1
|
Shelley KL, Garman EF. Identifying and avoiding radiation damage in macromolecular crystallography. Acta Crystallogr D Struct Biol 2024; 80:314-327. [PMID: 38700059 PMCID: PMC11066884 DOI: 10.1107/s2059798324003243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/15/2024] [Indexed: 05/05/2024] Open
Abstract
Radiation damage remains one of the major impediments to accurate structure solution in macromolecular crystallography. The artefacts of radiation damage can manifest as structural changes that result in incorrect biological interpretations being drawn from a model, they can reduce the resolution to which data can be collected and they can even prevent structure solution entirely. In this article, we discuss how to identify and mitigate against the effects of radiation damage at each stage in the macromolecular crystal structure-solution pipeline.
Collapse
Affiliation(s)
- Kathryn L. Shelley
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Institute for Protein Design, University of Washington, Seattle, Washington, USA
| | - Elspeth F. Garman
- Department of Biochemistry, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, United Kingdom
| |
Collapse
|
2
|
Marín‐Tovar Y, Serrano‐Posada H, Díaz‐Vilchis A, Rudiño‐Piñera E. PCNA from
Thermococcus gammatolerans
: A protein involved in chromosomal
DNA
metabolism intrinsically resistant at high levels of ionizing radiation. Proteins 2022; 90:1684-1698. [DOI: 10.1002/prot.26346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/17/2022] [Accepted: 04/01/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Yerli Marín‐Tovar
- Laboratorio de Bioquímica Estructural, Departamento de Medicina Molecular y Bioprocesos Instituto de Biotecnología (IBt), Universidad Nacional Autónoma de México (UNAM) Cuernavaca Mexico
| | - Hugo Serrano‐Posada
- Consejo Nacional de Ciencia y Tecnología (CONACyT), Laboratorio de Biología Sintética, Estructural y Molecular, Laboratorio de Agrobiotecnología, Tecnoparque CLQ Universidad de Colima Colima Mexico
| | - Adelaida Díaz‐Vilchis
- Laboratorio de Bioquímica Estructural, Departamento de Medicina Molecular y Bioprocesos Instituto de Biotecnología (IBt), Universidad Nacional Autónoma de México (UNAM) Cuernavaca Mexico
| | - Enrique Rudiño‐Piñera
- Laboratorio de Bioquímica Estructural, Departamento de Medicina Molecular y Bioprocesos Instituto de Biotecnología (IBt), Universidad Nacional Autónoma de México (UNAM) Cuernavaca Mexico
| |
Collapse
|
3
|
Novel quaternary structures of the human prion protein globular domain. Biochimie 2021; 191:118-125. [PMID: 34517052 DOI: 10.1016/j.biochi.2021.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/30/2021] [Accepted: 09/07/2021] [Indexed: 11/22/2022]
Abstract
Prion disease is caused by the misfolding of the cellular prion protein, PrPC, into a self-templating conformer, PrPSc. Nuclear magnetic resonance (NMR) and X-ray crystallography revealed the 3D structure of the globular domain of PrPC and the possibility of its dimerization via an interchain disulfide bridge that forms due to domain swap or by non-covalent association of two monomers. On the contrary, PrPSc is composed by a complex and heterogeneous ensemble of poorly defined conformations and quaternary arrangements that are related to different patterns of neurotoxicity. Targeting PrPC with molecules that stabilize the native conformation of its globular domain emerged as a promising approach to develop anti-prion therapies. One of the advantages of this approach is employing structure-based drug discovery methods to PrPC. Thus, it is essential to expand our structural knowledge about PrPC as much as possible to aid such drug discovery efforts. In this work, we report a crystallographic structure of the globular domain of human PrPC that shows a novel dimeric form and a novel oligomeric arrangement. We use molecular dynamics simulations to explore its structural dynamics and stability and discuss potential implications of these new quaternary structures to the conversion process.
Collapse
|
4
|
Mehr A, Henneberg F, Chari A, Görlich D, Huyton T. The copper(II)-binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography. Acta Crystallogr D Struct Biol 2020; 76:1222-1232. [PMID: 33263328 PMCID: PMC7709198 DOI: 10.1107/s2059798320013741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/13/2020] [Indexed: 12/04/2022] Open
Abstract
The growth of diffraction-quality crystals and experimental phasing remain two of the main bottlenecks in protein crystallography. Here, the high-affinity copper(II)-binding tripeptide GHK was fused to the N-terminus of a GFP variant and an MBP-FG peptide fusion. The GHK tag promoted crystallization, with various residues (His, Asp, His/Pro) from symmetry molecules completing the copper(II) square-pyramidal coordination sphere. Rapid structure determination by copper SAD phasing could be achieved, even at a very low Bijvoet ratio or after significant radiation damage. When collecting highly redundant data at a wavelength close to the copper absorption edge, residual S-atom positions could also be located in log-likelihood-gradient maps and used to improve the phases. The GHK copper SAD method provides a convenient way of both crystallizing and phasing macromolecular structures, and will complement the current trend towards native sulfur SAD and MR-SAD phasing.
Collapse
Affiliation(s)
- Alexander Mehr
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Fabian Henneberg
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ashwin Chari
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Trevor Huyton
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| |
Collapse
|
5
|
Nass K, Gorel A, Abdullah MM, V Martin A, Kloos M, Marinelli A, Aquila A, Barends TRM, Decker FJ, Bruce Doak R, Foucar L, Hartmann E, Hilpert M, Hunter MS, Jurek Z, Koglin JE, Kozlov A, Lutman AA, Kovacs GN, Roome CM, Shoeman RL, Santra R, Quiney HM, Ziaja B, Boutet S, Schlichting I. Structural dynamics in proteins induced by and probed with X-ray free-electron laser pulses. Nat Commun 2020; 11:1814. [PMID: 32286284 PMCID: PMC7156470 DOI: 10.1038/s41467-020-15610-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/20/2020] [Indexed: 11/10/2022] Open
Abstract
X-ray free-electron lasers (XFELs) enable crystallographic structure determination beyond the limitations imposed upon synchrotron measurements by radiation damage. The need for very short XFEL pulses is relieved through gating of Bragg diffraction by loss of crystalline order as damage progresses, but not if ionization events are spatially non-uniform due to underlying elemental distributions, as in biological samples. Indeed, correlated movements of iron and sulfur ions were observed in XFEL-irradiated ferredoxin microcrystals using unusually long pulses of 80 fs. Here, we report a femtosecond time-resolved X-ray pump/X-ray probe experiment on protein nanocrystals. We observe changes in the protein backbone and aromatic residues as well as disulfide bridges. Simulations show that the latter’s correlated structural dynamics are much slower than expected for the predicted high atomic charge states due to significant impact of ion caging and plasma electron screening. This indicates that dense-environment effects can strongly affect local radiation damage-induced structural dynamics. The local X-ray-induced dynamics that occur in protein crystals during serial femtosecond crystallography (SFX) measurements at XFELs are not well understood. Here the authors performed a time-resolved X-ray pump X-ray probe SFX experiment, and they observe distinct structural changes in the disulfide bridges and peptide backbone of proteins; complementing theoretical approaches allow them to further characterize the details of the X-ray induced ionization and local structural dynamics.
Collapse
Affiliation(s)
- Karol Nass
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Alexander Gorel
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Malik M Abdullah
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607, Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Andrew V Martin
- School of Science, RMIT University, 124 La Trobe Street, Melbourne, VIC, 3000, Australia
| | - Marco Kloos
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | | | - Andrew Aquila
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Thomas R M Barends
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | | | - R Bruce Doak
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Lutz Foucar
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Elisabeth Hartmann
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Mario Hilpert
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Mark S Hunter
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Zoltan Jurek
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607, Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Jason E Koglin
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Alexander Kozlov
- ARC Centre of Excellence for Advanced Molecular Imaging, School of Physics, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Alberto A Lutman
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Gabriela Nass Kovacs
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Christopher M Roome
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Robert L Shoeman
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Robin Santra
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607, Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany.,Department of Physics, Universität Hamburg, Jungiusstrasse 9, 20355, Hamburg, Germany
| | - Harry M Quiney
- ARC Centre of Excellence for Advanced Molecular Imaging, School of Physics, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Beata Ziaja
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607, Hamburg, Germany. .,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761, Hamburg, Germany. .,Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland.
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Ilme Schlichting
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany.
| |
Collapse
|
6
|
Radiation damage and dose limits in serial synchrotron crystallography at cryo- and room temperatures. Proc Natl Acad Sci U S A 2020; 117:4142-4151. [PMID: 32047034 PMCID: PMC7049125 DOI: 10.1073/pnas.1821522117] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Macromolecular X-ray crystallography (MX) is the most prolific structure determination method in structural biology but is limited by radiation damage. To reduce damage progression, MX is usually carried out at cryogenic temperatures, sometimes blocking functionally important conformational heterogeneity. Lacking this shortcoming, room temperature MX has gained momentum with the recent advent of serial crystallography, whereby distribution of the X-ray dose over thousands of crystals mitigates damage. Here, an approach to serial crystallography is presented allowing visualization of specific damage to amino acids at room temperature and determination of a dose limit above which structural information from electron density maps decreases due to radiation damage. This limit provides important guidance for the growing number of synchrotron room temperature MX experiments. Radiation damage limits the accuracy of macromolecular structures in X-ray crystallography. Cryogenic (cryo-) cooling reduces the global radiation damage rate and, therefore, became the method of choice over the past decades. The recent advent of serial crystallography, which spreads the absorbed energy over many crystals, thereby reducing damage, has rendered room temperature (RT) data collection more practical and also extendable to microcrystals, both enabling and requiring the study of specific and global radiation damage at RT. Here, we performed sequential serial raster-scanning crystallography using a microfocused synchrotron beam that allowed for the collection of two series of 40 and 90 full datasets at 2- and 1.9-Å resolution at a dose rate of 40.3 MGy/s on hen egg white lysozyme (HEWL) crystals at RT and cryotemperature, respectively. The diffraction intensity halved its initial value at average doses (D1/2) of 0.57 and 15.3 MGy at RT and 100 K, respectively. Specific radiation damage at RT was observed at disulfide bonds but not at acidic residues, increasing and then apparently reversing, a peculiar behavior that can be modeled by accounting for differential diffraction intensity decay due to the nonuniform illumination by the X-ray beam. Specific damage to disulfide bonds is evident early on at RT and proceeds at a fivefold higher rate than global damage. The decay modeling suggests it is advisable not to exceed a dose of 0.38 MGy per dataset in static and time-resolved synchrotron crystallography experiments at RT. This rough yardstick might change for proteins other than HEWL and at resolutions other than 2 Å.
Collapse
|
7
|
Dickerson JL, Garman EF. The potential benefits of using higher X-ray energies for macromolecular crystallography. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:922-930. [PMID: 31274414 DOI: 10.1107/s160057751900612x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/01/2019] [Indexed: 05/06/2023]
Abstract
Using X-ray energies higher than those normally used (5-15 keV) for macromolecular X-ray crystallography (MX) at synchrotron sources can theoretically increase the achievable signal as a function of dose and reduce the rate of radiation damage. In practice, a major stumbling block to the use of higher X-ray energy has been the reduced quantum efficiency of silicon detectors as the X-ray energy increases, but hybrid photon-counting CdTe detectors are optimized for higher X-ray energies, and their performance has been steadily improving. Here the potential advantages of using higher incident beam energy together with a CdTe detector for MX are explored, with a particular focus on the advantages that higher beam energies may have for MX experiments with microbeams or microcrystals. Monte Carlo simulations are presented here which for the first time include the efficiency responses of some available X-ray detectors, as well as the possible escape of photoelectrons from the sample and their entry from surrounding material. The results reveal a `sweet spot' at an incident X-ray energy of 26 keV, and show a greater than factor of two improvement in diffraction efficiency at this energy when using microbeams and microcrystals of 5 µm or less.
Collapse
Affiliation(s)
- Joshua L Dickerson
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Elspeth F Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| |
Collapse
|
8
|
Garman EF, Weik M. X-ray radiation damage to biological samples: recent progress. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:907-911. [PMID: 31274412 DOI: 10.1107/s1600577519009408] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 06/30/2019] [Indexed: 05/20/2023]
Abstract
With the continuing development of beamlines for macromolecular crystallography (MX) over the last few years providing ever higher X-ray flux densities, it has become even more important to be aware of the effects of radiation damage on the resulting structures. Nine papers in this issue cover a range of aspects related to the physics and chemistry of the manifestations of this damage, as observed in both MX and small-angle X-ray scattering (SAXS) on crystals, solutions and tissue samples. The reports include measurements of the heating caused by X-ray irradiation in ruby microcrystals, low-dose experiments examining damage rates as a function of incident X-ray energy up to 30 keV on a metallo-enzyme using a CdTe detector of high quantum efficiency as well as a theoretical analysis of the gains predicted in diffraction efficiency using these detectors, a SAXS examination of low-dose radiation exposure effects on the dissociation of a protein complex related to human health, theoretical calculations describing radiation chemistry pathways which aim to explain the specific structural damage widely observed in proteins, investigation of radiation-induced damage effects in a DNA crystal, a case study on a metallo-enzyme where structural movements thought to be mechanism related might actually be radiation-damage-induced changes, and finally a review describing what X-ray radiation-induced cysteine modifications can teach us about protein dynamics and catalysis. These papers, along with some other relevant literature published since the last Journal of Synchrotron Radiation Radiation Damage special issue in 2017, are briefly summarized below.
Collapse
Affiliation(s)
- Elspeth F Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Martin Weik
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38044 Grenoble, France
| |
Collapse
|
9
|
Taberman H, Bury CS, van der Woerd MJ, Snell EH, Garman EF. Structural knowledge or X-ray damage? A case study on xylose isomerase illustrating both. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:931-944. [PMID: 31274415 PMCID: PMC6613113 DOI: 10.1107/s1600577519005599] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 04/23/2019] [Indexed: 05/29/2023]
Abstract
Xylose isomerase (XI) is an industrially important metalloprotein studied for decades. Its reaction mechanism has been postulated to involve movement of the catalytic metal cofactor to several different conformations. Here, a dose-dependent approach was used to investigate the radiation damage effects on XI and their potential influence on the reaction mechanism interpreted from the X-ray derived structures. Radiation damage is still one of the major challenges for X-ray diffraction experiments and causes both global and site-specific damage. In this study, consecutive high-resolution data sets from a single XI crystal from the same wedge were collected at 100 K and the progression of radiation damage was tracked over increasing dose (0.13-3.88 MGy). The catalytic metal and its surrounding amino acid environment experience a build-up of free radicals, and the results show radiation-damage-induced structural perturbations ranging from an absolute metal positional shift to specific residue motions in the active site. The apparent metal movement is an artefact of global damage and the resulting unit-cell expansion, but residue motion appears to be driven by the dose. Understanding and identifying radiation-induced damage is an important factor in accurately interpreting the biological conclusions being drawn.
Collapse
Affiliation(s)
- Helena Taberman
- Macromolecular Crystallography (HZB-MX), Helmholtz-Zentrum Berlin, Albert-Einstein Straße 15, 12489 Berlin, Germany
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Charles S. Bury
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Mark J. van der Woerd
- Department of Enterprise Technology Services, 2001 Capitol Avenue, Cheyenne, WY 82001, USA
| | - Edward H. Snell
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Materials Design and Innovation, State University of New York at Buffalo, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Elspeth F. Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| |
Collapse
|
10
|
van den Bedem H, Wilson MA. Shining light on cysteine modification: connecting protein conformational dynamics to catalysis and regulation. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:958-966. [PMID: 31274417 PMCID: PMC6613112 DOI: 10.1107/s160057751900568x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/25/2019] [Indexed: 05/04/2023]
Abstract
Cysteine is a rare but functionally important amino acid that is often subject to covalent modification. Cysteine oxidation plays an important role in many human disease processes, and basal levels of cysteine oxidation are required for proper cellular function. Because reactive cysteine residues are typically ionized to the thiolate anion (Cys-S-), their formation of a covalent bond alters the electrostatic and steric environment of the active site. X-ray-induced photo-oxidation to sulfenic acids (Cys-SOH) can recapitulate some aspects of the changes that occur under physiological conditions. Here we propose how site-specific cysteine photo-oxidation can be used to interrogate ensuing changes in protein structure and dynamics at atomic resolution. Although this powerful approach can connect cysteine covalent modification to global protein conformational changes and function, careful biochemical validation must accompany all such studies to exclude misleading artifacts. New types of X-ray crystallography experiments and powerful computational methods are creating new opportunities to connect conformational dynamics to catalysis for the large class of systems that use covalently modified cysteine residues for catalysis or regulation.
Collapse
Affiliation(s)
- Henry van den Bedem
- Bioscience Division, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
| | - Mark A Wilson
- Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
| |
Collapse
|
11
|
Gotthard G, Aumonier S, De Sanctis D, Leonard G, von Stetten D, Royant A. Specific radiation damage is a lesser concern at room temperature. IUCRJ 2019; 6:665-680. [PMID: 31316810 PMCID: PMC6608634 DOI: 10.1107/s205225251900616x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/02/2019] [Indexed: 05/22/2023]
Abstract
Carrying out macromolecular crystallography (MX) experiments at cryogenic temperatures significantly slows the rate of global radiation damage, thus facilitating the solution of high-resolution crystal structures of macromolecules. However, cryo-MX experiments suffer from the early onset of so-called specific radiation damage that affects certain amino-acid residues and, in particular, the active sites of many proteins. Here, a series of MX experiments are described which suggest that specific and global radiation damage are much less decoupled at room temperature than they are at cryogenic temperatures. The results reported here demonstrate the interest in reviving the practice of collecting MX diffraction data at room temperature and allow structural biologists to favourably envisage the development of time-resolved MX experiments at synchrotron sources.
Collapse
Affiliation(s)
| | - Sylvain Aumonier
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | - Gordon Leonard
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | - Antoine Royant
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
- Université Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale), F-38000 Grenoble, France
| |
Collapse
|
12
|
Bugris V, Harmat V, Ferenc G, Brockhauser S, Carmichael I, Garman EF. Radiation-damage investigation of a DNA 16-mer. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:998-1009. [PMID: 31274421 DOI: 10.1107/s160057751900763x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/25/2019] [Indexed: 06/09/2023]
Abstract
In macromolecular crystallography, a great deal of effort has been invested in understanding radiation-damage progression. While the sensitivity of protein crystals has been well characterized, crystals of DNA and of DNA-protein complexes have not thus far been studied as thoroughly. Here, a systematic investigation of radiation damage to a crystal of a DNA 16-mer diffracting to 1.8 Å resolution and held at 100 K, up to an absorbed dose of 45 MGy, is reported. The RIDL (Radiation-Induced Density Loss) automated computational tool was used for electron-density analysis. Both the global and specific damage to the DNA crystal as a function of dose were monitored, following careful calibration of the X-ray flux and beam profile. The DNA crystal was found to be fairly radiation insensitive to both global and specific damage, with half of the initial diffraction intensity being lost at an absorbed average diffraction-weighted dose, D1/2, of 19 MGy, compared with 9 MGy for chicken egg-white lysozyme crystals under the same beam conditions but at the higher resolution of 1.4 Å. The coefficient of sensitivity of the DNA crystal was 0.014 Å2 MGy-1, which is similar to that observed for proteins. These results imply that the significantly greater radiation hardness of DNA and RNA compared with protein observed in a DNA-protein complex and an RNA-protein complex could be due to scavenging action by the protein, thereby protecting the DNA and RNA in these studies. In terms of specific damage, the regions of DNA that were found to be sensitive were those associated with some of the bound calcium ions sequestered from the crystallization buffer. In contrast, moieties farther from these sites showed only small changes even at higher doses.
Collapse
Affiliation(s)
- Valéria Bugris
- X-ray Crystallography Laboratory, Biological Research Centre, HAC-BRC, Temesvári krt. 62, Szeged 6726, Hungary
| | - Veronika Harmat
- X-ray Crystallography Laboratory, Biological Research Centre, HAC-BRC, Temesvári krt. 62, Szeged 6726, Hungary
| | - Györgyi Ferenc
- Nucleic Acid Synthesis Laboratory, Biological Research Centre, HAC-BRC, Temesvári krt. 62, Szeged 6726, Hungary
| | - Sándor Brockhauser
- X-ray Crystallography Laboratory, Biological Research Centre, HAC-BRC, Temesvári krt. 62, Szeged 6726, Hungary
| | - Ian Carmichael
- Notre Dame Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Elspeth F Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| |
Collapse
|
13
|
Abstract
Radiation damage still remains a major limitation and challenge in macromolecular X-ray crystallography. Some of the high-intensity radiation used for diffraction data collection experiments is absorbed by the crystals, generating free radicals. These give rise to radiation damage even at cryotemperatures (~100 K), which can lead to incorrect biological conclusions being drawn from the resulting structure, or even prevent structure solution entirely. Investigation of mitigation strategies and the effects caused by radiation damage has been extensive over the past fifteen years. Here, recent understanding of the physical and chemical phenomena of radiation damage is described, along with the global effects inflicted on the collected data and the specific effects observed in the solved structure. Furthermore, this review aims to summarise the progress made in radiation damage studies in macromolecular crystallography from the experimentalist’s point of view and to give an introduction to the current literature.
Collapse
|