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.
To promote the development of research as well as constant training, the Escuela Superior Politécnica de Chimborazo and the Department of Chemistry of the Faculty of Sciences organized the First International Congress of Chemistry Ecuador 2018 (I-CIQ-Ec-18) and the Pre-Congress Course "Introduction to Crystallographic Techniques" in Riobamba, Ecuador, with the collaboration of the IUCr, the Latin American Crystallographic Association (LACA) and the International Center for Diffraction Data (ICDD).
The Course was attended by students, teachers and researchers from different universities, mainly from the central region of the country, including the Central University of Ecuador, the University of the Armed Forces (ESPE), the University Yachay Tech, the Technical University of Ambato and the Escuela Superior Politécnica de Chimborazo. The participants came from different areas: chemistry, biotechnology, environmental biotechnology, geology and mines, mechanics, biochemistry, nanotechnology, chemical engineering and polymer engineering.
The Course was aimed at introducing crystallography and crystallographic techniques to promote the development of crystallography in Ecuador as well as satisfying the need for specialized training in the area of analysis by crystallographic techniques. Its objectives were as follows:
The trainers were IUCr Visiting Professors Diego Lamas (Universidad Nacional de San Martín, Argentina) and Graciela Díaz del Delgado (Universidad de Los Andes, Mérida, Venezuela), and Miguel Delgado (Universidad de Los Andes, Mérida, Venezuela).
The Congress was held to promote scientific research at the national level through the dissemination of research results in the area of chemistry, proposing the following objectives:
This event also included the participation of Professors Lamas and Díaz de Delgado, who gave the keynote lectures “The History and Current Impact of Crystallography” and “Characterization of Drugs and Medications by X-ray Diffraction in Polycrystalline and Mono-Crystal Samples”, respectively.
![[Congress]](https://www.iucr.org/__data/assets/image/0019/142642/Ecuador-congress.png)
Principal guest Ada Yonath (fourth from left) with organizers and speakers.
Professors Lamas, Díaz de Delgado and Delgado also participated in the event recognizing the Nobel Laureate Ada Yonath, which took place in the municipality of the city of Riobamba, and in a meeting with teachers and researchers from the Faculty of Sciences to establish networks and contacts for future projects.
Both the Pre-Congress Course and the Congress were received very well, exceeding expectations. There was interest in crystallography as well as analytical techniques, raising the possibility of working towards the development of an OpenLab in Ecuador.
The Escuela Superior Politécnica de Chimborazo, the Faculty of Sciences, Chemistry Department and the Organizing Committee of the I-CIQ-Ec-18 thank the IUCr, LACA and the ICDD for their support in developing both the Pre-Congress Course as well as for the participation of their representatives as keynote speakers in the Congress.
The XXV Conference of the Serbian Crystallographic Society was held from 21 to 23 June 2018 in Bajina Bašta, a small town located at the edge of Tara National Park in western Serbia. The conference was organised by the Serbian Crystallographic Society (SCS) and the Vinča Institute of Nuclear Sciences, University of Belgrade, under the patronage of the Ministry of Education, Science and Technological Development of the Republic of Serbia. The conference was attended by 70 participants from 14 countries. The programme was composed of welcome addresses, invited lectures (45 min), short oral presentations (15 min) and an extended poster session. The IUCr supported the conference by providing Visiting Professorships and a fund of USD2500 to assist young scientists to attend. The invitation to attend the conference as Visiting Professors (VPs) and plenary lecturers was kindly accepted by Vaclav Petříček (Academy of Sciences of the Czech Republic), Ivana Radosavljević Evans (Durham University, UK) and Christoph Janiak (Heinrich-Heine-Universität Düsseldorf, Germany). The SCS also had a pleasure of hosting three other eminent scientists: Anne Spasojevic-de Biré (CentraleSupélec, France), Piero Macchi (University of Bern, Switzerland) and Kittipong Chainok (Thammasat University, Thailand).
The IUCr fund for young scientists was used to support the travel and accommodation expenses for 16 young participants. These young scientists could choose to present their latest results through an oral or a poster presentation or both. The workshop “Crystallographic methods, tools and possibilities” was organised in the form of a two-day extended poster session. During this session, the young scientists were encouraged to present the challenging problems of their current research and to exchange ideas about problem solving with our international guests and other participants. The poster session was very well attended, with 33 posters being available for the whole duration of the conference. Two young scientists – Ivana Marjanović (University of Novi Sad, Serbia) and Predrag Dabić (University of Belgrade, Serbia) – were honoured with the IUCr Journals Poster Prizes for the best posters in the categories of Structural Chemistry and Materials, respectively, judged by Professors Spasojevic-de Biré, Chainok and Tamara Todorović (University of Belgrade, Serbia). An additional Poster Prize was provided by the SCS, which considered the best poster in all categories. The VPs prepared a special award for the best oral presentation given by the IUCr-supported young scientists, which was won by Marko Rodić (University of Novi Sad, Serbia) for his talk "Preliminary Results of Experimental Charge Density Determination of [Ni(L)py] (H2L = benzoylacetone S-methylisothiosemicarbazone)".
![[VP prize]](https://www.iucr.org/__data/assets/image/0020/142643/Marko-Rodic_Ivana-Radosavljevic-Evans.png)
Marko Rodić (left) receives his VP Prize, a copy of the IUCr/OUP book Fundamentals of Crystallography by Giacovazzo et al., from VP Ivana Radosavljević Evans.
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. 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. On the last day of the conference, all participants were invited on a guided excursion to the beautiful Tara Mountain, River Drina and Perućac Lake. The General Assembly of SCS evaluated the conference as very successful and the generous support from the IUCr was gratefully acknowledged. The presence of the excellent lecturers and the IUCr support for young scientists certainly contributed to the increased number of conference participants compared with the SCS conferences held in previous years.
Aperiodic crystals, once regarded as anomalies or outliers in the field of crystallography, have taken centre stage since Dan Shechtman's discovery of icosahedral quasicrystals in an Al–Mn alloy in 1982. Controversy followed centred on the proper definition of crystalline materials. Ultimately, quasicrystals and, more generally, aperiodic crystals were 'validated' and assumed their place among the vast array of crystalline forms when the definition of a crystal was modified to include them: “A material is a crystal if it has essentially a sharp diffraction pattern” (see the IUCr Online Dictionary of Crystallography entry on 'Crystal’).
Among the exciting research presented at Aperiodic 2018, some of the best was presented by students and young investigators. Four formal awards were given in recognition of these excellent studies, two of which are described in this open-access issue. Ashwin Shahani (University of Michigan, Ann Arbor, USA) recounts beautiful X-ray tomography experiments, in which growth and dissolution of the decagonal quasicrystal Al–Co–Ni (from the liquid phase) were observed as a function of time, and Paul Klar (Universidad del Pais Vasco, Spain) tackles the complex, and long-mysterious, mineral known as mullite.
Other exciting directions in aperiodic research presented at the conference are featured in this issue, along with a tribute to one of the founding fathers of superspace crystallography, Ted Janssen, whose contributions to the field are reviewed by Marc de Boissieu.
This article contains material extracted from the Guest editorial by Gloria Borgstahl, Alan I. Goldman and Patricia A. Thiel, "Aperiodic order coming of age: from inorganic materials to dynamic protein superstructures".
The IUCr would like to congratulate the following winners of IUCr Journals best student poster prizes.
Ivana Marjanović (second from left) (University of Novi Sad, Serbia), poster "One-Dimensional Silver(I)-5-Sulfosalicylate Ternary Coordination Polymer"; Predrag Dabić (right) (University of Belgrade, Serbia), poster "Photoluminescence, Structure and Polymorphism of K3ErSi2O7"; XXV Conference of the Serbian Crystallographic Society (Bajina Bašta, Serbia; 21-23 June 2018). Prizes presented by Anne Spasojevic-de Biré (left) and Tamara Todorović.
Giulia Novelli (second from left) (University of Edinburgh, UK), poster "Carbon molecules in space: a thermal equation of state study of solid hexamethylenetetramine"; Vittoria Marzaroli (second from right) (University of Parma, Italy), poster "Engineering novel porous 3D metallacrown frameworks through the ligand periphery design"; Breyan Ross (right) (Max Planck Institute of Biochemistry, Planegg, Germany), poster "DPP8 and DPP9 structure, mechanism and interaction with SUMO1"; ECM31 (Oviedo, Spain; 22-27 August 2018). Prizes presented by IUCr President, Sven Lidin.
Katarzyna Kurpiewska (right) (Jagiellonian University, Kraków, Poland), poster "High pressure protein crystallography (HPPX) lights and shadows", DLS-CCP4 Data Collection and Structure Solution Workshop (Diamond Light Source, UK; 2-9 December 2018). Prize presented by Kay Diederichs, Acta Cryst. D Co-editor.
The second Pan African Conference on Crystallography (PCCr2) was held from 28 January to 2 February 2019 in Accra, Ghana. The theme of the conference was 'Crystallography, a tool for sustainable development in Africa', and there were over 200 participants representing around 35 countries from Africa, Europe, North America, Asia and Australia. Activities included workshops, symposia, an exhibition, poster presentations and a varied social programme. The meeting was held jointly with the second African Light Source meeting (AfLS), highlighting the synergy between these two communities.
PCCr2 took place at the well-equipped Bank of Ghana conference centre on the lovely campus of the University of Ghana in Legon-Accra. Activities kicked off with a day of pre-conference workshops. The first of these, the Biostruct Africa workshop, was coordinated by Emmanuel Nji, a postdoctoral fellow at Stockholm University, Sweden. It covered protein crystallography, and included a remote session on beamline I04 at Diamond (UK). There was also an introductory crystallography workshop presented by Gilberto Artioli (University of Padova, Italy) and Claude Lecomte (Université de Lorraine, CRM2, Nancy, France), among others. This workshop included an OpenLab where participants could carry out analysis on their own samples using a benchtop instrument provided by Bruker. This instrument remained on site throughout the conference. During the conference a further well-attended workshop was organised by the Cambridge Crystallographic Data Centre (CCDC), UK, which was led by Amy Sarjeant and Suzanna Ward.
![[Opening Ceremony]](https://www.iucr.org/__data/assets/image/0020/142607/opening-ceremony.png)
A cross-section of participants at the opening ceremony in the Bank of Ghana Hall.
Ghana is an astonishingly friendly country (I have never encountered such a welcome from customs officials!) and this generous nature was particularly apparent at the official start of the meeting on Tuesday morning, where participants were met by Ghanaian music and dance from the Ghana Dance Ensemble Troupe of the University of Ghana. The opening ceremony was chaired by Robert Kingsford-Adaboh, Dean of the School of Physical and Mathematical Sciences and Chair of the Local Organizing Committee, and had many dignitaries in attendance, including the Pro-Vice Chancellor of the University of Ghana, Kwame Offei; the Provost of the College of Basic and Applied Sciences, Daniel Asiedu; Ivan Addai Mensah; His Excellency Özlem Ergün Ulueren (Ambassador, Embassy of Turkey); His Excellency Timothy Mwaba Walamba (High Commissioner, Zambian High Commission); and Richard Catlow (Foreign Secretary of the Royal Society, UK).
![[Dancers]](https://www.iucr.org/__data/assets/image/0019/142606/dancers.png)
A performance by the Ghana Dance Ensemble at the opening ceremony.
His Excellency the President of the Republic of Ghana’s keynote address was delivered by Kwabena Frimpong Boateng, Minister of Environment, Science, Technology and Innovation, on the theme 'Accelerating Africa’s Economic Growth and Industrial Competitiveness: the role of cutting-edge science, technology and its application'. His Excellency the President, Nana Addo Dankwa Akufo-Addo, described how science and technology have played a major role in the rapid advancement of developed countries and this fact cannot be lost on Africans. He indicated that it was imperative for African governments who desire to undertake a transformative agenda and eradicate poverty to allow science and technology to play a leading role in economic transformation. This clearly stated support of science and technology on the part of Ghana’s government was apparent throughout the meeting. The opening ceremony also included addresses from the chair of the International Organizing Committee, Professor Artioli; the chair of the African Light Source project, Simon Connell (University of Johannesburg, South Africa); and Michele Zema, IUCr Executive Outreach Officer (UK).
The conference consisted of three plenary lectures, as well as parallel sessions organised by both PCCr2 and AfLS. The first plenary was presented by Sir Tom Blundell (University of Cambridge, UK), who gave an inspirational lecture on structure-guided fragment-based drug discovery. A tour-de-force of remarkable science was presented with true modesty, resulting in a lecture all participants will remember. By describing ultrafast out-of-equilibrium transformation with time-resolved techniques at synchrotron and X-FEL facilities, Eric Collet (University of Rennes 1, France) convinced all delegates, with his usual enthusiasm, that the dynamics and thermodynamics of crystals can now be described at the femtosecond scale. Gavin Vaughan (ESRF, France) delivered an exciting plenary on ‘Advanced diffraction techniques for operando and ex situ studies of real systems’.
The PCCr2 parallel sessions covered a wide variety of topics. The session on Biological Macromolecular Crystallography, chaired by Richard Garratt (University of São Paulo, Brazil) and Wolf-Dieter Schubert (University of Pretoria, South Africa), was composed of six speakers including Africans active on the continent (Wolf-Dieter Schubert), Africans currently working abroad [Daouda Traore (Monash University, Australia), Emmanuel Nji and Mike Lawrence (Walter and Eliza Hall Institute, Parkville, Australia)] and non-Africans who have shown interest in the development of the field in the region [Silvia Onesti (Elettra Sincrotrone Trieste, Italy) and Menico Rizzi (University of Piemonte Orientale, Novara, Italy)]. The talks were very diverse in their subject matter, revealing the richness of the work being undertaken, and it was universally agreed that all were of very high quality. Topics raised ranged from techniques for the crystallization of membrane proteins to targets for drug development against diseases relevant to Africa and how information from structural studies on snail insulins could be used for improving the bioavailability of current therapies. The issue of alternative funding opportunities for Africans via international institutions was also raised. Although the community of biological crystallographers in Africa is still small, the session generated enthusiastic discussion among the participants.
The session on Molecular Materials and Large Facilities [chaired by Claude Lecomte and Jules Tenon (Cote D'Ivoire)] introduced the audience to some applications of synchrotron and neutron science to crystallography research. Pierre Fertey (Soleil, France), El-Eulmi Bendeif (Université de Lorraine, CRM2, Nancy, France) and Jason Benedict (SUNY Buffalo, USA) showed the necessity of using synchrotron X-rays to precisely detail structural phase transitions, molecular movements and PDF (pair distribution function) analysis of molecular materials. Bolivard Voufack (Dschang, Cameroon) presented the spin-resolved electron density of YTiO3 perovskite using an original combined synchrotron and polarized neutron refinement method. Patrice Kenfack (Dschang, Cameroon), discussed his research on hydrates.
The broad topic of Crystal Engineering and Structural Chemistry was addressed in a session organised by Delia Haynes (Stellenbosch University, South Africa), C. Malla Reddy and Magatte Camara (Ziguinchor University, Senegal). The session began with two keynote lectures: Alessia Bacchi (University of Parma, Italy), past president of the European Crystallographic Association (ECA), gave an accessible and inspiring presentation on using crystal engineering to produce crystalline forms of active ingredients for various applications, and Aurora Cruz-Cabeza delivered an excellent lecture on polymorphism and its relevance in crystal engineering. Jules Tenon then updated the audience on progress with the diffractometer centre in Abidjan. Christelle Dzesse Tekouo presented her work on metal–organic frameworks, and Dominik Schaniel (Université de Lorraine, CRM2, Nancy, France) discussed using a combination of photocrystallography and infrared spectroscopy to study linkage isomers. The session ended with an excellent and energetic presentation from Mamoudou Diallo on lanthanide-based materials.
![[Sessions]](https://www.iucr.org/__data/assets/image/0018/142605/sessions.png)
Speakers and chairs in the sessions on Biological Macromolecules (left) and Crystal Engineering and Structural Chemistry.
The Wednesday session on Chemical Databases was very well attended – perhaps due to the workshop run by CCDC on the previous day acting as a great ‘warm up’! Ms Ward and Dr Sarjeant started the session with two talks, firstly on the content and approach of the Cambridge Structural Database (CSD) and then on the new kinds of research that it can empower. Tom Blanton from the International Center for Diffraction Data (ICDD) then followed by giving a very insightful talk about how the Powder Diffraction File can be used in tandem with experimental work for investigating advanced materials. In a change from the programme, Philip Rodenbough, a science communicator from NYU Abu Dhabi, described his new approaches to education development that he is designing whilst based in Kenya and the Democratic Republic of Congo. The session was completed by a talk from Samuel Tetteh who discussed insights into some first-row transition metal complexes that were provided by a combined CSD and computational DFT study.
![[Calling stick]](https://www.iucr.org/__data/assets/image/0005/142619/calling-stick.png)
Simon Connell describing the calling stick to participants (photo: George Okyere Dwapanyin).
PCCr2 also included sessions on inorganic materials, diffraction physics and phase transitions. Speakers in the plenary sessions and the AfLS sessions were handed a traditional Ashanti speaking stick by session chairs before they could begin their presentation. At Ashanti tribal meetings, the chief used a calling stick to announce a meeting, and gave such a speaking stick to speakers, and the echoing of this tradition gave a wonderful local flair to the sessions. The plenary hall was also graced by a model of vitamin B12 donated to the University of Ghana by Dorothy Hodgkin, who accepted her Nobel Prize whilst visiting Ghana.
The final day of the conference was common to both PCCr2 and AfLS, and involved presentations on large-scale facilities, and a number of productive strategy sessions around moving the plans to construct an African synchrotron forward. The conference closed with a presentation on the progress made in forming an African Crystallographic Association, and a call for bids for the next PCCr.
The conference also included an exhibition, and an excellent poster session. Over 50 posters were presented by both postgraduate students and faculty, and six poster prizes, sponsored by CrystEngComm, IUCr and PCCr, were awarded.
![[Tom Blundell]](https://www.iucr.org/__data/assets/image/0020/142616/tom-blundell.png)
Sir Tom Blundell joins the Ghana Dance Ensemble at the banquet dinner (photo: George Okyere Dwapanyin).
Conference participants were treated to a busy social programme. A tour of Accra introduced delegates to the important monuments in the city, as well as to the skills required to haggle down a price at the fascinating artists' market. A superb conference dinner involved much drumming and dancing, both by the Ghana Dance Ensemble and by the delegates. After the close of the conference, a full day tour to the central region of Ghana was organised, which included an exhilarating canopy walk in the Kakum National Park, a thought-provoking tour of Elmina castle and some crocodiles!
![[Kakum]](https://www.iucr.org/__data/assets/image/0019/142471/kakum.jpg)
Conference participants enjoying the canopy walk at Kakum National Park (photo: George Okyere Dwapanyin).
PCCr2 was organised by a dedicated local organising committee, and was run with the support of an endlessly energetic group of students. The meeting was busy and productive, and all participants will have returned home with memories of collegiality and excellent science, the echoes of drums and a fondness for tilapia!
PCCr2 was a joint meeting with the second African Light Source meeting, and was held in partnership with the Ministry of Environment, Science, Technology and Innovation (MESTI) and the Ghana National Petroleum Company (GNPC). The joint meeting was under the auspices of the IUCr, the Executive Steering Committee of the African Crystallographic Association (AfCA), the United Nations Education, Scientific and Cultural Organization (UNESCO), International Atomic Energy Agency (IAEA), the Light Sources for Africa, Asia, Americas and the Middle East project (LAAAMP), and the African Academy of Sciences (AAS). We are grateful to all of our sponsors: MESTI, GNPC, Office of Research Innovation and Development-University of Ghana, Centre for Scientific and Industrial Research (CSIR-Ghana), Government of Benin, Bruker, UNESCO, International Centre for Theoretical Physics-LAAAMP, IUCr, the Royal Society of Chemistry, the Optical Society of America (OSA), Stellenbosch University, International Science Council (ISC), Elettra Sincrotrone Trieste, Diamond Light Source, Soleil synchrotron, XENOCS, Dectris, CCDC, STOE, British Crystallography Association (BCA), Italian Crystallography Association (AIC), French Crystallography Association (AFC), ECA, Société Française de Physique (SFP), ICDD, CrystEngComm, and the Universal Merchant Bank Ltd (UMB).
![[Group]](https://www.iucr.org/__data/assets/image/0003/142617/group.png)
Participants at PCCr2/AfLS2, with the calling stick front centre.
IUCr Journals are delighted to announce the appointment of three new Editors.
Having served for several years as a Co-editor for Acta Crystallographica Section A, Foundations and Advances, Angela Altomare will now be working alongside Simon Billinge in defining and developing the role of the journal as a whole.
Angela graduated cum laude in Physics at the University of Bari, in the beautiful Puglia region of Italy. She now oversees a highly active team of researchers at the Institute of Crystallography of the Italian National Research Council (CNR), where her work is focused on developing innovative crystallographic methodologies for structure solution from single-crystal and, mainly, powder diffraction data. The computer programs written by Angela and her team (notably EXPO and associated algorithms) are used worldwide to characterize the structures of a huge range of materials.
Angela is well known for her passion for sharing her knowledge and research with fellow scientists, frequently speaking or lecturing at national and international meetings and schools. She is an active member of the IUCr's Commission on Powder Diffraction and the Italian Crystallographic Association, and has served on several international programme committees, recently as Chair of the highly successful 15th European Powder Diffraction Conference.
Simon says he is delighted that Angela has agreed to take on this new role, as "her wealth of crystallographic experience and knowledge will help us take Acta A to the next level, as the community develops the theory for the much broader definition of crystallography that is needed in the 21st century - the crystallography of 'real' materials".
Janet Newman, Director of The Collaborative Crystallisation Centre (C3) at CSIRO, and a long-time Co-editor on our biological journals, has been appointed as a new Section Editor for Acta Crystallographica Section F, Structural Biology Communications.
Janet obtained a BSc (Hons) in inorganic chemistry from the University of Sydney, a PhD from the Swedish University of Agricultural Sciences, as well as post-doctoral fellowships at Columbia University and Los Alamos National Laboratory. After a stint in industry in California, Janet returned to Australia 13 years ago to set up and run the C3 macromolecular crystallization facility in Melbourne.
Janet's main interest is in developing tools to help make macromolecular crystallization more robust, including designing new crystallization screens, using machine learning to classify the outcomes of trials and developing software to help design optimization experiments. And she has a lifelong commitment to help everyone spell 'sulfate' correctly!
On hearing of her appointment, her fellow Acta F Section Editor, Mark van Raaij, welcomed Janet and said that 'it's great to have Janet's deep expertise, broad experience and her contagious enthusiasm on board at Acta F'.
Karena Chapman has been appointed as a Main Editor of Journal of Applied Crystallography, joining existing Editors Janos Hajdu and Garry McIntyre. Karena has been a valued member of JAC's Editorial Board since 2014.
Another chemistry graduate of the University of Sydney, Karena went on to join the X-ray Science Division at Argonne National Laboratory. There her research involved developing fundamental insights into the structure–function relationship in complex energy-relevant materials, as well as developing and supporting the world-leading Pair Distribution Function beamline, 11-ID-B, at the Advanced Photon Source. In her role as coordinator of the X-ray and Neutron Summer School she has also played a part in mentoring the next generation of crystallographers and scatterers. In September 2018 Karena took up the role of Professor in Materials Chemistry at Stony Brook University.
Garry commented 'We all look forward to working with Karena as a Main Editor of JAC, to continue the growth initiated by past editors and staff in the relevance, reach and impact of the journal. Janos added 'Karena's presence and critical input will help this exciting field of science and I hope it will also bring fresh air to the journal in general.'
IUCr Journals Editor-in-Chief Andrew Allen said 'While, sadly, this also marks my 'retirement' as a Main Editor of JAC, I really look forward to continuing to work with Karena, Janos and Garry. I know that JAC is in good hands, and will continue to prosper!'.
Few have exemplified the scale and impact of macromolecular crystallography like Tom Steitz. His lifelong passion was to bring chemical and biophysical mechanisms to life, and it drove him to the frontiers of what crystallography can do, and how to move them.
After his PhD studies with William Lipscomb on carboxypeptidase and postdoctoral studies with David Blow on the structure and mechanism of chymotrypsin, Tom moved first to Berkeley and then to Yale to set up his own research. Early on he presented pioneering studies of large-scale conformational changes in hexokinase that were associated with substrate binding and catalysis. These experiences stayed with him and became a lasting part of his anecdotes and advice. Quickly, Tom's research became devoted to the key principle of life – the central dogma that describes how genetic information in the form of DNA is transcribed into RNA and translated into proteins of function. Understanding how these processes take place and have evolved define our insight into life as we know it, and it was also very complementary to the grand work of his wife Joan Steitz, who had started her pioneering work on RNA through ribosomes and translation. Dedicated to his quest for the mechanisms of the central dogma, Tom's laboratory presented numerous first-in-class structures of protein–DNA and protein–RNA complexes.
As an undergraduate I learnt of his works from Stryer's Biochemistry. Later as a PhD student I came much closer to it. I was a student of Jens Nyborg at Aarhus University and worked on the crystal structure of the ternary complex of translation elongation factor EF-Tu, GTP and aminoacylated tRNA. Jens and Tom knew each other from the Blow lab, and we had heard rumours that Tom was also interested in that project after a successful attempt at the related elongation factor G, the ribosomal translocase, together with Peter Moore. Fortunately, I had the opportunity to meet him at the famous Erice School of Crystallography in 1994. That went well – he was easy to approach for a young scientist like me back then, and when I asked he responded, e.g. on their experiences with RNA modelling and refinement, sugar pucker, anti and syn conformations etc. The aminoacyl-tRNA:EF-Tu:GTP project had not really taken off in his laboratory. His honest care and interest for what I had to say and wanted to ask were warming and encouraging, and in science where so many consider it a race for trophies, the openness of his aims, strategies and very preliminary work was unusual and quite an example to follow. As he always put it – it is just not fun if what we are really happy about and want to talk about should remain a secret.
Later that year Peter Moore visited Aarhus and presented the EF-G structure from Yale that he and Tom had determined together with John Czworkowski and Jimin Wang (and that Arnthor Aevarsson, Anders Liljas and colleagues had also determined independently in Lund). In 1995 Paul Sigler also came to Aarhus, and he invited me to visit Yale, which I then did the following year after the very first and very exciting meeting of the RNA Society in Madison. To cut a long story short, it was an overwhelming experience to interview all the star groups at Yale, which also included for example Jennifer Doudna, Donald Engelman and Axel Brunger – a superhero community originally nucleated around Fred Richards, and all those laboratories with the very best people.
I had no doubt that the ribosome project with Peter and Tom at Yale was definitely the best choice for a postdoc.
Joining Tom's lab was a transformative experience. When I arrived in 1997, postdoc Nenad Ban, lab technician Betty Freeborn, Peter and Tom had already established a small dedicated ribosome group targeting the Haloarcula marismortui 50S subunit that Ada Yonath's research groups in Hamburg, Berlin and at the Weizmann had also worked on for more than ten years, but without a breakthrough on phasing. Nenad however had obtained low-resolution phases and from two independent sources even: (i) a W18 tungsten cluster derivative producing a single major site, which could be determined from Patterson maps and that produced a very low resolution map, and (ii) by molecular replacement using an H. marismortui 50S envelope obtained by cryo-EM by Joachim Frank's group in Albany. The W18 site derived from both methods was identical – this was clearly before the days of the `resolution revolution' in cryo-EM, and the consistency of the two methods was in itself highly rewarding. Very importantly, Nenad, Peter and Tom – with great input also from Jimin Wang, the wizard crystallographer in Tom's group – had just found out before I arrived that the 50S crystals had a very bad tendency for pseudomerohedral twinning. Some of the W18 derivative data sets would only produce Patterson peaks corresponding to a monoclinic form with twinning, whereas others clearly came from an orthorhombic form – P21 with C2221 twin-symmetry or proper C2221, respectively. That insight was game changing. With the W18 derivatives and compatible native data sets we could sort all data sets and distinguish them as either monoclinic twinned or orthorhombic using scaling statistics, and that was from just a few frames of indexed data during data collection at the synchrotron and using excellent advice in the DENZO/SCALEPACK package. After only a month we had identified another two heavy-atom cluster derivatives (a W11 cluster and Ta6Br12) and found the optimal combinations for MIRAS phasing extending to 9 Å resolution. We could publish the first crystallographic maps of the ribosome showing characteristic features of stalks and the central protuberance. Tom was super excited and came with numerous ideas and suggestions thereafter, including many old tricks from his chymotrypsin and hexokinase work. However, he knew very well how to prioritise ideas, which to go all out for and which to abandon quickly.
Our first step to extend the resolution was to obtain phases and maps from independent 50S crystal forms. One of the monoclinic twinned crystals was apparently only partially twinned – what if we could detwin it? Tom knew of some old Fortran code left in the lab by Adrian Goldman for a twin-fraction determination and a detwinning program that he had developed in the 1980s. We dug it out from old tapes and we also found Adrian's (absolutely brilliant) thesis, where the use of it was described. With help from postdoc Graham Cheetham we rewrote the code for the specific case of pseudomerohedral twinning in P21, got it compiled and ran it on the partially twinned data set. Amazingly, it worked: a twin fraction of about 0.35 and the detwinned data set could be solved by the MR procedure. Using higher resolution data sets of the cluster derivative and the MAMA multi-crystal averaging program by Gerard Kleywegt and Alwyn Jones from the Uppsala Software Factory, we could extend the maps to 5 Å resolution and localize several structures of large ribosomal subunit proteins and of the ribosomal RNA. This was quite conclusive, we thought, and knowing that Venki Ramakrishnan had reached similar results on the 30S subunit (presented at the 1999 ribosome meeting in Helsinore), the road suddenly seemed to open up towards the finish line, albeit still at some distance. Tom felt it was time for his sabbatical, and he took it in his own lab working with us on the early map interpretations and model building attempts.
Tom insisted that now we gave up on the cluster derivatives and instead turn to ordinary heavy-atom derivatives that we could easily locate by difference Fourier maps – if only we had enough sites we would get a sufficient signal for phasing. Peter Moore further convinced us by calculating transforms of the cluster derivatives to demonstrate that their amplitudes would almost vanish at a broad intermediate resolution range, where the cluster scattering properties disappear due to individual atom scattering interfering destructively. Tom also insisted that we should try the wonderful Os-hexamine compound that Jamie Cate and Jennifer Doudna had used for RNA crystallography. We had a tiny, small sample and indeed it produced 14 sites from a 1 mM soak but we could not get any more of it, and the 14 sites were not quite enough. Instead, we got similar compounds – Ir-hexamine from Jamie and Os-pentammine from a commercial source. It turned out that we should simply soak with as much compound as possible, and using 20–35 mM crystal soaking conditions we identified more than 40 sites and combined SIRAS, MIRAS and SAD phasing that also included a few other derivatives. These procedures were all handled well by expanded versions of CNS provided by Axel Brunger and Paul Adams.
At the same time we had developed a procedure to grow thick three-dimensional crystals that reproducibly diffracted to at least 3 Å resolution. With great input from Jeff Hansen we also finally nailed the twinning problem so that all crystals were now reproducibly orthorhombic – we simply needed to keep crystals in 1.7 M NaCl or KCl, not 1.2 M as we had used earlier. A single batch of crystals diffracted even further and we managed to collect a 2.4 Å resolution native data set. Combining phases of 3–4 Å resolution derivative data sets, and performing a very gentle density-modification procedure at 2.4 Å resolution with a solvent sphere radius gradually diminishing from 12 to 2.4 Å (a great tip by Eric de la Fortelle of the SHARP group working with Gerard Bricogne), we ended up with electron-density maps of absolutely stunning quality revealing the entire structure of the 50S subunit and basically all details of the RNA and the protein main and side chains. What a moment that was, after years of work – seeing thousands of nucleotides and more than 30 proteins reveal their intimate structure of the 50S subunit and with the peptidyl transferase centre at the middle – the ultimate link between genes and proteins in the central dogma.
Over a few months several of us, now also including PhD students Szilvia Szep, Martin Schmeing and Dan Klein, would trace individual proteins and RNA segments. We were greatly helped by an experimental version of O for RNA provided by Morten Kjeldgaard and we could carry out real-space refinement with TNT, and finally reciprocal space refinement of the entire 50S subunit with CNS. It all just clicked.
It is often said that Tom could have received numerous Nobel Prizes for his work on, for example, tRNA synthetases, RNA and DNA polymerases, and reverse transcriptases, and I couldn't agree more. He really knew how to keep difficult projects going forward, and during my three years as a postdoc on the 50S subunit I never doubted that we were guided in the right direction and always made progress. He would also, in general, be very aware and clear whether a project was `ripe' or not for structural biology, and he would give strong warnings against simple projects that would not tell us much but would still take time, such as determining structures of individual domains of a protein, where the complex with another macromolecule was the actual goal.
With Tom Steitz's passing we have lost a true hero and superhero of crystallography. In times where we all turn towards cryo-EM we should never forget that crystal structures paved the way and still produce the best and most accurate structures. In hindsight, it is also clear how methods developments in crystallography made it all possible – the developers should be remembered also, and Tom did that.
This article was originally published in Acta Cryst. D (2019) doi: 10.1107/S2059798319002390.
The XIV Annual Meeting of the Argentinean Association of Crystallography (AACr) was held from 31 October to 2 November 2018 at the Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica (CNEA, Atomic National Commission) Buenos Aires, Argentina. There were 148 registered participants from Argentina and several Latin American countries. The plenary lectures were presented by Mario Amzel (Johns Hopkins University, USA), María Lidia Herrera (UNSAM, Argentina), Gastón Garbarino (ESRF, France), Florean Meneau (LNLS, Brazil) and Mike Glazer (Oxford University, UK). Moreover, 11 semi-plenary talks, 18 oral contributions and 57 posters completed the event. Those participants in the poster session had the opportunity to give a 2 minute talk in a “Rapid Fire” session, which gave young scientists the opportunity to invite every participant to attend their poster. The topics addressed were very broad, including structure determination of organic, inorganic and coordination compounds; crystal architecture and design; phase transitions; solid solutions; structure–property relationships; synergy of diffraction and complementary techniques; and history. The meeting was a space to promote academic activity, allowing the discussion of scientific research, knowledge exchange and the generation of new collaborations. At the close of the meeting, a tribute was paid to Dr Bonfiglioli, a recently deceased crystallographer, who developed a large part of his work in this CNEA. The tribute was given by Aldo Craievich.
![[XIV Annual Meeting]](https://www.iucr.org/__data/assets/image/0010/142597/group.png)
Participants at the XIV Annual Meeting of the AACr.
![[Semi-plenary talk]](https://www.iucr.org/__data/assets/image/0011/142598/talk.png)
A semi-plenary talk during the XIV Annual Meeting of the AACr.
Following the Meeting, the X School of the AACr was held at the same location from 5 to 9 November. On this occasion, the School addressed “X-ray diffraction in the study of phase transitions” and 30 students had the opportunity to attend lectures by Professor Glazer, an expert on the subject, financed by the IUCr Visiting Professorship scheme. In addition, Leopoldo Suescun (from Uruguay) was in charge of the introduction to symmetry and space groups.
![[Mike Glazer]](https://www.iucr.org/__data/assets/image/0003/142599/glazer.png)
Mike Glazer during a lecture.
The Local Organizing Committee obtained financial support from the IUCr, Bioanalytica-Rigaku, Jenck-Shimadzu and the local funding agency: Ministerio de Ciencia y Tecnología. The event brought together 30 participants (postdocs, PhD, MSc and undergraduate students) from different countries: Argentina (17), Bolivia (1), Colombia (5), Cuba (1), Ecuador (1), Guatemala (1), Venezuela (2) and Uruguay (2). They all had the chance to learn the fundamentals of phase transitions and the use of X-ray diffraction techniques as an invaluable tool for the study of the associated structural details. For the practical aspects of the school the participants made use of a Bruker D8 Quest Eco diffractometer, installed in 2018, and APEX3 software and an Oxford Cryostream 800 Plus system. Thus, the participants experienced all the processes of single-crystal X-ray diffraction, from crystal selection and mounting, with practice samples and data. The students also had the opportunity to follow a temperature-driven phase transition using a Malvern Panalytical Empyrean diffractometer with a PIXcel3D detector and an Anton Paar hot stage.
![[Liliana Mogni]](https://www.iucr.org/__data/assets/image/0013/142600/mogni.png)
Liliana Mogni at the experimental tutorial session.
The school program consisted of a 40 hour schedule (24 hours of lectures, 14 for experimental and practical tutorial sessions and 2 for a final exam). A second questionnaire was given to the students, to be worked on at home and returned one week after the School had finished. This two-step exam was taken by 28 participants, who will receive academic credit for their participation in the School.
The students were asked for their opinions on different aspects of the School in an anonymous survey. The large majority of comments were positive, many of them including helpful remarks that will be a valuable help in the organization of future schools.
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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