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Jia L, Ruben EA, Suarez HJ, Olsen SK, Wasmuth EV. Single particle cryo-electron microscopy with an enhanced 200 kV cryo-TEM configuration achieves near-atomic resolution. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.593029. [PMID: 38766263 PMCID: PMC11100677 DOI: 10.1101/2024.05.07.593029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Single particle cryogenic electron microscopy (cryo-EM) as a structural biology methodology has become increasingly attractive and accessible to investigators in both academia and industry as this ever-advancing technology enables successful structural determination of a wide range of protein and nucleic acid targets. Although data for many high resolution cryo-EM structures are still obtained using a 300 kV cryogenic transmission electron microscope (cryo-TEM), a modern 200 kV cryo-TEM equipped with an advanced direct electron detector and energy filter is a cost-effective choice for most single particle applications, routinely achieving sub 3 angstrom (Å) resolution. Here, we systematically evaluate performance of one such high-end configuration - a 200 kV Glacios microscope coupled with a Falcon 4 direct electron detector and Selectris energy filter (Glacios-F4-S). First, we evaluated data quality on the standard benchmarking sample, rabbit muscle aldolase, using three of the most frequently used cryo-EM data collection software: SerialEM, Leginon and EPU, and found that - despite sample heterogeneity - all final reconstructions yield same overall resolutions of 2.6 Å and map quality when using either of the three software. Furthermore, comparison between Glacios-F4-S and a 300 kV cryo-TEM (Titan Krios with Falcon 4) revealed nominal resolution differences in overall reconstructions of a reconstituted human nucleosome core particle, achieving 2.8 and 2.5 Å, respectively. Finally, we performed comparative data analysis on the human RAD51 paralog complex, BCDX2, a four-protein complex of approximately 150 kilodaltons, and found that a small dataset (≤1,000 micrographs) was sufficient to generate a 3.3 Å reconstruction, with sufficient detail to resolve co-bound ligands, AMP-PNP and Mg +2 . In summary, this study provides evidence that the Glacios-F4-S operates equally well with all standard data collection software, and is sufficient to obtain high resolution structural information of novel macromolecular complexes, readily acquiring single particle data rivaling that of 300 kV cryo-TEMs.
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2
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Greber BJ. High-resolution cryo-EM of a small protein complex: The structure of the human CDK-activating kinase. Structure 2024:S0969-2126(24)00085-6. [PMID: 38565138 DOI: 10.1016/j.str.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/27/2023] [Accepted: 03/07/2024] [Indexed: 04/04/2024]
Abstract
The human CDK-activating kinase (CAK) is a multifunctional protein complex and key regulator of cell growth and division. Because of its critical functions in regulating the cell cycle and transcription initiation, it is a key target for multiple cancer drug discovery programs. However, the structure of the active human CAK, insights into its regulation, and its interactions with cellular substrates and inhibitors remained elusive until recently due to the lack of high-resolution structures of the intact complex. This review covers the progress in structure determination of the human CAK by cryogenic electron microscopy (cryo-EM), from early efforts to recent near-atomic resolution maps routinely resolved at 2Å or better. These results were enabled by the latest cryo-EM technologies introduced after the initial phase of the "resolution revolution" and allowed the application of high-resolution methods to new classes of molecular targets, including small protein complexes that were intractable using earlier technology.
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Affiliation(s)
- Basil J Greber
- Division of Structural Biology, The Institute of Cancer Research, London SW3 6JB, UK.
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3
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Cebi E, Lee J, Subramani VK, Bak N, Oh C, Kim KK. Cryo-electron microscopy-based drug design. Front Mol Biosci 2024; 11:1342179. [PMID: 38501110 PMCID: PMC10945328 DOI: 10.3389/fmolb.2024.1342179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 03/20/2024] Open
Abstract
Structure-based drug design (SBDD) has gained popularity owing to its ability to develop more potent drugs compared to conventional drug-discovery methods. The success of SBDD relies heavily on obtaining the three-dimensional structures of drug targets. X-ray crystallography is the primary method used for solving structures and aiding the SBDD workflow; however, it is not suitable for all targets. With the resolution revolution, enabling routine high-resolution reconstruction of structures, cryogenic electron microscopy (cryo-EM) has emerged as a promising alternative and has attracted increasing attention in SBDD. Cryo-EM offers various advantages over X-ray crystallography and can potentially replace X-ray crystallography in SBDD. To fully utilize cryo-EM in drug discovery, understanding the strengths and weaknesses of this technique and noting the key advancements in the field are crucial. This review provides an overview of the general workflow of cryo-EM in SBDD and highlights technical innovations that enable its application in drug design. Furthermore, the most recent achievements in the cryo-EM methodology for drug discovery are discussed, demonstrating the potential of this technique for advancing drug development. By understanding the capabilities and advancements of cryo-EM, researchers can leverage the benefits of designing more effective drugs. This review concludes with a discussion of the future perspectives of cryo-EM-based SBDD, emphasizing the role of this technique in driving innovations in drug discovery and development. The integration of cryo-EM into the drug design process holds great promise for accelerating the discovery of new and improved therapeutic agents to combat various diseases.
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Affiliation(s)
| | | | | | | | - Changsuk Oh
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
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4
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de la Cruz MJ, Eng ET. Scaling up cryo-EM for biology and chemistry: The journey from niche technology to mainstream method. Structure 2023; 31:1487-1498. [PMID: 37820731 PMCID: PMC10841453 DOI: 10.1016/j.str.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/31/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023]
Abstract
Cryoelectron microscopy (cryo-EM) methods have made meaningful contributions in a wide variety of scientific research fields. In structural biology, cryo-EM routinely elucidates molecular structure from isolated biological macromolecular complexes or in a cellular context by harnessing the high-resolution power of the electron in order to image samples in a frozen, hydrated environment. For structural chemistry, the cryo-EM method popularly known as microcrystal electron diffraction (MicroED) has facilitated atomic structure generation of peptides and small molecules from their three-dimensional crystal forms. As cryo-EM has grown from an emerging technology, it has undergone modernization to enable multimodal transmission electron microscopy (TEM) techniques becoming more routine, reproducible, and accessible to accelerate research across multiple disciplines. We review recent advances in modern cryo-EM and assess how they are contributing to the future of the field with an eye to the past.
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Affiliation(s)
- M Jason de la Cruz
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Edward T Eng
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA.
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5
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Dada L, Colomer JP, Manzano VE, Varela O. Synthesis of thiodisaccharides related to 4-thiolactose. Specific structural modifications increase the inhibitory activity against E. coli β-galactosidase. Org Biomol Chem 2023; 21:2188-2203. [PMID: 36806338 DOI: 10.1039/d2ob02301f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
In the search for new glycosidase inhibitors, a set of benzyl β-D-Gal-S-(1→4)-3-deoxy-4-thio-α-D-hexopyranosides was synthesized. Diverse configurations were installed at C-2 and C-4 of the glucose residue. The benzyl glycosidic group was kept intact or substituted by an electron-donating or electron-withdrawing group that could also participate in hydrogen bonding. All thiodisaccharides were found to be inhibitors of E. coli β-galactosidase. In general, benzyl thiodisaccharides were better inhibitors than those substituted (NO2 or NH2) on the benzyl ring. Thiodisaccharides containing a hexopyranoside, instead of a pentopyranoside, showed a weaker inhibitory activity, except for those having the α-D-xylo configuration, which exhibited inhibition constants of the same order of magnitude. These and previous results indicated that the inhibition process by thiodisaccharides is strongly dependent on the configuration of the 3-deoxy-4-thiopyranoside, as well as its substitution pattern (such as the presence of a benzyl glycoside). The enzyme-inhibitor interaction during the hydrolysis process involves a conformational selection resulting from rotation around the thioglycosidic bond and the flexibility of the terminal six-membered ring. Thus, the mentioned structural features of the inhibitor could give rise to favorable ground state conformations for the interaction with the enzyme, similar to those found for selected thiodisaccharides in the bound state. These studies demonstrated that the performance of thiodisaccharides as enzyme inhibitors could be increased by selecting the appropriate configuration and substitution of the hexopyranoside replacing the glucose moiety of 4-thiolactose.
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Affiliation(s)
- Lucas Dada
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-UBA, Centro de Investigación en Hidratos de Carbono (CIHIDECAR)
| | - Juan Pablo Colomer
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-UNC, Instituto de Investigaciones en Fisico-Química de Córdoba (INFIQC).,Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Edificio de Ciencias II, Córdoba, Argentina
| | - Verónica E Manzano
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-UBA, Centro de Investigación en Hidratos de Carbono (CIHIDECAR)
| | - Oscar Varela
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-UBA, Centro de Investigación en Hidratos de Carbono (CIHIDECAR)
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6
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Fréchin L, Holvec S, von Loeffelholz O, Hazemann I, Klaholz BP. High-resolution cryo-EM performance comparison of two latest-generation cryo electron microscopes on the human ribosome. J Struct Biol 2023; 215:107905. [PMID: 36241135 DOI: 10.1016/j.jsb.2022.107905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/23/2022] [Accepted: 10/05/2022] [Indexed: 11/29/2022]
Abstract
Recent technological advances in cryo electron microscopy (cryo-EM) have led to new opportunities in the structural biology field. Here we benchmark the performance of two 300 kV latest-generation cryo electron microscopes, Titan Krios G4 from Thermofisher Scientific and CRYO ARM 300 from Jeol, with regards to achieving high resolution single particle reconstructions on a real case sample. We compare potentially limiting factors such as drift rates, astigmatism & coma aberrations and performance during image processing and show that both microscopes, while comprising rather different technical setups & parameter settings and equipped with different types of energy filters & cameras, achieve a resolution of around 2 Å on the human ribosome, a non-symmetric object which constitutes a key drug target. Astigmatism correction, CTF refinement and correction of higher order aberrations through refinement in separate optics groups helped to account for astigmatism/coma caused by beam tilting during multi-spot and multi-hole acquisition in neighbouring holes without stage movement. The obtained maps resolve Mg2+ ions, water molecules, inhibitors and side-chains including chemical modifications. The fact that both instruments can resolve such detailed features will greatly facilitate understanding molecular mechanisms of various targets and helps in cryo-EM structure based drug design. The methods and analysis tools used here will be useful also to characterize existing instruments and optimize data acquisition settings and are applicable broadly to other drug targets in structural biology.
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Affiliation(s)
- Léo Fréchin
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Samuel Holvec
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Ottilie von Loeffelholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Isabelle Hazemann
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France.
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7
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Muenks A, Zepeda S, Zhou G, Veesler D, DiMaio F. Automatic and accurate ligand structure determination guided by cryo-electron microscopy maps. Nat Commun 2023; 14:1164. [PMID: 36859493 PMCID: PMC9976687 DOI: 10.1038/s41467-023-36732-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/15/2023] [Indexed: 03/03/2023] Open
Abstract
Advances in cryo-electron microscopy (cryoEM) and deep-learning guided protein structure prediction have expedited structural studies of protein complexes. However, methods for accurately determining ligand conformations are lacking. In this manuscript, we develop EMERALD, a tool for automatically determining ligand structures guided by medium-resolution cryoEM density. We show this method is robust at predicting ligands along with surrounding side chains in maps as low as 4.5 Å local resolution. Combining this with a measure of placement confidence and running on all protein/ligand structures in the EMDB, we show that 57% of ligands replicate the deposited model, 16% confidently find alternate conformations, 22% have ambiguous density where multiple conformations might be present, and 5% are incorrectly placed. For five cases where our approach finds an alternate conformation with high confidence, high-resolution crystal structures validate our placement. EMERALD and the resulting analysis should prove critical in using cryoEM to solve protein-ligand complexes.
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Affiliation(s)
- Andrew Muenks
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Samantha Zepeda
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Guangfeng Zhou
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA.
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8
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Fromm SA, O'Connor KM, Purdy M, Bhatt PR, Loughran G, Atkins JF, Jomaa A, Mattei S. The translating bacterial ribosome at 1.55 Å resolution generated by cryo-EM imaging services. Nat Commun 2023; 14:1095. [PMID: 36841832 PMCID: PMC9968351 DOI: 10.1038/s41467-023-36742-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/15/2023] [Indexed: 02/26/2023] Open
Abstract
Our understanding of protein synthesis has been conceptualised around the structure and function of the bacterial ribosome. This complex macromolecular machine is the target of important antimicrobial drugs, an integral line of defence against infectious diseases. Here, we describe how open access to cryo-electron microscopy facilities combined with bespoke user support enabled structural determination of the translating ribosome from Escherichia coli at 1.55 Å resolution. The obtained structures allow for direct determination of the rRNA sequence to identify ribosome polymorphism sites in the E. coli strain used in this study and enable interpretation of the ribosomal active and peripheral sites at unprecedented resolution. This includes scarcely populated chimeric hybrid states of the ribosome engaged in several tRNA translocation steps resolved at ~2 Å resolution. The current map not only improves our understanding of protein synthesis but also allows for more precise structure-based drug design of antibiotics to tackle rising bacterial resistance.
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Affiliation(s)
- Simon A Fromm
- EMBL Imaging Centre, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Kate M O'Connor
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - Michael Purdy
- Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland. .,MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
| | - Ahmad Jomaa
- Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA. .,Centre for Cell and Membrane Physiology, University of Virginia, Charlottesville, VA, USA.
| | - Simone Mattei
- EMBL Imaging Centre, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany. .,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany.
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9
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Fujita J, Makino F, Asahara H, Moriguchi M, Kumano S, Anzai I, Kishikawa JI, Matsuura Y, Kato T, Namba K, Inoue T. Epoxidized graphene grid for highly efficient high-resolution cryoEM structural analysis. Sci Rep 2023; 13:2279. [PMID: 36755111 PMCID: PMC9908306 DOI: 10.1038/s41598-023-29396-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Functionalization of graphene is one of the most important fundamental technologies in a wide variety of fields including industry and biochemistry. We have successfully achieved a novel oxidative modification of graphene using photoactivated ClO2· as a mild oxidant and confirmed the oxidized graphene grid is storable with its functionality for at least three months under N2 atmosphere. Subsequent chemical functionalization enabled us to develop an epoxidized graphene grid (EG-grid™), which effectively adsorbs protein particles for electron cryomicroscopy (cryoEM) image analysis. The EG-grid dramatically improved the particle density and orientation distribution. The density maps of GroEL and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were reconstructed at 1.99 and 2.16 Å resolution from only 504 and 241 micrographs, respectively. A sample solution of 0.1 mg ml-1 was sufficient to reconstruct a 3.10 Å resolution map of SARS-CoV-2 spike protein from 1163 micrographs. The map resolutions of β-galactosidase and apoferritin easily reached 1.81 Å and 1.29 Å resolution, respectively, indicating its atomic-resolution imaging capability. Thus, the EG-grid will be an extremely powerful tool for highly efficient high-resolution cryoEM structural analysis of biological macromolecules.
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Affiliation(s)
- Junso Fujita
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Fumiaki Makino
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL Ltd, 3-2-1 Musashino, Akishima, Tokyo, 196-8558, Japan
| | - Haruyasu Asahara
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Open and Transdisciplinary Research Initiatives, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Maiko Moriguchi
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shota Kumano
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Itsuki Anzai
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Jun-Ichi Kishikawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto, 603-8555, Japan
| | - Yoshiharu Matsuura
- Center for Infectious Disease Education and Research, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Laboratory of Virus Control, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,RIKEN Center for Biosystems Dynamics Research and SPring-8 Center, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Tsuyoshi Inoue
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Open and Transdisciplinary Research Initiatives, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,dotAqua Inc., 2-1 Yamadaoka, Suita, Osaka, Japan.
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10
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Daiß JL, Pilsl M, Straub K, Bleckmann A, Höcherl M, Heiss FB, Abascal-Palacios G, Ramsay EP, Tlučková K, Mars JC, Fürtges T, Bruckmann A, Rudack T, Bernecky C, Lamour V, Panov K, Vannini A, Moss T, Engel C. The human RNA polymerase I structure reveals an HMG-like docking domain specific to metazoans. Life Sci Alliance 2022; 5:5/11/e202201568. [PMID: 36271492 PMCID: PMC9438803 DOI: 10.26508/lsa.202201568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 06/20/2022] [Accepted: 08/09/2022] [Indexed: 11/24/2022] Open
Abstract
We characterize the human RNA polymerase I by evolutionary biochemistry and cryo-EM revealing a built-in structural domain that apparently serves as transcription factor–binding platform in metazoans. Transcription of the ribosomal RNA precursor by RNA polymerase (Pol) I is a major determinant of cellular growth, and dysregulation is observed in many cancer types. Here, we present the purification of human Pol I from cells carrying a genomic GFP fusion on the largest subunit allowing the structural and functional analysis of the enzyme across species. In contrast to yeast, human Pol I carries a single-subunit stalk, and in vitro transcription indicates a reduced proofreading activity. Determination of the human Pol I cryo-EM reconstruction in a close-to-native state rationalizes the effects of disease-associated mutations and uncovers an additional domain that is built into the sequence of Pol I subunit RPA1. This “dock II” domain resembles a truncated HMG box incapable of DNA binding which may serve as a downstream transcription factor–binding platform in metazoans. Biochemical analysis, in situ modelling, and ChIP data indicate that Topoisomerase 2a can be recruited to Pol I via the domain and cooperates with the HMG box domain–containing factor UBF. These adaptations of the metazoan Pol I transcription system may allow efficient release of positive DNA supercoils accumulating downstream of the transcription bubble.
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Affiliation(s)
- Julia L Daiß
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Michael Pilsl
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Kristina Straub
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Andrea Bleckmann
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Mona Höcherl
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Florian B Heiss
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Guillermo Abascal-Palacios
- Division of Structural Biology, The Institute of Cancer Research, London, UK
- Biofisika Institute (CSIC, UPV/EHU), Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Ewan P Ramsay
- Division of Structural Biology, The Institute of Cancer Research, London, UK
- Fondazione Human Technopole, Structural Biology Research Centre, Milan, Italy
| | | | - Jean-Clement Mars
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, Canada
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Québec, Canada
- Borden Laboratory, IRIC, Université de Montréal, Montréal, Québec, Canada
| | - Torben Fürtges
- Protein Crystallography, Department of Biophysics, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Astrid Bruckmann
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Till Rudack
- Protein Crystallography, Department of Biophysics, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Carrie Bernecky
- Institute of Science and Technology, Klosterneuburg, Austria
| | - Valérie Lamour
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Integrated Structural Biology, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Konstantin Panov
- School of Biological Sciences and PGJCCR, Queen’s University Belfast, Belfast, UK
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London, UK
- Fondazione Human Technopole, Structural Biology Research Centre, Milan, Italy
| | - Tom Moss
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, Canada
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Québec, Canada
| | - Christoph Engel
- Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
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11
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Cryo-electron structures of the extreme thermostable enzymes Sulfur Oxygenase Reductase and Lumazine Synthase. PLoS One 2022; 17:e0275487. [PMID: 36191023 PMCID: PMC9529111 DOI: 10.1371/journal.pone.0275487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/18/2022] [Indexed: 11/05/2022] Open
Abstract
Thermostable enzymes have the potential for use in a wide variety of biotechnological applications. Cryo-electron microscopy (cryo-EM) enables the imaging of biomolecules in their native aqueous environment. Here, we present high resolution cryo-EM structures of two thermostable enzymes that exhibit multimeric cage-like structures arranged into two different point-group symmetries. First, we determined the structure of the Sulfur Oxygenase Reductase (SOR) enzyme that catalyzes both the oxygenation and disproportionation of elemental sulfur in Archea and is composed of 24 homomeric units each of MW ≃ 35 kDa arranged in octahedral symmetry. The structure of SOR from Acidianus ambivalens (7X9W) was determined at 2.78 Å resolution. The active site of each subunit inside the central nanocompartment is composed of Fe3+ coordinated to two water molecules and the three amino acids (H86, H90 and E114). Second, we determined the structure of Lumazine Synthase (LS) from Aquifex aeolicus (7X7M) at 2.33 Å resolution. LS forms a cage-like structure consisting of 60 identical subunits each of MW ≃ 15 kDa arranged in a strict icosahedral symmetry. The LS subunits are interconnected by ion-pair network. Due to their thermostability and relatively easy purification scheme, both SOR and LS can serve as a model for the catalytic and structural characterization of biocatalysts as well as a benchmark for cryo-EM sample preparation, optimization of the acquisition parameters and 3D reconstruction.
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12
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Marco-Dufort B, Janczy JR, Hu T, Lütolf M, Gatti F, Wolf M, Woods A, Tetter S, Sridhar BV, Tibbitt MW. Thermal stabilization of diverse biologics using reversible hydrogels. SCIENCE ADVANCES 2022; 8:eabo0502. [PMID: 35930644 PMCID: PMC9355364 DOI: 10.1126/sciadv.abo0502] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Improving the thermal stability of biologics, including vaccines, is critical to reduce the economic costs and health risks associated with the cold chain. Here, we designed a versatile, safe, and easy-to-use reversible PEG-based hydrogel platform formed via dynamic covalent boronic ester cross-linking for the encapsulation, stabilization, and on-demand release of biologics. Using these reversible hydrogels, we thermally stabilized a wide range of biologics up to 65°C, including model enzymes, heat-sensitive clinical diagnostic enzymes (DNA gyrase and topoisomerase I), protein-based vaccines (H5N1 hemagglutinin), and whole viruses (adenovirus type 5). Our data support a generalized protection mechanism for the thermal stabilization of diverse biologics using direct encapsulation in reversible hydrogels. Furthermore, preliminary toxicology data suggest that the components of our hydrogel are safe for in vivo use. Our reversible hydrogel platform offers a simple material solution to mitigate the costs and risks associated with reliance on a continuous cold chain for biologic transport and storage.
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Affiliation(s)
- Bruno Marco-Dufort
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | | | - Tianjing Hu
- Nanoly Bioscience Inc., Denver, CO 80231, USA
| | - Marco Lütolf
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Francesco Gatti
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Morris Wolf
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Alex Woods
- Nanoly Bioscience Inc., Denver, CO 80231, USA
| | - Stephan Tetter
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Mark W. Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
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13
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Gerle C, Kishikawa JI, Yamaguchi T, Nakanishi A, Çoruh O, Makino F, Miyata T, Kawamoto A, Yokoyama K, Namba K, Kurisu G, Kato T. Structures of Multisubunit Membrane Complexes With the CRYO ARM 200. Microscopy (Oxf) 2022; 71:249-261. [PMID: 35861182 PMCID: PMC9535789 DOI: 10.1093/jmicro/dfac037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 11/18/2022] Open
Abstract
Progress in structural membrane biology has been significantly accelerated by the ongoing ‘Resolution Revolution’ in cryo-electron microscopy (cryo-EM). In particular, structure determination by single-particle analysis has evolved into the most powerful method for atomic model building of multisubunit membrane protein complexes. This has created an ever-increasing demand in cryo-EM machine time, which to satisfy is in need of new and affordable cryo-electron microscopes. Here, we review our experience in using the JEOL CRYO ARM 200 prototype for the structure determination by single-particle analysis of three different multisubunit membrane complexes: the Thermus thermophilus V-type ATPase VO complex, the Thermosynechococcus elongatus photosystem I monomer and the flagellar motor lipopolysaccharide peptidoglycan ring (LP ring) from Salmonella enterica.
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Affiliation(s)
- Christoph Gerle
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan.,RIKEN SPring-8 Center, Life Science Research Infrastructure Group, Sayo-gun, Hyogo 679-5148, Japan
| | - Jun-Ichi Kishikawa
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan
| | - Tomoko Yamaguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Atsuko Nakanishi
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan.,Research Center for Ultra-High Voltage Electron Microscopy, Osaka, University, Ibaraki, Osaka 567-0047, Japan
| | - Orkun Çoruh
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan.,Institute of Science and Technology Austria, Klosterneuburg, 3400 Austria
| | - Fumiaki Makino
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,JEOL Ltd., Akishima, Tokyo, Japan
| | - Tomoko Miyata
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Akihiro Kawamoto
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan
| | - Ken Yokoyama
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,RIKEN Center for Biosystems Dynamics Research, Suita, Osaka, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, Suita, Osaka, Japan
| | - Genji Kurisu
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, 3-2 Yamada Oka, Suita, Osaka 565-0871, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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14
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Heymann JB. The progressive spectral signal-to-noise ratio of cryo-electron micrograph movies as a tool to assess quality and radiation damage. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 220:106799. [PMID: 35405434 PMCID: PMC9149132 DOI: 10.1016/j.cmpb.2022.106799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/15/2022] [Accepted: 03/31/2022] [Indexed: 06/03/2023]
Abstract
BACKGROUND AND OBJECTIVE The quality of a cryoEM reconstruction is fundamentally a function of the signal-to-noise ratio (SNR) of the original micrographs. The SNR embodies multiple aspects of image formation, including microscope details and alignment, specimen composition and thickness, how it is recorded, and how the specimen degrades during imaging. With the advent of direct electron detectors and the recording of a series of images for each micrograph (a movie), we have an opportunity to count every electron and derive fully quantitative results. After alignment of the movie frames of a micrograph, we can calculate the SNR, or its spatial frequency equivalent, the spectral SNR (SSNR). This SSNR reflects residual movement between frames and the progressive effect of radiation damage. The goal is to develop a quantitative analysis of the SSNR and radiation damage to assess and improve the quality of micrographs. METHODS Several test cases were selected from the EMPIAR database and ten micrograph movies downloaded for each case. The movie frames were aligned as rigid bodies to compensate for stage and support movement. The SSNR for subsets of frames was then calculated to assess the effect of residual movement. The progressive SSNR (PSSNR) was subsequently calculated to determine the decrease in signal accumulation as a result of radiation damage. RESULTS In all cases the alignment of the movie frames compensated for global movement to the extent that the effect on the SSNR is negligible. The subset SSNR can be used as a tool to further confirm the extent of residual movement. The progressive SSNR indicates an increase in value up to an asymptote, consistent with the theory for radiation damage. Fitting these curves gives the inherent SNR before exposure, and the critical dose, which decreases with spatial frequency with an exponential parameter roughly between one and two. CONCLUSIONS The implementation of the PSSNR for movie frames provides a tool for assessing micrograph quality and progression of radiation damage. The estimation of the critical dose further quantifies radiation damage and may shed some light on the mechanisms of damage. These are likely both a function of the specimen composition and the imaging parameters used.
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Affiliation(s)
- J Bernard Heymann
- Laboratory for Structural Biology Research, NIAMS, NIH, Bethesda, MD 20892, USA; National Cryo-EM Program, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21701, USA.
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15
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Westphall MS, Lee KW, Salome AZ, Lodge JM, Grant T, Coon JJ. Three-dimensional structure determination of protein complexes using matrix-landing mass spectrometry. Nat Commun 2022; 13:2276. [PMID: 35478194 PMCID: PMC9046196 DOI: 10.1038/s41467-022-29964-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 04/07/2022] [Indexed: 11/20/2022] Open
Abstract
Native mass spectrometry (MS) is increasingly used to provide complementary data to electron microscopy (EM) for protein structure characterization. Beyond the ability to provide mass measurements of gas-phase biomolecular ions, MS instruments offer the ability to purify, select, and precisely control the spatial location of these ions. Here we present a modified Orbitrap MS system capable of depositing a native MS ion beam onto EM grids. We further describe the use of a chemical landing matrix that preserves the structural integrity of the deposited particles. With this system we obtain a three-dimensional reconstruction of the 800 kDa protein complex GroEL from gas-phase deposited GroEL ions. These data provide direct evidence that non-covalent protein complexes can indeed retain their condensed-phase structures following ionization and vaporization. Finally, we describe how further developments of this technology could pave the way to an integrated MS-EM technology with promise to provide improved cryo-EM sample preparation over conventional plunge-freezing techniques.
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Affiliation(s)
- Michael S. Westphall
- grid.14003.360000 0001 2167 3675Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI United States
| | - Kenneth W. Lee
- grid.14003.360000 0001 2167 3675Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI United States
| | - Austin Z. Salome
- grid.14003.360000 0001 2167 3675Department of Chemistry, University of Wisconsin-Madison, Madison, WI United States
| | - Jean M. Lodge
- grid.14003.360000 0001 2167 3675Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI United States
| | - Timothy Grant
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States. .,Morgridge Institute for Research, Madison, WI, United States.
| | - Joshua J. Coon
- grid.14003.360000 0001 2167 3675Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI United States ,grid.14003.360000 0001 2167 3675Department of Chemistry, University of Wisconsin-Madison, Madison, WI United States ,grid.509573.d0000 0004 0405 0937Morgridge Institute for Research, Madison, WI United States
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16
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Peck JV, Fay JF, Strauss JD. High-speed high-resolution data collection on a 200 keV cryo-TEM. IUCRJ 2022; 9:243-252. [PMID: 35371504 PMCID: PMC8895008 DOI: 10.1107/s2052252522000069] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/03/2022] [Indexed: 05/12/2023]
Abstract
Limitations to successful single-particle cryo-electron microscopy (cryo-EM) projects include stable sample generation, production of quality cryo-EM grids with randomly oriented particles embedded in thin vitreous ice and access to microscope time. To address the limitation of microscope time, methodologies to more efficiently collect data on a 200 keV Talos Arctica cryo-transmission electron microscope at speeds as fast as 720 movies per hour (∼17 000 per day) were tested. In this study, key parameters were explored to increase data collection speed including: (1) using the beam-image shift method to acquire multiple images per stage position, (2) employing UltrAufoil TEM grids with R0.6/1 hole spacing, (3) collecting hardware-binned data and (4) adjusting the image shift delay factor in SerialEM. Here, eight EM maps of mouse apoferritin at 1.8-1.9 Å resolution were obtained in the analysis with data collection times for each dataset ranging from 56 min to 2 h. An EM map of mouse apoferritin at 1.78 Å was obtained from an overnight data collection at a speed of 500 movies per hour and subgroup analysis performed, with no significant variation observed in data quality by image shift distance and image shift delay. The findings and operating procedures detailed herein allow for rapid turnover of single-particle cryo-EM structure determination.
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Affiliation(s)
- Jared V. Peck
- Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 101 Mason Farm, Chapel Hill, NC 27599, USA
| | - Jonathan F. Fay
- Biochemistry and Biophysics, 6107 Thurston Bowles Building, Chapel Hill, NC 27599, USA
| | - Joshua D. Strauss
- Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 101 Mason Farm, Chapel Hill, NC 27599, USA
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17
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Ravikumar A, Gopnarayan MN, Subramaniam S, Srinivasan N. Comparison of side-chain dispersion in protein structures determined by cryo-EM and X-ray crystallography. IUCRJ 2022; 9:98-103. [PMID: 35059214 PMCID: PMC8733892 DOI: 10.1107/s2052252521011945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
An evaluation of systematic differences in local structure and conformation in the interior of protein tertiary structures determined by crystallography and by cryo-electron microscopy (cryo-EM) is reported. The expectation is that any consistent differences between the derived atomic models could provide insights into variations in side-chain packing that result from differences in specimens prepared for analysis between these two methods. By computing an atomic packing score, which provides a quantitative measure of clustering of side-chain atoms in the core of the tertiary structures, it is found that, in general, for structures determined by cryo-EM, side chains are more dispersed than in structures determined by X-ray crystallography over a similar resolution range. This trend is also observed in the packing comparison at subunit interfaces. Similar trends were observed in the packing comparison at the core of tertiary structures of the same proteins determined by both X-ray and cryo-EM methods. It is proposed here that the reduced dispersion of side chains in protein crystals could be due to some level of dehydration in 3D crystals prepared for X-ray crystallography and also because the higher rate of freezing of protein samples for cryo-EM may enable preservation of a more native conformation.
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Affiliation(s)
- Ashraya Ravikumar
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India
| | | | - Sriram Subramaniam
- University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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18
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Dimos N, Helmer CPO, Chánique AM, Wahl MC, Kourist R, Hilal T, Loll B. CryoEM analysis of small plant biocatalysts at sub-2 Å resolution. Acta Crystallogr D Struct Biol 2022; 78:113-123. [PMID: 34981767 PMCID: PMC8725159 DOI: 10.1107/s205979832101216x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/16/2021] [Indexed: 12/02/2022] Open
Abstract
Enzyme catalysis has emerged as a key technology for developing efficient, sustainable processes in the chemical, biotechnological and pharmaceutical industries. Plants provide large and diverse pools of biosynthetic enzymes that facilitate complex reactions, such as the formation of intricate terpene carbon skeletons, with exquisite specificity. High-resolution structural analysis of these enzymes is crucial in order to understand their mechanisms and modulate their properties by targeted engineering. Although cryo-electron microscopy (cryoEM) has revolutionized structural biology, its applicability to high-resolution structural analysis of comparatively small enzymes has so far been largely unexplored. Here, it is shown that cryoEM can reveal the structures of plant borneol dehydrogenases of ∼120 kDa at or below 2 Å resolution, paving the way for the rapid development of new biocatalysts that can provide access to bioactive terpenes and terpenoids.
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Affiliation(s)
- Nicole Dimos
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, Pharmacy, Laboratory of Structural Biochemistry, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Carl P. O. Helmer
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, Pharmacy, Laboratory of Structural Biochemistry, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Andrea M. Chánique
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
- Department of Chemical and Bioprocesses Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7810000 Santiago, Chile
| | - Markus C. Wahl
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, Pharmacy, Laboratory of Structural Biochemistry, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany
- Macromolecular Crystallography, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Robert Kourist
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Tarek Hilal
- Institute of Chemistry and Biochemistry, Research Center of Electron Microscopy and Core Facility BioSupraMol, Free University of Berlin, Fabeckstrasse 36A, 14195 Berlin, Germany
| | - Bernhard Loll
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, Pharmacy, Laboratory of Structural Biochemistry, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany
- moloX GmbH, Takustrasse 6, 14195 Berlin, Germany
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19
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Lees JA, Dias JM, Han S. Applications of Cryo-EM in small molecule and biologics drug design. Biochem Soc Trans 2021; 49:2627-2638. [PMID: 34812853 PMCID: PMC8786282 DOI: 10.1042/bst20210444] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 02/03/2023]
Abstract
Electron cryo-microscopy (cryo-EM) is a powerful technique for the structural characterization of biological macromolecules, enabling high-resolution analysis of targets once inaccessible to structural interrogation. In recent years, pharmaceutical companies have begun to utilize cryo-EM for structure-based drug design. Structural analysis of integral membrane proteins, which comprise a large proportion of druggable targets and pose particular challenges for X-ray crystallography, by cryo-EM has enabled insights into important drug target families such as G protein-coupled receptors (GPCRs), ion channels, and solute carrier (SLCs) proteins. Structural characterization of biologics, such as vaccines, viral vectors, and gene therapy agents, has also become significantly more tractable. As a result, cryo-EM has begun to make major impacts in bringing critical therapeutics to market. In this review, we discuss recent instructive examples of impacts from cryo-EM in therapeutics design, focusing largely on its implementation at Pfizer. We also discuss the opportunities afforded by emerging technological advances in cryo-EM, and the prospects for future development of the technique.
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Affiliation(s)
- Joshua A. Lees
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
| | - Joao M. Dias
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
| | - Seungil Han
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
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20
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Insights into the bilayer-mediated toppling mechanism of a folate-specific ECF transporter by cryo-EM. Proc Natl Acad Sci U S A 2021; 118:2105014118. [PMID: 34408021 DOI: 10.1073/pnas.2105014118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Energy-coupling factor (ECF)-type transporters are small, asymmetric membrane protein complexes (∼115 kDa) that consist of a membrane-embedded, substrate-binding protein (S component) and a tripartite ATP-hydrolyzing module (ECF module). They import micronutrients into bacterial cells and have been proposed to use a highly unusual transport mechanism, in which the substrate is dragged across the membrane by a toppling motion of the S component. However, it remains unclear how the lipid bilayer could accommodate such a movement. Here, we used cryogenic electron microscopy at 200 kV to determine structures of a folate-specific ECF transporter in lipid nanodiscs and detergent micelles at 2.7- and 3.4-Å resolution, respectively. The structures reveal an irregularly shaped bilayer environment around the membrane-embedded complex and suggest that toppling of the S component is facilitated by protein-induced membrane deformations. In this way, structural remodeling of the lipid bilayer environment is exploited to guide the transport process.
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21
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Sub-3 Å Cryo-EM Structures of Necrosis Virus Particles via the Use of Multipurpose TEM with Electron Counting Camera. Int J Mol Sci 2021; 22:ijms22136859. [PMID: 34202259 PMCID: PMC8268952 DOI: 10.3390/ijms22136859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/31/2021] [Accepted: 06/22/2021] [Indexed: 11/17/2022] Open
Abstract
During this global pandemic, cryo-EM has made a great impact on the structure determination of COVID-19 proteins. However, nearly all high-resolution results are based on data acquired on state-of-the-art microscopes where their availability is restricted to a number of centers across the globe with the studies on infectious viruses being further regulated or forbidden. One potential remedy is to employ multipurpose microscopes. Here, we investigated the capability of 200 kV multipurpose microscopes equipped with a direct electron camera in determining the structures of infectious particles. We used 30 nm particles of the grouper nerve necrosis virus as a test sample and obtained the cryo-EM structure with a resolution as high as ∼2.7 Å from a setting that used electron counting. For comparison, we tested a high-end cryo-EM (Talos Arctica) using a similar virus (Macrobrachium rosenbergii nodavirus) to obtain virtually the same resolution. Those results revealed that the resolution is ultimately limited by the depth of field. Our work updates the density maps of these viruses at the sub-3Å level to allow for building accurate atomic models from de novo to provide structural insights into the assembly of the capsids. Importantly, this study demonstrated that multipurpose TEMs are capable of the high-resolution cryo-EM structure determination of infectious particles and is thus germane to the research on pandemics.
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22
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Greber BJ, Remis J, Ali S, Nogales E. 2.5 Å-resolution structure of human CDK-activating kinase bound to the clinical inhibitor ICEC0942. Biophys J 2021; 120:677-686. [PMID: 33476598 PMCID: PMC7896097 DOI: 10.1016/j.bpj.2020.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/11/2020] [Accepted: 12/21/2020] [Indexed: 12/22/2022] Open
Abstract
The human CDK-activating kinase (CAK), composed of CDK7, cyclin H, and MAT1, is involved in the control of transcription initiation and the cell cycle. Because of these activities, it has been identified as a promising target for cancer chemotherapy. A number of CDK7 inhibitors have entered clinical trials, among them ICEC0942 (also known as CT7001). Structural information can aid in improving the affinity and specificity of such drugs or drug candidates, reducing side effects in patients. Here, we have determined the structure of the human CAK in complex with ICEC0942 at 2.5 Å-resolution using cryogenic electron microscopy. Our structure reveals conformational differences of ICEC0942 compared with previous X-ray crystal structures of the CDK2-bound complex, and highlights the critical ability of cryogenic electron microscopy to resolve structures of drug-bound protein complexes without the need to crystalize the protein target.
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Affiliation(s)
- Basil J Greber
- Division of Structural Biology, The Institute of Cancer Research, London, United Kingdom; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, California; Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, California.
| | - Jonathan Remis
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, California
| | - Simak Ali
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, London, United Kingdom
| | - Eva Nogales
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, California; Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, California; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, University of California, Berkeley, Berkeley, California; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, California
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23
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Jung M, Kim D, Mun JY. Direct Visualization of Actin Filaments and Actin-Binding Proteins in Neuronal Cells. Front Cell Dev Biol 2020; 8:588556. [PMID: 33324645 PMCID: PMC7726226 DOI: 10.3389/fcell.2020.588556] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022] Open
Abstract
Actin networks and actin-binding proteins (ABPs) are most abundant in the cytoskeleton of neurons. The function of ABPs in neurons is nucleation of actin polymerization, polymerization or depolymerization regulation, bundling of actin through crosslinking or stabilization, cargo movement along actin filaments, and anchoring of actin to other cellular components. In axons, ABP–actin interaction forms a dynamic, deep actin network, which regulates axon extension, guidance, axon branches, and synaptic structures. In dendrites, actin and ABPs are related to filopodia attenuation, spine formation, and synapse plasticity. ABP phosphorylation or mutation changes ABP–actin binding, which regulates axon or dendritic plasticity. In addition, hyperactive ABPs might also be expressed as aggregates of abnormal proteins in neurodegeneration. Those changes cause many neurological disorders. Here, we will review direct visualization of ABP and actin using various electron microscopy (EM) techniques, super resolution microscopy (SRM), and correlative light and electron microscopy (CLEM) with discussion of important ABPs in neuron.
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Affiliation(s)
- Minkyo Jung
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Doory Kim
- Department of Chemistry, Research Institute for Convergence of Basic Sciences, Institute of Nano Science and Technology, Research Institute for Natural Sciences, Hanyang University, Seoul, South Korea
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea
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