of the ribosomal RNA intervening sequence of Tetrahymena,” Cell 31(1): 147-57 (Nov. 1982).