RNA was identified as a distinct nucleic acid and its roles clarified through a sequence of discoveries by several scientists over the 19th and 20th centuries. Key highlights include:
- Friedrich Miescher (1869): Isolated a substance from pus cells he termed "nuclein," later known as nucleic acids, laying the groundwork for understanding DNA and RNA. This marks the earliest recognition of nucleic acids as a distinct biological molecule.
- Early RNA roles and synthesis: The idea that RNA participates in protein synthesis emerged in the mid-20th century, with pivotal work showing RNA’s involvement in cellular processes and enzyme activities. The identification of RNA’s catalytic potential and its involvement in gene expression followed in subsequent decades.
- Discovery of messenger RNA (mRNA): The concept and identification of messenger RNA, the RNA transcript that conveys genetic information from DNA to ribosomes, were demonstrated by François Jacob, Jacques Monod, François Gros in the early 1960s, with critical experimental confirmation published in 1961. This established RNA as an informational intermediate, not just a structural molecule.
- RNA structure and sequencing milestones: The first RNA crystal structure was achieved in 1956 by Alex Rich and David Davies, marking a milestone in RNA structural biology. Later advances included sequencing milestones for RNA molecules, such as tRNA sequencing in the 1960s and 1970s, and broader genome sequencing efforts for RNA viruses in the 1970s.
- Nobel-winning RNA biology discoveries: In 1989, Sidney Altman and Thomas Cech demonstrated that RNA can act as a catalyst on its own (ribozyme activity), revealing RNA’s enzymatic capabilities and catalysis, a landmark shift in molecular biology. This work helped establish RNA’s central role in biology beyond merely transcribing genetic information.
If you’d like, I can tailor a concise timeline or provide citations from reliable sources for each milestone.