The IUCr Newsletter is the web magazine of the International Union of Crystallography. Since 1993, the IUCr Newsletter has been published quarterly and distributed to over 13,000 crystallographers worldwide. In August 2018, it was transformed into a dynamic digital platform with a fresh new look. Its aim remains to bring together the crystallographic community.
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William L. Duax Patricia Potter Jane Griffin The IUCr Newsletter is distributed electronically to 13,000 crystallographers and other interested individuals in 102 countries. Articles from the Newsletter are also available on this web site by following the links on the left-hand side. Feature articles, meeting announcements and reports, information on research or other items of potential interest to crystallographers may be submitted to the editor at any time. Items will be selected for publication on the basis of suitability, content, style, timeliness and appeal. Please send contributions to: newsletter@iucr.org Matters pertaining to advertisements should also be sent to the above address. Email address changes or corrections and requests to be added to the mailing list should be accomplished through the Subscribe and Unsubscribe hyperlinks above. Reuse permissions • The original article in which the material appeared is cited. • Copyright permission is indicated by the wording "Reproduced with permission of the International Union of Crystallography Newsletter". In electronic form, this acknowledgement must be visible at the same time as the reused materials, and must be hyperlinked to the IUCr Newsletter (http://www.iucr.org/news/newsletter). Please be sure to include the following information: • The title, author(s) and page extent of the article you wish to republish, or, in the case where you do not wish to reproduce the whole article, details of the section(s) to be reproduced. • The volume/issue number and year of publication in which the article appeared, and the page numbers of the article. • Details of the publication in which you wish to reprint the Newsletter material. • If the material is being edited or amended in any way, a copy of the final material as it will appear in your publication. • Contact details for yourself, including a postal address. |
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Annual Reports to the IUCr Executive Committee
The IUCr Newsletter (ISSN 1067-0696; coden IUC-NEB) is published quarterly (4x) by the International Union of Crystallography (IUCr Executive Secretary e-mail execsec@iucr.org). Members receive the IUCr Newsletter by virtue of country membership in the IUCr. Periodical postage rates paid at Buffalo, NY and additional mailing offices. POSTMASTER: Please send changes of address to IUCr Newsletter Editorial Office, c/o Hauptmann-Woodward Medical Research Institute, 700 Ellicott St. Buffalo, NY 14203 USA.
The Macromolecular Crystallography School "From data processing to structure refinement and beyond” was held at Sao Carlos Institute of Physics, University of Sao Paulo, Brazil, from 14 to 24 November 2018, and organized by João R. C. Muniz, Richard Garratt and Glaucius Oliva from the Sao Carlos Institute of Physics, and Kyle Stevenson and Ronan Keegan from STFC Rutherford Appleton Laboratory, Oxfordshire, UK. This workshop represents the continuation of the series that started in 2010 at the Institut Pasteur de Montevideo, Uruguay. As for the previous four editions in Uruguay and Brazil, the 2018 workshop was co-organized with the Collaborative Computational Project Number 4 (CCP4 - UK). We invited 18 teachers and tutors, gathering a group of leading experts in developing cutting-edge methods for protein crystallography and structural biology.
From 65 applications, we selected 24 students from seven different countries (Brazil, Mexico, Argentina, Chile, India, South Africa and UK). The oversubscription forced us to decline many good applications but it revealed that there is a need to keep this course running. Its visibility at the international level has become well established. The attendees were mostly advanced PhD students, postdocs and a few young research scientists. The idea in this respect was to prioritize people who could put this training into use in concrete research work as fast as possible.
During the workshop, lecturers guided the students through dedicated tutorials covering the main programs and state-of-the-art algorithms in macromolecular crystallography. The workshop was conceived to provide a strong theoretical background in the form of lectures, and hands-on abilities (problem-solving sessions) in the use of computational tools to exploit X-ray diffraction data (mostly brought by the students) and datasets with varying degrees of difficulty were also provided to students who did not bring their own. Particular emphasis was given to data processing, phasing/structure determination and model refinement/validation, also including, for the first time, sections on electron microscopy.
The course covered the following topics:
English was used throughout the course. Lectures were mainly scheduled in the mornings, with tutorials and hands-on practical classes in the afternoons. Practical classes were aimed at solving genuine problems brought in by the students (starting from the students’ X-ray diffraction data). Experimental data were assigned by the local organizers to the few students who had not brought their own data, so they could follow the tutorials and attempt to solve the structures during the problem-solving sessions. Two “Burning questions” sessions, as well as poster presentations (based on the students’ scientific research projects), reinforced active discussion times; the posters were on display during the whole course.
The Sao Carlos Institute of Physics is well equipped for practical structural biology courses. The Protein Crystallography Unit gives access to a state-of-the-art X-ray home source to perform single-crystal diffraction experiments under cryogenic temperatures, and other units in the institute allow for recombinant protein production/purification as well as in-solution biophysical characterizations.
It is important to highlight that most of the computational programs used during the workshop, many of them being the most widely used throughout the international macromolecular crystallography community, were taught directly by the program developers themselves, constituting a unique opportunity for intense and productive interaction. The aims of this workshop have been kept coherent since the first course in 2010, contributing to the explicit interest in consolidating continuity in a local Macromolecular Crystallography School. At the same time, we have clearly moved forward in incorporating improvements, and in keeping up to date with the latest developments in cutting-edge methods, thanks to the expertise of the participating teachers. This fulfils an urgent need to train young scientists in this discipline. This type of workshop not only allows solid training in theory and applications in biological crystallography but also fosters collaborative, interdisciplinary and inter-institutional research programs, consolidating regional networks in structural biology like the Center for Structural Biology of Mercosur (CeBEM).
The commitment of the teaching staff with the whole endeavour was outstanding, and the overall evaluation of the course was extremely positive. The social events accompanying the course - several dinners, the poster session, rafting in Brotas (a popular tourist attraction close to Sao Carlos) and the final barbecue - were very much appreciated and provided additional opportunities for informal interactions and discussions. Support from the Sao Carlos Institute of Physics, CeBEM, IUCr, Sao Paulo Research Foundation (FAPESP), CCP4 and the Coordination for the Improvement of Higher Education Personnel (CAPES) is greatly acknowledged.
For the 2020 edition, we are planning to put forward a web-based tool for interaction and dissemination of material and information, using the Moodle platform. We are also planning to include a final exam (optionally anonymous).
The First International Conference on "Crystal Engineering: From Molecule to Crystal" (CE:FMC2019) was held from 30 to 31 March 2019 in Raipur. Raipur is the capital city of Chhattisgarh state in central India. The conference was organized by the Department of Chemistry at the National Institute of Technology (NIT) Raipur, and was attended by 70 participants from India and neighboring countries. The two-day format included two Plenary lectures (1 hour each), four Keynote lectures (40 minutes each) and nine invited talks (30 minutes each). In addition, there were 10 oral (20 minutes each) and 20 flash oral (2 minutes each) contributions selected by the Scientific Committee from the submitted abstracts. The poster session enabled about 25 participants to share their work in this exciting meeting for the crystal engineering community.
The Indian Crystallographic Association (ICA) supported the conference by providing a fund of INR 25,000 for conference expenditure and two best poster and two best flash oral awards. The Science and Engineering Research Board, Department of Science and Technology (SERB-DST), India, supported the conference by providing a fund of INR 125,000 for travel/accommodation of Senior and Young Scientists and pre-conference printing. The invitation to attend the conference as Plenary lecturers was kindly accepted by Gautam R. Desiraju (IUCr Past President) and Edward R. T. Tiekink (Sunway University, Malaysia). The CE:FMC2019 also had the pleasure of hosting four other eminent scientists as Keynote speakers, Kumar Biradha (Associate Editor, Crystal Growth & Design; IIT Kharagpur, India), C. Malla Reddy (IISER Kolkata, India), Kittipong Chainok (Thammasat University, Thailand) and R. Vaidhyanathan (IISER Pune, India), and 10 young scientists as invited speakers.
In general, the conference covered a wide range of topics: single-crystal and powder diffraction, chemical crystallography, crystal engineering, charge density, quantum-chemical and database studies, and materials science. The event passed in an informal and friendly atmosphere with stimulating discussions during the sessions as well as in the coffee breaks, lunch and conference dinner. We hope that the conference helped our young colleagues to get better acquainted with the possibilities of contemporary crystallographic research and to recognize appropriate methods for further improvement of their work. The second conference in the series, CE:FMC2020, is scheduled to be held at Visvesvaraya National Institute of Technology Nagpur, India. The General Assembly of CE:FMC2019 evaluated the conference as very successful, and the generous support from the NIT Raipur, ICA, SERB-DST, IR TECH and TCI was gratefully acknowledged.![[CE:FMC 2]](https://www.iucr.org/__data/assets/image/0020/143570/CE-FMC2.png)
Since ancient times, humans have been fascinated by the beauty of crystals, their magic geometry, their intriguing shape, the existence of right angles and so on. These shapes have influenced the human mind, which has been most evident in the architecture of many buildings, skyscrapers and modern museums worldwide. During the second half of the 19th century, the architecture of many buildings was influenced by classical Greek architecture. However, at the beginning of the 20th century, the ideas of the Art Deco movement were expressed in the shape of large buildings. Later on, the Art Nouveau revival led to nonsymmetrical and curved constructions. But recently, it seems to be that modern architecture and the way that large buildings are being constructed are again being influenced by the shape of crystals.
Recently, I had the opportunity to visit Panama City on the occasion of the Open Forum for Science in Latin America and the Caribbean (CiLAC 2018), which took place on 22–24 October 2018. I was one of the panelists at the LAAAMP thematic session on 'Implementing Advanced Light Source facilities in Latin America and the Caribbean for sustainable socio-economic development', together with Michele Zema, IUCr Executive Outreach Officer (University of Pavia, Italy); Carlos Cabrera-Martínez (University of Puerto Rico, USA); Graciela Díaz de Delgado (Universidad de los Andes, Mérida, Venezuela); Diego G. Lamas (National University of San Martín, Argentina) and Richard Garratt (Universidade de São Paulo, Brazil).
During a break from the sessions, we walked along the most important streets in this beautiful Central American city. After a few blocks, a wonderful building came to our attention; it was perfectly shaped in the form of a screw axis (see below left) and it made us say altogether 'Crystallography is everywhere, even in Panama City'. This kind of building also reminded me of the Bankia building in Madrid, which has an orthorhombic shape, as well as others that resemble quartz crystals (below right).
![[buildings]](https://www.iucr.org/__data/assets/image/0020/143525/buildings.png)
Getting back to the CiLAC forum, we had a fantastic opportunity to discuss future developments of advanced light sources in the Latin America and the Caribbean region, and it was indeed great that such an important and strategic conference featured topics like synchrotron radiation and crystallography. For this, M. Zema and the whole LAAAMP Executive Committee have to be thanked for writing a good proposal and following up on their previous participation in the World Science Forum 2017 in Jordan. The CiLAC forum is a key regional space for debates and exchanges organized every two years in different cities of the region. It seeks to be a platform for outlining common positions and debating the scientific, technological and innovation agenda supporting sustainable development whilst simultaneously giving the region a strong voice in the global scope of the World Science Forum.
Our session was moderated by M. Zema, who started his opening speech with the most precise description I had ever heard about synchrotron radiation and advanced light sources, saying: 'Synchrotron light sources are the most sophisticated example of an open and multidisciplinary research infrastructure. They are comparable to supermicroscopes that probe the inner structure of matter. They produce very intense pulses of light, with wavelengths and intensities that allow detailed studies of objects ranging in size from human cells to viruses and proteins, down to atoms, with a precision that is not possible by other means. They allow researchers to investigate the structure and properties of a wide range of materials, from proteins ‒ to provide information for designing new and better drugs ‒ to probing novel materials for biotechnology, analyzing soils for green agriculture, to engineering applications, and the examination of archaeological artefacts'.
Most of the discussions were concentrated on the construction of synchrotron facilities in Latin American countries, such as Mexico, Puerto Rico and Cuba. The session was focused on discussing showcases and how advanced light sources successfully contributed to the socio-economic development of countries and regions, with particular reference to the Brazilian and SESAME experiences, by creating international scientific communities, improving education and creating new job opportunities.
In my contribution, I outlined a recent initiative of the Mexican Government to construct a synchrotron facility in the State of Hidalgo in the southeast of the Mexican Republic. It would be located in the Science Park area, where many industries and research centers have settled. Times of economic crisis are in reality times of many opportunities. If this Mexican synchrotron comes to fruition, it will reinforce the Mexican economy and enable it to provide for better technological opportunities, as happened in Brazil at the beginning of the 1990s. Besides this initiative, there are about 80 networks in Mexico sponsored by the National Council for Science and Technology (CONACYT). One of these – the Thematic Synchrotron Radiation Users' Network (RedTULS) – sponsors postgraduate students and academics to travel to synchrotron facilities. This network has allowed scientists to be trained and cultivated in the use of synchrotrons to support challenging research, which cannot be done by conventional instrumentation located in the universities. In his presentation, C. Cabrera-Martínez described the feasibility of constructing the first synchrotron in the Caribbeans, just in Puerto Rico. There are some investors from academia and government who are very much interested in this initiative. These two facilities (Mexico and Puerto Rico), which are at the business-planning stage at the moment, will create an environment that will encourage new scientific discoveries for the new millennium based on synchrotron light sources.
After returning home from CiLAC 2018, I received the good news that the State of Hidalgo has announced plans to invest USD 25 million as a seed contribution to develop a plan for a synchrotron light source in Mexico. The Mexican synchrotron facility will be completed by 2030. The facility will cost an estimated USD 800 million and its construction will take 10 years. Mexico could become the second Latin American country to host a synchrotron facility, after Brazil.
On 23 May 2019, the first crystal structure of a molecule synthesized and crystallized at the University of Abomey-Calavi in Cotonou, Benin, was solved during a crystallographic training session at the X-TechLab in Sèmè City, Benin, organized within the framework of the IUCr-UNESCO OpenLab in partnership with Bruker and LAAAMP.
The Programme Committee of this first crystallographic training session at the X-TechLab [note: a training session on X-ray microtomography was held in parallel with the crystallography class] was chaired by Claude Lecomte (CRM2, University of Lorraine, France) and the training staff included Professor Lecomte, Patrice Kenfack (University of Dschang, Cameroon), Florence Porcher (CEA Saclay, France), El-Eulmi Bendeif and Emmanuel Wenger (CRM2, University of Lorraine, France), Pierre Fertey (Synchrotron Soleil, France), Michele Zema (University of Pavia, Italy) and Eddy Martin (Bruker France).
Thirty students (PhD students, researchers and professors) took part in the training session, half of whom were from Benin and the other half from Burkina Faso, Togo, Congo-Brazzaville, Senegal, Cameroon and Chad. The IUCr provided EUR5000 for bursaries. Geometric crystallography and X-ray diffraction were taught during the first week, while the second week was devoted to hands-on single-crystal (14 participants) and powder (16 participants) diffraction.
All students who attended the school path on single-crystal diffraction collaborated in the solution and refinement of the crystal structure, under the supervision of Dr Bendeif. The compound studied was 4-(morpholine-4-carbonothioyl)benzoic acid (C12H13NO3S), a thioamide compound, in particular a morpholino(phenyl)methanethione derivative. These molecules inhibit the activity of the enzymes monoacylglycerol lipase and fatty acid amide hydrolase, with beneficial effects for anxiety, pain and neurodegenerative diseases, such as Alzheimer’s disease. For more information, see the Appendix below. The research team plans to submit its findings to Acta Crystallographica.
Three other original structure determinations of compounds synthesized in Cameroon were performed, which are also of publishable quality even though the data were collected at room temperature.
The staff of X-TechLab, and of Sèmè City, provided us with very modern teaching equipment and we also had a Bruker D8 QUEST ECO single-crystal diffractometer equipped with the latest version of the Photon II detector at our disposal. In addition, the school benefitted from free access to the Cambridge Structural Database (CSD) and related software through the CCDC FAIRE programme, and to IUCr Journals and International Tables for Crystallography through the IUCr Journal Grants Fund.
The general atmosphere was excellent with a lot of interested participants who asked many questions during this two-week training session (from 9 am to 8 pm!). At the end of the school, most participants were able to solve and refine crystal structures (the single-crystal group) or analyse the powder data files (the powder group) using the best freely available software. Professor Lecomte, who is Chair of the IUCr Crystallography in Africa initiative, expressed his gratitude to the school tutors, in particular Dr Bendeif, and to Bruker.
H. F. Agnimonhan, F. A. Gbaguidi and L. A. Ahoussi
Laboratory of Physics and Synthesis Organic Chemistry, Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, Benin4-(Morpholine-4-carbonothioyl)benzoic acid, C12H13NO3S, is a thioamide compound, in particular a morpholino(phenyl)methanethione derivative. Some studies have shown that certain morpholino(phenyl)methanethione derivatives inhibit the activity of the enzymes MGL (monoacylglycerol lipase) and FAAH (fatty acid amide hydrolase) (Kapanda et al., 2008; Draoui, 2009). FAAH and MGL catalyze the degradation reaction of anandamide and 2-arachidonoylglycerol, respectively (Mechoulam et al., 1995), which are endocannabinoids with beneficial effects in pathophysiological phenomena such as anxiety, pain and neurodegenerative diseases (e.g. Alzheimer's disease) (Walker et al., 2000; Scherma et al., 2008; Zvonok et al., 2008). In addition, we have studied other morpholino(phenyl)methanethione derivatives for their toxicity on Artemia salina Leach larvae and trypanocidal activity (Agnimonhan et al., 2012).
We synthesized the title compound, a novel molecule, to study its pharmacological properties, and have reported the effect of the K-10 catalyst on the green synthesis approach used (Agnimonhan et al., 2017). On 23 May 2019 during a crystallographic training session at the X-TechLab in Sèmè City, Benin, its crystal structure – which to our knowledge has never been studied previously – was determined by single-crystal X-ray diffraction analysis at 273 (2) K on a Bruker D8 Quest diffractometer. The compound crystallized in the monoclinic P21/n space group.
Agnimonhan, H. F., Ahoussi, L. A., Glinma, B., Kohoudé, J. M., Gbaguidi, F. A., Kpoviessi, S. D. S., Poupaert, J. H. & Accrombessi, G. C. (2017). Org. Chem. Curr. Res. 6, 180. https://doi.org/10.4172/2161-0401.1000180
Agnimonhan, H. F., Ahoussi, L. A., Kpoviessi, S. D. S., Gbaguidi, F. A., Kapanda, C. N., Bero, J., Hannaert, V., Quetin-Leclercq, J., Moudachirou, M., Poupaert, J. H. & Accrombessi, G. C. (2012). J. Appl. Pharm. Sci. 2, 62‒66.
Draoui, N. (2009). Synthèse, analyses et évaluations pharmacologiques de dévivés thioamides, thiourée et oxothioamides: inhibiteurs potentiels des enzymes de dégradation du système endocannabinoïde. Master en Sciences pharmaceutiques, Université catholique de Louvain, Belgium.
Kapanda, C. N., Muccioli, G. G., Labar, G., Draoui, N., Lambert, D. M. & Poupaert, J. H. (2008). Med. Chem. Res. 18, 243–254. https://doi.org/10.1007/s00044-008-9123-2
Mechoulam, R., Ben-Shabat, S., Hanus, L., Ligumsky, M., Kaminski, N. E., Schatz, A. R., Gopher, A., Almog, S., Martin, B. R., Compton, D. R., Pertwee, R.G., Griffine, G., Bayewitch, M., Barg, J. & Vogel, Z. (1995). Biochem. Pharmacol. 50, 83‒90.
Scherma, M., Medalie, J., Fratta, W., Vadivel, S. K., Makriyannis, A., Piomelli, D., Mikics, E., Haller, J., Yasar, S., Tanda, G. & Golberg, S. R. (2008). Neuropharmacol. 54, 129‒140.
Walker, J. M., Strangman, N. M. & Sanudo-Pena, M. C. (2000). J. Pain 1, 20‒32.
Zvonok, N., Pandarinathan, L., Johnston, M., Karageorgos, I., Janero, D. R., Krishnan, S. C. & Makriyannis, A. (2008). Chem. Biol. 15, 854‒862.
On 6 June 2019, the Cambridge Crystallographic Data Centre (CCDC) announced a huge milestone for structural chemistry with the addition of the millionth structure into the Cambridge Structural Database (CSD).
The CSD is the world's repository of highly curated experimentally determined organic and metal–organic crystal structures. It is used globally by scientists in over 70 countries to understand how molecules behave and interact in three dimensions in the solid form and ultimately how this affects physical properties.
As the interest in ‘Big Data’ continues to grow in a time where machine learning and automation are changing the way pharmaceutical, agrochemical and many other industries work, reaching such a significant milestone is a huge achievement for the CCDC and the wider scientific community that contribute to and rely on this resource.
Large volumes of data such as this enable scientists to generate more replete answers from a more complete and diverse volume of information, ensuring confidence in the insights being drawn from the data. Furthermore, CCDC’s focus on ensuring the integrity of the data within the CSD through stringent quality assurance and control steps adds even more value and confidence that scientists are obtaining the highest quality information to inform their research.
This rich data resource, alongside advanced search, 3D data mining, analysis and visualisation software from CCDC, enables scientists from both industry and academia to further their research and predict new outcomes. In addition, knowledge derived from the CSD underpins computational chemistry and molecular modelling and is relied on by industry for the development and manufacturing of new drugs and within academia to teach chemistry.
Jürgen Harter, CEO of CCDC, commented ‘This is truly an important milestone not only for CCDC but also for the wider scientific community. In addition to the value that lies in large sets of data like this to help scientists inform their research and decision making, we also pride ourselves on the high quality of the data, a result of the hard work of our expert in-house database team. Maintaining a policy of strict data interrogation ensures the value of the plentiful insights that can be drawn from the CSD, avoiding misinformation that can lead to wasted time, resources and ultimately cost.’
The 1,000,000th structure is an N-heterocycle produced by a chalcogen-bonding catalyst activating multiple reactions steps sequentially. In the paper the authors describe a class of extraordinary chalcogen-bonding catalysts that enable the assembly of discrete small molecules leading to the construction of N-heterocycles in a highly efficient manner. The structure was determined by Yao Wang and co-authors from Shandong University in China and published in the Journal of the American Chemical Society (JACS).
‘We’d like to congratulate Yao Wang and all of his co-authors, for publishing the millionth structure and we are so grateful to the 350,000 plus scientists from around the world that have contributed their data, enabling us to reach this milestone and placing the CSD as the go-to resource for structural information within the scientific community’, said Suzanna Ward, Head of the CSD.
Dr Wang commented ‘We are delighted to hear that our structure [1-(7,9-diacetyl-11-methyl-6H-azepino[1,2-a]indol-6-yl)propan-2-one; CSD Refcode XOPCAJ] is the millionth structure to enter the CSD! We have used the CSD for over 10 years because it is an excellent platform to report new crystal structures and an outstanding database to find inspiring chemical structures. It is a valuable resource to us and to many other scientists around the world so we are very proud to be associated with this milestone for the community.’
Peter Stang, Editor-in-Chief, JACS, said 'We are delighted to hear that the millionth structure in the CSD was published in JACS. We know our readers value the CSD as a trusted repository of structural data and some of our authors have demonstrated how this rich resource can accelerate scientific research. Our continued collaboration with the CCDC helps make this wealth of data more accessible to the community as well as helping us ensure the integrity of data published in our journals and we are proud to be associated with such a significant milestone in structural chemistry.'
When asked what’s next for the CSD, Dr Harter commented that although the use of the CSD in the pharmaceutical and agrochemical industries is already well-established, it is now fast becoming a fundamental resource for research into new materials such as batteries, paints, pigments and dyes, and in particular the development of gas storage frameworks and tailored catalysts. As environmental contamination and sustainability become increasingly important there is considerable potential on a global scale.
CCDC has noted a consistent rise in deposits from research taking place in China over recent years. 'It is an exciting time for life science and materials development research with markets such as China leading the way in scientific discovery. We are excited to see what insights we obtain from this market going forward,' Dr Harter commented.
CCDC also has plans to further draw on insights and trends from the data to inform the direction of future research across different industries.
This report is taken from a press release issued by the CCDC. For more information, see here or contact Lucy White. See also Suzanna Ward's article in this issue of the IUCr Newsletter.
Michael George Rossmann, who made monumental contributions to science, passed away peacefully in West Lafayette, Indiana, USA, on 14 May 2019 at the age of 88, following a courageous five-year battle with cancer. Michael was born in Frankfurt, Germany, on 30 July 1930. As a young boy, he emigrated to England with his mother just as World War II ignited. Michael was a highly innovative and energetic person, well known for his intensity, persistence and focus in pursuing his research goals. Michael was a towering figure in crystallography as a highly distinguished faculty member at Purdue University for 55 years. Michael made many seminal contributions to crystallography in a career that spanned the entirety of structural biology, beginning in the 1950s at Cambridge where the first protein structures were determined in the laboratories of Max Perutz (hemoglobin, 1960) and John Kendrew (myoglobin, 1958). Michael's work was central in establishing and defining the field of structural biology, which amazingly has described the structures of a vast array of complex biological molecules and assemblies in atomic detail. Knowledge of three-dimensional biological structure has important biomedical significance including understanding the basis of health and disease at the molecular level, and facilitating the discovery of many drugs.
Michael had enormous impact on developing methodology for the determination of macromolecular crystal structures. His grasp of mathematics was always a strength, as he continually developed methods that would become part of the standard repertoire of macromolecular crystallographic tools. Michael obtained undergraduate degrees in mathematics and physics at the University of London. For his graduate work, he studied crystal structures of organic compounds with J. Monteath Robertson at the University of Glasgow. Following his graduate studies he was a postdoctoral fellow with William N. Lipscomb at the University of Minnesota, USA, pursuing structures of relatively complicated organic crystals. In his work at Minnesota, Michael wrote computer programs (in machine language at the time) for crystal structure analysis, taking advantage of the new digital computers that would revolutionize the practice of crystallography. In a lecture by Dorothy Hodgkin at the Fourth IUCr Congress in Montreal in 1957, Michael learned about exciting work on the structure determination of hemoglobin by Max Perutz at Cambridge University. Michael wrote to Max and was given an offer to join the hemoglobin structure determination team.
Michael worked closely with Max Perutz and was instrumental in elucidating the hemoglobin structure by writing the computer programs required to solve and analyze these first structures, and by calculating the Fourier maps that gave rise to the hemoglobin structure. Max had been pursuing the crystal structure of hemoglobin since the late 1930s and was a protégé of Sir Lawrence Bragg, one of the giants of crystallography who had helped to create the field of X-ray crystallography with his father, Sir William Bragg. When Michael arrived at Cambridge he began to analyze the X-ray diffraction data that Max and Ann Cullis had collected for the native hemoglobin crystals and multiple heavy-atom derivatives.
He invented methods and created computer algorithms for reliable phasing using heavy-atom isomorphous replacement and the practical determination of protein structures. While processing and analyzing the existing heavy-atom derivative datasets, he developed the difference Patterson map using squared difference coefficients (|Fheavy| − |Fnative|)2 to assist in locating the relative positions of heavy atoms in the isomorphous datasets (Rossmann, 1960). Michael also applied similar considerations to locating heavy atoms using anomalous dispersion (Rossmann, 1961) and with David Blow developed the single isomorphous replacement method (Blow & Rossmann, 1961) and mathematical representations of combining phase information from multiple sources (isomorphous replacement, anomalous dispersion etc.) (Rossmann & Blow, 1961). By 1959, Michael had computed a 5.5 Å resolution electron-density map for hemoglobin that permitted a trace of the overall fold of this predominantly helical protein and revealed its three-dimensional relationship with myoglobin (Perutz et al., 1960).
During his extraordinarily productive time at Cambridge, Michael also proposed and created the foundations for the molecular replacement method, which became the predominant approach for solving three-dimensional structures of proteins and other large biological assemblies such as complex enzymes and viruses. Michael had been fascinated with what he learned from conversations with other scientists at Cambridge, often during afternoon tea. For example, Crick and Watson had hypothesized that viruses would contain many identical protein subunits based on considerations of their limited genomic capacity (Crick & Watson, 1956). Michael thought that the recurrence of biological structure in different environments, whether in a structure with multiple subunits (oligomeric enzymes, viruses etc.) or in different crystals, would provide the ability to phase (i.e. correctly image) crystal structures. Michael thought that this information could be used to help solve the phase problem for these otherwise intractable systems. The monumental paper that Michael wrote together with David Blow (Rossmann & Blow, 1962) presented the rotation function as a method for demonstrating the presence of rotational non-crystallographic symmetry within a crystallographic asymmetric unit and determining relative orientations. Walter Hoppe (Hoppe, 1957) had also hinted at a convolution of a similar type to find the orientation of known molecular fragments and these ideas were implemented by Robert Huber (Huber, 1965). Michael developed the rotation function based on the realization that the Patterson function would contain multiple copies of vector sets corresponding to the different orientations of the repeating units within the crystal. Rotation of the Patterson function by the angle relating the repeated objects should give 'peaks' where these vector sets were coincident, and Michael demonstrated its utility by detecting the relative orientation of the α and β chains in horse hemoglobin crystals. Later he and others would develop methods for locating the position of objects in crystals, so-called translation functions. He went on to champion these ideas, while along the way determining the structures of many crucial enzymes and viruses.
Currently, the molecular replacement method is the most common approach used for solving new macromolecular structures, accounting for some 85%+ of all new PDB structure depositions and the majority of all 150 000+ known structures. Molecular replacement is most frequently used to determine the orientation and location of related structures in new crystals. The search model can be the same as the new structure, or a homolog with significant three-dimensional similarity. The initial phases can then be refined using the actual sequence corresponding to the new structure using a wide variety of phasing approaches including isomorphous replacement, density modification and ultimately atomic model refinement. Non-crystallographic symmetry averaging is especially powerful in refining phases and producing electron-density maps with great clarity, particularly with systems that have a high degree of symmetry such as viruses, and modern computer program systems have facilitated use of these approaches by making the process more convenient.
Michael moved to Purdue University in 1964 to develop his own research program and apply his innovative methods to solve important biological structures. By 1971 he had determined the structure of the largest protein to date, the enzyme lactate dehydrogenase (Adams et al., 1970). Within a few years he solved another related glycolytic enzyme, lobster glyceraldehyde-3-phosphate dehydrogenase, and showed unexpectedly that a portion of the structures that bound nucleotide cofactors had highly similar structures. Based on these observations he suggested that the architecture of proteins evolved in the same way as the anatomy of animals (Buehner et al., 1973; Rossmann et al., 1974). This conserved part of protein anatomy is called the 'Rossmann fold' to recognize Michael's ingenious new idea. He had initially thought along these lines at Cambridge: when solving the structure of hemoglobin, a protein that carries oxygen in red blood cells, Michael saw that the two protein chains of hemoglobin had strong three-dimensional resemblance to each other despite lacking obvious sequence similarity, and also to myoglobin, which carries oxygen in muscle tissues. Although these concepts are very well accepted now, Michael's ideas often were greeted with resistance because they were revolutionary when suggested.
A driving force behind Michael's interest in pursuing more and more complicated biological structures and in technology development was his passion to study virus structure. Michael subsequently pioneered the structure solution of entire viruses in atomic detail, requiring considerable advances in technology to handle the larger unit cells and massive amounts of crystallographic data. Following the publication of the tomato bushy stunt virus structure (Harrison et al., 1978) from Stephen Harrison's group in 1978, Michael reported the structure of Southern bean mosaic virus (Abad-Zapatero et al., 1980), and the surprising revelation that the coat protein structures of these two plant viruses shared a common protein fold, an eight-stranded β-barrel also known as a 'jelly roll' fold. This work required the development of oscillation photography for data collection, and processing and post-refinement of the intensity data measured on X-ray film (Rossmann et al., 1979; Winkler et al., 1979). Writing programs and developing efficient algorithms for location of heavy atoms in the presence of non-crystallographic symmetry and averaging of the electron density were also massive undertakings, especially given the more limited computing resources of that era.
Michael shifted attention to animal viruses in the early 1980s. His work gained wide attention when he reported the structure of a common cold virus in 1985, human rhinovirus 14, the first animal virus described in atomic detail (Rossmann et al., 1985). The rhinovirus structure was a landmark in terms of its biological significance, illuminating principles of viral assembly, and interactions with neutralizing antibodies, cellular receptors and antiviral drugs. Michael’s career-long theme of making fundamental discoveries in molecular evolution struck once again – the coat protein structures of human rhinovirus 14 showed great similarity to the plant virus structures, in spite of having essentially no detectable sequence conservation!
The structure determination of rhinovirus itself was extraordinary, using a pioneering combination of high-intensity synchrotron radiation, high-speed supercomputing and the most convincing demonstration up to that time of phase extension using non-crystallographic symmetry averaging and reconstruction (Arnold et al., 1987). Heavy-atom phases were only available to 5 Å resolution from a single Au(CN)2 derivative, and phase extension via 20-fold non-crystallographic symmetry averaging and reconstruction in gradual steps to 3.5 Å resolution led to a complete trace of the four chains of VP1, VP2, VP3 and VP4 in the protomeric unit. Within three weeks a complete model of the >800 amino acids in the icosahedral asymmetric unit had been built using a newly acquired Evans & Sutherland computer graphics system. The phase extension was carried out to 3.0 Å resolution, and the refined phases were subsequently used as observations in atomic model refinement because of their accuracy (Arnold & Rossmann, 1988). Some of the current cryo-electron microscopy (cryo-EM) model refinements using the observed phases have adopted a similar methodological approach, where phases obtained experimentally from the EM determination are used as observations in reciprocal space-based refinement protocols. A great deal of programming was required to adapt the Rossmann laboratory software from earlier CDC6000 series computers (CDC6500 and CDC6600) to the Cyber 205 supercomputer, and many memorable adventures occurred during that process, including finding and fixing ‘bugs’ in the programs that sometimes may have existed since their initial implementations!
Following the common cold virus structure work, Michael solved the crystallographic structures of many other RNA viruses from plants and animals including polio-, coxsackie-, and cardioviruses. He also determined the crystal structures of DNA viruses including human, canine, feline and porcine parvoviruses. In addition, Michael solved the detailed structures of both small and large bacteriophages. To further probe biological function, Michael pursued the structures of complexes of viruses with their cellular receptors, neutralizing antibodies and small-molecule drugs. To study some of the complexes with cellular receptors and antibodies, Michael began to use cryo-EM. Tim Baker had set up an experimental facility at Purdue University for the study of virus structure by cryo-EM and, with Jack Johnson, studied interactions between plant viruses and cognate antibodies as a proof-of-concept for the study of such complexes (Wang et al., 1992). Michael and Baker used this approach to show that the ICAM-1 receptor for HRV14 bound in the canyon as predicted (Olson et al., 1993). In addition, Tom Smith and Baker studied a series of monoclonal Fab fragments attached to their cognate antigenic sites on HRV14.
As many viruses cannot be crystallized easily, Michael also recognized, fairly early on, the importance of cryo-EM for structural virology. When cryo-EM investigations can be augmented by crystallographic determination of the component proteins, they produce ‘pseudo atomic resolution’ structures of the whole virus, a method dubbed hybrid technology that Michael helped to develop. Today, cryo-EM is capable of producing high-resolution structures providing atomic detail with suitable samples, but during the 1990s the cryo-EM technology was limited to producing structures of viruses and other assemblies at resolutions in the 10–20 Å range, and the hybrid method was the approach that could provide interpretation of interactions as the molecular level of detail. With Tim Baker, Michael was able to use the hybrid method to determine the structure of the lipid enveloped alphaviruses Ross River virus (Cheng et al., 2002) and Sindbis virus (Zhang et al., 2002). Together with virologist Richard Kuhn who had joined the Purdue structural biology group, Michael determined the structures of flaviviruses, e.g. dengue virus (Kuhn et al., 2002) and West Nile virus (Mukhopadhyay et al., 2003), and mapped their interactions with antibodies and conformational changes when subjected to acidic conditions. In the astonishing Zika virus work, he and collaborator Richard Kuhn obtained a sample of the virus in February 2016 and published the complete atomic structure in Science in April (Sirohi et al., 2016). Michael’s laboratory was equipped by this time with state-of-the-art cryo-EM technology (Titan Krios and Gatan K2 Summit detector) underlying the ‘resolution revolution’ in EM that permits high-resolution structure determination of complex macromolecular structures from averaging of many thousands of randomly oriented single particles or viruses. As was characteristic for him throughout his research career when working on new topics and technological areas, Michael wrote computer programs to perform EM analyses including obtaining optimal fits of atomic models into cryo-EM electron-density maps. Over time, Michael also became emphatic that crystallography was ‘old fashioned’ and that cryo-EM was the wave of the future. But when good crystals can be obtained, there can be many advantages to solving crystal structures, especially given the extraordinary technological innovations that have occurred in this field, among which are synchrotrons, 100% quantum-efficient detectors, very powerful and flexible software packages and tremendously faster computing hardware along with massive data storage systems with rapid access.
Michael’s achievements, which have been recognized by many awards, are among the most impactful contributions to the chemical and life sciences: inventing crystallographic methodology used to solve most macromolecular structures; solving virus structures and developing the methods for doing so; and suggesting that proteins could evolve, with folded domains being the fundamental evolutionary unit. Michael was a Member of the US National Academy of Sciences (1984) and the American Academy of Arts and Sciences (1978), and was a Foreign Member of the Royal Society (1996). Among his most notable awards were the Ewald Prize, Gregori Aminoff Prize, Fankuchen Award, Louisa Gross Horwitz Prize, Gairdner Foundation Award, Paul Ehrlich and Ludwig Darmstaedter Prize, Sackler Prize in Biophysics, Stein and Moore Award from the Protein Society, and three consecutive NIH MERIT Awards. He held six honorary degrees from international universities and was a Member of the National Science Board (2000–2006), having been nominated by President Bill Clinton.
Michael was especially proud that the Ewald Prize (1996), the highest award given by the IUCr only once every three years, recognized his inventions in crystallographic methodology, including the molecular replacement method. The Fankuchen Award from the American Crystallographic Association (1986) was also especially fitting because Isador Fankuchen published the first diffraction patterns from virus crystals. Together Michael and Eddy Arnold edited Volume F of the International Tables for Crystallography, which was the first volume of the series that focused on macromolecular crystallography (Rossmann & Arnold, 2001). The first edition was published in 2001, with a second in 2012 including contributions from Daniel Himmel (Arnold et al., 2012), and a third is in preparation with the participation of Liang Tong. The third edition will be dedicated to the memory of Michael.
Michael trained a legion of scientists, including postdoctoral and graduate students who themselves have established many vibrant and productive research programs worldwide. Michael developed many close life-long friendships with his students and co-workers. Michael also played a key role in the education of young scientists in crystallography and structural biology. For example, he organized the first meeting of the International School for Crystallography in Erice, Italy, on the topic of macromolecular crystallography in 1976, when Dorothy Hodgkin was the Director. In 2006, Michael again organized the school on the topic of biological macromolecules and their assemblies, with Tom Blundell as Director of the School. The 2006 program included a strong representation of the field of cryo-EM, reflecting Michael’s interest in using that approach to image biological structures of ever-increasing complexity. The Erice school often has as many as 100 or more students at the graduate and postdoctoral level in attendance for a ten-day program that features a mix of talks on fundamental methodology and new results.
Michael and his dear wife of 55 years, Audrey, had three children. In addition to son Martin, and daughters Alice and Heather, he is also survived by four grandchildren. Following Audrey’s death, Michael met Karen Bogan. They were married a year ago and enjoyed great happiness together. At a Memorial Service in West Lafayette, following his death, many memories of him as a warm and influential family member, friend and mentor were shared, including his child-like curiosity about almost everything and diverse interests in exploring the natural world, both physically and intellectually.
Abad-Zapatero, C., Abdel-Meguid, S. S., Johnson, J. E., Leslie, A. G. W., Rayment, I., Rossmann, M. G., Suck, D. & Tsukihara, T. (1980). Nature, 286, 33–39.
Adams, M. J., Ford, G. C., Koekoek, R., Lentz, P. J. Jr, McPherson, A. Jr, Rossmann, M. G., Smiley, I. E., Schevitz, R. W. & Wonacott, A. J. (1970). Nature, 227, 1098–1103.
Arnold, E., Himmel, D. M. & Rossmann, M. G. (2012). Editors. International Tables for Crystallography, Vol. F, Crystallography of Biological Macromolecules. Chichester: Wiley.
Arnold, E. & Rossmann, M. G. (1988). Acta Cryst. A44, 270–283.
Blow, D. M. & Rossmann, M. G. (1961). Acta Cryst. 14, 1195–1202.
Buehner, M., Ford, G. C., Moras, D., Olsen, K. W. & Rossmann, M. G. (1973). Proc. Natl Acad. Sci. USA 70, 3052–3054.
Cheng, R. H., Kuhn, R. J., Olson, N. H., Rossmann, M. G., Choi, H. K., Smith, T. J. & Baker, T. S. (1995). Cell, 80, 621–630.
Crick, F. C. & Watson, J. D. (1956). Nature, 177, 473–475.
Harrison, S. C., Olson, A. J., Schutt, C. E., Winkler, F. K. & Bricogne, G. (1978). Nature 276, 368–373.
Hoppe, W. (1957). Acta Cryst. 10, 750–751.
Huber, R. (1965). Acta Cryst. 19, 353–356.
Kuhn, R. J., Zhang, W., Rossmann, M. G., Pletnev, S. V., Corver, J., Lenches, E., Jones, C. T., Mukhopadhyay, S., Chipman, P. R., Strauss, E. G., Baker, T. S. & Strauss, J. H. (2002). Cell 108, 717–725.
Mukhopadhyay, S., Kim, B. S., Chipman, P. R., Rossmann, M. G. & Kuhn, R. J. (2003). Science, 302, 248.
Olson, N. H., Kolatkar, P. R., Oliveira, M. A., Cheng, R. H., Greve, J. M., McClelland, A., Baker, T. S. & Rossmann, M. G. (1993). Proc. Natl Acad. Sci. USA, 90, 507–551.
Perutz, M. F., Rossmann, M. G., Cullis, A. F., Muirhead, H., Will, G. & North, A. C. T. (1960). Nature, 185, 416–422.
Rossmann, M. G. (1960). Acta Cryst. 13, 221–226.
Rossmann, M. G. (1961). Acta Cryst. 14, 383–388.
Rossmann, M. G. & Arnold, E. (2001). Editors. International Tables for Crystallography, Vol. F, Crystallography of Biological Macromolecules. Dordrecht: Kluwer Academic Publishers.
Rossmann, M. G., Arnold, E., Erickson, J. W., Frankenberger, E. A., Griffith, J. P., Hecht, H. J., Johnson, J. E., Kamer, G., Luo, M., Mosser, A. G., Rueckert, R. R., Sherry, B. & Vriend, G. (1985). Nature, 317, 145–153.
Rossmann, M. G. & Blow, D. M. (1961). Acta Cryst. 14, 641–647.
Rossmann, M. G. & Blow, D. M. (1962). Acta Cryst. 15, 24–31.
Rossmann, M. G., Moras, D. & Olsen, K. W. (1974). Nature (London), 250, 194–199.
Sirohi, D. Z., Chen, L., Sun, T., Klose, T. C., Pierson, M. G., Rossmann, M. G. & Kuhn, R. J. (2016). Science, 352, 467–470.
Wang, G. J., Porta, C., Chen, Z. G., Baker, T. S. & Johnson, J. E. (1992). Nature, 355, 275–278.
Winkler, F. K., Schutt, C. E. & Harrison, S. C. (1979). Acta Cryst. A35, 901–911.
Zhang, W., Mukhopadhyay, S., Pletnev, S. V., Baker, T. S., Kuhn, R. J. & Rossmann, M. G. (2002). J. Virol. 76, 11645–11658.
This obituary was originally published in Acta Cryst. (2019). D75, 523–527.
In photosynthetic organisms, carbon fixation must be coordinated with the light harvesting reactions to prevent unnecessary energy expenditure in the absence of light. The enzyme phosphoribulokinase (PRK) produces the substrate for the carbon fixation step and switches off reversibly by disulfide bond formation. How this works in β-cyanobacteria is reported in a recent article in Acta Cryst. F by Wilson et al. (2019) and the Proteopedia molecular tour accompanying the article.
The paper describes the dimeric structure of PRK from the cyanobacterium Synechococcus PCC6301. This enzyme catalyzes the transfer of a second phosphate group onto ribulose 5-phosphate, thus creating the ribulose-1,5-bisphosphate (RuBP) substrate for ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The need for RuBP is found in virtually all autotrophic organisms, and there are corresponding PRKs in all kingdoms. Phylogenetic analyses of PRKs show two broad classes of enzymes, prokaryotic homo-octameric systems and thiol-regulated dimeric enzymes.
Dimeric PRKs are found in cyanobacteria, green algae and higher plants, and in these organisms the formation of a disulfide bridge across the active site effectively closes down the enzyme. The blocking disulfide is controlled by the local redox environment, which in turn is coupled to the ambient light levels. The formation of a cysteine disulfide bond in the absence of light blocks substrate binding. PRKs from green algae and plants contain a conserved insertion, which might add an additional layer of regulation in eukaryotes. In dimeric archaeal PRKs, this redox mechanism is not possible, due to the absence of the necessary cysteine residues. Of note, β-cyanobacteria, algae and plants additionally shut down a second enzyme of the carbon fixation pathway, GAPDH, via complex formation with PRK and the adaptor protein CP12. CP12 also shows redox regulation, transitioning from an intrinsically disordered form into a structured oxidized form in the absence of light, which facilitates CP12’s interaction with PRK and GAPDH. Structure determination of this inactive complex is pursued by the Murray Lab at Imperial College, London, UK.
Results of a parallel study are reported in a recent paper by Gurrieri et al. (2019), which presents the structures of a plant chloroplast PRK and algal PRK. These show the same pattern of cysteine arrangement poised for controlling the activity of the enzyme, but coupled with a longer ‘clamp loop’, postulated to bring the regulatory thiol side chains into proximity as needed.
Enzymes from simpler hosts are not necessarily simpler to work with: the prokaryotic enzyme crystallized and diffracted well, but in a system where molecular replacement was insufficient, it required the addition of data from an osmium derivative to unambiguously describe the second PKR monomer (Wilson et al., 2019). The very same molecular replacement model (PDB entry 5b3f; Kono et al., 2016) was sufficient to solve the plant system (Gurrieri et al., 2019).
Gurrieri, L., Del Giudice, A., Demitri, N., Falini, G., Pavel, N. V., Zaffagnini, M., Polentarutti, M., Crozet, P., Marchand, C. H., Henri, J., Trost, P., Lemaire, S. D., Sparla, F. & Fermani, S. (2019). Arabidopsis and Chlamydomonas phosphoribulokinase crystal structures complete the redox structural proteome of the Calvin–Benson cycle. Proc. Natl Acad Sci. USA, 116, 8048–8053.
Kono, T., Mehrotra, S., Endo, C., Kizu, N., Matusda, M., Kimura, H., Mizohata, E., Inoue, T., Hasunuma, T., Yokota, A., Matsumura, H. & Ashida, H. (2017). A RuBisCO-mediated carbon metabolic pathway in methanogenic archaea. Nat. Commun. 8, 14007.
The seminal work of Dmitri Mendeleev 150 years ago revealed systematic interrelationships of all the chemical elements known and predicted at the time and, remarkably, of those subsequently discovered. Those elements are the stuff of which everything and everyone we see is made. The phenomenal natural evolution of our world, including of life itself, assembles the necessary major and often crucial minor elemental ingredients required for Nature’s grand design. Mendeleev’s Periodic Table of the Chemical Elements and its legacy gave us the tools and understanding to invent and design well beyond what Nature has provided.
Whereas empirical uses of materials date to the Bronze and Iron Ages, our electronics, pharmaceuticals and skyscrapers owe their existence to invention informed by knowledge of the properties of the elements and of the likely properties of myriad compounds and alloys that they form. Such research and invention continue apace in the laboratories of universities and companies with no end in sight. The community of materials researchers depends on, and fully participates in, this exciting progress. The International Union of Materials Research Societies (IUMRS) therefore enthusiastically endorses UNESCO’s declaration of 2019 as the International Year of the Periodic Table of Chemical Elements (IYPT2019).
According to IUMRS President Y. F. Han, “The thousands of researchers affiliated with our membership, who devote their careers to uncovering the next great innovation enabled by advanced materials, all rely on their early training which included Mendeleev’s Table and which remains invaluable in formulating the next new approach to solving problems and making new discoveries in the laboratory. It is therefore entirely appropriate for IUMRS to recognise this sesquicentennial anniversary on their behalf.”
The IUMRS is an association of some 14 professional societies spanning Asia, Africa, the Americas and Europe. Member societies serve scientists, engineers and sponsors who perform and support research on advanced materials and devices for the betterment of humanity and the planet. The IUMRS, which is a member of the International Science Council, has offices in Beijing, China; Singapore; Strasbourg, France; and Evanston, IL, USA.
This report is taken from a press release issued by the IUMRS. For more information, contact Fenfen Liang, Director, IUMRS Head Office.
The IUCr is a sponsor of IYPT2019.
The IUCr Newsletter (ISSN 1067-0696; coden IUC-NEB) is published electronically by the International Union of Crystallography. Feature articles, meeting announcements and reports, information on research or other items of potential interest to crystallographers may be submitted to the Editors at any time. Items will be selected for publication on the basis of suitability, content, style, timeliness and appeal.
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