This is an important year for crystallographers, with the IUCr International Congress in Calgary, Canada. The IUCr Congress takes place every three years, in a different country each time. I have been fortunate to attend almost every one since the Moscow meeting in 1966, and it has always been the most important event for me as a place to meet other crystallographers and friends and to make new contacts.

The Congress typically attracts 1500-2500 participants and features a wide variety of microsymposia, lectures, and social events. The real importance of the Congress, it seems to me, is that, despite all the international troubles in the world right now (and I am sorry to say, there are many), this is a special opportunity for us all to meet, irrespective of the current threats. It is worth recalling that the IUCr itself was born of the ravages of the Second World War, with the intention of unifying all of us with a common interest in Crystallography that superseded national boundaries and confrontations. In a sense, it is a kind of “United Nations” devoted to peaceful coexistence. If you are a crystallographer or someone interested in crystallography, I strongly recommend attending the Congress. This year, it will be held in a splendid location and is expected to be open to participants from all nations, regardless of political divides. I expect to be there, and I shall be touting for new articles for the Newsletter.

Readers of the IUCr Newsletter will have noticed that last year we changed from publishing four issues per year to six issues. Initially, I was worried we wouldn't have enough interesting material if we spread content across so many issues. However, I need not have worried, as it seems that we never found ourselves with too little material. In 2025, we published 132 articles, compared with 99 in 2024. Among these were 16 obituaries, 19 meeting reports, 15 feature articles, and many commentaries on various topics. Much is due to the hard work of the IUCr staff, especially the Head of IUCr Marketing, Kezia Bowman and her assistants. If you attend the Congress, make sure you visit the IUCr stand and meet the people who work so hard on our behalf.

In this issue, we have several articles that I think should interest you. I single out just a few here. For instance, Istvan Hargittai writes about his interview with Nobel Laureate Aaron Klug, renowned for his pioneering work on viral structures using electron microscopy. Aaron died in 2018 (see obituary), and Istvan’s article celebrates 100 years since his birth. You can read about his history and achievements, plus Aaron’s words recorded in the interview.

Another article is by Ilia Guzei, who discusses postage stamps issued in Pakistan illustrating the discovery of X-rays by Rӧntgen. It is interesting to see the scene of Rӧntgen’s laboratory. I think it is worth it at this point to reread the article, published a few years ago in the Newsletter, about the Ukrainian-born physicist Johan (Ivan) Puluj, who invented a special lamp that, unknowingly, produced X-rays a few years before Rӧntgen’s discovery. It seems that both knew each other.

Natalia Dubrovinskaia writes about an important monograph published in February 1911, 115 years ago, before the discovery of X-ray diffraction (for the record, the first experiments demonstrating X-ray diffraction were conducted by Friedrich and Knipping in April of that year). This was on diamond (Der Diamant) by Alexander Evgenjevich von Fersmann and Viktor Mordechai Goldschmidt and dealt with the morphologies exhibited by diamond crystals coming from many localities.

The various crystallographic databases are vital as useful compilations of crystal structures determined by crystallographers over many years. This is where one goes to download relevant structural information. However, there is much evidence of duplicate crystal structure data in the databases. This is discussed by Natalie Johnson, Ian Bruno, Seth Wiggin, and Matt Lightfoot, who argue that duplication may be acceptable in many cases.

There are many special commissions supported by the IUCr. One of them is the Nomenclature Commission. Now this may seem rather dry at first glance, but it is actually one of the really important commissions, for this is where knowledgeable crystallographers discuss together such matters as scientific definitions and notation that we all use in our own publications. Getting these correct is important for scientific communication. Unfortunately, many of our scientific colleagues seem unaware of this and consistently use incorrect terminology when discussing anything related to crystallography, which only spreads confusion. For example, take a look at the article by Massimo Nespolo. Recently, the Nomenclature Commission held a long discussion about how to refer to the number of formula units in a unit cell. The question, briefly, was: Can this number be fractional? You can read about the results of the discussion written by Carol Brock.

Looking back to the IUCr Congress of 2023 in Melbourne it will be recalled that a huge model of the structure of diamond was on display. Stuart Batten and others describe what they did with all the bits left over from the Congress. Model kits were created and sent to primary schools free of charge all over Australia and New Zealand. This is an excellent example of outreach.

Mike Glazer
Oxford

Cristy Nonato

Cristy Nonato is Full Professor at the School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, and Coordinator of the Protein Crystallography Laboratory of Ribeirão Preto. She is President of the Brazilian Association of Crystallography, a member of the IUCr Executive Committee, and Chair of the IUCr Meeting Support Committee. She also serves as a Section Editor for Structural Biology Communications, Acta Crystallographica F.

Louise Dawe

In the year following my PhD, I sat next to a woman I had never met before at an American Crystallographic Association (ACA) workshop on PLATON. As we worked through problems together, she introduced me to other women crystallographers at the meeting, and I immediately felt welcomed into the community. Since that first encounter in 2009, I have benefited from an extraordinary network of women mentors and colleagues who encouraged me to ask questions, participate in scientific and leadership activities, and engage in service to the community. That support helped build confidence and ultimately led me to roles in journal editing, teaching at ACA summer courses, and organizing workshops, including the Canadian Chemical Crystallography Workshop. I am deeply grateful for the sense of belonging that came from this mentorship, and I strive to pay it forward through my work with students and by encouraging others to engage in professional and service opportunities within our field.

Professor Louise Dawe (Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, Canada) has been appointed as a Section Editor for Acta Crystallographica Section B, Structural Science, Crystal Engineering, and Materials since 2023. She has served as a co-editor for Acta Crystallographica Section C since 2020 and, since 2022, as Teaching and Education Co-editor for the Journal of Applied Crystallography. Louise also holds several leadership roles within the crystallographic community, including Chair of the Canadian National Committee for Crystallography, Co-chair of the International Program Committee for the 27th IUCr Congress and General Assembly, and member of the IUCr Meeting Support Committee.

 

Image showing the overlay of different structure determinations of the compound ROY, famous for its ability to form multiple polymorphs. The CSD contains over 90 determinations of ROY; the image from CCDC’s Mercury visualiser shows an overlay of eight data collections that were determined by a Crystal Packing Similarity search to have a cluster of 15 molecules (the central molecule plus 14 others) in common, compared to the original report published in 2000.

“Duplicates of crystal structures are flooding databases, implicating repositories hosting organic, inorganic, and computer-generated crystals” was a claim made in a recent C&EN article expressing concerns that “duplicate structures haunt crystallography databases” and raising questions about “curation practices at databases” [1].

If true, this would of course be of concern to science, crystallography and those databases that set out to provide trusted access to quality research data. There are perhaps two aspects to this – how many duplicates are there and are they necessarily a bad thing?

In this article we explore these aspects from the perspective of an experimental crystal structure database and in particular the Cambridge Structural Database (CSD), a database of over 1.4 million experimentally measured organic and metal-organic crystal structures curated by the Cambridge Crystallographic Data Centre (CCDC).

While highlighting the issues researchers had found with structures predicted by GNoME – a deep learning tool that claimed to have predicted 2.2 million new crystal structures – the C&EN article also commented on work by Professor Vitaliy Kurlin from the University of Liverpool identifying near-duplicate structures in crystallographic databases made up of experimentally produced data [2]. The CSD was reported as having 8343 near-duplicate structures (0.92% of the CSD structures used in the analysis or 0.62% of the total CSD).

The CSD, like other experimental databases, aims to be a record of all published crystal structure models. Reproducibility has been a cornerstone of the scientific method for centuries. Scientific experiments are rarely performed once and may be repeated to ensure the same result is achieved. In structural chemistry, the same compound may be studied in a variety of different ways, under different conditions or by different research groups looking at the same or different aspects of a structure. If these structures are characterised by X-ray crystallography, this can result in the publication of multiple measurements of the same compound, sometimes even within one publication.

Unlike a computationally generated database of new crystal structures, near-duplicate structures of experimental data are expected as part of the scientific process. Equally, the same crystal structure may be used by authors in more than one article to support different scientific narratives. As Dr. Saulius Gražulis who maintains the Crystallography Open Database, which was also surveyed by Dr. Kurlin, noted in the C&EN article “The same structure published in two different journals or two different books is not a duplicate. It is a historical fact, which we preserve” [1].

The CSD has included multiple experimental determinations of the same compound since near its creation, over 60 years ago. This is reflected by the identifier scheme adopted early in the CSD’s history. Each structure in the CSD is assigned a CSD Refcode, comprising of 6 characters followed optionally by two digits. Different determinations of the same structure share the same 6 characters and vary in their digits, resulting in Refcode “families” that group together studies of the same compound. The earliest instance of the CSD – a book series called Molecular Structures & Dimensions published from 1970–1984 that includes bibliographic records and structural information about published X-ray structures – contains several instances of multiple determinations of the same structure [3]. One example is the entry for Hexamethylenetetramine (Figure 2), where a single publication reported six different collections of the compound at various temperatures and with different X-ray wavelengths. These entries were assigned Refcodes HXMTAM–HXMTAM05. To date, around 5% (or approximately 67,000 of 1,259,000) of the Refcode families in the CSD contain more than one entry.

Every new data collection for the same compound can add a valuable piece of information to the story of the structure and its properties. Multiple data collections of the same chemical compound can provide insight into how the structure of a compound changes with variations in temperature or pressure – discovering new polymorphs, identifying phase transitions in the structure or phenomena such as negative thermal expansion. The field of crystallography is also constantly developing and new instrumentation may lead to the determination of better-quality crystal structures of existing compounds.

More reliable information about hydrogen positions can come from measurements using neutron diffraction [4] – or as the result of measuring compounds with emerging techniques, like the growing increase in structures measured with electron diffraction [5]. Higher resolution collections can focus on the modelling of aspherical electron density in multipole refinements [6], while existing structures can be re-refined using techniques beyond the independent atom model of structure solution, like Hirshfeld Atom Refinement [7] or Transferable Aspherical Atom models.

Not all of these repeated collections will be near-duplicates. Different experimental conditions (such as changes in temperature) would, in many cases, result in a large enough difference of the atomic positions within the structural model that they wouldn’t be flagged by methods such as Professor Kurlin’s Pointwise Distance Distributions (PDD) technique, which uses an Earth-Movers Distance of less than 0.01 Å to identify pairs of structures that are near-duplicates. Near-duplicate structures are thus not necessarily structures with identical atomic positions, but those with very small differences in atomic coordinates. When differences are small it is not unreasonable to question why – are these indicative of a dataset that has been misappropriated or manipulated, an oversight on the part of the database or a legitimate scientific result?

One reason for a near-duplicate pair of structures could be multiple models of the same experimental data [6], [8]. In these cases a cross-reference is added in the CSD between structures, indicating that one structure is a re-refinement of another. Cross-references are links between structures and can be found in the desktop CSD software ConQuest (Figure 3), as well as accessible from the cross-references field [9] in the Entry Module of the CSD Python API. Cross-references in the CSD are added for re-refinements of the same data or re-interpretations of existing structural models. Duplicate data checks take place during the deposition and curation process with the aim of assigning these links between structures. Cross-references are also added between related structures in other Refcode families, highlighting structures of tautomers, stereoisomers and racemates in the CSD.

There may also be times when researchers deposit very similar models of the same structure to the CSD. This occurrence was acknowledged by Professor Kurlin and others in a recent paper discussing near-duplicate structures in the PDB [10]. These structures may have undergone a round or two of re-refinement, resulting in a small change in the atomic positions or atomic displacement parameters, or there may be different metadata present in the CIF. Oftentimes the reflection data is the same in both CIF files. As the CCDC’s policy is to be a record of published data, if there has been a separate deposition, both structural models are kept (and a cross-reference is added between structures).

However, there may be instances where a near-duplicate structure indicates a potential issue with the published crystal structures. Previous work by Professor Kurlin identified 5 pairs of structures in the CSD where the atomic coordinates were exact duplicates for different chemical compounds [11], [12]. These pairs were subsequently investigated by the CCDC and the journals, resulting in three structures being either updated or retracted. In the remaining cases, these structures have had a remark added highlighting Professor Kurlin’s findings to users.

The CCDC’s Retraction policy is that when a published journal article is retracted by the journal – for any reason, not necessarily due to a problem with the crystallographic data – that the associated data is labelled as retracted in the CSD [13]. If a structure is retracted then the publication record is maintained, but all atomic information (2D chemical diagram and 3D atomic coordinates) is removed along with other experimental data. A remark is also added to the entry indicating the article has been retracted along with a link to the retraction notice.

Data integrity is at the heart of the CCDC. We aim to be a trusted resource of crystallographic data, so as well as ensuring data is retracted promptly, we have been developing dedicated processes aimed at identifying potential cases of misconduct. Every structure in the CSD is curated by an expert curator, to ensure structures are findable and the information describing the entry is standardized. In recent years the CCDC has also developed workflows that are run prior to each data release to identify structures that may require further investigation. We work closely with publishers and contact the relevant journals if we have data integrity concerns involving any of the structures in the CSD and also investigate issues highlighted to us by our users [14]. We welcome discussion, collaboration with researchers or any ideas as to how we can continue improving to ensure the CSD remains a trusted resource for decades to come.

Whilst multiple collections of the same structure can be useful in some areas of research, this may not always be the case. To minimise biases that may be introduced by multiple determinations of the same structure or form when performing large scale structural analysis, the CCDC maintains four ‘best representative’ CSD subsets [15]. These are collections of the best representative structure of a compound at i) high temperature, ii) low temperature, iii) with all hydrogen positions modelled or iv) the model with the lowest R factor, for structures that meet certain data quality criteria. Searching or assessing data using one of these subsets will return only one record for each Refcode family (unless multiple polymorphs are present). Other search functionality, like filters, can also be applied to narrow down searches to help select the most relevant structures for an individual’s research.

So when should experimental databases be concerned about near-duplicate structures? Many of the structures identified as near-duplicates in experimental databases probably result from repeat collections of data for the same compounds and it is unlikely that every pair identified is a cause for concern. Near-duplicate structures should be assessed individually, to ensure that the similarities are rationalised, scientifically valid, and represented correctly in the databases. On the rare case that a potential concern with the data is identified, the publisher will be contacted and asked to investigate any similarities with other structures. An understanding of the aims of experimental crystallographic databases – as records of all published structures – along with good curation of the data will enable users to get the most out of a very valuable resource. As stated by the Executive Director of the CCDC, Suzanna Ward, in C&EN “It’s trying to make the data available and then allow users to pick fit-for-purpose data.” [1]

Note: The CCDC have contacted Professor Kurlin to request a list of near-duplicate structures identified in his research for further analysis.

All authors work for CCDC, an organisation that curates and maintains the Cambridge Structural Database. 

References

[1] D. S. Chawla, “Duplicate structures haunt crystallography databases,” Chemical & Engineering News, Dec. 2025, doi: https://doi.org/10.1021/cen-259818-Feature. Available: https://cen.acs.org/research-integrity/Duplicate-structures-haunt-crystallography-databases/103/web/2025/12. [Accessed: Jan. 15, 2026]↩

[2] D. Widdowson and V. Kurlin, “Pointwise Distance Distributions for detecting near-duplicates in large materials databases,” arXiv.org, Aug. 2021, doi: https://doi.org/10.1137/25M1736657. Available: https://arxiv.org/abs/2108.04798v4. [Accessed: Jan. 16, 2026]↩

[3] O. Kennard, Molecular Structures and Dimensions Volume A1: Interatomic Distances 1960-1965. Oosthoek Publishing Company, 1972.↩

[4] F. H. Allen and I. J. Bruno, “Bond lengths in organic and metal-organic compounds revisited: X—H bond lengths from neutron diffraction data,” Acta Crystallographica Section B Structural Science, vol. 66, no. 3, pp. 380–386, May 2010, doi: https://doi.org/10.1107/s0108768110012048↩

[5] C. G. Jones et al., “The CryoEM Method MicroED as a Powerful Tool for Small Molecule Structure Determination,” ACS Central Science, vol. 4, no. 11, pp. 1587–1592, Nov. 2018, doi: https://doi.org/10.1021/acscentsci.8b00760.↩

[6] R. Kamiński et al., “Statistical analysis of multipole-model-derived structural parameters and charge-density properties from high-resolution X-ray diffraction experiments,” Acta Crystallographica Section A Foundations and Advances, vol. 70, no. 1, pp. 72–91, Dec. 2013, doi: https://doi.org/10.1107/s2053273313028313↩

[7] S. C. Capelli, Hans-Beat Bürgi, B. Dittrich, S. Grabowsky, and D. Jayatilaka, “Hirshfeld atom refinement,” IUCrJ, vol. 1, no. 5, pp. 361–379, Aug. 2014, doi: https://doi.org/10.1107/s2052252514014845↩

[8] M. Chodkiewicz and K. Woźniak, “Towards improved accuracy of Hirshfeld atom refinement with an alternative electron density partition,” IUCrJ, vol. 12, no. 1, pp. 74–87, Jan. 2025, doi: https://doi.org/10.1107/s2052252524011242↩

[9] CCDC, “Entry API — CSD Python API 3.6.1 documentation,” 2019. Available: https://downloads.ccdc.cam.ac.uk/documentation/API/modules/entry_api.html#ccdc.entry.Entry.cross_references. [Accessed: Jan. 18, 2026]↩

[10] A. Wlodawer et al., “Duplicate entries in the Protein Data Bank: how to detect and handle them,” Acta Crystallographica Section D Structural Biology, vol. 81, no. 4, Mar. 2025, doi: https://doi.org/10.1107/s2059798325001883.↩

[11] O. Anosova, Vitaliy Kurlin, and M. Senechal, “The importance of definitions in crystallography,” IUCrJ, vol. 11, no. 4, pp. 453–463, May 2024, doi: https://doi.org/10.1107/s2052252524004056↩

[12] D. Widdowson, M. M. Mosca, A. Pulido, A. I. Cooper, and V. Kurlin, “Average minimum distances of periodic point sets – foundational invariants for mapping periodic crystals,” MATCH Communications in Mathematical and in Computer Chemistry, vol. 87, no. 3, pp. 529–559, Dec. 2021, doi: https://doi.org/10.46793/match.87-3.529w↩

[13] CCDC, “CCDC Support: Retractions in the Cambridge Structural Database,” 2025. Available: https://support.ccdc.cam.ac.uk/support/solutions/articles/103000353401-retractions-in-the-cambridge-structural-database. [Accessed: Jan. 15, 2026]↩

[14] CCDC, “I’ve found an entry in the CSD which either contains an error or does not correctly reflect the original publication. Who should I notify?,” CCDC, Aug. 01, 2024. Available: https://support.ccdc.cam.ac.uk/support/solutions/articles/103000306314-i-ve-found-an-entry-in-the-csd-which-either-contains-an-error-or-does-not-correctly-reflect-the-origi. [Accessed: Jan. 20, 2026]↩

[15] J. van de Streek, “Searching the Cambridge Structural Database for the `best’ representative of each unique polymorph,” Acta Crystallographica Section B Structural Science, vol. 62, no. 4, pp. 567–579, Jul. 2006, doi: https://doi.org/10.1107/s0108768106019677↩

The group photo of participants at the Opening Ceremony. First row, from left to right: Prof. Kazumasa Sugiyama, Prof. Shih-Ming Peng, Prof. Yu Wang, Prof. Genji Kurisu, Prof. Chun-Jung Chen, Minister Prof. Cheng-Wen Wu, Prof. Atsushi Nakagawa, Prof. Santiago García-Granda, Prof. Andrew H.-J. Wang, Prof. Geoff Jameson. The inset panel at the lower right shows the traditional drum performance with the AsCA 2025 signage.

The 19th Conference of the Asian Crystallographic Association (AsCA 2025), jointly hosted by Taiwan and Japan, was successfully held at the Taipei International Convention Center (TICC), Taipei, Taiwan, from 1 to 6 December 2025. The conference was organized by the International Union of Crystallography Committee of ROC, the Taiwan Crystallographic Group, the National Synchrotron Radiation Research Center (NSRRC) in Taiwan, and the Crystallographic Society of Japan (CrSJ), with additional support from Academia Sinica, the NCKU Center of Crystal Research, and the National Science and Technology Council (NSTC) in Taiwan as co-organizers.

As one of the major regional conferences associated with the International Union of Crystallography (IUCr), AsCA 2025 provided an important platform for presenting recent scientific advances and strengthening collaboration in crystallography and structural science across the Asia–Oceania region and beyond.

Organization and Scientific Program

AsCA 2025 was co-chaired by Professors Chun-Jung Chen (Taiwan) and Atsushi Nakagawa (Japan), working closely with a Local Organizing Committee (LOC) of 25 members from Taiwan and Japan and an International Program Committee (IPC) comprising 39 international representatives. The scientific program was extensive and well balanced, consisting of 66 sessions in total. These included four plenary lectures, seven keynote lectures, 35 microsymposia, two flash presentation sessions, two Rising Star sessions, two poster sessions, three exhibitor luncheon seminars, one CrSJ Award session, two AsCA Council meetings, one CrSJ Assembly, and one Taiwan Crystallographic Group Assembly.

In addition, four pre-conference workshops were held in Taipei, followed by two post-conference workshops in Taipei (Taiwan) and Okinawa (Japan), respectively. Together, the sessions, workshops and seminars covered fundamental and applied crystallography, structural biology, materials science, instrumentation, data analysis and emerging technologies. The workshops were particularly well received, providing hands-on experience with advanced methods, instrumentation and specialized software, and enabling participants to apply state-of-the-art techniques to diverse research challenges.

Opening Ceremony

The opening ceremony began with an energetic traditional drum performance symbolizing dynamic rhythm of unity, collaboration, progressive spirit of the crystallographic community, while highlighting the cultural heritage of Taiwan. Conference Co-Chairs Professors Chun-Jung Chen and Atsushi Nakagawa welcomed participants and expressed their gratitude to the organizing teams and attendees, emphasizing the importance of AsCA 2025 as a platform for scientific dialogue and regional partnership.

Opening remarks were delivered by Professor Cheng-Wen Wu, Minister of NSTC of Taiwan; Prof. Santiago García-Granda, President of IUCr; and Prof. Genji Kurisu, President of AsCA. Their addresses highlighted the significance of international collaboration and emphasized the pivotal contributions of crystallography and research facilities in advancing contemporary structural science. Academician Yu Wang (National Taiwan University and Academia Sinica) then presented a historical overview of AsCA, reflecting on its development and contributions to the Asia–Oceania crystallographic community. The ceremony concluded with a ceremonial drumming session involving invited guests, marking the official opening of AsCA 2025.

Participation and Scientific Highlights

The conference attracted 733 participants (510 male, 215 female, and 8 who preferred not to disclose gender) from 28 countries, reflecting strong international engagement and the growing influence of crystallography and structural science in the region. The core scientific program comprised 35 parallel microsymposium sessions across four meeting rooms, spanning six major disciplines: structural biology, chemical crystallography, physics, materials science, instrumentation and technology, and data science.

These sessions featured 115 invited speakers, including four plenary lecturers—Professors Ma. Louise Antonette N. De Las Peñas (Philippines), Yun Liu (Australia), Shun-ichi Sekine (Japan), and Seikh Mohammad Yusuf (India)—and seven keynote speakers. Their presentations highlighted cutting-edge methodologies, innovative applications of large-scale facilities, and interdisciplinary approaches that are shaping current and future developments in crystallography and structural science.

The conference additionally received 430 contributed abstracts, of which 104 were selected for oral presentations and 326 for poster presentations. This format provided opportunities for researchers at all career stages to present their work and engage in scientific discussion. Moreover, generous support from 25 international companies and organizations enabled the establishment of 21 exhibition booths, which enhanced the scientific communications and promoted participants’ research during the conference.

Awards and Support for Early-Career Researchers

AsCA 2025 placed strong emphasis on recognizing excellence and supporting early-career researchers by featuring several awards, which were adjudicated by an external committee comprising esteemed members and judges. Four Rising Star Awards honored four exceptional early-career researchers, with equal representation across the biological and non-biological research areas. Seventeen Poster Awards were conferred, including seven PDBj Awards for biological research and ten Rigaku Awards for non-biological research. Two Audience Spotlight Poster Awards were given to promote interaction during poster sessions.

In addition, eight Travel Fund Awards supported the participation of young researchers from the Philippines, Malaysia, Turkey, Poland and India. Financial support from the IUCr, through the young scientist-related awards and travel fund, is gratefully acknowledged. Moreover, two CrSJ-Award talks recognized outstanding scientific contributions in biological and non-biological fields. Collectively, these initiatives underscored AsCA’s commitment to inclusivity, mentorship and the development of the next generation of crystallographers.

Social Program and Networking

Beyond the scientific sessions, AsCA 2025 featured a rich social program designed to foster networking, friendship, and informal interaction among participants. Events included a welcome reception at TICC, a young scientist mixer gathering at Another Round Taipei, and a conference banquet featuring Aboriginal cultural performances and pup music following an exclusive and historical secret-tunnel tour at the Grand Hotel. International delegates were also offered complimentary access to the Taipei 101 Observatory.

Participants visited the Taiwan Photon Source (TPS) at NSRRC and enjoyed local sightseeing and an evening meal in the Hsinchu region. These activities created valuable opportunities for cross-generational and interdisciplinary engagement, and were particularly appreciated by early-career researchers seeking to connect with established scientists in an informal setting.

Closing Ceremony

The closing ceremony drew a full audience and opened with remarks from the Conference Co-Chairs, Prof. Chun-Jung Chen and Prof. Atsushi Nakagawa, who thanked participants and organizing committees for their strong engagement throughout the week. The high attendance observed even during the final session was highlighted as evidence of the scientific community's unwavering dedication and enthusiasm. Following these remarks, a series of prestigious awards were presented, including the Rising Star Awards, PDBj and Rigaku Best Poster Awards, Audience Spotlight Awards and a Lucky Draw.
  Subsequently, the current AsCA President, Professor Genji Kurisu, and his successor, Professor Geoffrey Brind Jameson, addressed the assembly, reflecting on the conference's significant outcomes and provided thoughtful commentary on the future trajectory of AsCA and its contributions to the crystallographic sciences. Promotional presentations for IUCr 2026 and AsCA 2027 highlighted upcoming opportunities for continued international involvement. The conference concluded with the Conference Co-Chairs formally declaring the successful completion of the AsCA 2025 main conference.

Post-Conference Activities

A half-day scientific tour of the TPS at NSRRC followed, with over 120 participants visiting advanced beamlines, experimental facilities, and accelerator instruments. Presentations highlighted developments in protein microcrystallography, bioSAXS, high-resolution powder diffraction, X-ray nanodiffraction, and tender X-ray absorption spectroscopy. After the TPS visit, attendees enjoyed an excursion to the Xiangshan Wetlands to observe indigenous crab species and take in a picturesque coastal sunset. The tour concluded at the Wave Market near Nanliao fishing harbor, where participants relished a seafood dinner featuring local specialties, creating a relaxed atmosphere conducive to informal conversations and networking.
  After one post-conference workshop related to crystallographic and cryo-EM structure solution at TICC, Taipei on Dec. 6, the final post-conference workshop— “Exploring new frontiers in electron microscopy-driven structural studies”, was held on 8–9 December 2025 at the Okinawa Industry Support Center in Naha, Japan. Attended by 30 participants, the workshop focused on recent advances and future directions in electron microscopy-based structural research and marked the conclusion of all official AsCA 2025 activities.

Conclusion

With 733 participants from 28 countries, AsCA 2025 exemplified the vitality, interdisciplinarity and international collaboration that characterize contemporary crystallography and structural science. More than a scientific meeting, the conference served as a hub for exchanging ideas, advancing technologies and fostering collaborations. By supporting innovative research, encouraging interdisciplinary dialogue and nurturing early-career scientists, AsCA 2025 strengthened the foundation for future developments and reinforced the Asia–Oceania region’s important role in the global crystallographic and structural community.

 

Liebe and Aaron Klug in 2003 in Cambridge at the 50th anniversary celebrations of the double helix, photograph by I. Hargittai

Aaron Klug – Centennial – Biophysicist and Biochemical Crystallographer of Broad Vision and Impact [1]

Origin and Starting in Science

Aaron Klug (1926–2018) was a member of the scientific staff of the Medical Research Council (MRC) Laboratory of Molecular Biology (LMB), Cambridge, U.K., when I recorded a long conversation with him in his office on October 9, 1998. This was the first of our several meetings. In 2000, during my wife's and my three-month visit to MRC LMB as guests of the Royal Society, Klug and I finalised what was to be the printed version of our conversations [2]. I quote extended parts from our conversations in this remembrance.

Klug was born in Lithuania, then an independent country (as it is once again), and was two years old when his Jewish family emigrated to South Africa. His paternal ancestors were cattle dealers and owned land, which was unusual for Jews. By the time Stalin’s Soviet Union occupied Lithuania in 1940, Klug and his immediate family had long gone, but other family members suffered from the Soviet rule and later from the Nazi German occupation. One member of his family fell as a soldier of the Red Army and another as a partizan. Nobody in the family who had stayed survived. After Klug was awarded the Nobel Prize in 1982, the Soviet Academy of Sciences attempted to claim Klug as its Nobel laureate (at the time, Lithuania was part of the Soviet Union). Klug’s wife, Liebe Klug (née Bobrow) was also from South Africa. She was a choreographer and later trained as a psychotherapist. Their two sons are academics, one, an economic historian in Israel and the other, a physical chemist in London. Klug spoke about his Jewishness in our conversation [2]:

“I am a professing Jew, and I go to the synagogue sometimes, but not as often as in earlier years. I grew up in South Africa and had a relatively free life. There was anti-Semitism in South Africa, but not so much. We grew up in Durban, where there were very few Jews, a few hundred families only. My elder brother and I were the only Jews in our primary school, and there were one or two bullies who would occasionally pick on us because we were Jews. The biggest bully must have learned it from his parents, since we must have been the first Jewish boys he had met. When my brother and I were together, we would fight back, but if either of us was alone, they would on rare occasions set on us. Some other boys sometimes stood up for us, so I learned some lessons early on.”

Curiosity made science into a life motif for Klug. Like many future scientists of his generation, he read Paul de Kruif’s book, Microbe Hunters. Klug started in medicine at the University of Witwatersrand in Johannesburg and became especially interested in biochemistry. He gave up anatomy but continued in physiology, biochemistry, and histology. Eventually, he switched from medicine to science, focusing on chemistry, physics, and mathematics for his B.Sc. degree. He took an M.Sc. degree under Professor R. W. James at the Physics Department at the University of Cape Town. From this point, his career in science was straightforward. In his words [2]:

“James had been a colleague of Lawrence Bragg in Manchester, and I learned a lot from him, from the way he clearly set out a problem. I wanted to understand quantum mechanics, wave mechanics, relativity, and similar areas. My research was on small-molecule crystallography. We had to build our own apparatus, and I built a microdensitometer to measure the densities of spots on X-ray diffraction photographs. Then I went to Cambridge because Cambridge was the place to go, and I taught myself quantum chemistry in preparation. I did not quite know what I wanted to do but had some idea that I wanted to do some nonorthodox crystallography. But Bragg would not allow this. He was the head of the Cavendish Laboratory, and he wanted me to work on silicates. He told me that the MRC [Medical Research Council] unit, where Perutz was working, was full. But I did not have any strong feelings about any particular branch. Some people know exactly what they want to do from the very beginning; I did not. I was just wandering about. Then, after my Ph.D. and a year in the Colloid Science Department in Cambridge, I went to London on a Nuffield Fellowship and, by chance, met Rosalind Franklin.”

Klug worked at Birkbeck College, University of London, between 1954 and 1961 and at the MRC Laboratory of Molecular Biology (LMB) in Cambridge from 1962 to the end of his professional life. He served as director of MRC LMB from 1986 to 1996. He was a Fellow of Peterhouse in Cambridge and Director of Studies in Natural Sciences from 1962 to 1986, and then stayed on as an Honorary Fellow. He was elected Fellow of the Royal Society (FRS) in 1969. The citation of his election reads [3]:

“Mathematical physicist and crystallographer distinguished for his contributions to molecular biology, especially the structure of viruses. Development of a theory of simultaneous temperature and phase changes in steels led him to apply related mathematical methods to the problem of diffusion and chemical reactions of gases in thin layers of haemoglobin solutions and in red blood cells. Then the late Rosalind Franklin introduced him to the X-ray study of tobacco mosaic virus to which he contributed by his application and further development of Cochran and Crick's theory of diffraction from helical chain molecules. Klug's most important work is concerned with the structure of spherical viruses. Together with D. Caspar he developed a general theory of spherical shells built up of a regular array of asymmetric particles. Klug and his collaborators verified the theory by X-ray and electron microscope studies, thereby revealing new and hitherto unsuspected features of virus structure.”

The Royal Society citation singled out the roles of Rosalind Franklin and Donald L. D. Caspar played in Klug’s research career. They both achieved seminal results in studying virus structures. In 1956, Caspar [4] and Franklin [5] published two back-to-back papers in Nature, demonstrating that the viral RNA was deeply embedded within the helical protein rod of the TMV virus. In 1962, Caspar and Klug reported their discovery of the icosahedral virus structures. [6] Klug followed the advice from Rosalind Franklin in developing his virus research, in which he joined forces with Caspar. In Klug’s words [2]:

“Both Rosalind and I thought that I ought to develop a field of my own. The first X-ray pictures of spherical virus crystals had been taken by Bernal and Carlisle at Birkbeck College, and there were still some crystals there. Donald Caspar had started at Yale on tomato bushy stunt virus. Crick and Watson had published a paper on the symmetry of spherical viruses and predicted that they must have the symmetry of one of the cubic point groups, but left it at that. Their work, however, inspired Caspar to get hold of some crystals of bushy stunt, and he came to the Cavendish Laboratory in 1955 and obtained low-resolution X-ray photographs that strongly indicated fivefold symmetry. Caspar had already become our colleague and friend because he had written an important paper on TMV. Caspar had provided the first one-dimensional electron-density map of the virus rod. Rosalind had solved the structure of the protein helix without the RNA. The two together showed that the virus rod had a hole down its axis and that the RNA was located in the middle of the helical protein array. Pauling said that this was all nonsense, that the virus could not have a hole in the middle. He was very magisterial, acting the great man. I was going to write a paper ‘on the role of the hole’ in TMV because that is where, as I said earlier, the RNA enters during the virus assembly.”

“When Caspar came to Birkbeck, we looked in the refrigerator, and we found crystals from the late 1930s. Caspar took the bushy stunt virus, and I took turnip yellow mosaic virus. I knew that bushy stunt had a simpler unit cell, but Caspar was the first to begin the work, so he had the first choice. John Finch and I showed that the turnip yellow mosaic also had fivefold symmetry. Then, in 1959, Finch and I showed that the polio virus also had fivefold symmetry. This was important because people in those days believed that animal and plant viruses must be different.”

“After we had published this paper, I received a letter from one of Buckminster Fuller’s collaborators. He sent me a book with pictures of many geodesic domes. There was a controversy at that time about the symmetry of the protein shell of turnip yellow mosaic virus, which had been suggested to have statistical symmetry only, from the estimates of the number of the protein subunits. In the electron microscope, one could see 32 knobs and 32 times 5 is 160 subunits, which seemed reasonable. Our study showed, however, that this was not statistical symmetry – there had to be perfect icosahedral symmetry in the protein shell. We had the advantage of having protein-only crystals and also crystals of the virus with the RNA inside the shell. I started thinking about the icosahedron and read the book The Dymaxion World of Buckminster Fuller by Robert W. Marks. The book has a language of its own, but, in effect, I “translated” it and realized that what Fuller was doing in his icosahedral domes was making small, forced changes in the perfect geometry to accommodate more than 60 units. I realized that in the virus particle, one could automatically get approximate equivalence provided that the proteins or the contacts between them were flexible. I introduced the word quasiequivalence. Caspar made a cardboard model in which he also showed departures from perfect symmetry. So, we got together and wrote the Caspar–Klug paper referred to above.”

The interactions between Klug and Franklin extended beyond Franklin’s premature death. Not long prior to my first conversation with Klug I read in a book review in Nature something like that premature death can be a shrewd career move, for Rosalind Franklin became almost instantly a hero for feminists. This statement rather upset me, but in our conversation, Klug handled this issue with his customary calm [2]:

“Yes, that is true. Because of an early death, you lose sight of the person. I knew quite a bit about Franklin’s earlier DNA work, because she came to Birkbeck College straight after her DNA work, and she applied her experience in the DNA work to the virus study. After her death, I read not only her papers but her notebooks. When Watson’s book The Double Helix came out, I had an advance copy, and I decided to find out what she had done, because he wrote about her being an obstructionist. I saw that she had gotten very close to the answer, but most people did not know she had existed because her work had been lost sight of. Watson’s book placed her very firmly as a protagonist in the story. It is very clear to me that if she had lived, she might have shared the Nobel Prize with Watson and Crick. That is what Watson thinks, too. There would have been a dilemma for the Nobel committee, because Wilkins had started the DNA work at King’s, and there can only be three people sharing the Prize. Now, Rosalind was not Francis Crick, not as imaginative. But she would have got the structure out in the end on her own. Crick and I have discussed this many times. One can see it from her notebooks, painfully working out the existence of two chains, in the A form running in opposite directions, but she had not grasped the relationship between the A and the B forms of DNA, which she had discovered. I have written about this. She would have solved it, but it would have come out in stages. For the feminists, however, she has become a doomed heroine, and they have seized upon her as an icon, which, of course, is not her fault. Rosalind was not a feminist in the ordinary sense, but she was determined to be treated equally, just like anybody else. All the protagonists in Watson’s book are portrayed with their failings, but the person who perhaps comes out worst in Watson’s book is Wilkins. It was Rosalind’s famous X-ray photograph that he showed Watson, but we must remember that in those days, people were much more open. Wilkins and Franklin were very different personalities and didn’t get on: if she had been a man, it would have been the same.”

In 1982, Aaron Klug received an unshared Nobel Prize in Chemistry “for his development of crystallographic electron microscopy and his structural elucidation of biologically important nucleic acid-protein complexes.” Here I continue quoting from our conversations, starting with what he said about his prize-winning research and related studies.

Research Scientist

At the conclusion of your Nobel lecture in 1982, you predicted that the subjects of research in molecular biology would become increasingly complex and made a specific point about structural studies connecting the cellular and the molecular.

It is happening in the way that people have been using electron microscopy, for example. There are now low-resolution structures for the ribosome, the biological factory, which makes proteins. There is also now an X-ray structure to about 8Å resolution at Yale on the 50S subunit of the ribosome. This has a molecular weight of 1 million kilodaltons. Another group is analyzing crystals of the 30S subunit, the second “half” of the ribosome. John Walker’s enzyme F1 ATPase had a mass of 330 kilodaltons, which was a triumph for crystallography at the time. One of the things we had to do when studying the nucleosome was to show that it was biologically relevant. Our critics at that time thought that what we were studying was artificial. But, in fact, we did a lot of studies by X-ray diffraction on intact nuclei, and we also used enzymatic digestion as a probe to cut the DNA inside the nucleus, comparing it with the isolated nucleosome. More generally, we used all sorts of methods to make sure that the components we studied in vitro represented not artifacts of reconstruction but the real thing.

You obviously convinced your critics.

Yes, but this was unglamorous work. It is the biochemical background, not often stressed in the papers, which, in the main, shows only the results. Our critics could not believe that something so highly ordered as a nucleosome could be formed inside the cell, but we were able to crystallize the nucleosome. We now know that there is considerable order in the cell. Of course, it is not perfect crystalline order, but it is ordered. It is important that we carry out biochemical and biological tests along with the crystallographic studies. People call me a crystallographer, and I do do crystallography, but it is biochemical crystallography, that is what we should call it. The chemistry is vital.

In your research, structure determination and new methodologies appear to have equal importance.

Absolutely. Without the new methodology, we would not have been able to solve the structures. When we started out to use electron microscopy for our virus structure studies (to complement the X-ray work), we thought that we would just get an overall view of the structure. People had not realized that you could extract much more information from electron microscope images. In 1969, when we demonstrated the first three-dimensional image reconstruction of virus particles and bacterial flagella at a meeting in New York, Sturkey, an electron diffractionist, called it a “load of crap.” What he did not understand was that we were dealing with relatively weakly scattering objects. We demonstrated this, for example, on multilayers of cell walls, which could be analyzed by electron microscopy and diffraction, taking into account the overlapping layers. A tremendous amount of background work went into three-dimensional image reconstruction before we began to understand what was going on. Sturkey had a theoretical point that we were ignoring multiple scattering, but we justified it. Because of your own research in electron diffraction, you will understand the point about multiple scattering, and so do I, and so did Sturkey. I have a Ph.D. in physics and do know some physics and mathematics.

When you say “methodology,” I started out with electron microscopy with the simple view that it was well understood. In fact, I realized soon enough that this was not the case. I had the good fortune to be a non-expert. When you are a non-expert, you do not come with many presuppositions. There were various people working in the field trying to get “the perfect picture,” and I realized that there was no such thing. I introduced the approach of taking a series of micrographs in the electron microscope at various degrees of defocusing and then correcting them for the contrast transfer function. With this method, we could create an image of transparent objects, that is, non-stained biological specimens.

The technology developed in the course of practical studies. We started out with a real problem in a helical virus, and I soon realized that we could make a three-dimensional reconstruction by using the theory of helical diffraction. Every time you tilted the specimen, you could recover another function in the mathematical expansion of the electron density. I had developed the approach for Rosalind Franklin’s X-ray studies of the tobacco mosaic virus (TMV). Later, I saw that it was a special case of a more general principle in Fourier theory.

The method also became the basis of the principle of the X-ray CAT scanner. Hounsfield and Cormack received the Nobel Prize in 1979 for computer-assisted tomography (CAT). Hounsfield read my Nature paper of January 1968 and took out a patent for CAT in August 1968. I had realized earlier that you could apply it to medical radiography, and I went to see some radiographers, but they told me that they did not need this “fancy stuff.” They said, “We understand exactly what we see in a medical X-radiograph,” but I asked them about the radiation doses used.

The X-ray tomography of the time used a moving source of X-rays and a moving film, so all the density, except in one purely geometrical optics plane, was out of focus, the rest blurring the radiograph. I said to them: “Look, you are giving a much bigger dose than you have to, and the question is how much more information do you get?” Later, it was shown mathematically that you could get more information for a given dose by image reconstruction by CAT scanning than by X-ray tomography, and CAT scanning has become the standard method. Some people think that I should have got the Nobel Prize with Hounsfield. This story illustrates the important point in science that you sometimes find the solution to a problem from another field.

I have worked on about five major problems in my life. Each has taken about 10 years with overlaps between them:

--The structure and assembly of the tobacco mosaic virus (TMV)
--Spherical viruses and electron microscopy
--Structure of transfer RNA (tRNA) and later an RNA enzyme (ribozyme)
--Chromatin and nucleosome
--Zinc finger proteins

We were building a model of TMV in 1958 for the World Exhibition in Brussels. The overall structure had been worked out by Rosalind Franklin and me with Ken Holmes and John Finch. I showed the model in my Nobel lecture. Rosalind was in the hospital most of the time, and she died of cancer in March 1958. We did not know the exact shape of the protein subunit, and we had great trouble in building the model. An architect friend, who was building the model for us, built us a jig I had designed to start the helix, and I realized at that point that in order to build such a structure, you need a specific nucleation event. There is a big difference between ordinary polymers and biological macromolecules. The key to biological specificity is a set of weak interactions. A polymer chemist could start building the model in the middle or at any other point. But for us, it was important to find the special sequence for initiating nucleation.

My Ph.D. work in the Cavendish Laboratory was on a problem of kinetics of phase transition in solids. There, one had to use the concept of the nucleation of the new phase. That was many years before, but something must have remained in my brain about nucleation. So, I realized that in thinking about TMV assembly, you must separate nucleation and growth, and I identified in this disk-shaped protein structure the source of the nucleation. At the time, I thought that the end of the TMV RNA initiated the conversion of the cylindrical disk form of the coat protein into two helical turns of the virus. It turned out that the detail in this picture was wrong. Finally, we understood that the nucleation of the virus assembly is accomplished by a hairpin of viral RNA getting inserted into the central hole of the protein disk, between the two layers of the subunits. The RNA has a special sequence, which includes guanine repeats, and we knew that there were three bases for every protein sequence. So, it was clear that it must be the nucleating sequence, and my colleagues Butler and Zimmern proved it.

A. N. Whitehead was a famous philosopher who coauthored Principia Mathematica with Bertrand Russell, and he said, “It is more important that an idea be fruitful than that it be correct.” When I put together my Nobel lecture for publication, the editor wanted to cut out the picture depicting our initial idea of nucleation. He said it was wrong. I replied that it was indeed wrong in detail, but everything essential was in there, so including it would show how science is a process of establishing the truth. The protein disk is an obligatory component for the formation of the virus. It performs two simultaneous functions. One is starting the physical assembly of the protein subunit, nucleation. At the same time, it recognizes a special sequence of the viral RNA, determining the specificity of interaction.

Many people think that science is just the application of various formulas. Some of it is, but they need to understand that, in a developing field, there are many steps on the way, and you can sometimes take the right step for the wrong reason. I worked on TMV from 1954, when I joined Rosalind Franklin, to the 1970s, when we were finally able to prove the mechanism of the assembly. Even after many years, this is the most detailed system of its kind that has been worked out. This was an important achievement, and for me, TMV was my first major scientific adventure.

The third entry on your list of major projects is the structure of tRNA [the first two have been covered in the quotations from the conversation above.]

That was at the time when studies of protein synthesis were at the forefront of molecular biology. The recognition of the genetic code was an important issue. Francis Crick was in the Lab [MRC LMB], and he said we must find out the structure of tRNA, and we did. In one loop of tRNA, there is a codon that recognizes the code of the messenger RNA, the three bases specifying the amino acid. At the other end of tRNA there is the site of attachment of the amino acid. I was busy with viruses and TMV, but it was coming to an end for me. I could not be like Max Perutz, spending the greater part of my life’s work on one thing, no matter how momentous.

Because of my experience with RNA in TMV, I was the only one in the Lab with any experience on the properties and structure of RNA. My colleague Brian Clark was working on protein synthesis, and he was producing large quantities of tRNA. There are many different tRNAs, more than one for each amino acid, and we were the first to get crystals of tRNA.

As is often the case in science, it was a chapter of accidents. We all thought that it would be too difficult to crystallize tRNA and so planned to crystallize parts of the tRNA “cloverleaf” (the secondary structure). There was a man in Germany who said he could grow crystals of tRNA. It turned out to be all faked. But before I found out that it was faked, I thought, “If this man can crystallize tRNA, we should be able to do it.” Later, others wrote a paper in Nature exposing him. I realized he was a phony, and I tell you how. When he came to our lab, we asked him about his crystals, and he said they were lost on the ferry. But he described them to us as blue crystals because he used a copper solution to crystallize them. I asked him what sort of camera he used to take his X-ray pictures, and he said it was a Guinier camera. I knew quite a bit about X-ray cameras, and I knew he could not have recorded the low-angle reflections he was talking about, and I told him so. He realized that I had trapped him, so he said that they had built a special attachment! But his original claim was important for us in setting us to work on the tRNA crystals. So, we got our crystals and solved the structure and were in competition with Alex Rich at MIT, who had followed our first crystallization. Although they were the first in publishing, they published the wrong structure, having misinterpreted their map. Our work on the tRNA structure had important consequences for later work in that one of the metals binding to the molecule caused it to act as a metalloenzyme, which cleaved the RNA. This led me later to work on RNA enzymes (ribozymes).

Thus, understanding how metals bind RNA turned out to be important. This was scholarly work, which did not get into the headlines. But this understanding was very useful for ribozymes. In the meantime, I had abandoned the RNA work and moved to study chromatin. One of our referees on a visiting committee asked me, “How can you give up this tRNA work?” And I got a bad mark from him, but I pointed out to him that I wanted to tackle another major problem, the structure of chromatin. By this time, I had also given up electron microscopy, which by then had been established as a major addition to structural biology.

The first RNA enzyme we studied was, in fact, tRNA itself with a metal attached. We were using lead as a heavy atom, and we never could solve the structure. The reason, which we did not know at the time, was that the bound lead was cleaving the RNA. People had, in the meantime, found that some viral RNAs could splice themselves. John Dewan, an American postdoc, was a bioinorganic chemist, and I put him on this problem and our first paper appeared in 1983. We solved the structure of the uncleaved form of Pb-tRNA and the cleaved form. It showed very clearly how the lead atom was being held at low pH, where there were no hydroxyl ions around. Actually, I know some chemistry, strange as it may seem. At higher pH, the lead carries the hydroxyl ions so one gets base-catalyzed cleavage. We had some difficulties in publishing our report of this work, because one of the referees said that the turnover of the reaction here is only one per minute and enzymes work much faster than that. I had to explain to the editor that these things do not happen spontaneously − it may be only one a minute, but in the absence of the metal, the reaction would take years. The editor overruled the referee, but it was quite interesting to learn someone else’s notion of what an enzyme is.

You mentioned chromatin as one of your major areas of research.

We worked on chromatin at different levels. The higher-order structure of chromatin was described in detail with nice diagrams in my paper for the Welch Conference in 1985. [7] At this level of research, we did X-ray work on fibers, and you can learn a lot even about imperfect structures from X-ray diffraction.

At one point, in the 1930s, J. D. Bernal opted for studying more perfect rather than less perfect systems when he and W. T. Astbury divided their work along these lines, although he later regretted his choice.

Bernal was right at the time because, without the knowledge of the ordered structures, you could not interpret the fibre structures. It is also understandable that this choice bothered him because, in a sense, the ordered structures are the less interesting ones. In the chromatin study, we also used X-ray solution scattering. We also produced crystals of the nucleosome and solved its structure to low resolution. Both were needed for interpreting the chromatin structure. The electron microscopy showed very little order. The genes that are not being transcribed are packaged in chromatin, so the bulk of DNA material is there. There is a hierarchic organization in chromatin. The DNA is stored in the 300-Å-diameter fibers, which are further organized in loops. There are active and inactive units. What about the genes that are being transcribed into RNA? They are the ones being used for producing RNA, and they form the so-called active chromatin. In about 1982, I decided to begin the study of the structure of active chromatin by a combination of chemistry, biochemistry, X-rays, and electron microscopy.

You don’t seem to have ever abandoned the metalloenzyme work.

I always wanted to follow up the work on tRNA and the RNA enzymes. There was another American postdoc, Bill Scott, who wanted to work on tRNA. But, instead, I suggested to him a real RNA enzyme. So, we began working on a real RNA enzyme, the “hammerhead” ribozyme, and were able to solve its native structure and also capture various stages in the catalyzed reaction by fast freezing. I gave this up when Scott returned to the United States, and I became more embroiled in my zinc finger work.

We are gradually coming to my present interest, the zinc fingers. The American biochemists D. D. Brown and R. G. Roeder discovered that there was a protein “transcription factor IIIA,” or TFIIIA, vital for accurate transcription of the 5S RNA genes. It binds to a regulatory region of DNA. Switching on a gene uses regions in it, called promoters or regulatory sequences, to which specific transcription factors bind that specifically recognize these sequences. A combination of these protein switches on a gene, which means that they form a complex to recruit the polymerase, which copies the DNA into RNA. So, this study was about the regulation of gene expression, not the mechanism of transcription.

I started out by hoping to find structures of the complex of proteins, which switch on these RNA genes. We started with one of them, the TFIIIA. I put a bright research student from America, Jonathan Miller, on this project. At first, we could not purify TFIIIA. I realized that something must have been wrong with our protocol. But Brown and Roeder succeeded. They were molecular biologists and were working on a scale of micrograms, using protein and DNA electrophoresis in gels, and not on the milligram scale of biochemistry. We wanted to extract the protein on a much larger scale for biochemical and crystallographic studies. Brown and Roeder were also adding chelating agents to take out metals, since metals will hydrolyze RNA and DNA. The protein also contained many cysteines, so they used mercaptans for protection of SH groups. This was totally deleterious, and the reason is very simple. The structure which we discovered shows that this protein has repetitive elements in it (Fig. 4), nine repetitive elements. Each repetitive unit contains two conserved cysteines and two histidines, and these are well-known ligands for the metal zinc. They also contain conserved tyrosines or phenylalanines and other aromatic hydrophobic amino acids, which form a hydrophobic core. So, there were repetitive zinc-binding domains in this transcription factor. Ultimately, other people and ourselves have shown our model to be correct by 2D NMR and by X-ray crystallography. We called the units zinc fingers because they are stabilized by zinc and grip or grasp the DNA. It is a modular system, and this was a new concept. In such a system, each finger recognizes a short specific sequence of DNA, and these different fingers can be combined to produce a larger DNA-binding protein domain. There is a combinatorial principle at work here, within a given protein.

The single finger is the module, and it is a stable unit. The individual fingers are joined in a flexible way. Each finger can have chemical distinctiveness, the same structure but with a variation of the particular amino acids that contact and recognize the DNA. This work took us many years, but when you discover something new, many others begin working on it, and that spoils the fun.

In studying the rules of recognition, we did not systematically change the amino acids one by one to make a strong binder to DNA. Rather, we used the phage display method of chemical combinatorics, which we did not invent but we adapted it for the zinc fingers. We made a library of 6 or 7 million variants in the finger recognition site and applied a selection process to pick out the strongest binders for a given DNA target. At the end, we had the specific zinc fingers for binding DNA and tested them by a reverse experiment, that is, by randomizing DNA and seeing to which DNA sequence the finger bound preferentially. This was physical biochemistry rather than molecular biology. Going from in vitro experiments to real systems, we designed a protein de novo, which is bound to a sequence of an oncogene, a cancer gene, and switched it off when present in a mouse cell line. We can now design proteins, using zinc fingers that can combine with desired DNA targets. Of course, what we put into the cell is not the protein, it is the DNA construct used to transfect the cell.

I have given a concentrated account of 50 years of scientific research. Now I have a small group of five people, a student, a visitor, a technician, and two temporary associates. I have to concentrate on a few things. I am a “retired worker” in MRC parlance, I have a small office and a lab upstairs. A European Union grant supports my oncogene research.

President of the Royal Society and Science Policy

Are you an insider in British life?

I was not until very recently. Yes, I think, I am an insider now, by virtue of the Royal Society. If it is a question about how much one influences people, one inevitably meets a lot of people at the Royal Society, and some of them are influential. Then, we have to deal with the government. We produce reports and papers. It’s a lot of hard work. I am nearing the end of my third year as President of the Royal Society, and the term is for five years.

Does the British government take the advice of the Royal Society?

Sometimes.

About questions like the mad cow disease (BSE)?

We publish reports and responses to parliamentary and other enquiries. We published a report on genetically modified plants, the best study there was at the time on the subject. In the Royal Society, you can get a group of scientists together and everything is done for free, nobody gets paid, including the President. For the GM (genetically modified food) report, I was a member of the group. We looked at the different regulations and saw that there were many regulatory bodies but no one was looking after the whole picture. We learned this from the days of BSE, which was a much more pressing problem, that there were many organizations dealing with the problem, but no coordination. Now the government is acting on this. We give advice whether asked for or not. We are in effect the Academy of Science of the United Kingdom, but we draw our Fellows from the whole Commonwealth, since we include India, Canada, and others. Currently, one fourth of our Fellows work abroad.

Would you care to comment on Russian science?

It is terrible to see it collapse. It was strong in physics and chemistry, but the biological sciences never recovered from Lysenko. The Royal Society had a scheme of helping Soviet science and got a special sum from the government to try to do so, but it was not on a large scale. We help individual scientists. Some come here. But the way the whole thing has collapsed is a tragedy.

Quite a few great British scientists have left the country, like Crick, Brenner, Dewar, Barton. Would you care to comment on this?

Crick left because he was reaching the age of retirement at MRC, and he had been offered a very good position in the United States with no limit of tenure. He is still active at well over 80 and at the MRC he would have had to retire at 65. It was an ill-advised policy, which is relaxed now. Brenner went to the States more recently. In this country, Max Perutz was the first former head of an MRC laboratory to stay on in the same lab.

I would like to ask you about science and nationalism. When Harry Kroto won the Nobel Prize in 1996, I saw a headline, “Kroto scored one for Britain.”

That happened only recently; in the earlier days, people paid little attention to the Nobel Prize in this country. It was not like on the Continent, where these things were regarded as terribly important. When Britain ran an empire, they did not think much of science and just took it for granted that it was of high quality. These things seem to count for more since Britain has become a moderate-size European nation.

Do you have a stand on human cloning?

I am against it now. A Royal Society paper has called for a moratorium on any embryo experiments beyond 14 days. That fitted in with earlier legislation on embryo research, which was drawn up with input from the Royal Society. The notion of cloning a human being is personally rather abhorrent to me. It is hard to say why, rationally.

You are a member of the Order of Merit and President of the Royal Society. Is there anything more you could have achieved?

I do not think of it that way. I did not enter a race; I entered science out of curiosity. I do not think I could have done more and would not want anything else anyway. I am trying to keep my research group going, and that is my main scientific interest. There are times when I almost resent having to go to London for about two days a week, to promote science in various ways, but it is my duty. Various people told me that it was my duty to undertake the Presidency; I had turned it down five years previously when I felt I could do more for science at the Laboratory of Molecular Biology.

Who are your heroes?

I do not have heroes and never had any. Of course, I marvel at the mind of the Einstein of 1905, to create relativity and so much else. There are certain people I admire enormously, like Francis Crick, and I learned a lot from him.

Any hobbies?

I read and read quite widely. I read ancient history and collect Greek and Roman coins. I cannot afford the more expensive ones but look out for affordable ones with historical connections. I have also begun to collect old Jewish coins from the Hasmonean times and also from the Roman procurators.

At the turn of the century, would you care to look back on the science of the twentieth century?

The general view of science is that science has been a rather bad thing. People only think about the harm it is doing, and we have a big backlash against it.

People forget the benefits it has brought. People often confuse science and the application of technology.

However, in the end, things like nuclear energy will just be inevitable, unless solar energy proves practical.

Would you agree that the two main areas of success of science in the twentieth century were nuclear physics and molecular biology?

I think so, yes, it has to be. Quantum physics and atomic energy and molecular biology. But, in fact, molecular biology is now a set of techniques and approaches, and it will become part of biochemistry and genetics. It was historically very important for molecular biology to define itself. Sometimes you have to define yourself against what exists. When I was a research student in the 1950s, the biochemists never thought in terms of DNA transmitting information. They thought of proteins as the molecules of life. This is why it was important to use another name. It is like religion in a way. You had to define the Protestant religion against the Catholic during the Reformation. Eventually, molecular biology will be absorbed into biochemistry.

There is a notion that we are living now in a post-molecular-biology era.

There is probably some truth in that because molecular biology is now all-pervasive; the biochemists and cell biologists now do molecular biology, and ever since the development of the polymerase chain reaction (PCR), all the medical people can do some molecular biology. Every medical student can now clone a gene.

Would you venture to say what the next frontier will be?

That is fairly obvious although I do not know how long it will take, but neuroscience, the workings of the nervous system and particularly the brain. If I were starting over again, I probably would go into neurobiology. Whether I would have the taste for those kinds of experiments, I do not know, but I find neural networks fascinating.

My scientific life has been one in which I worked on relatively messy systems, which physicists would not touch. On the other hand, I was able to bring some rigour into them by doing things properly and by developing new techniques, and it suited me very well. Those of us here in the Lab have helped create the subject, so it bears our image. But now cell biology has become so important, and I do not know whether you can make any progress with the brain without finding out more about the interactions between sets of molecules. One just has to start.

Thinking about science, you have to start even though you do not know where the end will be. I have been lucky because I had a good preparation without planning it and started my career when a new subject was opening up here and have had the opportunity to work for the MRC. This is a very enlightened body, which has let me work on long-term projects. Research is not just going from mountain top to mountain top, you also have to work in the valleys, and that takes time and freedom.

References

[1] This remembrance is based on a chapter in our new book in preparation, I. Hargittai, M. Hargittai, Echoes of Discovery: Inspiring Conversations with Nobel Laureates and Other Luminaries. Singapore: Jenny Stanford Publishing, tentative publishing date 2026.↩

[2] Hargittai, I. (2002). “Aaron Klug.” In Candid Science II: Conversations with Famous Biomedical Scientists. London: Imperial College Press, Chapter 20, pp. 306–329.↩

[4] Caspar D.L.D. (1956). “Structure of tobacco mosaic virus: radial density distribution in the tobacco mosaic virus particle.” Nature 177, 928.↩

[5] Franklin, R.E. (1956). “Structure of tobacco mosaic virus: location of the ribonucleic acid in the tobacco mosaic virus particle.” Nature 177, 928–930.↩

[6] Caspar, D.L.D., Klug, A. (1962). “Physical principles in the construction of regular viruses.” Cold Spring Harbor Symp. Quant. Biol. 27, 1–24.↩

[7] The Robert A. Welch Foundation Conferences on Chemical Research. XXIX. Genetic Chemistry: The Molecular Basis of Heredity, Proceedings Volume; 1985, pp. 133–160.↩

Istvan Hargittai is at the Budapest University of Technology and Economics.

One particularly memorable event at the IUCr2023 Congress in Melbourne was the building of the largest crystal structure model ever built (IUCr Newsletter 2023, 31(4)). In the more than two years since the Congress, the Bragg Your Pattern team behind the record-breaking model has been busy converting a conference highlight into a lasting legacy for school children across two countries.

The final model built, which was the structure of diamond, contained 62,356 atoms connected by 121,547 bonds, totalling 183,903 total components. These came from individual model kits, and once the conference finished, the laborious process of breaking the model back down again and putting the components back into their original individual boxes began. These kits are now being sent, free of charge, to primary schools all over Australia and New Zealand.

The inspiration for this project came from a similar previous project led by one of the team (SRB). The Elements Sets project (www.elementsets.net) created and donated more than 1600 sets containing 37 pure samples of chemical elements to secondary schools all over Australia, which will aid 1.5 million student lessons on the periodic table over the next decade. The Crystal Explorer kits now aim for a similar reach for primary school students across the region.

In addition to the model contents (at minimum, 91 tetrahedral atoms and 140 bonds, though we are erring on the side of generosity in reassembling the kits, which is being done by weight), we have written a 56-page glossy booklet to accompany each set. Support from ANSTO enabled the booklet to be produced by a professional graphic designer. It contains step-by-step instructions for building four different models (diamond, Lonsdaleite, buckminsterfullerene, and sodalite), a cut-out class activity for graphite, and background information on each structure. Further supporting resources, including further models to make, will be added over time on the project website (www.braggyourpattern.com), which also contains the link to the order form.

Because of the limited number of sets we have available, the kits are restricted to schools with primary-aged students in Australia and New Zealand, and the activities in the kits have been deliberately pitched at this age group. There is also only one kit per school (or two if a large school (400+ primary students)), but kits are completely free of charge (we even cover postage!) thanks to the generous support of the Society of Crystallographers of Australia and New Zealand (SCANZ). Priority was given in the early rounds for rural, regional and remote schools, and for government (public) schools. However, they are now open for any primary school in Australia and New Zealand.

To date, more than 4,700 schools have been contacted directly, with 293 kits ordered by 263 schools.  Orders have been received from (and sent to) schools as far apart as Tom Price, in outback Western Australia, to the Chatham Islands, 800km east of the South Island of New Zealand, giving a total span of over 6300km between sets. With the new school year about to start in the Southern Hemisphere, we now expect a fresh influx of orders in the coming weeks.

Finally, a portion of the kits is also being kept back to be included in outreach kits to be deposited with custodians in major cities around Australia and New Zealand. These will be available for loan by crystallographers for use in school outreach visits and other similar events. These outreach kits will not only include the Crystal Explorer kits, but also other activities based on the Crystal-a-con outreach event held at the IUCr2023 Congress (IUCr Newsletter 2023, 31(4)). Successful trials of these outreach kits have already been held at schools in Perth and regional NSW.

 

Professor Jiban Kanti Dattagupta, a nationally and internationally acclaimed crystallographer, passed away peacefully at his residence in Newtown, Kolkata, on January 22, 2026. A visionary scientist and dedicated educator, he leaves behind a profound legacy in the field of structural biology. He is survived by his beloved wife, Mrs. Sagarika Dattagupta, his daughter, son-in-law, and grandchildren.

Early Life and Education

Born on May 1, 1945, in Brahmanbaria (in pre-independence, undivided Bengal), Prof. Dattagupta was the youngest son of the late Mr. Jagadish Chandra Dattagupta and Mrs. Mrinmoyee Dattagupta. He spent his formative years in Hailakandi, Assam, where he completed his early education.
His academic journey was marked by excellence:

• Undergraduate: Physics, Scottish Church College, Kolkata.
• Post-Graduation: Indian Institute of Technology (IIT), Kharagpur.
• Doctorate: Ph.D. in Crystallography from the Saha Institute of Nuclear Physics (SINP), Kolkata, under the mentorship of Prof. N.N. Saha.

A Pioneer in Protein Crystallography

Prof. Dattagupta’s career was defined by his role as a pioneer. After a productive tenure (1972–1976) with the renowned crystallographer Prof. Wolfram Saenger in Göttingen, Germany, he returned to India to join the faculty of the Crystallography and Molecular Biology Division at SINP.
In a landmark contribution to regional science, he established the first protein crystallography laboratory in Eastern India. His international collaborations continued throughout his career, including a two-year stint as a visiting fellow at Edgar Meyer’s laboratory, Texas A&M University (USA), between 1981 and 1983. Even after his formal retirement, he continued to serve the scientific community as an Emeritus Professor of CSIR at SINP.

Leadership and Scientific Legacy

Prof. Dattagupta’s research primarily focused on structure-based protein engineering. His work was widely published in prestigious, peer-reviewed journals, including EMBO J, Nucleic Acids Research, Journal of Molecular Biology, and Biochemistry.
His leadership extended to several national and international bodies:

• Indian Crystallographic Association (ICA): Founder Secretary (2001–2003), Vice President (2004–2007), and President (2008–2010).
• Fellowships: Fellow of the National Academy of Sciences (Allahabad) and the West Bengal Academy of Science and Technology.
• International Membership: Active member of the International Union of Crystallography (IUCr).

Prof. Jiban Kanti Dattagupta will be remembered not only for his scientific brilliance and the institutions he helped build but also for his lifelong commitment to mentoring generations of students in the intricacies of protein crystallography.

ROBOLAB is the automated protein and protein-complex crystallization platform of the Brazilian Biosciences National Laboratory (LNBio), located at the Brazilian Center for Research in Energy and Materials (CNPEM), in Campinas, São Paulo, Brazil. Established to support projects in structural biology, biotechnology and drug discovery, ROBOLAB has consolidated itself as a strategic infrastructure that provides comprehensive protein crystallization services, combining high throughput, advanced automation and specialized technical and scientific support.
A major advantage of ROBOLAB is its location within the same research campus that hosts Sirius, the Brazilian fourth-generation synchrotron light source. This close physical and scientific integration enable a seamless workflow from crystal production to X-ray diffraction data collection. Crystals obtained at ROBOLAB can be directly diffracted at MANACÁ Sirius beamline, significantly accelerating structure determination and maximizing experimental success. This unique ecosystem places ROBOLAB within an internationally competitive environment for cutting-edge structural biology research.
The platform operates under an open-access policy, offering all its services free of charge to the scientific community. ROBOLAB serves researchers from academic and research institutions in Brazil, Latin America and other regions worldwide, contributing to the democratization of access to advanced crystallization technologies. The services offered include high-throughput crystallization screening, crystal optimization and refinement, co-crystallization with ligands and support for crystal cryoprotection and freezing for X-ray diffraction experiments (Figure 1). The entire process is supported by full technical assistance and scientific consulting, from experimental design to data interpretation.

In addition to crystallization services, users may benefit from the integrated scientific facilities available at LNBio/CNPEM. Protein production of recombinant targets can be performed using the facilities of the Protein Purification Laboratory (LPP), while comprehensive sample quality control prior to crystallization can be carried out at the Spectroscopy and Calorimetry Laboratory (LEC). These facilities provide access to techniques for assessing sample purity, homogeneity, stability and biophysical properties, ensuring that only high-quality samples are advanced to crystallization trials.
Access to ROBOLAB is granted through the submission of proposals via the SAU Online system, managed by the CNPEM User’s Office. All proposals undergo technical and scientific evaluation and once approved, experiments are scheduled according to infrastructure availability. Samples may be delivered in person at CNPEM in Campinas or shipped via specialized transport. From that point onward, all experimental procedures are carried out by the ROBOLAB technical team, ensuring standardization, quality and traceability at every stage.
ROBOLAB was designed to operate in a high-throughput environment, based on automation, precision and reproducibility. Its workflow is fully integrated and robotic, bringing together multiple stages of the crystallization process within a single coordinated platform. This approach ensures experimental efficiency, reduced sample consumption and increased success rates in obtaining crystals suitable for structural studies.
The initial experimental stage consists of crystallization condition screening, performed using well-established commercial screening kits. This strategy enables the systematic evaluation of nearly 600 distinct conditions, covering a broad range of precipitants, buffers, salts and additives. Crystallization drops are set up at nanoliter volumes using the high-precision Mosquito Xtal3 liquid-handling robot (SPT Labtech), ensuring high reproducibility, significant sample savings, and reliable plate preparation. This screening stage is essential for identifying promising crystallization conditions for each protein system (Figure 2).

Once conditions of interest are identified, ROBOLAB provides full support for refinement and optimization, if necessary, which is carried out in an automated manner using the Formulator 34 (Formulatrix). This system allows rational and precise customization of crystallization conditions, enabling fine adjustments of parameters such as pH, salt concentration, precipitants and additives. This approach significantly improves crystal size, quality and reproducibility, meeting the requirements for high-resolution X-ray diffraction experiments.
After plate setup, experiments are incubated and monitored using two automated imaging systems, Rock Imager 1000 (Formulatrix), operating at 4°C and 18°C (Figure 3). Periodic image acquisition under visible and UV light enables detailed identification of protein crystals, microcrystals, salt crystals and other crystallization outcomes. All generated images are made available through the Rock Maker Web platform (Formulatrix), providing remote access and allowing real-time monitoring of crystal formation and evolution, independent of the user’s location.
Experimental data and images remain available for remote access, allowing users to monitor, select and archive information of interest. Crystallization plates are stored under controlled temperature conditions for up to two years, ensuring traceability, reproducibility and experimental security over time.

By integrating state-of-the-art infrastructure, internationally recognized equipment, specialized technical expertise and direct access to the Sirius synchrotron light source, combined with a free-access model, ROBOLAB plays a central role in strengthening structural biology in Brazil. The platform directly contributes to scientific and technological advancement by supporting high-impact research projects and expanding national and international capabilities in biomolecular structure determination.
Submit your proposal and turn your protein into a structure with the support of ROBOLAB.

Useful Links: 

SAU Online - CNPEM User’s Office - proposal submission and user access

CNPEM - Brazilian Center for Research in Energy and Materials

ROBOLAB - Automated Protein Crystallization Laboratory at LNBio

LPP - Protein Purification Laboratory at LNBio

LEC - Spectroscopy and Calorimetry Laboratory at LNBio

MANACÁ Beamline - Macromolecular Micro and Nano Crystallography at Sirius