| 1. |
- Agirre, Jon, et al.
(författare)
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The CCP4 suite: integrative software for macromolecular crystallography
- 2023
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Ingår i: Acta Crystallographica Section D. - : INT UNION CRYSTALLOGRAPHY. - 2059-7983. ; 79, s. 449-461
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Tidskriftsartikel (refereegranskat)abstract
- The Collaborative Computational Project No. 4 (CCP4) is a UK-led international collective with a mission to develop, test, distribute and promote software for macromolecular crystallography. The CCP4 suite is a multiplatform collection of programs brought together by familiar execution routines, a set of common libraries and graphical interfaces. The CCP4 suite has experienced several considerable changes since its last reference article, involving new infrastructure, original programs and graphical interfaces. This article, which is intended as a general literature citation for the use of the CCP4 software suite in structure determination, will guide the reader through such transformations, offering a general overview of the new features and outlining future developments. As such, it aims to highlight the individual programs that comprise the suite and to provide the latest references to them for perusal by crystallographers around the world.
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| 2. |
- Meijers, Rob, et al.
(författare)
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Structural evidence for a ligand coordination switch in liver alcohol dehydrogenase
- 2007
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 46:18, s. 5446-5454
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Tidskriftsartikel (refereegranskat)abstract
- The use of substrate analogues as inhibitors provides a way to understand and manipulate enzyme function. Here we report two 1 A resolution crystal structures of liver alcohol dehydrogenase in complex with NADH and two inhibitors: dimethyl sulfoxide and isobutyramide. Both structures present a dynamic state of inhibition. In the dimethyl sulfoxide complex structure, the inhibitor is caught in transition on its way to the active site using a flash-freezing protocol and a cadmium-substituted enzyme. One inhibitor molecule is partly located in the first and partly in the second coordination sphere of the active site metal. A hydroxide ion bound to the active site metal lies close to the pyridine ring of NADH, which is puckered in a twisted boat conformation. The cadmium ion is coordinated by both the hydroxide ion and the inhibitor molecule, providing structural evidence of a coordination switch at the active site metal ion. The structure of the isobutyramide complex reveals the partial formation of an adduct between the isobutyramide inhibitor and NADH. It provides evidence of the contribution of a shift from the keto to the enol tautomer during aldehyde reduction. The different positions of the inhibitors further refine the knowledge of the dynamics of the enzyme mechanism and explain how the crowded active site can facilitate the presence of a substrate and a metal-bound hydroxide ion.
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| 3. |
- Cohen, Serge X., et al.
(författare)
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Towards complete validated models in the next generation of ARP/wARP
- 2004
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Ingår i: Acta Crystallographica Section D. - 0907-4449 .- 1399-0047. ; 60:Pt 12 Pt 1, s. 2222-9
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Tidskriftsartikel (refereegranskat)abstract
- The design of a new versatile control system that will underlie future releases of the automated model-building package ARP/wARP is presented. A sophisticated expert system is under development that will transform ARP/wARP from a very useful model-building aid to a truly automated package capable of delivering complete, well refined and validated models comparable in quality to the result of intensive manual checking, rebuilding, hypothesis testing, refinement and validation cycles of an experienced crystallographer. In addition to the presentation of this control system, recent advances, ideas and future plans for improving the current model-building algorithms, especially for completing partially built models, are presented. Furthermore, a concept for integrating validation routines into the iterative model-building process is also presented.
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| 4. |
- Han, Huijong, et al.
(författare)
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The XBI BioLab for life science experiments at the European XFEL
- 2021
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Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 54, s. 7-21
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Tidskriftsartikel (refereegranskat)abstract
- The science of X-ray free-electron lasers (XFELs) critically depends on the performance of the X-ray laser and on the quality of the samples placed into the X-ray beam. The stability of biological samples is limited and key biomolecular transformations occur on short timescales. Experiments in biology require a support laboratory in the immediate vicinity of the beamlines. The XBI BioLab of the European XFEL (XBI denotes XFEL Biology Infrastructure) is an integrated user facility connected to the beamlines for supporting a wide range of biological experiments. The laboratory was financed and built by a collaboration between the European XFEL and the XBI User Consortium, whose members come from Finland, Germany, the Slovak Republic, Sweden and the USA, with observers from Denmark and the Russian Federation. Arranged around a central wet laboratory, the XBI BioLab provides facilities for sample preparation and scoring, laboratories for growing prokaryotic and eukaryotic cells, a Bio Safety Level 2 laboratory, sample purification and characterization facilities, a crystallization laboratory, an anaerobic laboratory, an aerosol laboratory, a vacuum laboratory for injector tests, and laboratories for optical microscopy, atomic force microscopy and electron microscopy. Here, an overview of the XBI facility is given and some of the results of the first user experiments are highlighted.
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| 5. |
- Meijers, Rob, et al.
(författare)
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On the Enzymatic Activation of NADH
- 2001
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 276:12, s. 9316-9321
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Tidskriftsartikel (refereegranskat)abstract
- Atomic (1 Å) resolution x-ray structures of horse liver alcohol dehydrogenase in complex with NADH revealed the formation of an adduct in the active site between a metal-bound water and NADH. Furthermore, a pronounced distortion of the pyridine ring of NADH was observed. A series of quantum chemical calculations on the water-nicotinamide adduct showed that the puckering of the pyridine ring in the crystal structures can only be reproduced when the water is considered a hydroxide ion. These observations provide fundamental insight into the enzymatic activation of NADH for hydride transfer.
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| 6. |
- Sobolev, Egor, et al.
(författare)
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Megahertz single-particle imaging at the European XFEL
- 2020
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Ingår i: Communications Physics. - : Springer Science and Business Media LLC. - 2399-3650. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of high repetition-rate X-ray free-electron lasers (XFELs) powered by superconducting accelerator technology enables the measurement of significantly more experimental data per day than was previously possible. The European XFEL is expected to provide 27,000 pulses per second, over two orders of magnitude more than any other XFEL. The increased pulse rate is a key enabling factor for single-particle X-ray diffractive imaging, which relies on averaging the weak diffraction signal from single biological particles. Taking full advantage of this new capability requires that all experimental steps, from sample preparation and delivery to the acquisition of diffraction patterns, are compatible with the increased pulse repetition rate. Here, we show that single-particle imaging can be performed using X-ray pulses at megahertz repetition rates. The results obtained pave the way towards exploiting high repetition-rate X-ray free-electron lasers for single-particle imaging at their full repetition rate.
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