Ada Yonath

Nobel Prize in Chemistry


Ribosomes are cellular machines that are essential for protein synthesis, found in all organisms from bacteria to humans. For many years, scientists understood what ribosomes did, but no one yet knew how they worked. They had trouble studying the particles’ structure using X-ray crystallography because their large size, complexity and instability made their crystallisation extremely difficult. 

Professor Ada Yonath set about tackling this challenge. Although her initial attempts to crystallise ribosomes were fraught with technical challenges, Professor Yonath persevered. Her conviction that what others said was impossible could be done was inspired in part by the fact that the ribosomes of winter-sleeping polar bears are periodically organised on the inner side of the membranes of their cells — something she had read about by chance while recovering from a cycling accident.

Assuming that pressure cause ribosomes to have tight organisation as a way of minimising their deterioration during stress, Professor Yonath looked for ribosomes of bacteria   living under extreme conditions. She turned to the Dead Sea bacteria, which are known for their ability to withstand high salinity and temperatures. At the time, others criticised her decision to work with the little-known bacteria, but the discovery of heat-stable enzymes that revolutionised molecular biology soon silenced them. By the early 1980s, Professor Yonath was able to create the first ribosome crystals, taking advantage of the unusually stable ribosomes of her organism of choice.  

In 2009, Professor Yonath was awarded the Nobel Prize in Chemistry for her discovery of the structure of ribosomes. Based on the understanding of ribosomal function she uncovered, scientists can now explain how antibiotics act on bacteria. Because ribosomes are a major target for antibiotics, knowledge of these cellular structures go a long way in helping today’s researchers design new classes of antibiotics to tackle the growing threat of antibiotic resistance.

Aside from the intense scepticism that her work faced in the early days, Professor Yonath had to overcome several scientific difficulties, such as how ribosome crystals decay almost instantly when measured. To address this, she invented a new method for collecting data that was adopted as routine protocol throughout the world within just a few months — another reason she attained the Nobel Prize. 

Professor Yonath has received many international awards and honours, including the Israel Prize in 2002, the Wolf Prize in Chemistry in 2006, the Albert Einstein World Award of Science in 2008, and the L'Oreal-UNESCO Award for Women in Science in 2008. In 2015, she was awarded honorary degrees from the Medical University of Lodz, De La Salle University in the Philippines and the Joseph Fourier University in France.