Skip to content
Nobel Jews
Portrait of Aaron Klug
Photo: Rob Bogaerts for Anefo, [1] Dutch National Archives, The Hague, Fotocollectie Algemeen Nederlands Persbureau (ANEFO), 1945-1989 Bestanddeelnummer 930-2390 · CC BY-SA 3.0 nl via Wikimedia Commons

Nobel Prize in Chemistry · 1982

Aaron Klug

He taught electron microscopes to see in 3D, revealing how viruses and chromosomes are built, and found the DNA-gripping zinc finger.

The Nobel citation: “for his development of crystallographic electron microscopy and his structural elucidation of biologically important nucleic acid-protein complexes”
Born
August 11, 1926, Zelvas, Lithuania
Died
November 20, 2018
Affiliation at the time
MRC Laboratory of Molecular Biology, United Kingdom

Chemistry prize

1982

Awarded alone.

Age that year

56years

Born in 1926.

Sources cited

20

Fact-checked September 24, 2026.

  • The South African government told US officials he was a communist, so he was refused a US visa. He stayed in Britain, and at a London lab he met Rosalind Franklin.
  • He was the sole winner of the 1982 Nobel Prize in Chemistry, for turning flat electron-microscope pictures into 3D maps of life's molecular machines.
  • In 1985 his lab discovered zinc fingers, small DNA-gripping protein modules. About 3% of human genes contain the zinc-finger design.
  • He grew up in a Yiddish-speaking family and was reading the newspaper by the age of three and a half.
  • At 15 he won a scholarship to study medicine in Johannesburg, in the same class as another future Nobel laureate, Sydney Brenner.

The breakthrough

Crystallographic electron microscopy: 3D pictures of viruses, chromatin and more

An electron microscope can see things far too small for ordinary light, but it has two big problems with living matter. Its pictures are flat, like X-ray shadows, so the front and back of a virus pile on top of each other. And biological molecules are made of light atoms, so the images are faint, while a strong beam burns them. Klug showed that these faint, blurry pictures hold far more information than they seem to. Using the mathematics that crystallographers use to read X-ray patterns, he could separate real detail from noise. In 1968, with David DeRosier, he took the next step: combining many flat views of the same object, taken from different angles, into one three-dimensional map. Think of working out the shape of a sculpture from its shadows as you turn it in front of a lamp. Their first target was the tail of a virus that infects bacteria. Klug used the methods, along with X-ray diffraction, to work out how viruses such as tobacco mosaic virus build themselves from protein pieces and genetic material. He also studied chromatin, the DNA-protein mix inside chromosomes, and showed how DNA wraps around a core of histone proteins in a particle called the nucleosome. Later, in 1985, his group found zinc fingers, small modules that let a protein grip a specific stretch of DNA.[1],[3],[4],[5],[6],[9],[11],[16]

“It was Rosalind Franklin who set me the example of tackling large and difficult problems.”
Aaron Klug, From his Nobel lecture on 8 December 1982, recalling the colleague who introduced him to virus research and died in 1958.[3]

What it meant for humanity

Klug's work is basic science, and most of its value reached people through other scientists. His 3D reconstruction methods were a founding step for cryo-electron microscopy, which earned three other scientists the 2017 Nobel Prize in Chemistry. The Nobel committee's scientific background for that prize traces the field back to Klug's work in the 1960s and his 1968 paper with DeRosier. Today the Electron Microscopy Data Bank, the global archive of 3D electron microscope maps, holds more than 62,000 entries. When COVID-19 emerged, a team used cryo-electron microscopy to map the coronavirus spike protein within weeks and published it in February 2020, calling the spike a key target for vaccines, antibody drugs and tests. His chromatin research showed that almost all the DNA in a cell's nucleus is packed in a regular way, work that shaped the study of how genes are switched on and off. Roger Kornberg, who began studying chromatin as a postdoc under Klug, went on to win the 2006 Nobel Prize in Chemistry. Zinc fingers opened another path. Because the modules can be linked like beads to recognise longer DNA sequences, scientists learned to design new ones that switch chosen genes on or off, or cut DNA at a chosen spot. In a 2014 trial, doctors used zinc-finger scissors to disable the CCR5 gene, a doorway HIV uses to enter cells, in the immune cells of 12 people with HIV, and found the treatment safe within the limits of the study. As director of the MRC Laboratory of Molecular Biology, Klug helped set up the Sanger Centre, which played a key role in the Human Genome Project, and he steered early lab work on the tau protein in Alzheimer's disease.

  • In 1968 he and David DeRosier made the first 3D reconstruction from electron micrographs, a founding step for the cryo-electron microscopy recognised by the 2017 Nobel Prize in Chemistry.[6],[9],[10]
  • The Electron Microscopy Data Bank, the global archive of 3D electron microscope maps, held 62,430 entries as of 23 September 2026.[14]
  • In February 2020, researchers used cryo-electron microscopy to map the coronavirus spike protein, a key target for COVID-19 vaccines, antibody drugs and tests.[15]
  • His 1985 discovery of zinc fingers led to designed DNA-binding proteins; in 2014 zinc-finger gene editing was tested in 12 people with HIV and judged safe within the study's limits.[11],[12],[13]
  • As director of the MRC Laboratory of Molecular Biology, he helped found the Sanger Centre, a key contributor to the Human Genome Project.[5],[6]

Impact in numbers

Klug's impact runs through methods and ideas rather than a single product. His way of turning many flat electron-microscope images into one 3D map became part of the foundation of cryo-electron microscopy, now a standard tool for seeing the machinery of cells, viruses and drug targets. His chromatin and nucleosome work showed that the DNA inside a cell nucleus is packed in an orderly, repeating way. His discovery of zinc fingers gave biologists a modular DNA-gripping part they could redesign, leading to targeted gene switches and a gene-editing method already tested in people. These contributions are real but spread across thousands of later studies and therapies, many still experimental, so we do not assign a number of lives saved or people helped; any figure would be invented rather than measured.

Fundamental scienceHealthTechnology

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 or serious controversy is documented from Klug's research or conduct. The gene-editing uses of zinc fingers are still young: in the 2014 HIV trial, one serious adverse event, a transfusion reaction, was linked to the cell infusion, and HIV became undetectable in only one of four patients who could be evaluated after stopping their usual drugs.

Against the odds

Klug was born in 1926 in Želva, a small town in Lithuania. Seeing little future there, his family left for Durban, South Africa, when he was about two. They got in just in time: in 1930 South Africa passed a quota law that sharply limited immigration from Eastern Europe, aimed mainly at Jews, and in 1937 an Aliens Act shut out most Jews fleeing Nazi Germany. The town he left was destroyed as a Jewish community. In July and August 1941, after Germany invaded, almost all the Jews of the Želva area were killed with the help of local collaborators, part of a Holocaust that murdered about 90 percent of Lithuania's Jews. Klug's mother died of pneumonia when he was six, and an aunt helped raise him. He shot through school two years ahead of his classmates and entered university at 15. After his Cambridge doctorate, his career was nearly blocked by politics: the South African government told American officials he was a communist, because of a youth group he had belonged to, and he was refused a US visa during the McCarthy era. He stayed in Britain instead.

  • 1930

    Discrimination

    Soon after the family arrived, South Africa's 1930 quota law curtailed immigration of Eastern European Jews, and a 1937 Aliens Act kept out Jews fleeing Nazi Germany.[19]

  • 1941

    Other

    In July and August 1941 almost all the Jews of the Želva area, the town where he was born, were murdered with the help of local collaborators. About 90 percent of Lithuania's Jews were killed in the Holocaust.[17],[18]

  • 1932

    Other

    His mother died of pneumonia when he was six; her younger sister helped raise him and his brother and later married his father.[8],[20]

  • 1952

    Discrimination

    After his PhD he was refused a US visa: the South African government told US authorities he was a communist because of a youth group he had belonged to.[6],[7],[20]

Jewish background

Both parents JewishCulturally Jewish

Klug was born in Lithuania to Jewish parents, Lazar and Bella (née Silin) Klug, in a Yiddish-speaking family. His father had a traditional Jewish education, went to synagogue regularly and studied the Talmud; after Klug moved to England, his father mailed him passages from it. As a boy in Durban, Klug attended Hebrew classes. The Guardian's obituary says that he, his wife and their sons kept a strong connection to their Jewish cultural roots, going to synagogue and observing festivals. He visited Israel many times, especially Ben-Gurion University of the Negev in Beersheba, which in 2013 founded a research centre in his name.[2],[6],[7],[8],[20]

Key dates

  1. August 11, 1926

    Born in Želva (Zelvas), Lithuania, to Lazar and Bella Klug.[1],[2]

  2. 1928

    At about age two (sources give 1928 or 1929), moves with his family to Durban, South Africa, where his mother's relatives lived.[2],[6],[8],[20]

  3. 1945

    Completes a science degree at the University of the Witwatersrand after switching from medicine.[2],[5]

  4. 1946

    Earns an MSc in physics at the University of Cape Town under the X-ray crystallographer R. W. James.[5],[7]

  5. 1949

    Moves to Cambridge on scholarships for a PhD (completed 1952–53) modelling phase changes in cooling steel.[2],[5],[6],[20]

  6. 1953

    Refused a US visa, he joins J. D. Bernal's lab at Birkbeck College, London, and begins work on viruses with Rosalind Franklin.[2],[6],[7],[20]

  7. 1958

    After Franklin's death, takes over leadership of her virus research group.[5],[6]

  8. 1962

    Moves with his group to the new MRC Laboratory of Molecular Biology in Cambridge.[2],[5]

  9. 1968

    With David DeRosier, publishes the first 3D reconstruction from electron micrographs.[6],[9]

  10. 1974

    His group solves the crystal structure of a transfer RNA molecule.[5]

  11. 1982

    Wins the Nobel Prize in Chemistry as sole laureate.[1],[4]

  12. 1985

    With Jonathan Miller and Andrew McLachlan, discovers zinc-finger DNA-binding modules.[5],[11]

  13. 1995

    Becomes President of the Royal Society (to 2000) and is appointed to the Order of Merit; he had been knighted in 1988.[5]

  14. November 20, 2018

    Dies at age 92.[1],[5]

Sources

  1. 1.Aaron Klug – Facts · NobelPrize.org
  2. 2.Aaron Klug – Biographical · NobelPrize.org, 1982
  3. 3.From Macromolecules to Biological Assemblies (Nobel lecture) · NobelPrize.org, 1982
  4. 4.The Nobel Prize in Chemistry 1982 – Press release · Royal Swedish Academy of Sciences / NobelPrize.org, 1982
  5. 5.Aaron Klug (1926 - 2018) · MRC Laboratory of Molecular Biology, 2018
  6. 6.Aaron Klug (1926–2018) · Nature (Kenneth Holmes), 2018
  7. 7.Sir Aaron Klug: 1926–2018 · UCT News, University of Cape Town, 2018
  8. 8.Obituary: Sir Aaron Klug · The Jewish Chronicle (Julie Carbonara), 2018
  9. 9.The development of cryo-electron microscopy: Scientific background on the Nobel Prize in Chemistry 2017 · Royal Swedish Academy of Sciences / NobelPrize.org, 2017
  10. 10.The Nobel Prize in Chemistry 2017 – Press release · Royal Swedish Academy of Sciences / NobelPrize.org, 2017
  11. 11.Repetitive zinc-binding domains in the protein transcription factor IIIA from Xenopus oocytes (Miller, McLachlan, Klug, EMBO J) · PubMed, 1985
  12. 12.The discovery of zinc fingers and their applications in gene regulation and genome manipulation (Klug, Annu Rev Biochem) · PubMed, 2010
  13. 13.Gene editing of CCR5 in autologous CD4 T cells of persons infected with HIV (Tebas et al., N Engl J Med) · PubMed, 2014
  14. 14.Electron Microscopy Data Bank (EMDB) home page · EMBL-EBI, 2026
  15. 15.Cryo-EM structure of the 2019-nCoV spike in the prefusion conformation (Wrapp et al., Science) · PubMed, 2020
  16. 16.Aaron Klug: A Scientific Retrospective · MRC Laboratory of Molecular Biology
  17. 17.Lithuania – Holocaust Encyclopedia · United States Holocaust Memorial Museum
  18. 18.Želva Jewish cemetery · Jewish Heritage Lithuania, 2023
  19. 19.A Vocabulary of Difference: How Jews Were Denied Entry to South Africa in the 1930s · Leo Baeck Institute London
  20. 20.Sir Aaron Klug obituary · The Guardian, 2018

Fact-checked on September 24, 2026 by a separate AI fact-checking pass that re-opened the sources, with 8 corrections made. How we check

Suggest a correction