Ribonucleic acid (RNA) discovered
Ribonucleic acid (RNA) is a crucial molecule involved in various biological processes, particularly in the synthesis of proteins. The discovery and study of RNA gained significant momentum in the mid-1950s, particularly through the work of biochemists Marianne Grunberg-Manago and Severo Ochoa at New York University. They focused on an enzyme known as polynucleotide phosphorylase (PNP), isolated from the bacterium Azotobacter. Grunberg-Manago's experiments revealed that this enzyme could facilitate the assembly of ribonucleotides into RNA in a laboratory setting, although it was later clarified that its primary function was not RNA synthesis but rather RNA degradation.
This groundbreaking research was pivotal as it demonstrated the feasibility of synthesizing RNA strands outside of living cells, paving the way for advancements in understanding the genetic code and protein synthesis. By the early 1960s, these developments contributed significantly to the comprehension of how genetic information is translated into functional proteins, ultimately influencing various fields such as genetics, molecular biology, and biotechnology. The implications of RNA research continue to resonate in contemporary science, highlighting the molecule's integral role in cellular function and genetic expression.
On this Page
Subject Terms
Ribonucleic acid (RNA) discovered
The Event Using an enzyme extracted from bacteria, RNA—the material that transmits genetic information from deoxyribonucleic acid (DNA) for protein production—was synthesized in a cell-free system
Date Discovery published on November 11, 1955
The structure of DNA had been defined only two years before, published simultaneously by James Watson, Francis Crick, Maurice Wilkins, and Rosalind Franklin. The synthesis of RNA in test tubes, outside of a cell, provided a mechanism for understanding the process by which genetic information is translated into protein.
In the mid-1950’s, Marianne Grunberg-Manago, a French biochemist working with Severo Ochoa at New York University, was studying the process by which energy-rich phosphate bonds are utilized in biochemical reactions. Ochoa had isolated an enzyme that would soon be called polynucleotide phosphorylase (PNP) from the bacterium Azotobacter. Grunberg-Manago observed that if one mixed the enzyme with ribonucleotide diphosphates and appropriate accessory atoms and molecules, that the ribonucleotides could be assembled into a polymer of RNA. At the time, the researchers believed this was the actual RNA-synthesizing enzyme in the cell.
Within a year, it became clear that the function of the enzyme was not RNA synthesis; somewhat ironically, it represented a mechanism for the cell to degrade RNA. Nevertheless, the significance of the work included the demonstration that it is possible to synthesize RNA in a test tube, and that the enzyme provides one mechanism to do so in the laboratory.
Impact
The ability to synthesize RNA strands that could direct the formation of protein in cell-free systems was instrumental in defining the genetic code by the early 1960’s, and important to the understanding of protein synthesis itself.
Bibliography
Chamberlin, M., and P. Berg. “Deoxyribonucleic Acid-directed Synthesis of Ribonucleic Acid by an Enzyme from Escherichia coli.” Proceedings of the National Academy of Sciences USA 48 (1962): 81-94. Description of the process by which the authors synthesized RNA in a test tube.
Echols, Harrison. Operators and Promotors. Berkeley: University of California Press, 2001. History of molecular biology and the role played by leading scientists in its development. The presence of numerous diagrams and glossary help simplify the presentation.
Judson, Horace. The Eighth Day of Creation. New York: Cold Spring Harbor Laboratory Press, 1996. Probably the most complete work dealing with the history of molecular biology in a format for the nonspecialist.