1
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Galaz-Montoya JG. The advent of preventive high-resolution structural histopathology by artificial-intelligence-powered cryogenic electron tomography. Front Mol Biosci 2024; 11:1390858. [PMID: 38868297 PMCID: PMC11167099 DOI: 10.3389/fmolb.2024.1390858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 05/08/2024] [Indexed: 06/14/2024] Open
Abstract
Advances in cryogenic electron microscopy (cryoEM) single particle analysis have revolutionized structural biology by facilitating the in vitro determination of atomic- and near-atomic-resolution structures for fully hydrated macromolecular complexes exhibiting compositional and conformational heterogeneity across a wide range of sizes. Cryogenic electron tomography (cryoET) and subtomogram averaging are rapidly progressing toward delivering similar insights for macromolecular complexes in situ, without requiring tags or harsh biochemical purification. Furthermore, cryoET enables the visualization of cellular and tissue phenotypes directly at molecular, nanometric resolution without chemical fixation or staining artifacts. This forward-looking review covers recent developments in cryoEM/ET and related technologies such as cryogenic focused ion beam milling scanning electron microscopy and correlative light microscopy, increasingly enhanced and supported by artificial intelligence algorithms. Their potential application to emerging concepts is discussed, primarily the prospect of complementing medical histopathology analysis. Machine learning solutions are poised to address current challenges posed by "big data" in cryoET of tissues, cells, and macromolecules, offering the promise of enabling novel, quantitative insights into disease processes, which may translate into the clinic and lead to improved diagnostics and targeted therapeutics.
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Affiliation(s)
- Jesús G. Galaz-Montoya
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, United States
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2
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Van Veen D, Galaz-Montoya JG, Shen L, Baldwin P, Chaudhari AS, Lyumkis D, Schmid MF, Chiu W, Pauly J. Missing Wedge Completion via Unsupervised Learning with Coordinate Networks. Int J Mol Sci 2024; 25:5473. [PMID: 38791508 PMCID: PMC11121946 DOI: 10.3390/ijms25105473] [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: 04/10/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024] Open
Abstract
Cryogenic electron tomography (cryoET) is a powerful tool in structural biology, enabling detailed 3D imaging of biological specimens at a resolution of nanometers. Despite its potential, cryoET faces challenges such as the missing wedge problem, which limits reconstruction quality due to incomplete data collection angles. Recently, supervised deep learning methods leveraging convolutional neural networks (CNNs) have considerably addressed this issue; however, their pretraining requirements render them susceptible to inaccuracies and artifacts, particularly when representative training data is scarce. To overcome these limitations, we introduce a proof-of-concept unsupervised learning approach using coordinate networks (CNs) that optimizes network weights directly against input projections. This eliminates the need for pretraining, reducing reconstruction runtime by 3-20× compared to supervised methods. Our in silico results show improved shape completion and reduction of missing wedge artifacts, assessed through several voxel-based image quality metrics in real space and a novel directional Fourier Shell Correlation (FSC) metric. Our study illuminates benefits and considerations of both supervised and unsupervised approaches, guiding the development of improved reconstruction strategies.
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Affiliation(s)
- Dave Van Veen
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA;
| | - Jesús G. Galaz-Montoya
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; (J.G.G.-M.); (W.C.)
| | - Liyue Shen
- Department of Electrical and Computer Engineering, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Philip Baldwin
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA;
- Department of Genetics, The Salk Institute of Biological Sciences, La Jolla, CA 92037, USA;
| | | | - Dmitry Lyumkis
- Department of Genetics, The Salk Institute of Biological Sciences, La Jolla, CA 92037, USA;
- Graduate School of Biological Sciences, University of California San Diego, La Jolla, CA 92037, USA
| | - Michael F. Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA;
| | - Wah Chiu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; (J.G.G.-M.); (W.C.)
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA;
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - John Pauly
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA;
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3
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Van Veen D, Galaz-Montoya JG, Shen L, Baldwin P, Chaudhari AS, Lyumkis D, Schmid MF, Chiu W, Pauly J. Missing Wedge Completion via Unsupervised Learning with Coordinate Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.12.589090. [PMID: 38712113 PMCID: PMC11071277 DOI: 10.1101/2024.04.12.589090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Cryogenic electron tomography (cryoET) is a powerful tool in structural biology, enabling detailed 3D imaging of biological specimens at a resolution of nanometers. Despite its potential, cryoET faces challenges such as the missing wedge problem, which limits reconstruction quality due to incomplete data collection angles. Recently, supervised deep learning methods leveraging convolutional neural networks (CNNs) have considerably addressed this issue; however, their pretraining requirements render them susceptible to inaccuracies and artifacts, particularly when representative training data is scarce. To overcome these limitations, we introduce a proof-of-concept unsupervised learning approach using coordinate networks (CNs) that optimizes network weights directly against input projections. This eliminates the need for pretraining, reducing reconstruction runtime by 3 - 20× compared to supervised methods. Our in silico results show improved shape completion and reduction of missing wedge artifacts, assessed through several voxel-based image quality metrics in real space and a novel directional Fourier Shell Correlation (FSC) metric. Our study illuminates benefits and considerations of both supervised and unsupervised approaches, guiding the development of improved reconstruction strategies.
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Affiliation(s)
- Dave Van Veen
- Dept. of Electrical Engineering, Stanford University
| | | | - Liyue Shen
- Dept. of Electrical and Computer Engineering, University of Michigan
| | - Philip Baldwin
- Dept. of Biochemistry and Molecular Pharmacology, Baylor College of Medicine
- Dept. of Genetics, The Salk Institute for Biological Sciences
| | | | - Dmitry Lyumkis
- Dept. of Genetics, The Salk Institute for Biological Sciences
- Graduate School of Biological Sciences, University of California San Diego
| | - Michael F. Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory
| | - Wah Chiu
- Dept. of Bioengineering, Stanford University
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory
- Dept. of Microbiology and Immunology, Stanford University
| | - John Pauly
- Dept. of Electrical Engineering, Stanford University
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4
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Chen L, Fukata Y, Murata K. In situ cryo-electron tomography: a new method to elucidate cytoplasmic zoning at the molecular level. J Biochem 2024; 175:187-193. [PMID: 38102736 DOI: 10.1093/jb/mvad102] [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: 10/05/2023] [Accepted: 11/15/2023] [Indexed: 12/17/2023] Open
Abstract
Cryo-electron microscopy was developed as a powerful tool for imaging biological specimens in near-native conditions. Nowadays, advances in technology, equipment and computations make it possible to obtain structures of biomolecules with near-atomic resolution. Furthermore, cryo-electron tomography combined with continuous specimen tilting allows structural analysis of heterogeneous biological specimens. In particular, when combined with a cryo-focused ion beam scanning electron microscope, it becomes possible to directly analyse the structure of the biomolecules within cells, a process known as in situ cryo-electron tomography. This technique has the potential to visualize cytoplasmic zoning, involving liquid-liquid phase separation, caused by biomolecular networks in aqueous solutions, which has been the subject of recent debate. Here, we review advances in structural studies of biomolecules to study cytoplasmic zoning by in situ cryo-electron tomography.
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Affiliation(s)
- Lin Chen
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- School of life sciences, Zhejiang Chinese Medical University, No. 548 Binwen Road, Binjiang District, Hangzhou 310053, China
| | - Yuko Fukata
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
| | - Kazuyoshi Murata
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
- Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan
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5
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Cai L, Liu H, Zhang W, Xiao S, Zeng Q, Dang S. Cryo-EM structure of cyanophage P-SCSP1u offers insights into DNA gating and evolution of T7-like viruses. Nat Commun 2023; 14:6438. [PMID: 37833330 PMCID: PMC10575957 DOI: 10.1038/s41467-023-42258-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023] Open
Abstract
Cyanophages, together with their host cyanobacteria, play important roles in marine biogeochemical cycles and control of marine food webs. The recently identified MPP-C (Marine Picocyanobacteria Podovirus clade C) cyanophages, belonging to the T7-like podoviruses, contain the smallest genomes among cyanopodoviruses and exhibit distinct infection kinetics. However, understanding of the MPP-C cyanophage infection process is hindered by the lack of high-resolution structural information. Here, we report the cryo-EM structure of the cyanophage P-SCSP1u, a representative member of the MPP-C phages, in its native form at near-atomic resolution, which reveals the assembly mechanism of the capsid and molecular interaction of the portal-tail complex. Structural comparison of the capsid proteins of P-SCSP1u and other podoviruses with known structures provides insights into the evolution of T7-like viruses. Furthermore, our study provides the near-atomic resolution structure of portal-tail complex for T7-like viruses. On the basis of previously reported structures of phage T7, we identify an additional valve and gate to explain the DNA gating mechanism for the T7-like viruses.
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Affiliation(s)
- Lanlan Cai
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China
| | - Hang Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Wen Zhang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Shiwei Xiao
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
- HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China.
- Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
- HKUST-Shenzhen Research Institute, Nanshan, Shenzhen 518057, China.
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6
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Bhatt P, Engel BA, Reuhs M, Simsek H. Cyanophage technology in removal of cyanobacteria mediated harmful algal blooms: A novel and eco-friendly method. CHEMOSPHERE 2023; 315:137769. [PMID: 36623591 DOI: 10.1016/j.chemosphere.2023.137769] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/27/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Cyanophages are highly abundant specific viruses that infect cyanobacterial cells. In recent years, the cyanophages and cyanobacteria interactions drew attention to environmental restoration due to their discovery in marine and freshwater systems. Cyanobacterial harmful algal blooms (cyanoHABs) are increasing throughout the world and contaminating aquatic ecosystems. The blooms cause severe environmental problems including unpleasant odors and cyanotoxin production. Cyanotoxins have been reported to be lethal agents for living beings and can harm animals, people, aquatic species, recreational activities, and drinking water reservoirs. Biological remediation of cyanoHABs in aquatic systems is a sustainable and eco-friendly approach to increasing surface water quality. Therefore, this study compiles the fragmented information with the solution of removal of cyanoHABs using cyanophage therapy techniques. To date, scant information exists in terms of bloom formation, cyanophage occurrence, and mode of action to remediate cyanoHABs. Overall, this study illustrates cyanobacterial toxin production and its impacts on the environment, the mechanisms involved in the cyanophage-cyanobacteria interaction, and the application of cyanophages for the removal of toxic cyanobacterial blooms.
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Affiliation(s)
- Pankaj Bhatt
- Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Bernard A Engel
- Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Mikael Reuhs
- Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Halis Simsek
- Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, IN, 47907, USA.
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7
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Burton-Smith RN, Murata K. Cryo-electron Microscopy of Protein Cages. Methods Mol Biol 2023; 2671:173-210. [PMID: 37308646 DOI: 10.1007/978-1-0716-3222-2_11] [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] [Indexed: 06/14/2023]
Abstract
Protein cages are one of the most widely studied objects in the field of cryogenic electron microscopy-encompassing natural and synthetic constructs, from enzymes assisting protein folding such as chaperonin to virus capsids. Tremendous diversity of morphology and function is demonstrated by the structure and role of proteins, some of which are nearly ubiquitous, while others are present in few organisms. Protein cages are often highly symmetrical, which helps improve the resolution obtained by cryo-electron microscopy (cryo-EM). Cryo-EM is the study of vitrified samples using an electron probe to image the subject. A sample is rapidly frozen in a thin layer on a porous grid, attempting to keep the sample as close to a native state as possible. This grid is kept at cryogenic temperatures throughout imaging in an electron microscope. Once image acquisition is complete, a variety of software packages may be employed to carry out analysis and reconstruction of three-dimensional structures from the two-dimensional micrograph images. Cryo-EM can be used on samples that are too large or too heterogeneous to be amenable to other structural biology techniques like NMR or X-ray crystallography. In recent years, advances in both hardware and software have provided significant improvements to the results obtained using cryo-EM, recently demonstrating true atomic resolution from vitrified aqueous samples. Here, we review these advances in cryo-EM, especially in that of protein cages, and introduce several tips for situations we have experienced.
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Affiliation(s)
- Raymond N Burton-Smith
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute for Natural Sciences, Okazaki, Aichi, Japan
- National Institute for Physiological Sciences (NIPS), National Institute for Natural Sciences, Okazaki, Aichi, Japan
| | - Kazuyoshi Murata
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute for Natural Sciences, Okazaki, Aichi, Japan.
- National Institute for Physiological Sciences (NIPS), National Institute for Natural Sciences, Okazaki, Aichi, Japan.
- Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan.
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8
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Structural Insights into the Chaperone-Assisted Assembly of a Simplified Tail Fiber of the Myocyanophage Pam3. Viruses 2022; 14:v14102260. [PMID: 36298815 PMCID: PMC9608196 DOI: 10.3390/v14102260] [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: 09/13/2022] [Revised: 10/09/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
At the first step of phage infection, the receptor-binding proteins (RBPs) such as tail fibers are responsible for recognizing specific host surface receptors. The proper folding and assembly of tail fibers usually requires a chaperone encoded by the phage genome. Despite extensive studies on phage structures, the molecular mechanism of phage tail fiber assembly remains largely unknown. Here, using a minimal myocyanophage, termed Pam3, isolated from Lake Chaohu, we demonstrate that the chaperone gp25 forms a stable complex with the tail fiber gp24 at a stoichiometry of 3:3. The 3.1-Å cryo-electron microscopy structure of this complex revealed an elongated structure with the gp25 trimer embracing the distal moieties of gp24 trimer at the center. Each gp24 subunit consists of three domains: the N-terminal α-helical domain required for docking to the baseplate, the tumor necrosis factor (TNF)-like and glycine-rich domains responsible for recognizing the host receptor. Each gp25 subunit consists of two domains: a non-conserved N-terminal β-sandwich domain that binds to the TNF-like and glycine-rich domains of the fiber, and a C-terminal α-helical domain that mediates trimerization/assembly of the fiber. Structural analysis enabled us to propose the assembly mechanism of phage tail fibers, in which the chaperone first protects the intertwined and repetitive distal moiety of each fiber subunit, further ensures the proper folding of these highly plastic structural elements, and eventually enables the formation of the trimeric fiber. These findings provide the structural basis for the design and engineering of phage fibers for biotechnological applications.
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Swanson NA, Hou CFD, Cingolani G. Viral Ejection Proteins: Mosaically Conserved, Conformational Gymnasts. Microorganisms 2022; 10:microorganisms10030504. [PMID: 35336080 PMCID: PMC8954989 DOI: 10.3390/microorganisms10030504] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial viruses (or bacteriophages) have developed formidable ways to deliver their genetic information inside bacteria, overcoming the complexity of the bacterial-cell envelope. In short-tailed phages of the Podoviridae superfamily, genome ejection is mediated by a set of mysterious internal virion proteins, also called ejection or pilot proteins, which are required for infectivity. The ejection proteins are challenging to study due to their plastic structures and transient assembly and have remained less characterized than classical components such as the phage coat protein or terminase subunit. However, a spate of recent cryo-EM structures has elucidated key features underscoring these proteins' assembly and conformational gymnastics that accompany their expulsion from the virion head through the portal protein channel into the host. In this review, we will use a phage-T7-centric approach to critically review the status of the literature on ejection proteins, decipher the conformational changes of T7 ejection proteins in the pre- and post-ejection conformation, and predict the conservation of these proteins in other Podoviridae. The challenge is to relate the structure of the ejection proteins to the mechanisms of genome ejection, which are exceedingly complex and use the host's machinery.
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Affiliation(s)
- Nicholas A. Swanson
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA; (N.A.S.); (C.-F.D.H.)
- Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Chun-Feng D. Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA; (N.A.S.); (C.-F.D.H.)
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA; (N.A.S.); (C.-F.D.H.)
- Correspondence: ; Tel.: +01-(215)-503-4573
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10
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Abstract
Helicobacter pylori plays a causative role in gastric diseases. The pathogenicity of H. pylori depends on its ability to colonize the stomach guided by motility. FliY is a unique flagellar motor switch component coexisting with the classical FliG, FliM, and FliN switch proteins in some bacteria and has been shown to be essential for flagellation. However, the functional importance of FliY in H. pylori flagellar motor assembly is not well understood. Here, we applied cryo-electron tomography and subtomogram averaging to analyze the in situ structures of flagellar motors from wild-type strain, fliY-null mutant and complementation mutants expressing the N-terminal or C-terminal domain of FliY. Loss of full-length FliY or its C-terminal domain interrupted the formation of an intact C ring and soluble export apparatus, as well as the hook and flagellar filaments. Complementation with FliY C-terminal domain restored all these missing components of flagellar motor. Taken together, these results provide structural insights into the roles of FliY, especially its C-terminal domain in flagellar motor assembly in H. pylori. IMPORTANCEHelicobacter pylori is the major risk factor related with gastric diseases. Flagellar motor is one of the most important virulence factors in H. pylori. However, the assembly mechanism of H. pylori flagellar motor is not fully understood yet. Previous report mainly described the overall structures of flagellum but had not focused on its specific components. Here, we focus on H. pylori flagellar C-ring protein FliY. We directly visualize the flagellar structures of H. pylori wild-type and FliY N-/C-terminal complementary strains by cryo-electron tomography and subtomogram averaging. Our results show that deletion of FliY or its C-terminal domain causes the loss of C ring, whereas deletion of FliY N-terminal does not affect C-ring assembly and flagellar structures. Our results provide direct evidence that C-ring protein FliY, especially its C-terminal domain, plays an indispensable role in H. pylori motor assembly and flagellar formation. This study will deepen our understanding about H. pylori pathogenesis.
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11
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Host Cyanobacteria Killing by Novel Lytic Cyanophage YongM: A Protein Profiling Analysis. Microorganisms 2022; 10:microorganisms10020257. [PMID: 35208712 PMCID: PMC8875764 DOI: 10.3390/microorganisms10020257] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 02/01/2023] Open
Abstract
Cyanobacteria are autotrophic prokaryotes that can proliferate robustly in eutrophic waters through photosynthesis. This can lead to outbreaks of lake “water blooms”, which result in water quality reduction and environmental pollution that seriously affect fisheries and aquaculture. The use of cyanophages to control the growth of cyanobacteria is an important strategy to tackle annual cyanobacterial blooms. YongM is a novel lytic cyanophage with a broad host spectrum and high efficiency in killing its host, cyanobacteria FACHB-596. However, changes in cyanophage protein profile during infestation and killing of the host remains unknown. To characterize the proteins and its regulation networks involved in the killing of host cyanobacteria by YongM and evaluate whether this strain YongM could be used as a chassis for further engineering to be a powerful tool in dealing with cyanobacterial blooms, we herein applied 4D label-free high-throughput quantitative proteomics to analyze differentially expressed proteins (DEPs) involved in cyanobacteria host response infected 1 and 8 h with YongM cyanophage. Metabolic pathways, such as photosynthesis, photosynthesis-antennal protein, oxidative phosphorylation, ribosome, carbon fixation, and glycolysis/glycol-isomerization were significantly altered in the infested host, whereas DEPs were associated with the metabolic processes of photosynthesis, precursor metabolites, energy production, and organic nitrogen compounds. Among these DEPs, key proteins involved in YongM-host interaction may be photosystem I P700 chlorophyll-a apolipoprotein, carbon dioxide concentration mechanism protein, cytochrome B, and some YongM infection lysis-related enzymes. Our results provide comprehensive information of protein profiles during the invasion and killing of host cyanobacteria by its cyanophage, which may shed light on future design and manipulation of artificial cyanophages against water blooms.
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12
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Burton-Smith RN, Murata K. Cryo-Electron Microscopy of the Giant Viruses. Microscopy (Oxf) 2021; 70:477-486. [PMID: 34490462 DOI: 10.1093/jmicro/dfab036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 11/12/2022] Open
Abstract
High resolution study of the giant viruses presents one of the latest challenges in cryo-electron microscopy of viruses. Too small for light microscopy, but too large for easy study at high resolution by electron microscopy, they range in size from ~0.2-2 μm, from high symmetry icosahedral viruses such as Paramecium burseria Chlorella virus 1 to asymmetric forms like Tupanvirus or Pithovirus. To attain high resolution, two strategies exist to study these large viruses by cryo-EM: firstly, increasing the acceleration voltage of the electron microscope to improve sample penetration and overcome the limitations imposed by electro-optical physics at lower voltages, and secondly the method of "block-based reconstruction" pioneered by Michael G. Rossmann and his collaborators, which resolves the latter limitation through an elegant leveraging of high symmetry, but cannot overcome sample penetration limitations. In addition, more recent advances in both computational capacity and image processing also yield assistance in studying the giant viruses. Especially, the inclusion of Ewald sphere correction can provide large improvements in attainable resolutions for 300 kV electron microscopes. Despite this, the study of giant viruses remains a significant challenge.
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Affiliation(s)
- Raymond N Burton-Smith
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan.,National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Kazuyoshi Murata
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan.,National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, Japan.,Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
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13
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Swanson NA, Lokareddy RK, Li F, Hou CFD, Leptihn S, Pavlenok M, Niederweis M, Pumroy RA, Moiseenkova-Bell VY, Cingolani G. Cryo-EM structure of the periplasmic tunnel of T7 DNA-ejectosome at 2.7 Å resolution. Mol Cell 2021; 81:3145-3159.e7. [PMID: 34214465 DOI: 10.1016/j.molcel.2021.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/27/2021] [Accepted: 06/01/2021] [Indexed: 11/15/2022]
Abstract
Hershey and Chase used bacteriophage T2 genome delivery inside Escherichia coli to demonstrate that DNA, not protein, is the genetic material. Seventy years later, our understanding of viral genome delivery in prokaryotes remains limited, especially for short-tailed phages of the Podoviridae family. These viruses expel mysterious ejection proteins found inside the capsid to form a DNA-ejectosome for genome delivery into bacteria. Here, we reconstitute the phage T7 DNA-ejectosome components gp14, gp15, and gp16 and solve the periplasmic tunnel structure at 2.7 Å resolution. We find that gp14 forms an outer membrane pore, gp15 assembles into a 210 Å hexameric DNA tube spanning the host periplasm, and gp16 extends into the host cytoplasm forming a ∼4,200 residue hub. Gp16 promotes gp15 oligomerization, coordinating peptidoglycan hydrolysis, DNA binding, and lipid insertion. The reconstituted gp15:gp16 complex lacks channel-forming activity, suggesting that the pore for DNA passage forms only transiently during genome ejection.
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Affiliation(s)
- Nicholas A Swanson
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Ravi K Lokareddy
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Fenglin Li
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Chun-Feng David Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Sebastian Leptihn
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Hangzhou, China
| | - Mikhail Pavlenok
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
| | - Ruth A Pumroy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
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14
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Kobayashi A, Takayama Y, Hirakawa T, Okajima K, Oide M, Oroguchi T, Inui Y, Yamamoto M, Matsunaga S, Nakasako M. Common architectures in cyanobacteria Prochlorococcus cells visualized by X-ray diffraction imaging using X-ray free electron laser. Sci Rep 2021; 11:3877. [PMID: 33594220 PMCID: PMC7886902 DOI: 10.1038/s41598-021-83401-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 02/02/2021] [Indexed: 11/24/2022] Open
Abstract
Visualization of intracellular structures and their spatial organization inside cells without any modification is essential to understand the mechanisms underlying the biological functions of cells. Here, we investigated the intracellular structure of cyanobacteria Prochlorococcus in the interphase by X-ray diffraction imaging using X-ray free-electron laser. A number of diffraction patterns from single cells smaller than 1 µm in size were collected with high signal-to-noise ratio with a resolution of up to 30 nm. From diffraction patterns, a set of electron density maps projected along the direction of the incident X-ray were retrieved with high reliability. The most characteristic structure found to be common among the cells was a C-shaped arrangement of 100-nm sized high-density spots, which surrounded a low-density area of 100 nm. Furthermore, a three-dimensional map reconstructed from the projection maps of individual cells was non-uniform, indicating the presence of common structures among cyanobacteria cells in the interphase. By referring to the fluorescent images for distributions of thylakoid membranes, nucleoids, and carboxysomes, we inferred and represented their spatial arrangements in the three-dimensional map. The arrangement allowed us to discuss the relevance of the intracellular organization to the biological functions of cyanobacteria.
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Affiliation(s)
- Amane Kobayashi
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Yuki Takayama
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
- Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Takeshi Hirakawa
- Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Koji Okajima
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Mao Oide
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Tomotaka Oroguchi
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Yayoi Inui
- Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Masaki Yamamoto
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Sachihiro Matsunaga
- Department of Applied Biological Science Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Masayoshi Nakasako
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan.
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan.
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15
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You S, Wang M, Jiang Y, Jiang T, Liu Y, Liu X, Yang Q, Shao H. The Genome Sequence of a Novel Cyanophage S-B64 from the Yellow Sea, China. Curr Microbiol 2019; 76:681-686. [PMID: 30949805 DOI: 10.1007/s00284-019-01680-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 03/27/2019] [Indexed: 11/25/2022]
Abstract
A novel cyanophage, S-B64, which can infect marine Synechococcus WH8102, was isolated from the coastal waters of the Yellow Sea using the liquid serial dilution method. Morphological study by transmission electron microscopy revealed that the cyanophage belongs to Podovirus. It's genome, which was completely sequenced, contains a 151,867 bp DNA molecule with a G+C content of 41.78% and 186 potential open reading frames. The functions of the genes include cyanophage structure, cyanophage packaging, DNA replication and regulation. After primary characterization, it was found that the latent period is about 3 h, and it lysed after 8 h, the burst size is about 23 virions per cell. This information will provide an important benchmark for further research on the interaction between cyanophages and their hosts.
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Affiliation(s)
- Siyuan You
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Min Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
- Key Lab of Polar Oceanography and Global Ocean Change, Ocean University of China, Qingdao, 266003, China.
| | - Yong Jiang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
- Key Lab of Polar Oceanography and Global Ocean Change, Ocean University of China, Qingdao, 266003, China.
| | - Tong Jiang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yundan Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xinxin Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Qingwei Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Hongbing Shao
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
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16
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Evans CT, Payton O, Picco L, Allen MJ. Algal Viruses: The (Atomic) Shape of Things to Come. Viruses 2018; 10:E490. [PMID: 30213102 PMCID: PMC6165301 DOI: 10.3390/v10090490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/30/2018] [Accepted: 09/07/2018] [Indexed: 01/15/2023] Open
Abstract
Visualization of algal viruses has been paramount to their study and understanding. The direct observation of the morphological dynamics of infection is a highly desired capability and the focus of instrument development across a variety of microscopy technologies. However, the high temporal (ms) and spatial resolution (nm) required, combined with the need to operate in physiologically relevant conditions presents a significant challenge. Here we present a short history of virus structure study and its relation to algal viruses and highlight current work, concentrating on electron microscopy and atomic force microscopy, towards the direct observation of individual algae⁻virus interactions. Finally, we make predictions towards future algal virus study direction with particular focus on the exciting opportunities offered by modern high-speed atomic force microscopy methods and instrumentation.
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Affiliation(s)
- Christopher T Evans
- Plymouth Marine Laboratory, Plymouth PL1 3DH, UK.
- Interface Analysis Centre, Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK.
| | - Oliver Payton
- Interface Analysis Centre, Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK.
| | - Loren Picco
- Interface Analysis Centre, Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK.
- Department of Physics, Virginia Commonwealth University, Richmond, VA 23284, USA.
| | - Michael J Allen
- Plymouth Marine Laboratory, Plymouth PL1 3DH, UK.
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.
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17
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Jin J, Galaz-Montoya JG, Sherman MB, Sun SY, Goldsmith CS, O'Toole ET, Ackerman L, Carlson LA, Weaver SC, Chiu W, Simmons G. Neutralizing Antibodies Inhibit Chikungunya Virus Budding at the Plasma Membrane. Cell Host Microbe 2018; 24:417-428.e5. [PMID: 30146390 DOI: 10.1016/j.chom.2018.07.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/05/2018] [Accepted: 07/26/2018] [Indexed: 01/29/2023]
Abstract
Neutralizing antibodies (NAbs) are traditionally thought to inhibit virus infection by preventing virion entry into target cells. In addition, antibodies can engage Fc receptors (FcRs) on immune cells to activate antiviral responses. We describe a mechanism by which NAbs inhibit chikungunya virus (CHIKV), the most common alphavirus infecting humans, by preventing virus budding from infected human cells and activating IgG-specific Fcγ receptors. NAbs bind to CHIKV glycoproteins on the infected cell surface and induce glycoprotein coalescence, preventing budding of nascent virions and leaving structurally heterogeneous nucleocapsids arrested in the cytosol. Furthermore, NAbs induce clustering of CHIKV replication spherules at sites of budding blockage. Functionally, these densely packed glycoprotein-NAb complexes on infected cells activate Fcγ receptors, inducing a strong, antibody-dependent, cell-mediated cytotoxicity response from immune effector cells. Our findings describe a triply functional antiviral pathway for NAbs that might be broadly applicable across virus-host systems, suggesting avenues for therapeutic innovation through antibody design.
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Affiliation(s)
- Jing Jin
- Blood Systems Research Institute, San Francisco, CA 94118, USA; Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Jesús G Galaz-Montoya
- Departments of Bioengineering, Microbiology and Immunology, and Photon Science, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
| | - Michael B Sherman
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Stella Y Sun
- Departments of Bioengineering, Microbiology and Immunology, and Photon Science, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
| | - Cynthia S Goldsmith
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - Eileen T O'Toole
- Boulder Laboratory for 3-D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Larry Ackerman
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Lars-Anders Carlson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå 901 87, Sweden
| | - Scott C Weaver
- Institute for Human Infections and Immunity and Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Wah Chiu
- Departments of Bioengineering, Microbiology and Immunology, and Photon Science, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
| | - Graham Simmons
- Blood Systems Research Institute, San Francisco, CA 94118, USA; Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
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18
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Stass R, Ilca SL, Huiskonen JT. Beyond structures of highly symmetric purified viral capsids by cryo-EM. Curr Opin Struct Biol 2018; 52:25-31. [PMID: 30096461 DOI: 10.1016/j.sbi.2018.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 07/24/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
Cryogenic transmission electron microscopy (cryo-EM) is widely used to determine high-resolution structures of symmetric virus capsids. The method holds promise for extending studies beyond purified capsids and their symmetric protein shells. The non-symmetric genome component has been addressed in dsRNA cypoviruses and ssRNA bacteriophages Qβ and MS2. The structure of human herpes simplex virus type 1 capsids has been determined within intact virions to resolve capsid-tegument interactions. Electron tomography under cryogenic conditions (cryo-ET), has allowed resolving an early membrane fusion intermediate of Rift Valley fever virus. Antibody-affinity based sample grids allow capturing of virions directly from cell cultures or even clinical samples. These and other emerging methods will support studies to address viral entry, assembly and neutralization processes at increasingly high resolutions and native conditions.
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Affiliation(s)
- Robert Stass
- Division of Structural Biology, Wellcome Centre for Human Genetics, Roosevelt Drive, University of Oxford, OX3 7BN Oxford, UK
| | - Serban L Ilca
- Division of Structural Biology, Wellcome Centre for Human Genetics, Roosevelt Drive, University of Oxford, OX3 7BN Oxford, UK
| | - Juha T Huiskonen
- Division of Structural Biology, Wellcome Centre for Human Genetics, Roosevelt Drive, University of Oxford, OX3 7BN Oxford, UK; Helsinki Institute of Life Science HiLIFE and Molecular and Integrative Biosciences Research Program, Faculty of Biological and Environmental Sciences, Viikinkaari 1, University of Helsinki, 00014 Helsinki, Finland.
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19
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Murata K, Kaneko Y. Visualization of DNA Compaction in Cyanobacteria by High-voltage Cryo-electron Tomography. J Vis Exp 2018. [PMID: 30080205 PMCID: PMC6126509 DOI: 10.3791/57197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol describes how to visualize the transient DNA compaction in cyanobacteria. DNA compaction is a dramatic cytoplasmic event recently found to occur in some cyanobacteria before cell division. However, due to the large cell size and the transient character, it is difficult to investigate the structure in detail. To overcome the difficulties, first, DNA compaction is reproducibly produced in the cyanobacterium Synechococcus elongatus PCC 7942 by synchronous culture using 12 h each light/dark cycle. Second, DNA compaction is monitored by fluorescence microscopy and captured by rapid freezing. Third, the detailed structure of DNA compacted cells is visualized in three dimensions (3D) by high voltage cryo-electron tomography. This set of methods is widely applicable to investigate transient structures in bacteria, e.g. cell division, chromosome segregation, phage infection etc., which are monitored by fluorescence microscopy and directly visualized by cryo-electron tomography at appropriate time points.
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Affiliation(s)
| | - Yasuko Kaneko
- Graduate School of Science and Engineering, Saitama University
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20
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Breaking Symmetry in Viral Icosahedral Capsids as Seen through the Lenses of X-ray Crystallography and Cryo-Electron Microscopy. Viruses 2018; 10:v10020067. [PMID: 29414851 PMCID: PMC5850374 DOI: 10.3390/v10020067] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 01/26/2018] [Accepted: 01/31/2018] [Indexed: 12/19/2022] Open
Abstract
The majority of viruses on Earth form capsids built by multiple copies of one or more types of a coat protein arranged with 532 symmetry, generating an icosahedral shell. This highly repetitive structure is ideal to closely pack identical protein subunits and to enclose the nucleic acid genomes. However, the icosahedral capsid is not merely a passive cage but undergoes dynamic events to promote packaging, maturation and the transfer of the viral genome into the host. These essential processes are often mediated by proteinaceous complexes that interrupt the shell’s icosahedral symmetry, providing a gateway through the capsid. In this review, we take an inventory of molecular structures observed either internally, or at the 5-fold vertices of icosahedral DNA viruses that infect bacteria, archea and eukaryotes. Taking advantage of the recent revolution in cryo-electron microscopy (cryo-EM) and building upon a wealth of crystallographic structures of individual components, we review the design principles of non-icosahedral structural components that interrupt icosahedral symmetry and discuss how these macromolecules play vital roles in genome packaging, ejection and host receptor-binding.
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21
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Furfaro LL, Chang BJ, Payne MS. Applications for Bacteriophage Therapy during Pregnancy and the Perinatal Period. Front Microbiol 2018; 8:2660. [PMID: 29375525 PMCID: PMC5768649 DOI: 10.3389/fmicb.2017.02660] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/20/2017] [Indexed: 12/19/2022] Open
Abstract
Pregnant women and their unborn children are a population that is particularly vulnerable to bacterial infection. Physiological changes that occur during pregnancy affect the way women respond to such infections and the options that clinicians have for treatment. Antibiotics are still considered the best option for active infections and a suitable prophylaxis for prevention of potential infections, such as vaginal/rectal Streptococcus agalactiae colonization prior to birth. The effect of such antibiotic use on the developing fetus, however, is still largely unknown. Recent research has suggested that the fetal gut microbiota plays a critical role in fetal immunologic programming. Hence, even minor alterations in this microbiota may have potentially significant downstream effects. An ideal antibacterial therapeutic for administration during pregnancy would be one that is highly specific for its target, leaving the surrounding microbiota intact. This review first provides a basic overview of the challenges a clinician faces when administering therapeutics to a pregnant patient and then goes on to explore common bacterial infections in pregnancy, use of antibiotics for treatment/prevention of such infections and the consequences of such treatment for the mother and infant. With this background established, the review then explores the potential for use of bacteriophage (phage) therapy as an alternative to antibiotics during the antenatal period. Many previous reviews have highlighted the revitalization of and potential for phage therapy for treatment of a range of bacterial infections, particularly in the context of the increasing threat of widespread antibiotic resistance. However, information on the potential for the use of phage therapeutics in pregnancy is lacking. This review aims to provide a thorough overview of studies of this nature and discuss the feasibility of bacteriophage use during pregnancy to treat and/or prevent bacterial infections.
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Affiliation(s)
- Lucy L. Furfaro
- Division of Obstetrics and Gynecology, School of Medicine, The University of Western Australia, Crawley, WA, Australia
| | - Barbara J. Chang
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Matthew S. Payne
- Division of Obstetrics and Gynecology, School of Medicine, The University of Western Australia, Crawley, WA, Australia
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22
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Zhao X, Tian K, He RL, Yau SST. Establishing the phylogeny of Prochlorococcus with a new alignment-free method. Ecol Evol 2017; 7:11057-11065. [PMID: 29299281 PMCID: PMC5743538 DOI: 10.1002/ece3.3535] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/04/2017] [Accepted: 09/14/2017] [Indexed: 11/11/2022] Open
Abstract
Prochlorococcus marinus, one of the most abundant marine cyanobacteria in the global ocean, is classified into low-light (LL) and high-light (HL) adapted ecotypes. These two adapted ecotypes differ in their ecophysiological characteristics, especially whether adapted for growth at high-light or low-light intensities. However, some evolutionary relationships of Prochlorococcus phylogeny remain to be resolved, such as whether the strains SS120 and MIT9211 form a monophyletic group. We use the Natural Vector (NV) method to represent the sequence in order to identify the phylogeny of the Prochlorococcus. The natural vector method is alignment free without any model assumptions. This study added the covariances of amino acids in protein sequence to the natural vector method. Based on these new natural vectors, we can compute the Hausdorff distance between the two clades which represents the dissimilarity. This method enables us to systematically analyze both the dataset of ribosomal proteomes and the dataset of 16s-23s rRNA sequences in order to reconstruct the phylogeny of Prochlorococcus. Furthermore, we apply classification to inspect the relationship of SS120 and MIT9211. From the reconstructed phylogenetic trees and classification results, we may conclude that the SS120 does not cluster with MIT9211. This study demonstrates a new method for performing phylogenetic analysis. The results confirm that these two strains do not form a monophyletic clade in the phylogeny of Prochlorococcus.
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Affiliation(s)
- Xin Zhao
- Department of Mathematical Sciences Tsinghua University Beijing China
| | - Kun Tian
- Department of Mathematical Sciences Tsinghua University Beijing China
| | - Rong L He
- Department of Biological Sciences Chicago State University Chicago IL USA
| | - Stephen S-T Yau
- Department of Mathematical Sciences Tsinghua University Beijing China
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23
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Murata K, Wolf M. Cryo-electron microscopy for structural analysis of dynamic biological macromolecules. Biochim Biophys Acta Gen Subj 2017; 1862:324-334. [PMID: 28756276 DOI: 10.1016/j.bbagen.2017.07.020] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 07/22/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Since the introduction of what became today's standard for cryo-embedding of biological macromolecules at native conditions more than 30years ago, techniques and equipment have been drastically improved and the structure of biomolecules can now be studied at near atomic resolution by cryo-electron microscopy (cryo-EM) while capturing multiple dynamic states. Here we review the recent progress in cryo-EM for structural studies of dynamic biological macromolecules. SCOPE OF REVIEW We provide an overview of the cryo-EM method and introduce contemporary studies to investigate biomolecular structure and dynamics, including examples from the recent literature. MAJOR CONCLUSIONS Cryo-EM is a powerful tool for the investigation of biological macromolecular structures including analysis of their dynamics by using advanced image-processing algorithms. The method has become even more widely applicable with present-day single particle analysis and electron tomography. GENERAL SIGNIFICANCE The cryo-EM method can be used to determine the three-dimensional structure of biomacromolecules in near native condition at close to atomic resolution, and has the potential to reveal conformations of dynamic molecular complexes. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
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Affiliation(s)
- Kazuyoshi Murata
- National Institute for Physiological Sciences, 38 Myodaiji, Okazaki, Aichi 444-8585, Japan.
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology, 7542 Onna, Onna-Son, Kunigami, Okinawa 904-0411, Japan.
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24
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Galaz-Montoya JG, Ludtke SJ. The advent of structural biology in situ by single particle cryo-electron tomography. BIOPHYSICS REPORTS 2017; 3:17-35. [PMID: 28781998 PMCID: PMC5516000 DOI: 10.1007/s41048-017-0040-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/30/2017] [Indexed: 01/06/2023] Open
Abstract
Single particle tomography (SPT), also known as subtomogram averaging, is a powerful technique uniquely poised to address questions in structural biology that are not amenable to more traditional approaches like X-ray crystallography, nuclear magnetic resonance, and conventional cryoEM single particle analysis. Owing to its potential for in situ structural biology at subnanometer resolution, SPT has been gaining enormous momentum in the last five years and is becoming a prominent, widely used technique. This method can be applied to unambiguously determine the structures of macromolecular complexes that exhibit compositional and conformational heterogeneity, both in vitro and in situ. Here we review the development of SPT, highlighting its applications and identifying areas of ongoing development.
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Affiliation(s)
- Jesús G Galaz-Montoya
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030 USA
| | - Steven J Ludtke
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030 USA
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