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Portrait of Ada E. Yonath
Photo: Hareesh N. Nampoothiri, Own WorkHome Page: Haree Fotografie · CC BY-SA 3.0 via Wikimedia Commons

Nobel Prize in Chemistry · 2009

Ada E. Yonath

She spent two decades mapping the cell's protein factory atom by atom, then showed where antibiotics grip it.

The Nobel citation: “for studies of the structure and function of the ribosome”
Born
June 22, 1939, Jerusalem, British Mandate of Palestine (now Israel)
Died
August 31, 2026
Shared with
Venkatraman Ramakrishnan, Thomas A. Steitz
Affiliation at the time
Weizmann Institute of Science, Israel

Chemistry prize

2009

Shared with 2 other laureates.

Age that year

70years

Born in 1939.

Sources cited

23

Fact-checked September 24, 2026.

  • Her team made about 25,000 attempts before growing the first ribosome crystals in 1980, at a time when most experts thought it could not be done.
  • Her key idea came while she recovered from a bicycle accident and read about hibernating bears, whose cells pack ribosomes into neat, orderly arrays.
  • After first using a heat-loving bacterium, she also grew ribosome crystals from a salt-loving microbe that lives in the Dead Sea.
  • In 2009 she became the first Israeli woman to win a Nobel Prize and the first woman in 45 years to win the chemistry prize.
  • After her prize, Israelis coined a saying inspired by her famous curls: curly hair means a head full of ribosomes.

The breakthrough

Crystallizing the ribosome and mapping it atom by atom (1980-2001)

Every living cell builds its proteins in ribosomes, tiny machines that read genetic instructions carried by messenger RNA and link amino acids, one by one, into chains. By the 1970s scientists knew what ribosomes did but not what they looked like up close. To see a molecule atom by atom, researchers use X-ray crystallography. First they must coax millions of copies of the molecule to line up in a crystal, like a marching band in perfect formation, so that X-rays bounce off in a pattern that can be decoded. A bacterial ribosome, built from three RNA chains and more than 50 proteins, seemed far too big, floppy and fragile for that. Yonath tried anyway. Inspired by hibernating bears that store their ribosomes in orderly arrays, she chose ribosomes from hardy microbes. In 1980 her team grew the first ribosome crystals, from a heat-loving bacterium; a salt-loving microbe from the Dead Sea followed. When strong X-rays kept wrecking them, she and colleagues froze the crystals to about -185°C, a method called cryo-crystallography. After two more decades of work, her teams published complete atomic structures of both halves of a bacterial ribosome in 2000 and 2001, alongside rival groups led by Thomas Steitz and Venkatraman Ramakrishnan. The structures showed that the ribosome's working heart is made of RNA, not protein. Her lab then mapped where more than 20 antibiotics lodge inside it.[2],[3],[5],[6],[8]

“I became the World's dreamer, the village fool, the so-called scientist, and the person driven by fantasies.”
Ada E. Yonath, From her Nobel autobiography (2009), describing how leading scientists reacted when she explained her plan to solve the ribosome's structure.[2]

What it meant for humanity

Yonath's work began as curiosity about how life makes proteins, but it bears directly on medicine. The ribosome is the target of about half of all antibacterial drugs, according to the Nobel committee's scientific background, yet doctors had used many of these drugs for decades without seeing exactly where they grip. In 2001 her team showed, atom by atom, how chloramphenicol, clindamycin and three macrolides, including erythromycin, bind to the part of the ribosome that joins amino acids. Her lab went on to map more than 20 antibiotics, explaining how the drugs stop bacteria, why they largely spare human cells, and how bacteria mutate to resist them. The Nobel committee said such models are now used to design new antibiotics. One drug shows both the promise and the limits. In 2007 her group, working with GlaxoSmithKline scientists, found that pleuromutilin antibiotics make the ribosome's pocket close tightly around them. The US label for lefamulin, a pleuromutilin approved in 2019 for community-acquired pneumonia, describes the same induced fit, and in 2016 her lab and the drug's maker, Nabriva, solved lefamulin's structure on the ribosome of Staphylococcus aureus. But lefamulin was discovered in 2006, before that structure, and sold poorly; Nabriva began winding down in 2023. The need remains large: WHO links drug-resistant bacteria to more than 4.7 million deaths in 2021. Beyond drugs, the crystal-freezing method she championed spread through structural biology, she founded Israel's first protein crystallography lab, and as Israel's first woman Nobel laureate she became a model for generations of young scientists.

  • In 2001 her team showed exactly where chloramphenicol, clindamycin, erythromycin and two other macrolides bind inside the bacterial ribosome: entirely on its RNA, not its proteins.[14]
  • Her lab mapped more than 20 ribosome-targeting antibiotics, revealing how they work, why they largely spare human cells and how bacteria become resistant.[3],[7],[8]
  • Her 2007 finding that pleuromutilin drugs make the ribosome's pocket close tightly around them matches the mechanism on the US label for lefamulin, a pleuromutilin approved in 2019.[15],[17]
  • The ribosome is the target of about half of all antibacterial drugs, and WHO links drug-resistant bacteria to more than 4.7 million deaths in 2021, so knowing how these drugs grip matters.[6],[19]
  • In 1970 she founded Israel's first protein crystallography lab, which for nearly a decade was the only one in the country.[2],[8],[11]
  • In 2016 her lab and Nabriva solved lefamulin's structure on a Staphylococcus aureus ribosome, but the drug, discovered in 2006, sold poorly, and Nabriva began winding down in 2023.[16],[18]

Impact in numbers

Yonath's contribution is knowledge rather than a product. She showed that the ribosome could be crystallized, drove the methods that made its atomic structure possible, and, with Steitz and Ramakrishnan, revealed how the machine that builds every protein works, including an RNA core she proposed may be a remnant of the first protein-making machine in early life. Her maps of more than 20 antibiotics bound to the ribosome, the target of about half of all antibacterial drugs, help explain how these drugs work and how bacteria resist them, and the Nobel committee noted that such structures are used to develop new antibiotics. We make no quantified claim. Most antibiotics her work illuminates were discovered decades earlier, and the one newer drug her lab studied closely, lefamulin, was found before its structure was solved and sold poorly. Counting lives saved would require a causal link we cannot document. Her legacy also includes Israel's first protein crystallography lab and the scientists she trained.

Fundamental scienceHealth

No number is given here on purpose. Some contributions cannot be counted honestly, and we would rather describe them than invent a figure.

The double edge

No harm is known to flow from Yonath's research. Its promise for new antibiotics has been only partly realized so far, and the one newer drug her lab studied closely sold poorly. The controversies centered on credit and politics. The race to solve the ribosome was intense, and the three-person Nobel limit left out other key contributors. Her lab's first high-resolution model of the small subunit differed in some atomic details from a rival's and was later refined. Outside the lab, her 2009 call to stop holding Palestinian prisoners drew criticism in Israel.

  • Minor

    Remarks on Palestinian prisoners drew criticism

    In October 2009, days after her Nobel was announced, Yonath said Israel should not imprison Palestinians it calls terrorists, arguing that holding them encourages kidnappings such as that of soldier Gilad Shalit. Some Israeli academics defended her right to speak; a former Weizmann chemist said she had commented without thinking. She later opposed the government's 2023 judicial overhaul.[9],[10],[12]

  • Minor

    A prize for three, a discovery by many

    The Nobel is limited to three winners, and others with seminal ribosome work, including Harry Noller, Peter Moore and Joachim Frank, were left out. Ramakrishnan has described 1999-2000, when his group and hers raced to solve the small subunit, as a tense and unpleasant time. The Nobel committee credits Steitz's group with first solving the key phase problem for the large subunit.[6],[13]

  • Minor

    An early atomic model needed refinement

    Her lab's 3.3-angstrom structure of the small subunit, published in 2000, broadly matched Ramakrishnan's 3.0-angstrom structure but differed in some atomic details. According to the Nobel committee's scientific background, a follow-up structure from her own lab in 2001 removed the discrepancies.[6],[23]

Against the odds

Yonath was born in Jerusalem, then under British rule, in June 1939, months before Germany invaded Poland, the country her parents had left in 1933. Roughly 2.8 to 3 million of Poland's 3.35 million Jews were murdered in the Holocaust. As a child she lived through the 1947-48 siege of Jewish Jerusalem, when about 100,000 people were cut off, shelled and put on rationed food and water. Her own hardships were mostly poverty and loss. Her family shared an apartment with two other families, and her father, a rabbi who ran a grocery, was often in hospital and died when she was 11. From then on she worked, cleaning floors, washing dishes, babysitting and tutoring, and in Tel Aviv she paid her school fees by teaching other students. She chose chemistry partly because studying close to home let her care for her ailing mother. In science she then faced two decades of disbelief and ridicule from colleagues who called her quest impossible. No source we found records antisemitic discrimination against her personally: she grew up in a Jewish community and built her career in Israel. Her odds were set by poverty, war and a field that doubted her.

  • 1942

    Other

    The Polish Jewish world her parents left in 1933 was nearly destroyed in the Holocaust: roughly 2.8 to 3 million of Poland's 3.35 million Jews were murdered. No source we found says what happened to relatives who stayed.[1],[20]

  • 1948

    War

    As a child in Jerusalem she lived through the 1947-48 siege, when the city's roughly 100,000 Jewish residents were cut off from supplies, under constant shelling, and living on rationed food and water.[2],[21]

  • —

    Poverty

    Her father died after years of illness when she was 11. She began cleaning, washing dishes, babysitting and tutoring to help support her mother and younger sister.[2],[11],[22]

  • 1980

    Other

    For about two decades many leading scientists met her plan to crystallize the ribosome with disbelief, sarcasm and ridicule, calling her a dreamer and a fool.[2],[7],[8]

Jewish background

Both parents JewishIdentified as Jewish, secular

Yonath was born in Jerusalem in 1939 to poor Jewish parents who had emigrated from Poland in 1933. Her father was a rabbi from a family of rabbis, and both parents were raised in religious homes. They ran a grocery store and lived in Jerusalem's Geula neighborhood, where all the nearby schools followed her parents' religious principles. Her parents chose instead to send her to a prestigious secular school in Beit Hakerem. She served in the Israeli army's medical corps and built her career at Israel's Weizmann Institute. The sources we found say little about her own religious practice.[1],[2],[7],[10],[11]

Key dates

  1. 1933

    Her parents emigrate from Poland to British-ruled Palestine.[1],[11]

  2. June 22, 1939

    Born in Jerusalem into a poor family that shares a rented apartment with two other families.[1],[2]

  3. 1953

    After her father, a rabbi, dies when she is 11, she works to help the family; in 1953 she moves to Tel Aviv with her mother and sister and finishes high school.[2],[11],[22]

  4. 1964

    After army service in the medical corps, completes bachelor's and master's studies at the Hebrew University of Jerusalem.[2],[11]

  5. 1968

    Earns her PhD in X-ray crystallography at the Weizmann Institute, studying collagen; postdocs at Carnegie Mellon and MIT follow.[5],[8],[9]

  6. 1970

    Returns to the Weizmann Institute and founds Israel's first protein crystallography lab.[2],[8]

  7. 1980

    With Heinz-Günter Wittmann's Max Planck group in Berlin, grows the first 3D crystals of the ribosome's large subunit.[5],[6],[8],[9]

  8. 1989

    With Håkon Hope and colleagues, pioneers flash-freezing ribosome crystals against X-ray damage, reviving an approach first tried at Weizmann in the late 1960s.[2],[6],[9]

  9. 2000

    Her teams publish the atomic structure of the ribosome's small subunit; the large subunit follows in 2001.[6],[8],[23]

  10. October 25, 2001

    Shows in Nature exactly how five clinically used antibiotics, including erythromycin, bind to the bacterial ribosome.[14]

  11. 2002

    Receives the Israel Prize in Chemistry.[8],[11]

  12. October 7, 2009

    Named a winner of the Nobel Prize in Chemistry with Venkatraman Ramakrishnan and Thomas A. Steitz.[1],[4]

  13. August 31, 2026

    Dies at 87, still running an active lab at the Weizmann Institute.[1],[8],[9]

Sources

  1. 1.Ada E. Yonath - Facts · NobelPrize.org (Nobel Prize Outreach), 2009
  2. 2.Ada E. Yonath - Biographical · NobelPrize.org (Nobel Foundation), 2009
  3. 3.Hibernating Bears, Antibiotics and the Evolving Ribosome (Nobel Lecture, 8 December 2009) · NobelPrize.org (Nobel Foundation), 2009
  4. 4.The Nobel Prize in Chemistry 2009 - Press release · The Royal Swedish Academy of Sciences, 2009
  5. 5.The key to life at the atomic level (Popular information, Nobel Prize in Chemistry 2009) · The Royal Swedish Academy of Sciences, 2009
  6. 6.Scientific Background on the Nobel Prize in Chemistry 2009: Structure and Function of the Ribosome · The Royal Swedish Academy of Sciences, 2009
  7. 7.Ada Yonath (Women who changed science) · NobelPrize.org (Nobel Prize Outreach)
  8. 8.Prof. Ada Yonath, Nobel Laureate and a Model of Scientific Perseverance, Has Passed Away · Weizmann Institute of Science (Weizmann Wonder Wander), 2026
  9. 9.Ada Yonath, Nobel laureate and crystallographer, dies at 87 · Chemical & Engineering News (American Chemical Society), 2026
  10. 10.Nobel Prize-winning Israeli chemist Ada Yonath dies at 87 · The Times of Israel, 2026
  11. 11.כלת פרס נובל, פרופ' עדה יונת, הלכה לעולמה (Nobel laureate Prof. Ada Yonath has died) · Ynet, 2026
  12. 12.Professors respond to Yonath's comments on terrorists · Ynetnews, 2009
  13. 13.Biology's Nobel molecule factory · Chemistry World (Royal Society of Chemistry), 2009
  14. 14.Structural basis for the interaction of antibiotics with the peptidyl transferase centre in eubacteria (Nature 413:814-821) · PubMed (National Library of Medicine), 2001
  15. 15.Induced-fit tightens pleuromutilins binding to ribosomes and remote interactions enable their selectivity (PNAS 104:4291-4296) · PubMed (National Library of Medicine), 2007
  16. 16.A novel pleuromutilin antibacterial compound, its binding mode and selectivity mechanism · Scientific Reports (Nature Portfolio), 2016
  17. 17.XENLETA (lefamulin) prescribing information, initial US approval 2019 · US Food and Drug Administration, 2019
  18. 18.Antibiotic developer Nabriva to wind down · Chemical & Engineering News (American Chemical Society), 2023
  19. 19.Antimicrobial resistance (fact sheet) · World Health Organization
  20. 20.Jewish Losses during the Holocaust: By Country · United States Holocaust Memorial Museum (Holocaust Encyclopedia)
  21. 21.Jerusalem under siege, December 1947 - June 1948 · IDF and Defense Establishment Archives
  22. 22.Ada Yonath: From cleaning floors to survive aged 11 to Nobel Prize-winner · The Jewish Chronicle, 2011
  23. 23.Structure of functionally activated small ribosomal subunit at 3.3 angstroms resolution (Cell 102:615-623) · PubMed (National Library of Medicine), 2000

Fact-checked on September 24, 2026 by a separate AI fact-checking pass that re-opened the sources, with 11 corrections made. How we check

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