Credit: © 2003 NPG

The genetic information coded into the nucleobase sequence of DNA serves as a blueprint for the production of the many different proteins found in the cell. The path from DNA to protein is not a direct one, however, and involves an intermediate — messenger RNA (mRNA). In a process known as transcription, a strand of DNA templates the formation of a complementary piece of mRNA, which is then translated into a string of amino acids that fold up to form a protein.

In recognition of his X-ray crystallographic studies that shed light on the first of these process — transcription — Roger Kornberg was awarded the Nobel Prize in Chemistry in 2006. Three years later, the second step in this biosynthetic pathway — translation — has been similarly recognized. The conversion of mRNA into proteins is accomplished by structures known as ribosomes, which themselves are huge conglomerates of proteins and RNA strands. Bacterial ribosomes, for example, are made up of a small and a large subunit, with molecular weights of approximately 800,000 and 1.5 million Da, respectively. It is for their X-ray studies of ribosomes — and the subsequent insight into their structure and function that this has provided — that Ramakrishnan, Steitz and Yonath have been awarded the 2009 Nobel Prize in Chemistry.

The work of the three new Laureates has led to a better understanding of the molecular basis of translation and may have wider implications for human health and medicine. Their structural studies have revealed how antibiotics can bind to ribosomes in different ways to disrupt protein synthesis — and this may lead to the development of new antibiotics in the fight against multiresistant bacteria.

 FURTHER READING

The Nobel Prize in Chemistry 2009