Ada Yonath

Ada Yonath was born in Jerusalem on June 22, 1939, into an Orthodox Jewish family of limited means.[1] Her parents, who were born in Poland, were Zionists who had immigrated to Palestine six years before her birth.[3][4] Her father was a rabbi, and he and her mother operated a neighborhood grocery.[3] The family lived in Jerusalem’s Geula neighborhood and shared a four-room apartment with two other families.[1][2] Although her parents were religious, they enrolled her in a secular school in the city’s Beit Hakerem neighborhood.[1]

Her childhood included an early interest in experimenting and finding out how the world worked.[3][4] She recalled conducting experiments on the family balcony, and one attempt to measure a balcony’s height had painful consequences: at the age of five, she stacked household furniture, fell into the garden, and broke her arm.[3][4] After her father’s death during her childhood, her mother raised Ada and her younger sister amid continuing financial hardship.[3][4] Yonath began working before she was 12, combining paid work with her education.[2]

In 1953, Yonath moved with her mother and younger sister to Tel Aviv, where she attended Tichon Hadash.[4] She helped support the family while studying, taking jobs that included washing floors and winding thread in a towel workshop.[4] Mathematics tutoring became another source of income; she taught other students, including children of new immigrants, and used her earnings to help pay her school tuition.[2][4] Her secondary education thus proceeded alongside practical responsibilities for the family’s finances.[4]

After finishing school, Yonath served in the Israel Defense Forces Medical Corps, where she was responsible for the first cycle of a medical officers’ course.[4] She then studied at the Hebrew University of Jerusalem from 1959 to 1964, earning a bachelor’s degree in chemistry in 1962 and a master’s degree in biochemistry in 1964.[2][4] Her university studies also included physics and biophysics.[1][3] She continued her education at the Weizmann Institute of Science in Rehovot, completing a doctorate in X-ray crystallography with distinction in 1968.[4] Her doctoral research investigated collagen using X-ray crystallography.[4]

In 1970, Yonath returned to Israel and established the country’s first protein-crystallography laboratory in the Weizmann Institute’s chemistry department.[2][5] For almost a decade, it remained Israel’s only laboratory of its kind.[2] Before returning, she had undertaken postdoctoral research at Carnegie Mellon University and the Massachusetts Institute of Technology.[2] At MIT she began investigating ribosome structure through X-ray crystallography and developed new approaches to examining the structural characteristics of large, complex molecules.[6] Her research and teaching appointments also included work at the University of Chicago and the Mellon Institute.[7]

Yonath’s institutional career at Weizmann developed alongside her ribosome research.[6] She served as a scientist from 1970 to 1974 and as a senior scientist from 1974 to 1983, became an associate professor in 1984, and attained a full professorship in 1988.[6][2] She headed the Structural Chemistry Department in 1989–1990 and the Structural Biology Department in 1992–1994.[2] Her appointments also included the Martin S. Kimmel Professorship of Structural Biology and leadership of the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly.[2] From 1988 to 2004 she directed the Mazer Center for Structural Biology.[4]

Her research leadership extended beyond Israel without replacing her work at Weizmann.[2] From 1986 to 2004, she simultaneously headed the Max Planck Research Units for Ribosomal Structure in Hamburg, Germany.[2] The Weizmann and Max Planck teams she led subsequently participated in determining the structures of bacterial ribosomal subunits.[4] Her career therefore combined the development of an Israeli structural-biology laboratory with sustained research activity at a major German scientific institution.[2][4]

The central problem she pursued was how the ribosome translates genetic instructions into proteins.[1] Ribosomes are complexes of RNA and protein, composed of a large and a small subunit, that carry out protein synthesis.[6] They assemble proteins using instructions carried by messenger RNA.[3] Yonath sought a three-dimensional structural description of this machinery that would illuminate protein biosynthesis rather than merely identify its components.[1] The work also had potential relevance to antibiotics because many of those drugs target ribosomes.[3] Her investigations of ribosome structure were additionally relevant to understanding antibody production.[5]

By the late 1970s, Yonath had undertaken the challenge of determining both ribosomal structure and the mechanisms through which ribosomes function.[4] X-ray crystallography required the biological material under investigation to be made into crystals, but ribosomes were regarded as too complex and unstable to crystallize successfully.[4] Their ability to adopt multiple conformations added to the difficulty of obtaining suitable crystals.[3] Other leading research groups had failed, and skepticism concerned not simply the speed of progress but whether the proposed approach could work at all.[4]

The project was difficult to establish financially and organizationally as well as experimentally.[7] Yonath recalled that the first four or five years were especially challenging for securing funding and recruiting researchers.[7] She described deciphering the ribosome as requiring scientific courage, original thinking, and unconventional developments.[7] Early results were difficult to explain, and she encountered disbelief and ridicule within the international scientific community.[1][8] In her own account, she continued because she could see progress, however small, and remained interested in the scientific problems themselves.[8] During this period, she was also balancing demanding laboratory work with caring for a young child.[8]

Yonath and her colleagues made approximately 25,000 attempts before producing their first ribosome crystals in 1980.[4] Her early studies used ribosomes from the bacterium Bacillus stearothermophilus.[6] In that year she became the first person to determine the three-dimensional atomic arrangement of a large ribosomal subunit.[6] The initial crystals nevertheless left substantial problems unresolved: in her account, they yielded less than one-thousandth of the data required to determine a structure because they deteriorated rapidly under radiation.[4] Producing crystals and making them stable enough for prolonged investigation were therefore separate experimental challenges.[4]

One source of inspiration came from an observation about hibernating polar bears.[8] Yonath learned that their ribosomes were arranged in dense patterns and considered whether harsh environmental conditions might encourage similarly dense packing.[8] She began crystallizing ribosomes from bacteria adapted to extreme environments, including bacteria from the Dead Sea.[8] These experiments formed part of her search for biological material that could withstand the conditions needed for structural investigation.[8] Her eventual research also included the small ribosomal subunit of Thermus thermophilus, whose atomic structure she determined at a resolution of 3.3 angstroms.[6]

A major methodological contribution was cryocrystallography, in which protein crystals are rapidly cooled to reduce radiation damage during X-ray crystallography.[6] Yonath and her team developed a cryo technique in 1987 that advanced ribosome research and structural biology more broadly.[3] The method addressed a central limitation of the early experiments: exposure to the X-rays needed to obtain structural information could destroy the delicate crystals before sufficient data had been collected.[4][8] Rapid cooling helped protect the crystals and made extended investigation possible.[8]

Yonath later recounted how she and her colleagues tried protecting ribosome crystals with oil and deep cooling after learning about a technique used for another delicate crystal.[8] At a test conducted at a Stanford University accelerator, they obtained a diffraction image that remained usable much longer than previous images.[8] Members of a scientific review committee watched from a balcony through binoculars and recognized that the approach was succeeding when the researchers did not have to replace the crystal.[8] In her account, crystallographers adopted the method broadly within four months.[8] The crystallographic techniques she developed subsequently came into wide use.[8]

By 2000, the research teams Yonath led at Weizmann and the Max Planck Society had determined the full spatial structures of the two subunits of a bacterial ribosome.[4] This achievement followed roughly two decades of work after the first crystals were obtained.[4] It provided structural information about the cellular complex responsible for translating genetic instructions into proteins.[2] The accomplishment was ranked among the year’s most important scientific developments and included among its ten important scientific breakthroughs.[2][4]

The structures revealed features of ribosomal architecture that helped explain how protein synthesis proceeds.[6] Among them were tunnel-like structures through which newly synthesized polypeptide chains pass.[6] Yonath’s work on the small subunit of Thermus thermophilus supplied a further atomic-level view of one of the ribosome’s two principal components.[6] Across the research recognized by the Nobel Prize, she, Ramakrishnan, and Steitz used X-ray crystallography to map the positions of the ribosome’s hundreds of thousands of atoms.[9] Their three-dimensional models also showed how antibiotics bind to ribosomes and interfere with their function in bacteria.[9]

Antibiotic action became a major application of Yonath’s structural research.[2] In 2001, her teams determined how several prominent antibiotics bind to bacterial ribosomes and prevent bacteria from producing proteins.[4] These findings illuminated both antibiotic activity and bacterial resistance, while pointing toward the design of new antibiotics and improvements to existing treatments.[4] Her later investigations examined antibiotic atomic structures and the ways those structures affect drug activity and interactions with cellular machinery.[6]

The antibiotic studies extended across numerous drugs rather than a single compound.[2][3] Yonath determined structures of more than a dozen antibiotic complexes and identified their ribosome-binding sites.[3] Her work elucidated the modes of action of more than 20 antibiotics targeting the ribosome and contributed insight into antibiotic selectivity and drug resistance.[3] Studies of more than a dozen antibiotic families helped establish a basis for structure-based drug design.[2] She also suggested that understanding ribosomal activity might help scientists investigate uncontrolled protein production associated with diseases including cancer.[7]

On October 7, 2009, Yonath was named a joint recipient of the Nobel Prize in Chemistry with Venkatraman Ramakrishnan and Thomas Steitz for studies of ribosome structure and function.[10] The award recognized their demonstration of what the ribosome looks like and how it functions at atomic resolution through X-ray crystallography.[7] The prize of 10 million Swedish kronor was divided equally among the three laureates.[10] At the ceremony in Stockholm, Yonath received a gold medal and diploma.[11] She expressed the hope that the award would encourage Israeli children, both girls and boys, to become interested in science and chemistry.[11]

Yonath continued working long after the Nobel recognition.[12] Until the final days of her life, she researched, published papers, maintained an active laboratory, and collaborated with scientists around the world.[12] She died on August 31, 2026, at the age of 87.[4][12] Her scientific activity thus continued beyond the structural discoveries and awards for which she had become internationally known.[12]

Yonath was the first Israeli woman to receive a Nobel Prize, the fourth woman to win the Nobel Prize in Chemistry, and the first female chemistry laureate since 1964.[2] She was also the first woman from the Middle East to win a Nobel Prize in the sciences.[13] These distinctions accompanied recognition of research that connected fundamental questions about protein synthesis with detailed explanations of antibiotic action.[2][9] Her Nobel work joined atomic-level descriptions of cellular machinery to models showing how drugs interfere with bacterial ribosomes.[9]

Her methodological legacy extended beyond the ribosome structures themselves.[2] The cryo-bio-crystallographic advances developed during her long research effort changed the practical study of delicate biological crystals and were widely adopted in structural biology.[2][8] Rapid cooling reduced radiation damage, addressing the instability that had limited the useful data obtainable from early ribosome crystals.[4][8] The research therefore produced both structural results and techniques that other crystallographers could apply.[2][8] At Weizmann, her establishment of Israel’s first protein-crystallography laboratory also created a national research facility that remained unique in the country for almost a decade.[2]

The antibiotic studies supplied another lasting application of her work.[2] By revealing drug-binding sites and explaining the action of numerous antibiotic families, her research helped pave the way for structure-based drug design.[2] The findings also contributed to understanding how bacteria develop resistance and how antibiotics can selectively affect bacterial protein-making machinery.[3][4] Her investigations connected the atomic structures of drugs with their biological activity rather than treating antibiotic action solely as an observed effect.[9] The resulting structural models showed how binding to a ribosome could interfere with bacterial function.[9]

Yonath’s scientific honors preceded the Nobel Prize by many years.[6][2] She was elected to the Israel Academy of Sciences and Humanities in 2000 and the United States National Academy of Sciences in 2003.[6] Her academy memberships also included a European science academy.[4] She received the Israel Prize in Chemistry in 2002, the Louisa Gross Horwitz Prize for Biology or Biochemistry in 2005, the Paul Ehrlich and Ludwig Darmstaedter Prize in 2007, and the Albert Einstein World Award of Science in 2008.[2][4] These honors recognized her work during the period in which ribosomal structures and their antibiotic interactions were becoming accessible to detailed investigation.[2][4]

Other awards included the Wolf Prize, the EMET Prize, the First European Crystallography Prize, the Kolthoff Prize, the Kilby International Award, and the Harvey Prize.[2][4] In 2008 she was one of five regional laureates of the L’Oréal-UNESCO For Women in Science award.[4] Over her career she received approximately 40 honorary doctorates.[12] The breadth of this recognition encompassed Israeli national prizes, international scientific awards, academy elections, and honors from universities.[2][4]

In 2018, Ecuador’s National Assembly honored Yonath with a medal of scientific merit.[14] At the ceremony, she spoke about understanding the interconnection of the genetic code across living beings and described the investigation of antibiotic action as a task that had taken her 20 years.[14] Her remarks returned to the connection between the basic biological question that had motivated the ribosome project and the medical relevance of its results.[1][14] At her Nobel ceremony, she had similarly emphasized the award’s possible value in encouraging a new generation of Israeli children to pursue science.[11]

Family life remained part of Yonath’s account of her scientific career.[4][8] Her daughter, Dr. Hagit Yonath, became a physician and medical department head at Sheba Medical Center.[4] Yonath especially cherished a “world’s best grandmother” award given to her by her granddaughter.[4] At the age of five, that granddaughter invited her to explain ribosomes to the other children in kindergarten.[4] Alongside international scientific honors, this family recognition occupied a particularly valued place in her life.[4]

In 2009, within a week of learning that she would receive the Nobel Prize, Yonath called for the unconditional release of all Hamas prisoners.[11] She argued that holding Palestinians captive encouraged their motivation to harm Israel and its citizens.[11] The position formed a politically contentious part of her public activity at the time of her Nobel recognition.[11]

Yonath also advocated scientific and academic independence and opposed attempts to politicize Israeli science and culture.[2] In 2023, she joined six other Israeli Nobel laureates in warning that the government’s proposed judicial overhaul would harm research and higher education.[2] Their intervention placed her among prominent scientists participating in the public dispute over the proposed changes.[2]