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Ibrahim M, Fransson T, Chatterjee R, Cheah MH, Hussein R, Lassalle L, Sutherlin KD, Young ID, Fuller FD, Gul S, Kim IS, Simon PS, de Lichtenberg C, Chernev P, Bogacz I, Pham CC, Orville AM, Saichek N, Northen T, Batyuk A, Carbajo S, Alonso-Mori R, Tono K, Owada S, Bhowmick A, Bolotovsky R, Mendez D, Moriarty NW, Holton JM, Dobbek H, Brewster AS, Adams PD, Sauter NK, Bergmann U, Zouni A, Messinger J, Kern J, Yachandra VK, Yano J. Untangling the sequence of events during the S 2 → S 3 transition in photosystem II and implications for the water oxidation mechanism. Proc Natl Acad Sci U S A 2020; 117:12624-12635. [PMID: 32434915 PMCID: PMC7293653 DOI: 10.1073/pnas.2000529117] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In oxygenic photosynthesis, light-driven oxidation of water to molecular oxygen is carried out by the oxygen-evolving complex (OEC) in photosystem II (PS II). Recently, we reported the room-temperature structures of PS II in the four (semi)stable S-states, S1, S2, S3, and S0, showing that a water molecule is inserted during the S2 → S3 transition, as a new bridging O(H)-ligand between Mn1 and Ca. To understand the sequence of events leading to the formation of this last stable intermediate state before O2 formation, we recorded diffraction and Mn X-ray emission spectroscopy (XES) data at several time points during the S2 → S3 transition. At the electron acceptor site, changes due to the two-electron redox chemistry at the quinones, QA and QB, are observed. At the donor site, tyrosine YZ and His190 H-bonded to it move by 50 µs after the second flash, and Glu189 moves away from Ca. This is followed by Mn1 and Mn4 moving apart, and the insertion of OX(H) at the open coordination site of Mn1. This water, possibly a ligand of Ca, could be supplied via a "water wheel"-like arrangement of five waters next to the OEC that is connected by a large channel to the bulk solvent. XES spectra show that Mn oxidation (τ of ∼350 µs) during the S2 → S3 transition mirrors the appearance of OX electron density. This indicates that the oxidation state change and the insertion of water as a bridging atom between Mn1 and Ca are highly correlated.
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Miller KR, Paretsky JD, Follmer AH, Heinisch T, Mittra K, Gul S, Kim IS, Fuller FD, Batyuk A, Sutherlin KD, Brewster AS, Bhowmick A, Sauter NK, Kern J, Yano J, Green MT, Ward TR, Borovik AS. Artificial Iron Proteins: Modeling the Active Sites in Non-Heme Dioxygenases. Inorg Chem 2020; 59:6000-6009. [PMID: 32309932 PMCID: PMC7219546 DOI: 10.1021/acs.inorgchem.9b03791] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An important class of non-heme dioxygenases contains a conserved Fe binding site that consists of a 2-His-1-carboxylate facial triad. Results from structural biology show that, in the resting state, these proteins are six-coordinate with aqua ligands occupying the remaining three coordination sites. We have utilized biotin-streptavidin (Sav) technology to design new artificial Fe proteins (ArMs) that have many of the same structural features found within active sites of these non-heme dioxygenases. An Sav variant was isolated that contains the S112E mutation, which installed a carboxylate side chain in the appropriate position to bind to a synthetic FeII complex confined within Sav. Structural studies using X-ray diffraction (XRD) methods revealed a facial triad binding site that is composed of two N donors from the biotinylated ligand and the monodentate coordination of the carboxylate from S112E. Two aqua ligands complete the primary coordination sphere of the FeII center with both involved in hydrogen bond networks within Sav. The corresponding FeIII protein was also prepared and structurally characterized to show a six-coordinate complex with two exogenous acetato ligands. The FeIII protein was further shown to bind an exogenous azido ligand through replacement of one acetato ligand. Spectroscopic studies of the ArMs in solution support the results found by XRD.
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Sauter NK, Rose JP, Bhat TN. Transactions from the 69th Annual Meeting of the American Crystallographic Association: Data best practices-current state and future needs. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:021301. [PMID: 32232073 PMCID: PMC7093206 DOI: 10.1063/4.0000011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 06/10/2023]
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Wolff AM, Young ID, Sierra RG, Brewster AS, Martynowycz MW, Nango E, Sugahara M, Nakane T, Ito K, Aquila A, Bhowmick A, Biel JT, Carbajo S, Cohen AE, Cortez S, Gonzalez A, Hino T, Im D, Koralek JD, Kubo M, Lazarou TS, Nomura T, Owada S, Samelson AJ, Tanaka T, Tanaka R, Thompson EM, van den Bedem H, Woldeyes RA, Yumoto F, Zhao W, Tono K, Boutet S, Iwata S, Gonen T, Sauter NK, Fraser JS, Thompson MC. Comparing serial X-ray crystallography and microcrystal electron diffraction (MicroED) as methods for routine structure determination from small macromolecular crystals. IUCRJ 2020; 7:306-323. [PMID: 32148858 PMCID: PMC7055375 DOI: 10.1107/s205225252000072x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
Innovative new crystallographic methods are facilitating structural studies from ever smaller crystals of biological macromolecules. In particular, serial X-ray crystallography and microcrystal electron diffraction (MicroED) have emerged as useful methods for obtaining structural information from crystals on the nanometre to micrometre scale. Despite the utility of these methods, their implementation can often be difficult, as they present many challenges that are not encountered in traditional macromolecular crystallography experiments. Here, XFEL serial crystallography experiments and MicroED experiments using batch-grown microcrystals of the enzyme cyclophilin A are described. The results provide a roadmap for researchers hoping to design macromolecular microcrystallography experiments, and they highlight the strengths and weaknesses of the two methods. Specifically, we focus on how the different physical conditions imposed by the sample-preparation and delivery methods required for each type of experiment affect the crystal structure of the enzyme.
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Sauter NK, Kern J, Yano J, Holton JM. Towards the spatial resolution of metalloprotein charge states by detailed modeling of XFEL crystallographic diffraction. Acta Crystallogr D Struct Biol 2020; 76:176-192. [PMID: 32038048 PMCID: PMC7008510 DOI: 10.1107/s2059798320000418] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 01/14/2020] [Indexed: 12/25/2022] Open
Abstract
Oxidation states of individual metal atoms within a metalloprotein can be assigned by examining X-ray absorption edges, which shift to higher energy for progressively more positive valence numbers. Indeed, X-ray crystallography is well suited for such a measurement, owing to its ability to spatially resolve the scattering contributions of individual metal atoms that have distinct electronic environments contributing to protein function. However, as the magnitude of the shift is quite small, about +2 eV per valence state for iron, it has only been possible to measure the effect when performed with monochromated X-ray sources at synchrotron facilities with energy resolutions in the range 2-3 × 10-4 (ΔE/E). This paper tests whether X-ray free-electron laser (XFEL) pulses, which have a broader bandpass (ΔE/E = 3 × 10-3) when used without a monochromator, might also be useful for such studies. The program nanoBragg is used to simulate serial femtosecond crystallography (SFX) diffraction images with sufficient granularity to model the XFEL spectrum, the crystal mosaicity and the wavelength-dependent anomalous scattering factors contributed by two differently charged iron centers in the 110-amino-acid protein, ferredoxin. Bayesian methods are then used to deduce, from the simulated data, the most likely X-ray absorption curves for each metal atom in the protein, which agree well with the curves chosen for the simulation. The data analysis relies critically on the ability to measure the incident spectrum for each pulse, and also on the nanoBragg simulator to predict the size, shape and intensity profile of Bragg spots based on an underlying physical model that includes the absorption curves, which are then modified to produce the best agreement with the simulated data. This inference methodology potentially enables the use of SFX diffraction for the study of metalloenzyme mechanisms and, in general, offers a more detailed approach to Bragg spot data reduction.
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Andrews LC, Bernstein HJ, Sauter NK. Converting three-space matrices to equivalent six-space matrices for Delone scalars in S 6. ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 2020; 76:79-83. [PMID: 31908351 PMCID: PMC7045903 DOI: 10.1107/s2053273319014542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/25/2019] [Indexed: 11/29/2022]
Abstract
Given a matrix for transforming vectors in the three-space of unit-cell edge vectors, the corresponding matrix to transform vectors in the six-space of Delone scalars is derived. The transformations from the primitive cells of the centered Bravais lattices to the corresponding centered cells have conventionally been listed as three-by-three matrices that transform three-space lattice vectors. Using those three-by-three matrices when working in the six-dimensional space of lattices represented as Selling scalars as used in Delone (Delaunay) reduction, one could transform to the three-space representation, apply the three-by-three matrices and then back-transform to the six-space representation, but it is much simpler to have the equivalent six-by-six matrices and apply them directly. The general form of the transformation from the three-space matrix to the corresponding matrix operating on Selling scalars (expressed in space S6) is derived, and the particular S6matrices for the centered Delone types are listed. (Note: in his later publications, Boris Delaunay used the Russian version of his surname, Delone.)
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Bernstein HJ, Andrews LC, Diaz JA, Jakoncic J, Nguyen T, Sauter NK, Soares AS, Wei JY, Wlodek MR, Xerri MA. Best practices for high data-rate macromolecular crystallography (HDRMX). STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:014302. [PMID: 31934601 PMCID: PMC6952294 DOI: 10.1063/1.5128498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 12/11/2019] [Indexed: 05/13/2023]
Abstract
In macromolecular crystallography, higher flux, smaller beams, and faster detectors open the door to experiments with very large numbers of very small samples that can reveal polymorphs and dynamics but require re-engineering of approaches to the clustering of images both at synchrotrons and XFELs (X-ray free electron lasers). The need for the management of orders of magnitude more images and limitations of file systems favor a transition from simple one-file-per-image systems such as CBF to image container systems such as HDF5. This further increases the load on computers and networks and requires a re-examination of the presentation of metadata. In this paper, we discuss three important components of this problem-improved approaches to the clustering of images to better support experiments on polymorphs and dynamics, recent and upcoming changes in metadata for Eiger images, and software to rapidly validate images in the revised Eiger format.
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Brewster AS, Bhowmick A, Bolotovsky R, Mendez D, Zwart PH, Sauter NK. SAD phasing of XFEL data depends critically on the error model. Acta Crystallogr D Struct Biol 2019; 75:959-968. [PMID: 31692470 PMCID: PMC6834081 DOI: 10.1107/s2059798319012877] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/17/2019] [Indexed: 11/11/2022] Open
Abstract
A nonlinear least-squares method for refining a parametric expression describing the estimated errors of reflection intensities in serial crystallographic (SX) data is presented. This approach, which is similar to that used in the rotation method of crystallographic data collection at synchrotrons, propagates error estimates from photon-counting statistics to the merged data. Here, it is demonstrated that the application of this approach to SX data provides better SAD phasing ability, enabling the autobuilding of a protein structure that had previously failed to be built. Estimating the error in the merged reflection intensities requires the understanding and propagation of all of the sources of error arising from the measurements. One type of error, which is well understood, is the counting error introduced when the detector counts X-ray photons. Thus, if other types of random errors (such as readout noise) as well as uncertainties in systematic corrections (such as from X-ray attenuation) are completely understood, they can be propagated along with the counting error, as appropriate. In practice, most software packages propagate as much error as they know how to model and then include error-adjustment terms that scale the error estimates until they explain the variance among the measurements. If this is performed carefully, then during SAD phasing likelihood-based approaches can make optimal use of these error estimates, increasing the chance of a successful structure solution. In serial crystallography, SAD phasing has remained challenging, with the few examples of de novo protein structure solution each requiring many thousands of diffraction patterns. Here, the effects of different methods of treating the error estimates are estimated and it is shown that using a parametric approach that includes terms proportional to the known experimental uncertainty, the reflection intensity and the squared reflection intensity to improve the error estimates can allow SAD phasing even from weak zinc anomalous signal.
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Bolotovsky R, Brewster AS, Bhowmick A, Mendez D, Sauter NK. Using a supercomputer for massive parallel merging of XFEL reflections. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319098362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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35
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Bernstein HJ, Andrews LC, Diaz J, Jakoncic J, Sauter NK, Soares A, Wlodek MR. Best practices for high data-rate macromolecular crystallography (HDRMX). Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319099343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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36
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Andrews LC, Bernstein HJ, Diaz J, Sauter NK, Soares A, Wlodek MR. Faster, simpler Bravais lattice determination in S6. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319098325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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37
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Brewster AS, Bhowmick A, Bolotovsky R, Mendez D, Sauter NK. Processing data from new XFELs in cctbx.xfel and DIALS. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319098155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Bhowmick A, Brewster AS, Sauter NK. SASE–MAD protein structure determination and charge assignment to metal sites using XFEL crystallography. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319098532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Andrews LC, Bernstein HJ, Sauter NK. A space for lattice representation and clustering. ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 2019; 75:593-599. [PMID: 31041913 PMCID: PMC6492488 DOI: 10.1107/s2053273319002729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/22/2019] [Indexed: 11/25/2022]
Abstract
Algorithms for defining the difference between two lattices are described. They are based on the work of Selling and Delone (Delaunay). Algorithms for quantifying the differences between two lattices are used for Bravais lattice determination, database lookup for unit cells to select candidates for molecular replacement, and recently for clustering to group together images from serial crystallography. It is particularly desirable for the differences between lattices to be computed as a perturbation-stable metric, i.e. as distances that satisfy the triangle inequality, so that standard tree-based nearest-neighbor algorithms can be used, and for which small changes in the lattices involved produce small changes in the distances computed. A perturbation-stable metric space related to the reduction algorithm of Selling and to the Bravais lattice determination methods of Delone is described. Two ways of representing the space, as six-dimensional real vectors or equivalently as three-dimensional complex vectors, are presented and applications of these metrics are discussed. (Note: in his later publications, Boris Delaunay used the Russian version of his surname, Delone.)
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Andrews LC, Bernstein HJ, Sauter NK. Selling reduction versus Niggli reduction for crystallographic lattices. ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 2019; 75:115-120. [PMID: 30575589 PMCID: PMC6302928 DOI: 10.1107/s2053273318015413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022]
Abstract
The unit-cell reduction described by Selling and used by Delone (whose early publications were under the spelling Delaunay) is explained in a simple form. The transformations needed to implement the reduction are listed. The simplicity of this reduction contrasts with the complexity of Niggli reduction.
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Kern J, Chatterjee R, Young ID, Fuller FD, Lassalle L, Ibrahim M, Gul S, Fransson T, Brewster AS, Alonso-Mori R, Hussein R, Zhang M, Douthit L, de Lichtenberg C, Cheah MH, Shevela D, Wersig J, Seuffert I, Sokaras D, Pastor E, Weninger C, Kroll T, Sierra RG, Aller P, Butryn A, Orville AM, Liang M, Batyuk A, Koglin JE, Carbajo S, Boutet S, Moriarty NW, Holton JM, Dobbek H, Adams PD, Bergmann U, Sauter NK, Zouni A, Messinger J, Yano J, Yachandra VK. Structures of the intermediates of Kok's photosynthetic water oxidation clock. Nature 2018; 563:421-425. [PMID: 30405241 DOI: 10.1038/s41586-018-0681-2] [Citation(s) in RCA: 297] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/22/2018] [Indexed: 12/18/2022]
Abstract
Inspired by the period-four oscillation in flash-induced oxygen evolution of photosystem II discovered by Joliot in 1969, Kok performed additional experiments and proposed a five-state kinetic model for photosynthetic oxygen evolution, known as Kok's S-state clock or cycle1,2. The model comprises four (meta)stable intermediates (S0, S1, S2 and S3) and one transient S4 state, which precedes dioxygen formation occurring in a concerted reaction from two water-derived oxygens bound at an oxo-bridged tetra manganese calcium (Mn4CaO5) cluster in the oxygen-evolving complex3-7. This reaction is coupled to the two-step reduction and protonation of the mobile plastoquinone QB at the acceptor side of PSII. Here, using serial femtosecond X-ray crystallography and simultaneous X-ray emission spectroscopy with multi-flash visible laser excitation at room temperature, we visualize all (meta)stable states of Kok's cycle as high-resolution structures (2.04-2.08 Å). In addition, we report structures of two transient states at 150 and 400 µs, revealing notable structural changes including the binding of one additional 'water', Ox, during the S2→S3 state transition. Our results suggest that one water ligand to calcium (W3) is directly involved in substrate delivery. The binding of the additional oxygen Ox in the S3 state between Ca and Mn1 supports O-O bond formation mechanisms involving O5 as one substrate, where Ox is either the other substrate oxygen or is perfectly positioned to refill the O5 position during O2 release. Thus, our results exclude peroxo-bond formation in the S3 state, and the nucleophilic attack of W3 onto W2 is unlikely.
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Pande K, Donatelli JJ, Malmerberg E, Foucar L, Poon BK, Sutter M, Botha S, Basu S, Bruce Doak R, Dörner K, Epp SW, Englert L, Fromme R, Hartmann E, Hartmann R, Hauser G, Hattne J, Hosseinizadeh A, Kassemeyer S, Lomb L, Montero SFC, Menzel A, Rolles D, Rudenko A, Seibert MM, Sierra RG, Schwander P, Ourmazd A, Fromme P, Sauter NK, Bogan M, Bozek J, Bostedt C, Schlichting I, Kerfeld CA, Zwart PH. Free-electron laser data for multiple-particle fluctuation scattering analysis. Sci Data 2018; 5:180201. [PMID: 30277481 PMCID: PMC6167951 DOI: 10.1038/sdata.2018.201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/09/2018] [Indexed: 01/26/2023] Open
Abstract
Fluctuation X-ray scattering (FXS) is an emerging experimental technique in which solution scattering data are collected using X-ray exposures below rotational diffusion times, resulting in angularly anisotropic X-ray snapshots that provide several orders of magnitude more information than traditional solution scattering data. Such experiments can be performed using the ultrashort X-ray pulses provided by a free-electron laser source, allowing one to collect a large number of diffraction patterns in a relatively short time. Here, we describe a test data set for FXS, obtained at the Linac Coherent Light Source, consisting of close to 100 000 multi-particle diffraction patterns originating from approximately 50 to 200 Paramecium Bursaria Chlorella virus particles per snapshot. In addition to the raw data, a selection of high-quality pre-processed diffraction patterns and a reference SAXS profile are provided.
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Brewster AS, Waterman DG, Parkhurst JM, Gildea RJ, Young ID, O’Riordan LJ, Yano J, Winter G, Evans G, Sauter NK. Improving signal strength in serial crystallography with DIALS geometry refinement. Acta Crystallogr D Struct Biol 2018; 74:877-894. [PMID: 30198898 PMCID: PMC6130462 DOI: 10.1107/s2059798318009191] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/25/2018] [Indexed: 01/31/2023] Open
Abstract
The DIALS diffraction-modeling software package has been applied to serial crystallography data. Diffraction modeling is an exercise in determining the experimental parameters, such as incident beam wavelength, crystal unit cell and orientation, and detector geometry, that are most consistent with the observed positions of Bragg spots. These parameters can be refined by nonlinear least-squares fitting. In previous work, it has been challenging to refine both the positions of the sensors (metrology) on multipanel imaging detectors such as the CSPAD and the orientations of all of the crystals studied. Since the optimal models for metrology and crystal orientation are interdependent, alternate cycles of panel refinement and crystal refinement have been required. To simplify the process, a sparse linear algebra technique for solving the normal equations was implemented, allowing the detector panels to be refined simultaneously against the diffraction from thousands of crystals with excellent computational performance. Separately, it is shown how to refine the metrology of a second CSPAD detector, positioned at a distance of 2.5 m from the crystal, used for recording low-angle reflections. With the ability to jointly refine the detector position against the ensemble of all crystals used for structure determination, it is shown that ensemble refinement greatly reduces the apparent nonisomorphism that is often observed in the unit-cell distributions from still-shot serial crystallography. In addition, it is shown that batching the images by timestamp and re-refining the detector position can realistically model small, time-dependent variations in detector position relative to the sample, and thereby improve the integrated structure-factor intensity signal and heavy-atom anomalous peak heights.
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Sauter NK, Holton J, Kern J, Yano J, Yachandra V. Metalloprotein oxidation states spatially resolved by anomalous dispersion crystallography. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s0108767318096198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Bernstein HJ, Andrews LC, Jakoncic J, Soares A, Sauter NK. Improving unit-cell distance algorithms for clustering MX images. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s0108767318097581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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46
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Ke TW, Brewster AS, Yu SX, Ushizima D, Yang C, Sauter NK. A convolutional neural network-based screening tool for X-ray serial crystallography. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:655-670. [PMID: 29714177 PMCID: PMC5929353 DOI: 10.1107/s1600577518004873] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/26/2018] [Indexed: 05/24/2023]
Abstract
A new tool is introduced for screening macromolecular X-ray crystallography diffraction images produced at an X-ray free-electron laser light source. Based on a data-driven deep learning approach, the proposed tool executes a convolutional neural network to detect Bragg spots. Automatic image processing algorithms described can enable the classification of large data sets, acquired under realistic conditions consisting of noisy data with experimental artifacts. Outcomes are compared for different data regimes, including samples from multiple instruments and differing amounts of training data for neural network optimization.
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Winter G, Waterman DG, Parkhurst JM, Brewster AS, Gildea RJ, Gerstel M, Fuentes-Montero L, Vollmar M, Michels-Clark T, Young ID, Sauter NK, Evans G. DIALS: implementation and evaluation of a new integration package. Acta Crystallogr D Struct Biol 2018; 74:85-97. [PMID: 29533234 PMCID: PMC5947772 DOI: 10.1107/s2059798317017235] [Citation(s) in RCA: 652] [Impact Index Per Article: 108.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/30/2017] [Indexed: 01/07/2023] Open
Abstract
The DIALS project is a collaboration between Diamond Light Source, Lawrence Berkeley National Laboratory and CCP4 to develop a new software suite for the analysis of crystallographic X-ray diffraction data, initially encompassing spot finding, indexing, refinement and integration. The design, core algorithms and structure of the software are introduced, alongside results from the analysis of data from biological and chemical crystallography experiments.
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Roedig P, Ginn HM, Pakendorf T, Sutton G, Harlos K, Walter TS, Meyer J, Fischer P, Duman R, Vartiainen I, Reime B, Warmer M, Brewster AS, Young ID, Michels-Clark T, Sauter NK, Kotecha A, Kelly J, Rowlands DJ, Sikorsky M, Nelson S, Damiani DS, Alonso-Mori R, Ren J, Fry EE, David C, Stuart DI, Wagner A, Meents A. High-speed fixed-target serial virus crystallography. Nat Methods 2017; 14:805-810. [PMID: 28628129 PMCID: PMC5588887 DOI: 10.1038/nmeth.4335] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 05/15/2017] [Indexed: 12/19/2022]
Abstract
We report a method for serial X-ray crystallography at X-ray free-electron lasers (XFELs), which allows for full use of the current 120-Hz repetition rate of the Linear Coherent Light Source (LCLS). Using a micropatterned silicon chip in combination with the high-speed Roadrunner goniometer for sample delivery, we were able to determine the crystal structures of the picornavirus bovine enterovirus 2 (BEV2) and the cytoplasmic polyhedrosis virus type 18 polyhedrin, with total data collection times of less than 14 and 10 min, respectively. Our method requires only micrograms of sample and should therefore broaden the applicability of serial femtosecond crystallography to challenging projects for which only limited sample amounts are available. By synchronizing the sample exchange to the XFEL repetition rate, our method allows for most efficient use of the limited beam time available at XFELs and should enable a substantial increase in sample throughput at these facilities.
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Popp D, Loh ND, Zorgati H, Ghoshdastider U, Liow LT, Ivanova MI, Larsson M, DePonte DP, Bean R, Beyerlein KR, Gati C, Oberthuer D, Arnlund D, Brändén G, Berntsen P, Cascio D, Chavas LMG, Chen JPJ, Ding K, Fleckenstein H, Gumprecht L, Harimoorthy R, Mossou E, Sawaya MR, Brewster AS, Hattne J, Sauter NK, Seibert M, Seuring C, Stellato F, Tilp T, Eisenberg DS, Messerschmidt M, Williams GJ, Koglin JE, Makowski L, Millane RP, Forsyth T, Boutet S, White TA, Barty A, Chapman H, Chen SL, Liang M, Neutze R, Robinson RC. Flow-aligned, single-shot fiber diffraction using a femtosecond X-ray free-electron laser. Cytoskeleton (Hoboken) 2017; 74:472-481. [PMID: 28574190 DOI: 10.1002/cm.21378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/25/2017] [Accepted: 05/29/2017] [Indexed: 01/26/2023]
Abstract
A major goal for X-ray free-electron laser (XFEL) based science is to elucidate structures of biological molecules without the need for crystals. Filament systems may provide some of the first single macromolecular structures elucidated by XFEL radiation, since they contain one-dimensional translational symmetry and thereby occupy the diffraction intensity region between the extremes of crystals and single molecules. Here, we demonstrate flow alignment of as few as 100 filaments (Escherichia coli pili, F-actin, and amyloid fibrils), which when intersected by femtosecond X-ray pulses result in diffraction patterns similar to those obtained from classical fiber diffraction studies. We also determine that F-actin can be flow-aligned to a disorientation of approximately 5 degrees. Using this XFEL-based technique, we determine that gelsolin amyloids are comprised of stacked β-strands running perpendicular to the filament axis, and that a range of order from fibrillar to crystalline is discernable for individual α-synuclein amyloids.
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Brewster AS, Young ID, Sauter NK. Improving the models for diffraction used in serial crystallographic data reduction. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s010876731709643x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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