1
|
Dutta M, Acharya P. Cryo-electron microscopy in the study of virus entry and infection. Front Mol Biosci 2024; 11:1429180. [PMID: 39114367 PMCID: PMC11303226 DOI: 10.3389/fmolb.2024.1429180] [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: 05/07/2024] [Accepted: 06/12/2024] [Indexed: 08/10/2024] Open
Abstract
Viruses have been responsible for many epidemics and pandemics that have impacted human life globally. The COVID-19 pandemic highlighted both our vulnerability to viral outbreaks, as well as the mobilization of the scientific community to come together to combat the unprecedented threat to humanity. Cryo-electron microscopy (cryo-EM) played a central role in our understanding of SARS-CoV-2 during the pandemic and continues to inform about this evolving pathogen. Cryo-EM with its two popular imaging modalities, single particle analysis (SPA) and cryo-electron tomography (cryo-ET), has contributed immensely to understanding the structure of viruses and interactions that define their life cycles and pathogenicity. Here, we review how cryo-EM has informed our understanding of three distinct viruses, of which two - HIV-1 and SARS-CoV-2 infect humans, and the third, bacteriophages, infect bacteria. For HIV-1 and SARS-CoV-2 our focus is on the surface glycoproteins that are responsible for mediating host receptor binding, and host and cell membrane fusion, while for bacteriophages, we review their structure, capsid maturation, attachment to the bacterial cell surface and infection initiation mechanism.
Collapse
Affiliation(s)
- Moumita Dutta
- Duke Human Vaccine Institute, Durham, NC, United States
| | - Priyamvada Acharya
- Duke Human Vaccine Institute, Durham, NC, United States
- Department of Surgery, Durham, NC, United States
- Department of Biochemistry, Duke University, Durham, NC, United States
| |
Collapse
|
2
|
Koonin EV, Kuhn JH, Dolja VV, Krupovic M. Megataxonomy and global ecology of the virosphere. THE ISME JOURNAL 2024; 18:wrad042. [PMID: 38365236 PMCID: PMC10848233 DOI: 10.1093/ismejo/wrad042] [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: 11/22/2023] [Revised: 12/22/2023] [Accepted: 12/28/2023] [Indexed: 02/18/2024]
Abstract
Nearly all organisms are hosts to multiple viruses that collectively appear to be the most abundant biological entities in the biosphere. With recent advances in metagenomics and metatranscriptomics, the known diversity of viruses substantially expanded. Comparative analysis of these viruses using advanced computational methods culminated in the reconstruction of the evolution of major groups of viruses and enabled the construction of a virus megataxonomy, which has been formally adopted by the International Committee on Taxonomy of Viruses. This comprehensive taxonomy consists of six virus realms, which are aspired to be monophyletic and assembled based on the conservation of hallmark proteins involved in capsid structure formation or genome replication. The viruses in different major taxa substantially differ in host range and accordingly in ecological niches. In this review article, we outline the latest developments in virus megataxonomy and the recent discoveries that will likely lead to reassessment of some major taxa, in particular, split of three of the current six realms into two or more independent realms. We then discuss the correspondence between virus taxonomy and the distribution of viruses among hosts and ecological niches, as well as the abundance of viruses versus cells in different habitats. The distribution of viruses across environments appears to be primarily determined by the host ranges, i.e. the virome is shaped by the composition of the biome in a given habitat, which itself is affected by abiotic factors.
Collapse
Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, United States
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD 21702, United States
| | - Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, United States
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, 75015 Paris, France
| |
Collapse
|
3
|
Hawkins DEDP, Godwin OC, Antson AA. Viral Genomic DNA Packaging Machinery. Subcell Biochem 2024; 104:181-205. [PMID: 38963488 DOI: 10.1007/978-3-031-58843-3_9] [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: 07/05/2024]
Abstract
Tailed double-stranded DNA bacteriophage employs a protein terminase motor to package their genome into a preformed protein shell-a system shared with eukaryotic dsDNA viruses such as herpesviruses. DNA packaging motor proteins represent excellent targets for antiviral therapy, with Letermovir, which binds Cytomegalovirus terminase, already licensed as an effective prophylaxis. In the realm of bacterial viruses, these DNA packaging motors comprise three protein constituents: the portal protein, small terminase and large terminase. The portal protein guards the passage of DNA into the preformed protein shell and acts as a protein interaction hub throughout viral assembly. Small terminase recognises the viral DNA and recruits large terminase, which in turn pumps DNA in an ATP-dependent manner. Large terminase also cleaves DNA at the termination of packaging. Multiple high-resolution structures of each component have been resolved for different phages, but it is only more recently that the field has moved towards cryo-EM reconstructions of protein complexes. In conjunction with highly informative single-particle studies of packaging kinetics, these structures have begun to inspire models for the packaging process and its place among other DNA machines.
Collapse
Affiliation(s)
- Dorothy E D P Hawkins
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK.
| | - Owen C Godwin
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK
- Structural Biology, The Francis Crick Institute, London, UK
| | - Alfred A Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK.
- Structural Biology, The Francis Crick Institute, London, UK.
| |
Collapse
|
4
|
Rūmnieks J, Füzik T, Tārs K. Structure of the Borrelia Bacteriophage φBB1 Procapsid. J Mol Biol 2023; 435:168323. [PMID: 37866476 DOI: 10.1016/j.jmb.2023.168323] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
Bacteriophages of Borrelia burgdorferi are a biologically important but under-investigated feature of the Lyme disease-causing spirochete. No virulent borrelial viruses have been identified, but all B. burgdorferi isolates carry a prophage φBB1 as resident circular plasmids. Like its host, the φBB1 phage is quite distinctive and shares little sequence similarity with other known bacteriophages. We expressed φBB1 head morphogenesis proteins in Escherichia coli which resulted in assembly of homogeneous prolate procapsid structures and used cryo-electron microscopy to determine the three-dimensional structure of these particles. The φBB1 procapsids consist of 415 copies of the major capsid protein and an equal combined number of three homologous capsid decoration proteins that form trimeric knobs on the outside of the particle. One of the end vertices of the particle is occupied by a portal assembled from twelve copies of the portal protein. The φBB1 scaffolding protein is entirely α-helical and has an elongated shape with a small globular domain in the middle. Within the tubular section of the procapsid, the internal scaffold is built of stacked rings, each composed of 32 scaffolding protein molecules, which run in opposite directions from both caps with a heterogeneous part in the middle. Inside the portal-containing cap, the scaffold is organized asymmetrically with ten scaffolding protein molecules bound to the portal. The φBB1 procapsid structure provides better insight into the vast structural diversity of bacteriophages and presents clues of how elongated bacteriophage particles might be assembled.
Collapse
Affiliation(s)
- Jānis Rūmnieks
- Latvian Biomedical Research and Study Center, Rātsupītes 1, 1067 Riga, Latvia.
| | - Tibor Füzik
- Structural Virology, Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Kaspars Tārs
- Latvian Biomedical Research and Study Center, Rātsupītes 1, 1067 Riga, Latvia; Faculty of Biology, University of Latvia, Jelgavas 1, 1004 Riga, Latvia
| |
Collapse
|
5
|
Jia X, Gao Y, Huang Y, Sun L, Li S, Li H, Zhang X, Li Y, He J, Wu W, Venkannagari H, Yang K, Baker ML, Zhang Q. Architecture of the baculovirus nucleocapsid revealed by cryo-EM. Nat Commun 2023; 14:7481. [PMID: 37980340 PMCID: PMC10657434 DOI: 10.1038/s41467-023-43284-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 11/03/2023] [Indexed: 11/20/2023] Open
Abstract
Baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been widely used as a bioinsecticide and a protein expression vector. Despite their importance, very little is known about the structure of most baculovirus proteins. Here, we show a 3.2 Å resolution structure of helical cylindrical body of the AcMNPV nucleocapsid, composed of VP39, as well as 4.3 Å resolution structures of both the head and the base of the nucleocapsid composed of over 100 protein subunits. AcMNPV VP39 demonstrates some features of the HK97-like fold and utilizes disulfide-bonds and a set of interactions at its C-termini to mediate nucleocapsid assembly and stability. At both ends of the nucleocapsid, the VP39 cylinder is constricted by an outer shell ring composed of proteins AC104, AC142 and AC109. AC101(BV/ODV-C42) and AC144(ODV-EC27) form a C14 symmetric inner layer at both capsid head and base. In the base, these proteins interact with a 7-fold symmetric capsid plug, while a portal-like structure is seen in the central portion of head. Additionally, we propose an application of AlphaFold2 for model building in intermediate resolution density.
Collapse
Affiliation(s)
- Xudong Jia
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yuanzhu Gao
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
- Cryo-EM Facility Center, Southern University of Science and Technology, Shenzhen, China
| | - Yuxuan Huang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Linjun Sun
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Siduo Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Hongmei Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Xueqing Zhang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yinyin Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Jian He
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Wenbi Wu
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Harikanth Venkannagari
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, TX, 77030, USA
| | - Kai Yang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Matthew L Baker
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, TX, 77030, USA.
| | - Qinfen Zhang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China.
| |
Collapse
|
6
|
Podgorski JM, Freeman K, Gosselin S, Huet A, Conway JF, Bird M, Grecco J, Patel S, Jacobs-Sera D, Hatfull G, Gogarten JP, Ravantti J, White SJ. A structural dendrogram of the actinobacteriophage major capsid proteins provides important structural insights into the evolution of capsid stability. Structure 2023; 31:282-294.e5. [PMID: 36649709 PMCID: PMC10071307 DOI: 10.1016/j.str.2022.12.012] [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: 09/13/2022] [Revised: 10/31/2022] [Accepted: 12/19/2022] [Indexed: 01/19/2023]
Abstract
Many double-stranded DNA viruses, including tailed bacteriophages (phages) and herpesviruses, use the HK97-fold in their major capsid protein to make the capsomers of the icosahedral viral capsid. After the genome packaging at near-crystalline densities, the capsid is subjected to a major expansion and stabilization step that allows it to withstand environmental stresses and internal high pressure. Several different mechanisms for stabilizing the capsid have been structurally characterized, but how these mechanisms have evolved is still not understood. Using cryo-EM structure determination of 10 capsids, structural comparisons, phylogenetic analyses, and Alphafold predictions, we have constructed a detailed structural dendrogram describing the evolution of capsid structural stability within the actinobacteriophages. We show that the actinobacteriophage major capsid proteins can be classified into 15 groups based upon their HK97-fold.
Collapse
Affiliation(s)
- Jennifer M Podgorski
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Krista Freeman
- Clapp Hall, Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Sophia Gosselin
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Alexis Huet
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - James F Conway
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mary Bird
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - John Grecco
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Shreya Patel
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA
| | - Deborah Jacobs-Sera
- Clapp Hall, Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Graham Hatfull
- Clapp Hall, Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Johann Peter Gogarten
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA; Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268-3125, USA
| | - Janne Ravantti
- University of Helsinki, Molecular and Integrative Biosciences Research Programme, Helsinki, Finland
| | - Simon J White
- Biology/Physics Building, Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit-3125, Storrs, CT 06269-3125, USA.
| |
Collapse
|
7
|
Xiao H, Zhou J, Yang F, Liu Z, Song J, Chen W, Liu H, Cheng L. Assembly and Capsid Expansion Mechanism of Bacteriophage P22 Revealed by High-Resolution Cryo-EM Structures. Viruses 2023; 15:v15020355. [PMID: 36851569 PMCID: PMC9965877 DOI: 10.3390/v15020355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
The formation of many double-stranded DNA viruses, such as herpesviruses and bacteriophages, begins with the scaffolding-protein-mediated assembly of the procapsid. Subsequently, the procapsid undergoes extensive structural rearrangement and expansion to become the mature capsid. Bacteriophage P22 is an established model system used to study virus maturation. Here, we report the cryo-electron microscopy structures of procapsid, empty procapsid, empty mature capsid, and mature capsid of phage P22 at resolutions of 2.6 Å, 3.9 Å, 2.8 Å, and 3.0 Å, respectively. The structure of the procapsid allowed us to build an accurate model of the coat protein gp5 and the C-terminal region of the scaffolding protein gp8. In addition, interactions among the gp5 subunits responsible for procapsid assembly and stabilization were identified. Two C-terminal α-helices of gp8 were observed to interact with the coat protein in the procapsid. The amino acid interactions between gp5 and gp8 in the procapsid were consistent with the results of previous biochemical studies involving mutant proteins. Our structures reveal hydrogen bonds and salt bridges between the gp5 subunits in the procapsid and the conformational changes of the gp5 domains involved in the closure of the local sixfold opening and a thinner capsid shell during capsid maturation.
Collapse
Affiliation(s)
- Hao Xiao
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Junquan Zhou
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Fan Yang
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Zheng Liu
- Kobilka Institute of Innovative Drug Discovery, School of Medicine, Chinese University of Hong Kong, Shenzhen 518172, China
| | - Jingdong Song
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China
| | - Wenyuan Chen
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| | - Hongrong Liu
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| | - Lingpeng Cheng
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| |
Collapse
|
8
|
Li F, Hou CFD, Yang R, Whitehead R, Teschke CM, Cingolani G. High-resolution cryo-EM structure of the Shigella virus Sf6 genome delivery tail machine. SCIENCE ADVANCES 2022; 8:eadc9641. [PMID: 36475795 PMCID: PMC9728967 DOI: 10.1126/sciadv.adc9641] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Sf6 is a bacterial virus that infects the human pathogen Shigella flexneri. Here, we describe the cryo-electron microscopy structure of the Sf6 tail machine before DNA ejection, which we determined at a 2.7-angstrom resolution. We built de novo structures of all tail components and resolved four symmetry-mismatched interfaces. Unexpectedly, we found that the tail exists in two conformations, rotated by ~6° with respect to the capsid. The two tail conformers are identical in structure but differ solely in how the portal and head-to-tail adaptor carboxyl termini bond with the capsid at the fivefold vertex, similar to a diamond held over a five-pronged ring in two nonidentical states. Thus, in the mature Sf6 tail, the portal structure does not morph locally to accommodate the symmetry mismatch but exists in two energetic minima rotated by a discrete angle. We propose that the design principles of the Sf6 tail are conserved across P22-like Podoviridae.
Collapse
Affiliation(s)
- 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
| | - Ruoyu Yang
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Richard Whitehead
- Department of Molecular and Cell Biology, Department of Chemistry, University of Connecticut, 91 N Eagleville Road, Storrs, CT 06269, USA
| | - Carolyn M. Teschke
- Department of Molecular and Cell Biology, Department of Chemistry, University of Connecticut, 91 N Eagleville Road, Storrs, CT 06269, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| |
Collapse
|
9
|
A Capsid Structure of Ralstonia solanacearum podoviridae GP4 with a Triangulation Number T = 9. Viruses 2022; 14:v14112431. [PMID: 36366529 PMCID: PMC9698820 DOI: 10.3390/v14112431] [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: 09/30/2022] [Revised: 10/26/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
GP4, a new Ralstonia solanacearum phage, is a short-tailed phage. Few structures of Ralstonia solanacearum phages have been resolved to near-atomic resolution until now. Here, we present a 3.7 Å resolution structure of the GP4 head by cryo-electron microscopy (cryo-EM). The GP4 head contains 540 copies of major capsid protein (MCP) gp2 and 540 copies of cement protein (CP) gp1 arranged in an icosahedral shell with a triangulation number T = 9. The structures of gp2 and gp1 show a canonical HK97-like fold and an Ig-like fold, respectively. The trimeric CPs stick on the surface of the head along the quasi-threefold axis of the icosahedron generating a sandwiched three-layer electrostatic complementary potential, thereby enhancing the head stability. The assembly pattern of the GP4 head provides a platform for the further exploration of the interaction between Ralstonia solanacearum and corresponding phages.
Collapse
|
10
|
Lokareddy RK, Hou CFD, Doll SG, Li F, Gillilan RE, Forti F, Horner DS, Briani F, Cingolani G. Terminase Subunits from the Pseudomonas-Phage E217. J Mol Biol 2022; 434:167799. [PMID: 36007626 PMCID: PMC10026623 DOI: 10.1016/j.jmb.2022.167799] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022]
Abstract
Pseudomonas phages are increasingly important biomedicines for phage therapy, but little is known about how these viruses package DNA. This paper explores the terminase subunits from the Myoviridae E217, a Pseudomonas-phage used in an experimental cocktail to eradicate P. aeruginosa in vitro and in animal models. We identified the large (TerL) and small (TerS) terminase subunits in two genes ∼58 kbs away from each other in the E217 genome. TerL presents a classical two-domain architecture, consisting of an N-terminal ATPase and C-terminal nuclease domain arranged into a bean-shaped tertiary structure. A 2.05 Å crystal structure of the C-terminal domain revealed an RNase H-like fold with two magnesium ions in the nuclease active site. Mutations in TerL residues involved in magnesium coordination had a dominant-negative effect on phage growth. However, the two ions identified in the active site were too far from each other to promote two-metal-ion catalysis, suggesting a conformational change is required for nuclease activity. We also determined a 3.38 Å cryo-EM reconstruction of E217 TerS that revealed a ring-like decamer, departing from the most common nonameric quaternary structure observed thus far. E217 TerS contains both N-terminal helix-turn-helix motifs enriched in basic residues and a central channel lined with basic residues large enough to accommodate double-stranded DNA. Overexpression of TerS caused a more than a 4-fold reduction of E217 burst size, suggesting a catalytic amount of the protein is required for packaging. Together, these data expand the molecular repertoire of viral terminase subunits to Pseudomonas-phages used for phage therapy.
Collapse
Affiliation(s)
- Ravi K Lokareddy
- 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
| | - Steven G Doll
- 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
| | - Richard E Gillilan
- Macromolecular Diffraction Facility, Cornell High Energy Synchrotron Source (MacCHESS), Cornell University, 161 Synchrotron Drive, Ithaca, NY 14853, USA
| | - Francesca Forti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - David S Horner
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy.
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| |
Collapse
|
11
|
Davis CR, Backos D, Morais MC, Churchill MEA, Catalano CE. Characterization of a Primordial Major Capsid-Scaffolding Protein Complex in Icosahedral Virus Shell Assembly. J Mol Biol 2022; 434:167719. [PMID: 35820453 DOI: 10.1016/j.jmb.2022.167719] [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: 02/26/2022] [Revised: 06/07/2022] [Accepted: 07/06/2022] [Indexed: 12/15/2022]
Abstract
Capsid assembly pathways are strongly conserved in the complex dsDNA viruses, where major capsid proteins (MCP) self-assemble into icosahedral procapsid shells, chaperoned by a scaffolding protein. Without a scaffold, the capsid proteins aggregate and form aberrant structures. This, coupled with the rapid co-polymerization of MCP and scaffolding proteins, has thwarted characterization of the earliest steps in shell assembly. Here we interrogate the structure and biophysical properties of a soluble, assembly-deficient phage lambda major capsid protein, MCP(W308A). The mutant protein is folded, soluble to high concentrations and binds to the scaffolding protein in an apparent SP2:MCP(W308A)1 stoichiometry but does not assemble beyond this initiating complex. The MCP(W308A) crystal structure was solved to 2.7 Å revealing the canonical HK97 fold in a "pre-assembly" conformation featuring the conserved N-arm and E-loops folded into the body of the protein. Structural, biophysical and computational analyses suggest that MCP(W308A) is thermodynamically trapped in this pre-assembly conformation precluding self-association interactions required for shell assembly. A model is described wherein dynamic interactions between MCP proteins play an essential role in high fidelity viral shell assembly. Scaffold-chaperoned MCP polymerization is a strongly conserved process in all the large dsDNA viruses and our results provide insight into this primordial complex in solution and have broad biological significance in our understanding of virus assembly mechanisms.
Collapse
Affiliation(s)
- Christal R Davis
- Program in Structural Biology and Biochemistry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Donald Backos
- Department of Pharmaceutical Chemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Marc C Morais
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Mair E A Churchill
- Program in Structural Biology and Biochemistry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Carlos E Catalano
- Program in Structural Biology and Biochemistry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmaceutical Chemistry, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
12
|
Lokareddy RK, Hou CFD, Li F, Yang R, Cingolani G. Viral Small Terminase: A Divergent Structural Framework for a Conserved Biological Function. Viruses 2022; 14:v14102215. [PMID: 36298770 PMCID: PMC9611059 DOI: 10.3390/v14102215] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 11/07/2022] Open
Abstract
The genome packaging motor of bacteriophages and herpesviruses is built by two terminase subunits, known as large (TerL) and small (TerS), both essential for viral genome packaging. TerL structure, composition, and assembly to an empty capsid, as well as the mechanisms of ATP-dependent DNA packaging, have been studied in depth, shedding light on the chemo-mechanical coupling between ATP hydrolysis and DNA translocation. Instead, significantly less is known about the small terminase subunit, TerS, which is dispensable or even inhibitory in vitro, but essential in vivo. By taking advantage of the recent revolution in cryo-electron microscopy (cryo-EM) and building upon a wealth of crystallographic structures of phage TerSs, in this review, we take an inventory of known TerSs studied to date. Our analysis suggests that TerS evolved and diversified into a flexible molecular framework that can conserve biological function with minimal sequence and quaternary structure conservation to fit different packaging strategies and environmental conditions.
Collapse
|
13
|
Fang Q, Tang WC, Fokine A, Mahalingam M, Shao Q, Rossmann MG, Rao VB. Structures of a large prolate virus capsid in unexpanded and expanded states generate insights into the icosahedral virus assembly. Proc Natl Acad Sci U S A 2022; 119:e2203272119. [PMID: 36161892 PMCID: PMC9546572 DOI: 10.1073/pnas.2203272119] [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: 02/27/2022] [Accepted: 08/31/2022] [Indexed: 11/18/2022] Open
Abstract
Many icosahedral viruses assemble proteinaceous precursors called proheads or procapsids. Proheads are metastable structures that undergo a profound structural transition known as expansion that transforms an immature unexpanded head into a mature genome-packaging head. Bacteriophage T4 is a model virus, well studied genetically and biochemically, but its structure determination has been challenging because of its large size and unusually prolate-shaped, ∼1,200-Å-long and ∼860-Å-wide capsid. Here, we report the cryogenic electron microscopy (cryo-EM) structures of T4 capsid in both of its major conformational states: unexpanded at a resolution of 5.1 Å and expanded at a resolution of 3.4 Å. These are among the largest structures deposited in Protein Data Bank to date and provide insights into virus assembly, head length determination, and shell expansion. First, the structures illustrate major domain movements and ∼70% additional gain in inner capsid volume, an essential transformation to contain the entire viral genome. Second, intricate intracapsomer interactions involving a unique insertion domain dramatically change, allowing the capsid subunits to rotate and twist while the capsomers remain fastened at quasi-threefold axes. Third, high-affinity binding sites emerge for a capsid decoration protein that clamps adjacent capsomers, imparting extraordinary structural stability. Fourth, subtle conformational changes at capsomers' periphery modulate intercapsomer angles between capsomer planes that control capsid length. Finally, conformational changes were observed at the symmetry-mismatched portal vertex, which might be involved in triggering head expansion. These analyses illustrate how small changes in local capsid subunit interactions lead to profound shifts in viral capsid morphology, stability, and volume.
Collapse
Affiliation(s)
- Qianglin Fang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
- School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Wei-Chun Tang
- Bacteriophage Medical Research Center, Department of Biology, The Catholic University of America, Washington, DC 20064
| | - Andrei Fokine
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | - Marthandan Mahalingam
- Bacteriophage Medical Research Center, Department of Biology, The Catholic University of America, Washington, DC 20064
| | - Qianqian Shao
- School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Michael G. Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | - Venigalla B. Rao
- Bacteriophage Medical Research Center, Department of Biology, The Catholic University of America, Washington, DC 20064
| |
Collapse
|
14
|
Tail proteins of phage SU10 reorganize into the nozzle for genome delivery. Nat Commun 2022; 13:5622. [PMID: 36153309 PMCID: PMC9509320 DOI: 10.1038/s41467-022-33305-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 09/12/2022] [Indexed: 12/23/2022] Open
Abstract
Escherichia coli phage SU10 belongs to the genus Kuravirus from the class Caudoviricetes of phages with short non-contractile tails. In contrast to other short-tailed phages, the tails of Kuraviruses elongate upon cell attachment. Here we show that the virion of SU10 has a prolate head, containing genome and ejection proteins, and a tail, which is formed of portal, adaptor, nozzle, and tail needle proteins and decorated with long and short fibers. The binding of the long tail fibers to the receptors in the outer bacterial membrane induces the straightening of nozzle proteins and rotation of short tail fibers. After the re-arrangement, the nozzle proteins and short tail fibers alternate to form a nozzle that extends the tail by 28 nm. Subsequently, the tail needle detaches from the nozzle proteins and five types of ejection proteins are released from the SU10 head. The nozzle with the putative extension formed by the ejection proteins enables the delivery of the SU10 genome into the bacterial cytoplasm. It is likely that this mechanism of genome delivery, involving the formation of the tail nozzle, is employed by all Kuraviruses. E. coli phage SU10 has a short non-contractile tail. Here, the authors show that after cell binding, nozzle proteins and tail fibers of SU10 change conformation to form a nozzle that enables the delivery of the phage DNA into the bacterial cytoplasm.
Collapse
|
15
|
Fung HKH, Grimes S, Huet A, Duda RL, Chechik M, Gault J, Robinson C, Hendrix R, Jardine P, Conway J, Baumann C, Antson A. Structural basis of DNA packaging by a ring-type ATPase from an archetypal viral system. Nucleic Acids Res 2022; 50:8719-8732. [PMID: 35947691 PMCID: PMC9410871 DOI: 10.1093/nar/gkac647] [Citation(s) in RCA: 4] [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: 05/03/2022] [Revised: 07/06/2022] [Accepted: 07/24/2022] [Indexed: 12/24/2022] Open
Abstract
Many essential cellular processes rely on substrate rotation or translocation by a multi-subunit, ring-type NTPase. A large number of double-stranded DNA viruses, including tailed bacteriophages and herpes viruses, use a homomeric ring ATPase to processively translocate viral genomic DNA into procapsids during assembly. Our current understanding of viral DNA packaging comes from three archetypal bacteriophage systems: cos, pac and phi29. Detailed mechanistic understanding exists for pac and phi29, but not for cos. Here, we reconstituted in vitro a cos packaging system based on bacteriophage HK97 and provided a detailed biochemical and structural description. We used a photobleaching-based, single-molecule assay to determine the stoichiometry of the DNA-translocating ATPase large terminase. Crystal structures of the large terminase and DNA-recruiting small terminase, a first for a biochemically defined cos system, reveal mechanistic similarities between cos and pac systems. At the same time, mutational and biochemical analyses indicate a new regulatory mechanism for ATPase multimerization and coordination in the HK97 system. This work therefore establishes a framework for studying the evolutionary relationships between ATP-dependent DNA translocation machineries in double-stranded DNA viruses.
Collapse
Affiliation(s)
- Herman K H Fung
- Department of Biology, University of York, York, YO10 5DD, UK
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Shelley Grimes
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alexis Huet
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Robert L Duda
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Maria Chechik
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Joseph Gault
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Roger W Hendrix
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Paul J Jardine
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - James F Conway
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | | | - Alfred A Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, UK
| |
Collapse
|
16
|
David Hou CF, Swanson NA, Li F, Yang R, Lokareddy RK, Cingolani G. Cryo-EM structure of a kinetically trapped dodecameric portal protein from the Pseudomonas-phage PaP3. J Mol Biol 2022; 434:167537. [DOI: 10.1016/j.jmb.2022.167537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/09/2022] [Accepted: 03/04/2022] [Indexed: 10/18/2022]
|
17
|
Wang C, Zeng J, Wang J. Structural basis of bacteriophage lambda capsid maturation. Structure 2022; 30:637-645.e3. [PMID: 35026161 DOI: 10.1016/j.str.2021.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/12/2021] [Accepted: 12/15/2021] [Indexed: 01/10/2023]
Abstract
Bacteriophage lambda is an excellent model system for studying capsid assembly of double-stranded DNA (dsDNA) bacteriophages, some dsDNA archaeal viruses, and herpesviruses. HK97 fold coat proteins initially assemble into a precursor capsid (procapsid) and subsequent genome packaging triggers morphological expansion of the shell. An auxiliary protein is required to stabilize the expanded capsid structure. To investigate the capsid maturation mechanism, we determined the cryo-electron microscopy structures of the bacteriophage lambda procapsid and mature capsid at 3.88 Å and 3.76 Å resolution, respectively. Besides primarily rigid body movements of common features of the major capsid protein gpE, large-scale structural rearrangements of other domains occur simultaneously. Assembly of intercapsomers within the procapsid is facilitated by layer-stacking effects at 3-fold vertices. Upon conformational expansion of the capsid shell, the missing top layer is fulfilled by cementing the gpD protein against the internal pressure of DNA packaging. Our structures illuminate the assembly mechanisms of dsDNA viruses.
Collapse
Affiliation(s)
- Chang Wang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, P. R. China
| | - Jianwei Zeng
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, P. R. China.
| | - Jiawei Wang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, P. R. China.
| |
Collapse
|
18
|
Predicting the capsid architecture of phages from metagenomic data. Comput Struct Biotechnol J 2022; 20:721-732. [PMID: 35140890 PMCID: PMC8814770 DOI: 10.1016/j.csbj.2021.12.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 12/29/2022] Open
Abstract
Tailed phages are viruses that infect bacteria and are the most abundant biological entities on Earth. Their ecological, evolutionary, and biogeochemical roles in the planet stem from their genomic diversity. Known tailed phage genomes range from 10 to 735 kilobase pairs thanks to the size variability of the protective protein capsids that store them. However, the role of tailed phage capsids’ diversity in ecosystems is unclear. A fundamental gap is the difficulty of associating genomic information with viral capsids in the environment. To address this problem, here, we introduce a computational approach to predict the capsid architecture (T-number) of tailed phages using the sequence of a single gene—the major capsid protein. This approach relies on an allometric model that relates the genome length and capsid architecture of tailed phages. This allometric model was applied to isolated phage genomes to generate a library that associated major capsid proteins and putative capsid architectures. This library was used to train machine learning methods, and the most computationally scalable model investigated (random forest) was applied to human gut metagenomes. Compared to isolated phages, the analysis of gut data reveals a large abundance of mid-sized (T = 7) capsids, as expected, followed by a relatively large frequency of jumbo-like tailed phage capsids (T ≥ 25) and small capsids (T = 4) that have been under-sampled. We discussed how to increase the method’s accuracy and how to extend the approach to other viruses. The computational pipeline introduced here opens the doors to monitor the ongoing evolution and selection of viral capsids across ecosystems.
Collapse
|
19
|
Cryo-EM Structures of Two Bacteriophage Portal Proteins Provide Insights for Antimicrobial Phage Engineering. Viruses 2021; 13:v13122532. [PMID: 34960800 PMCID: PMC8703570 DOI: 10.3390/v13122532] [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: 09/30/2021] [Revised: 12/07/2021] [Accepted: 12/10/2021] [Indexed: 11/17/2022] Open
Abstract
Widespread antibiotic resistance has returned attention to bacteriophages as a means of managing bacterial pathogenesis. Synthetic biology approaches to engineer phages have demonstrated genomic editing to broaden natural host ranges, or to optimise microbicidal action. Gram positive pathogens cause serious pastoral animal and human infections that are especially lethal in newborns. Such pathogens are targeted by the obligate lytic phages of the Salasmaviridae and Guelinviridae families. These phages have relatively small ~20 kb linear protein-capped genomes and their compact organisation, relatively few structural elements, and broad host range, are appealing from a phage-engineering standpoint. In this study, we focus on portal proteins, which are core elements for the assembly of such tailed phages. The structures of dodecameric portal complexes from Salasmaviridae phage GA1, which targets Bacillus pumilus, and Guelinviridae phage phiCPV4 that infects Clostridium perfringens, were determined at resolutions of 3.3 Å and 2.9 Å, respectively. Both are found to closely resemble the related phi29 portal protein fold. However, the portal protein of phiCPV4 exhibits interesting differences in the clip domain. These structures provide new insights on structural diversity in Caudovirales portal proteins and will be essential for considerations in phage structural engineering.
Collapse
|
20
|
Cui N, Yang F, Zhang JT, Sun H, Chen Y, Yu RC, Chen ZP, Jiang YL, Han SJ, Xu X, Li Q, Zhou CZ. Capsid Structure of Anabaena Cyanophage A-1(L). J Virol 2021; 95:e0135621. [PMID: 34549983 PMCID: PMC8610606 DOI: 10.1128/jvi.01356-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/19/2021] [Indexed: 01/09/2023] Open
Abstract
A-1(L) is a freshwater cyanophage with a contractile tail that specifically infects Anabaena sp. PCC 7120, one of the model strains for molecular studies of cyanobacteria. Although isolated for half a century, its structure remains unknown, which limits our understanding on the interplay between A-1(L) and its host. Here we report the 3.35 Å cryo-EM structure of A-1(L) capsid, representing the first near-atomic resolution structure of a phage capsid with a T number of 9. The major capsid gp4 proteins assemble into 91 capsomers, including 80 hexons: 20 at the center of the facet and 60 at the facet edge, in addition to 11 identical pentons. These capsomers further assemble into the icosahedral capsid, via gradually increasing curvatures. Different from the previously reported capsids of known-structure, A-1(L) adopts a noncovalent chainmail structure of capsid stabilized by two kinds of mortise-and-tenon inter-capsomer interactions: a three-layered interface at the pseudo 3-fold axis combined with the complementarity in shape and electrostatic potential around the 2-fold axis. This unique capsomer construction enables A-1(L) to possess a rigid capsid, which is solely composed of the major capsid proteins with an HK97 fold. IMPORTANCE Cyanobacteria are the most abundant photosynthetic bacteria, contributing significantly to the biomass production, O2 generation, and CO2 consumption on our planet. Their community structure and homeostasis in natural aquatic ecosystems are largely regulated by the corresponding cyanophages. In this study, we solved the structure of cyanophage A-1(L) capsid at near-atomic resolution and revealed a unique capsid construction. This capsid structure provides the molecular details for better understanding the assembly of A-1(L), and a structural platform for future investigation and application of A-1(L) in combination with its host Anabaena sp. PCC 7120. As the first isolated freshwater cyanophage that infects the genetically tractable model cyanobacterium, A-1(L) should become an ideal template for the genetic engineering and synthetic biology studies.
Collapse
Affiliation(s)
- Ning Cui
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Feng Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Jun-Tao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Hui Sun
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Yu Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Rong-Cheng Yu
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Zhi-Peng Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Shu-Jing Han
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Xudong Xu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Qiong Li
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| |
Collapse
|
21
|
Zhang JT, Yang F, Du K, Li WF, Chen Y, Jiang YL, Li Q, Zhou CZ. Structure and assembly pattern of a freshwater short-tailed cyanophage Pam1. Structure 2021; 30:240-251.e4. [PMID: 34727518 DOI: 10.1016/j.str.2021.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/18/2021] [Accepted: 10/08/2021] [Indexed: 11/19/2022]
Abstract
Despite previous structural analyses of bacteriophages, quite little is known about the structures and assembly patterns of cyanophages. Using cryo-EM combined with crystallography, we solve the near-atomic-resolution structure of a freshwater short-tailed cyanophage, Pam1, which comprises a 400-Å-long tail and an icosahedral capsid of 650 Å in diameter. The outer capsid surface is reinforced by trimeric cement proteins with a β-sandwich fold, which structurally resemble the distal motif of Pam1's tailspike, suggesting its potential role in host recognition. At the portal vertex, the dodecameric portal and connected adaptor, followed by a hexameric needle head, form a DNA ejection channel, which is sealed by a trimeric needle. Moreover, we identify a right-handed rifling pattern that might help DNA to revolve along the wall of the ejection channel. Our study reveals the precise assembly pattern of a cyanophage and lays the foundation to support its practical biotechnological and environmental applications.
Collapse
Affiliation(s)
- Jun-Tao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Feng Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Kang Du
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Wei-Fang Li
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yuxing Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Qiong Li
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| |
Collapse
|
22
|
High Resolution Structure of the Mature Capsid of Ralstonia solanacearum Bacteriophage ϕRSA1 by Cryo-Electron Microscopy. Int J Mol Sci 2021; 22:ijms222011053. [PMID: 34681713 PMCID: PMC8538268 DOI: 10.3390/ijms222011053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 12/16/2022] Open
Abstract
The ϕRSA1 bacteriophage has been isolated from Ralstonia solanacearum, a gram negative bacteria having a significant economic impact on many important crops. We solved the three-dimensional structure of the ϕRSA1 mature capsid to 3.9 Å resolution by cryo-electron microscopy. The capsid shell, that contains the 39 kbp of dsDNA genome, has an icosahedral symmetry characterized by an unusual triangulation number of T = 7, dextro. The ϕRSA1 capsid is composed solely of the polymerization of the major capsid protein, gp8, which exhibits the typical “Johnson” fold first characterized in E. coli bacteriophage HK97. As opposed to the latter, the ϕRSA1 mature capsid is not stabilized by covalent crosslinking between its subunits, nor by the addition of a decoration protein. We further describe the molecular interactions occurring between the subunits of the ϕRSA1 capsid and their relationships with the other known bacteriophages.
Collapse
|
23
|
Rao VB, Fokine A, Fang Q. The remarkable viral portal vertex: structure and a plausible model for mechanism. Curr Opin Virol 2021; 51:65-73. [PMID: 34619513 DOI: 10.1016/j.coviro.2021.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 08/23/2021] [Accepted: 09/12/2021] [Indexed: 01/20/2023]
Abstract
Many icosahedral viruses including tailed bacteriophages and herpes viruses have a unique portal vertex where a dodecameric protein ring is associated with a fivefold capsid shell. While the peripheral regions of the portal ring are involved in capsid assembly, its central channel is used to transport DNA into and out of capsid during genome packaging and infection. Though the atomic structure of this highly conserved, turbine-shaped, portal is known for nearly two decades, its molecular mechanism remains a mystery. Recent high-resolution in situ structures reveal various conformational states of the portal and the asymmetric interactions between the 12-fold portal and the fivefold capsid. These lead to a valve-like mechanism for this symmetry-mismatched portal vertex that regulates DNA flow through the channel, a critical function for high fidelity assembly of an infectious virion.
Collapse
Affiliation(s)
- Venigalla B Rao
- Bacteriophage Medical Research Center, Department of Biology, The Catholic University of America, Washington, DC 20064, USA.
| | - Andrei Fokine
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Qianglin Fang
- School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, Guangdong, China
| |
Collapse
|
24
|
Mo Y, Keller N, delToro D, Ananthaswamy N, Harvey SC, Rao VB, Smith DE. Function of a viral genome packaging motor from bacteriophage T4 is insensitive to DNA sequence. Nucleic Acids Res 2021; 48:11602-11614. [PMID: 33119757 PMCID: PMC7672480 DOI: 10.1093/nar/gkaa875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/12/2020] [Accepted: 09/29/2020] [Indexed: 01/20/2023] Open
Abstract
Many viruses employ ATP-powered motors during assembly to translocate DNA into procapsid shells. Previous reports raise the question if motor function is modulated by substrate DNA sequence: (i) the phage T4 motor exhibits large translocation rate fluctuations and pauses and slips; (ii) evidence suggests that the phage phi29 motor contacts DNA bases during translocation; and (iii) one theoretical model, the ‘B-A scrunchworm’, predicts that ‘A-philic’ sequences that transition more easily to A-form would alter motor function. Here, we use single-molecule optical tweezers measurements to compare translocation of phage, plasmid, and synthetic A-philic, GC rich sequences by the T4 motor. We observed no significant differences in motor velocities, even with A-philic sequences predicted to show higher translocation rate at high applied force. We also observed no significant changes in motor pausing and only modest changes in slipping. To more generally test for sequence dependence, we conducted correlation analyses across pairs of packaging events. No significant correlations in packaging rate, pausing or slipping versus sequence position were detected across repeated measurements with several different DNA sequences. These studies suggest that viral genome packaging is insensitive to DNA sequence and fluctuations in packaging motor velocity, pausing and slipping are primarily stochastic temporal events.
Collapse
Affiliation(s)
- Youbin Mo
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nicholas Keller
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Damian delToro
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Neeti Ananthaswamy
- Department of Biology, The Catholic University of America, District of Columbia, 20064, USA
| | - Stephen C Harvey
- Department of Biochemistry and Biophysics, Univ. of Pennsylvania, Philadelphia, PA 19104, USA
| | - Venigalla B Rao
- Department of Biology, The Catholic University of America, District of Columbia, 20064, USA
| | - Douglas E Smith
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
25
|
Niazi M, Florio TJ, Yang R, Lokareddy RK, Swanson NA, Gillilan RE, Cingolani G. Biophysical analysis of Pseudomonas-phage PaP3 small terminase suggests a mechanism for sequence-specific DNA-binding by lateral interdigitation. Nucleic Acids Res 2020; 48:11721-11736. [PMID: 33125059 PMCID: PMC7672466 DOI: 10.1093/nar/gkaa866] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 09/19/2020] [Accepted: 10/21/2020] [Indexed: 12/17/2022] Open
Abstract
The genome packaging motor of tailed bacteriophages and herpesviruses is a powerful nanomachine built by several copies of a large (TerL) and a small (TerS) terminase subunit. The motor assembles transiently at the portal vertex of an empty precursor capsid (or procapsid) to power genome encapsidation. Terminase subunits have been studied in-depth, especially in classical bacteriophages that infect Escherichia coli or Salmonella, yet, less is known about the packaging motor of Pseudomonas-phages that have increasing biomedical relevance. Here, we investigated the small terminase subunit from three Podoviridae phages that infect Pseudomonas aeruginosa. We found TerS is polymorphic in solution but assembles into a nonamer in its high-affinity heparin-binding conformation. The atomic structure of Pseudomonas phage PaP3 TerS, the first complete structure for a TerS from a cos phage, reveals nine helix-turn-helix (HTH) motifs asymmetrically arranged around a β-stranded channel, too narrow to accommodate DNA. PaP3 TerS binds DNA in a sequence-specific manner in vitro. X-ray scattering and molecular modeling suggest TerS adopts an open conformation in solution, characterized by dynamic HTHs that move around an oligomerization core, generating discrete binding crevices for DNA. We propose a model for sequence-specific recognition of packaging initiation sites by lateral interdigitation of DNA.
Collapse
Affiliation(s)
- Marzia Niazi
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Tyler J Florio
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Ruoyu Yang
- 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
| | - Nicholas A Swanson
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Richard E Gillilan
- Macromolecular Diffraction Facility, Cornell High Energy Synchrotron Source (MacCHESS), Cornell University, 161 Synchrotron Drive, Ithaca, NY 14853, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| |
Collapse
|
26
|
Dedeo CL, Teschke CM, Alexandrescu AT. Keeping It Together: Structures, Functions, and Applications of Viral Decoration Proteins. Viruses 2020; 12:v12101163. [PMID: 33066635 PMCID: PMC7602432 DOI: 10.3390/v12101163] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 12/14/2022] Open
Abstract
Decoration proteins are viral accessory gene products that adorn the surfaces of some phages and viral capsids, particularly tailed dsDNA phages. These proteins often play a "cementing" role, reinforcing capsids against accumulating internal pressure due to genome packaging, or environmental insults such as extremes of temperature or pH. Many decoration proteins serve alternative functions, including target cell recognition, participation in viral assembly, capsid size determination, or modulation of host gene expression. Examples that currently have structures characterized to high-resolution fall into five main folding motifs: β-tulip, β-tadpole, OB-fold, Ig-like, and a rare knotted α-helical fold. Most of these folding motifs have structure homologs in virus and target cell proteins, suggesting horizontal gene transfer was important in their evolution. Oligomerization states of decoration proteins range from monomers to trimers, with the latter most typical. Decoration proteins bind to a variety of loci on capsids that include icosahedral 2-, 3-, and 5-fold symmetry axes, as well as pseudo-symmetry sites. These binding sites often correspond to "weak points" on the capsid lattice. Because of their unique abilities to bind virus surfaces noncovalently, decoration proteins are increasingly exploited for technology, with uses including phage display, viral functionalization, vaccination, and improved nanoparticle design for imaging and drug delivery. These applications will undoubtedly benefit from further advances in our understanding of these versatile augmenters of viral functions.
Collapse
|
27
|
The Mottled Capsid of the Salmonella Giant Phage SPN3US, a Likely Maturation Intermediate with a Novel Internal Shell. Viruses 2020; 12:v12090910. [PMID: 32825132 PMCID: PMC7552025 DOI: 10.3390/v12090910] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/13/2020] [Accepted: 08/18/2020] [Indexed: 12/29/2022] Open
Abstract
“Giant” phages have genomes of >200 kbp, confined in correspondingly large capsids whose assembly and maturation are still poorly understood. Nevertheless, the first assembly product is likely to be, as in other tailed phages, a procapsid that subsequently matures and packages the DNA. The associated transformations include the cleavage of many proteins by the phage-encoded protease, as well as the thinning and angularization of the capsid. We exploited an amber mutation in the viral protease gene of the Salmonella giant phage SPN3US, which leads to the accumulation of a population of capsids with distinctive properties. Cryo-electron micrographs reveal patterns of internal density different from those of the DNA-filled heads of virions, leading us to call them “mottled capsids”. Reconstructions show an outer shell with T = 27 symmetry, an embellishment of the HK97 prototype composed of the major capsid protein, gp75, which is similar to some other giant viruses. The mottled capsid has a T = 1 inner icosahedral shell that is a complex network of loosely connected densities composed mainly of the ejection proteins gp53 and gp54. Segmentation of this inner shell indicated that a number of densities (~12 per asymmetric unit) adopt a “twisted hook” conformation. Large patches of a proteinaceous tetragonal lattice with a 67 Å repeat were also present in the cell lysate. The unexpected nature of these novel inner shell and lattice structures poses questions as to their functions in virion assembly.
Collapse
|
28
|
Dou T, Li Z, Zhang J, Evilevitch A, Kurouski D. Nanoscale Structural Characterization of Individual Viral Particles Using Atomic Force Microscopy Infrared Spectroscopy (AFM-IR) and Tip-Enhanced Raman Spectroscopy (TERS). Anal Chem 2020; 92:11297-11304. [PMID: 32683857 DOI: 10.1021/acs.analchem.0c01971] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Viruses are infections species that infect a large spectrum of living systems. Although displaying a wide variety of shapes and sizes, they are all composed of nucleic acid encapsulated into a protein capsid. After virions enter the host cell, they replicate to produce multiple copies of themselves. They then lyse the host, releasing virions to infect new cells. The high proliferation rate of viruses is the underlying cause of their fast transmission among living species. Although many viruses are harmless, some of them are responsible for severe diseases such as AIDS, viral hepatitis, and flu. Traditionally, electron microscopy is used to identify and characterize viruses. This approach is time- and labor-consuming, which is problematic upon pandemic proliferation of previously unknown viruses, such as H1N1 and COVID-19. Herein, we demonstrate a novel diagnosis approach for label-free identification and structural characterization of individual viruses that is based on a combination of nanoscale Raman and infrared spectroscopy. Using atomic force microscopy-infrared (AFM-IR) spectroscopy, we were able to probe structural organization of the virions of Herpes Simplex Type 1 viruses and bacteriophage MS2. We also showed that tip-enhanced Raman spectroscopy (TERS) could be used to reveal protein secondary structure and amino acid composition of the virus surface. Our results show that AFM-IR and TERS provide different but complementary information about the structure of complex biological specimens. This structural information can be used for fast and reliable identification of viruses. This nanoscale bimodal imaging approach can be also used to investigate the origin of viral polymorphism and study mechanisms of virion assembly.
Collapse
Affiliation(s)
- Tianyi Dou
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Zhandong Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States.,Center for Phage Technology, Texas A&M University, College Station, Texas 77843, United States
| | - Alex Evilevitch
- Department of Experimental Medical Science, Virus Biophysics Group, BMC Biomedical Center, Lund University, Lund, SE-221 00S, Sweden
| | - Dmitry Kurouski
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| |
Collapse
|
29
|
Hardy JM, Dunstan RA, Grinter R, Belousoff MJ, Wang J, Pickard D, Venugopal H, Dougan G, Lithgow T, Coulibaly F. The architecture and stabilisation of flagellotropic tailed bacteriophages. Nat Commun 2020; 11:3748. [PMID: 32719311 PMCID: PMC7385642 DOI: 10.1038/s41467-020-17505-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 07/01/2020] [Indexed: 12/31/2022] Open
Abstract
Flagellotropic bacteriophages engage flagella to reach the bacterial surface as an effective means to increase the capture radius for predation. Structural details of these viruses are of great interest given the substantial drag forces and torques they face when moving down the spinning flagellum. We show that the main capsid and auxiliary proteins form two nested chainmails that ensure the integrity of the bacteriophage head. Core stabilising structures are conserved in herpesviruses suggesting their ancestral origin. The structure of the tail also reveals a robust yet pliable assembly. Hexameric rings of the tail-tube protein are braced by the N-terminus and a β-hairpin loop, and interconnected along the tail by the splayed β-hairpins. By contrast, we show that the β-hairpin has an inhibitory role in the tail-tube precursor, preventing uncontrolled self-assembly. Dyads of acidic residues inside the tail-tube present regularly-spaced motifs well suited to DNA translocation into bacteria through the tail.
Collapse
Affiliation(s)
- Joshua M Hardy
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Rhys A Dunstan
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Rhys Grinter
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Matthew J Belousoff
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Jiawei Wang
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Derek Pickard
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Hariprasad Venugopal
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC, Australia
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Trevor Lithgow
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Microbiology, Monash University, Clayton, VIC, Australia.
| | - Fasséli Coulibaly
- Infection & Immunity Program, Biomedicine Discovery Institute & Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
| |
Collapse
|
30
|
Bárdy P, Füzik T, Hrebík D, Pantůček R, Thomas Beatty J, Plevka P. Structure and mechanism of DNA delivery of a gene transfer agent. Nat Commun 2020; 11:3034. [PMID: 32541663 PMCID: PMC7296036 DOI: 10.1038/s41467-020-16669-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/17/2020] [Indexed: 11/09/2022] Open
Abstract
Alphaproteobacteria, which are the most abundant microorganisms of temperate oceans, produce phage-like particles called gene transfer agents (GTAs) that mediate lateral gene exchange. However, the mechanism by which GTAs deliver DNA into cells is unknown. Here we present the structure of the GTA of Rhodobacter capsulatus (RcGTA) and describe the conformational changes required for its DNA ejection. The structure of RcGTA resembles that of a tailed phage, but it has an oblate head shortened in the direction of the tail axis, which limits its packaging capacity to less than 4,500 base pairs of linear double-stranded DNA. The tail channel of RcGTA contains a trimer of proteins that possess features of both tape measure proteins of long-tailed phages from the family Siphoviridae and tail needle proteins of short-tailed phages from the family Podoviridae. The opening of a constriction within the RcGTA baseplate enables the ejection of DNA into bacterial periplasm.
Collapse
Affiliation(s)
- Pavol Bárdy
- Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
| | - Tibor Füzik
- Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Dominik Hrebík
- Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic
| | - Roman Pantůček
- Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
| | - J Thomas Beatty
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, V6T 1Z3, BC, Canada
| | - Pavel Plevka
- Central European Institute of Technology, Masaryk University, 625 00, Brno, Czech Republic.
| |
Collapse
|
31
|
Koonin EV, Dolja VV, Krupovic M, Varsani A, Wolf YI, Yutin N, Zerbini FM, Kuhn JH. Global Organization and Proposed Megataxonomy of the Virus World. Microbiol Mol Biol Rev 2020; 84:e00061-19. [PMID: 32132243 PMCID: PMC7062200 DOI: 10.1128/mmbr.00061-19] [Citation(s) in RCA: 324] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Viruses and mobile genetic elements are molecular parasites or symbionts that coevolve with nearly all forms of cellular life. The route of virus replication and protein expression is determined by the viral genome type. Comparison of these routes led to the classification of viruses into seven "Baltimore classes" (BCs) that define the major features of virus reproduction. However, recent phylogenomic studies identified multiple evolutionary connections among viruses within each of the BCs as well as between different classes. Due to the modular organization of virus genomes, these relationships defy simple representation as lines of descent but rather form complex networks. Phylogenetic analyses of virus hallmark genes combined with analyses of gene-sharing networks show that replication modules of five BCs (three classes of RNA viruses and two classes of reverse-transcribing viruses) evolved from a common ancestor that encoded an RNA-directed RNA polymerase or a reverse transcriptase. Bona fide viruses evolved from this ancestor on multiple, independent occasions via the recruitment of distinct cellular proteins as capsid subunits and other structural components of virions. The single-stranded DNA (ssDNA) viruses are a polyphyletic class, with different groups evolving by recombination between rolling-circle-replicating plasmids, which contributed the replication protein, and positive-sense RNA viruses, which contributed the capsid protein. The double-stranded DNA (dsDNA) viruses are distributed among several large monophyletic groups and arose via the combination of distinct structural modules with equally diverse replication modules. Phylogenomic analyses reveal the finer structure of evolutionary connections among RNA viruses and reverse-transcribing viruses, ssDNA viruses, and large subsets of dsDNA viruses. Taken together, these analyses allow us to outline the global organization of the virus world. Here, we describe the key aspects of this organization and propose a comprehensive hierarchical taxonomy of viruses.
Collapse
Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
| | - Mart Krupovic
- Institut Pasteur, Archaeal Virology Unit, Department of Microbiology, Paris, France
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Structural Biology Research Unit, Department of Clinical Laboratory Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - F Murilo Zerbini
- Departamento de Fitopatologia/Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| |
Collapse
|
32
|
Singh AR, Košmrlj A, Bruinsma R. Finite Temperature Phase Behavior of Viral Capsids as Oriented Particle Shells. PHYSICAL REVIEW LETTERS 2020; 124:158101. [PMID: 32357054 PMCID: PMC7219451 DOI: 10.1103/physrevlett.124.158101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/16/2020] [Indexed: 05/02/2023]
Abstract
A general phase plot is proposed for discrete particle shells that allows for thermal fluctuations of the shell geometry and of the inter-particle connectivities. The phase plot contains a first-order melting transition, a buckling transition, and a collapse transition and is used to interpret the thermodynamics of microbiological shells.
Collapse
Affiliation(s)
- Amit R Singh
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Currently at Department of Mechanical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India
| | - Andrej Košmrlj
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08540, USA
- Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544, USA
| | - Robijn Bruinsma
- Departments of Physics and Astronomy, and Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
33
|
Bayfield OW, Steven AC, Antson AA. Cryo-EM structure in situ reveals a molecular switch that safeguards virus against genome loss. eLife 2020; 9:e55517. [PMID: 32286226 PMCID: PMC7234808 DOI: 10.7554/elife.55517] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/13/2020] [Indexed: 01/01/2023] Open
Abstract
The portal protein is a key component of many double-stranded DNA viruses, governing capsid assembly and genome packaging. Twelve subunits of the portal protein define a tunnel, through which DNA is translocated into the capsid. It is unknown how the portal protein functions as a gatekeeper, preventing DNA slippage, whilst allowing its passage into the capsid, and how these processes are controlled. A cryo-EM structure of the portal protein of thermostable virus P23-45, determined in situ in its procapsid-bound state, indicates a mechanism that naturally safeguards the virus against genome loss. This occurs via an inversion of the conformation of the loops that define the constriction in the central tunnel, accompanied by a hydrophilic-hydrophobic switch. The structure also shows how translocation of DNA into the capsid could be modulated by a changing mode of protein-protein interactions between portal and capsid, across a symmetry-mismatched interface.
Collapse
Affiliation(s)
- Oliver W Bayfield
- York Structural Biology Laboratory, Department of Chemistry, University of YorkYorkUnited Kingdom
- Laboratory of Structural Biology Research, National Institute of Arthritis Musculoskeletal and Skin Diseases, National Institutes of HealthBethesdaUnited States
| | - Alasdair C Steven
- Laboratory of Structural Biology Research, National Institute of Arthritis Musculoskeletal and Skin Diseases, National Institutes of HealthBethesdaUnited States
| | - Alfred A Antson
- York Structural Biology Laboratory, Department of Chemistry, University of YorkYorkUnited Kingdom
| |
Collapse
|
34
|
Fang Q, Tang WC, Tao P, Mahalingam M, Fokine A, Rossmann MG, Rao VB. Structural morphing in a symmetry-mismatched viral vertex. Nat Commun 2020; 11:1713. [PMID: 32249784 PMCID: PMC7136217 DOI: 10.1038/s41467-020-15575-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/14/2020] [Indexed: 11/26/2022] Open
Abstract
Large biological structures are assembled from smaller, often symmetric, sub-structures. However, asymmetry among sub-structures is fundamentally important for biological function. An extreme form of asymmetry, a 12-fold-symmetric dodecameric portal complex inserted into a 5-fold-symmetric capsid vertex, is found in numerous icosahedral viruses, including tailed bacteriophages, herpesviruses, and archaeal viruses. This vertex is critical for driving capsid assembly, DNA packaging, tail attachment, and genome ejection. Here, we report the near-atomic in situ structure of the symmetry-mismatched portal vertex from bacteriophage T4. Remarkably, the local structure of portal morphs to compensate for symmetry-mismatch, forming similar interactions in different capsid environments while maintaining strict symmetry in the rest of the structure. This creates a unique and unusually dynamic symmetry-mismatched vertex that is central to building an infectious virion. In icosahedral viruses, a symmetry-mismatched portal vertex is assembled by inserting a 12-fold-symmetric portal complex into a 5-fold-symmetric capsid environment. Here, the authors report a near-atomic-resolution in situ cryo-electron microscopy structure of this symmetrically mismatched viral vertex from bacteriophage T4.
Collapse
Affiliation(s)
- Qianglin Fang
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Wei-Chun Tang
- Department of Biology, The Catholic University of America, Washington, DC, 20064, USA
| | - Pan Tao
- Department of Biology, The Catholic University of America, Washington, DC, 20064, USA
| | - Marthandan Mahalingam
- Department of Biology, The Catholic University of America, Washington, DC, 20064, USA
| | - Andrei Fokine
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Michael G Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Venigalla B Rao
- Department of Biology, The Catholic University of America, Washington, DC, 20064, USA.
| |
Collapse
|
35
|
Luque D, Castón JR. Cryo-electron microscopy for the study of virus assembly. Nat Chem Biol 2020; 16:231-239. [PMID: 32080621 DOI: 10.1038/s41589-020-0477-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022]
Abstract
Although viruses are extremely diverse in shape and size, evolution has led to a limited number of viral classes or lineages, which is probably linked to the assembly constraints of a viable capsid. Viral assembly mechanisms are restricted to two general pathways, (i) co-assembly of capsid proteins and single-stranded nucleic acids and (ii) a sequential mechanism in which scaffolding-mediated capsid precursor assembly is followed by genome packaging. Cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET), which are revolutionizing structural biology, are central to determining the high-resolution structures of many viral assemblies as well as those of assembly intermediates. This wealth of cryo-EM data has also led to the development and redesign of virus-based platforms for biomedical and biotechnological applications. In this Review, we will discuss recent viral assembly analyses by cryo-EM and cryo-ET showing how natural assembly mechanisms are used to encapsulate heterologous cargos including chemicals, enzymes, and/or nucleic acids for a variety of nanotechnological applications.
Collapse
Affiliation(s)
- Daniel Luque
- Centro Nacional de Microbiología/ISCIII, Majadahonda, Madrid, Spain
| | - José R Castón
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB-CSIC), Campus Cantoblanco, Madrid, Spain.
| |
Collapse
|
36
|
Maurer JB, Oh B, Moyer CL, Duda RL. Capsids and Portals Influence Each Other's Conformation During Assembly and Maturation. J Mol Biol 2020; 432:2015-2029. [PMID: 32035900 DOI: 10.1016/j.jmb.2020.01.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/04/2020] [Accepted: 01/14/2020] [Indexed: 01/22/2023]
Abstract
The portal proteins of tailed bacteriophage and Herpesvirus capsids form dodecameric rings that occupy one capsid vertex and are incorporated during the assembly of capsid precursors called procapsids or proheads. Portals are essential and serve as the pore for DNA transit and the site of tail attachment; however, bacteriophage HK97 capsid proteins assemble efficiently without a portal when expressed from plasmids. Following portal co-expression, portals were incorporated into about half of the proheads that were made. In the absence of active capsid maturation protease, uncleaved proheads formed dimers, trimers, and tetramers of proheads during purification, but only if they had portals. These appeared bound to membrane-like fragments by their portals and could be disaggregated by detergents, supporting a role for membranes in their formation and in capsid assembly. The precursors to prohead oligomers were detected in cell extracts. These were able to bind to Octyl-Sepharose and could be released by detergent, while uncleaved proheads without portal or cleaved proheads with portal did not bind. Our results document a discrete change in the HK97 portal's hydrophobicity induced by cleavage of the procapsid shell in which it is embedded. Additionally, we detected an increase in the rate of expansion induced by the presence of a portal complex in cleaved HK97 proheads. These results suggest that portals and capsids influence each other's conformation during assembly. The formation of prohead oligomers also provides a rapid and sensitive assay for identification and analysis of portal incorporation mutants.
Collapse
Affiliation(s)
- Joshua B Maurer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Bonnie Oh
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Crystal L Moyer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Robert L Duda
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| |
Collapse
|
37
|
Ignatiou A, Brasilès S, El Sadek Fadel M, Bürger J, Mielke T, Topf M, Tavares P, Orlova EV. Structural transitions during the scaffolding-driven assembly of a viral capsid. Nat Commun 2019; 10:4840. [PMID: 31649265 PMCID: PMC6813328 DOI: 10.1038/s41467-019-12790-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/25/2019] [Indexed: 11/11/2022] Open
Abstract
Assembly of tailed bacteriophages and herpesviruses starts with formation of procapsids (virion precursors without DNA). Scaffolding proteins (SP) drive assembly by chaperoning the major capsid protein (MCP) to build an icosahedral lattice. Here we report near-atomic resolution cryo-EM structures of the bacteriophage SPP1 procapsid, the intermediate expanded procapsid with partially released SPs, and the mature capsid with DNA. In the intermediate state, SPs are bound only to MCP pentons and to adjacent subunits from hexons. SP departure results in the expanded state associated with unfolding of the MCP N-terminus and straightening of E-loops. The newly formed extensive inter-capsomere bonding appears to compensate for release of SPs that clasp MCP capsomeres together. Subsequent DNA packaging instigates bending of MCP A domain loops outwards, closing the hexons central opening and creating the capsid auxiliary protein binding interface. These findings provide a molecular basis for the sequential structural rearrangements during viral capsid maturation.
Collapse
Affiliation(s)
- Athanasios Ignatiou
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Sandrine Brasilès
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Mehdi El Sadek Fadel
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Jörg Bürger
- Max-Planck-Institut für Molekulare Genetik, Microscopy and Cryo-Electron Microscopy Group, Ihnestraße 63-73, 14195, Berlin, Germany
- Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Thorsten Mielke
- Max-Planck-Institut für Molekulare Genetik, Microscopy and Cryo-Electron Microscopy Group, Ihnestraße 63-73, 14195, Berlin, Germany
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Paulo Tavares
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France.
| | - Elena V Orlova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK.
| |
Collapse
|
38
|
Principles for enhancing virus capsid capacity and stability from a thermophilic virus capsid structure. Nat Commun 2019; 10:4471. [PMID: 31578335 PMCID: PMC6775164 DOI: 10.1038/s41467-019-12341-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 08/31/2019] [Indexed: 12/21/2022] Open
Abstract
The capsids of double-stranded DNA viruses protect the viral genome from the harsh extracellular environment, while maintaining stability against the high internal pressure of packaged DNA. To elucidate how capsids maintain stability in an extreme environment, we use cryoelectron microscopy to determine the capsid structure of thermostable phage P74-26 to 2.8-Å resolution. We find P74-26 capsids exhibit an overall architecture very similar to those of other tailed bacteriophages, allowing us to directly compare structures to derive the structural basis for enhanced stability. Our structure reveals lasso-like interactions that appear to function like catch bonds. This architecture allows the capsid to expand during genome packaging, yet maintain structural stability. The P74-26 capsid has T = 7 geometry despite being twice as large as mesophilic homologs. Capsid capacity is increased with a larger, flatter major capsid protein. Given these results, we predict decreased icosahedral complexity (i.e. T ≤ 7) leads to a more stable capsid assembly. Viral capsids need to protect the genome against harsh environmental conditions and cope with high internal pressure from the packaged genome. Here, the authors determine the structure of the thermostable phage P74-26 capsid at 2.8-Å resolution and identify features underlying enhanced capsid capacity and structural stability.
Collapse
|
39
|
Dedeo CL, Cingolani G, Teschke CM. Portal Protein: The Orchestrator of Capsid Assembly for the dsDNA Tailed Bacteriophages and Herpesviruses. Annu Rev Virol 2019; 6:141-160. [PMID: 31337287 PMCID: PMC6947915 DOI: 10.1146/annurev-virology-092818-015819] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Tailed, double-stranded DNA bacteriophages provide a well-characterized model system for the study of viral assembly, especially for herpesviruses and adenoviruses. A wealth of genetic, structural, and biochemical work has allowed for the development of assembly models and an understanding of the DNA packaging process. The portal complex is an essential player in all aspects of bacteriophage and herpesvirus assembly. Despite having low sequence similarity, portal structures across bacteriophages share the portal fold and maintain a conserved function. Due to their dynamic role, portal proteins are surprisingly plastic, and their conformations change for each stage of assembly. Because the maturation process is dependent on the portal protein, researchers have been working to validate this protein as a potential antiviral drug target. Here we review recent work on the role of portal complexes in capsid assembly, including DNA packaging, as well as portal ring assembly and incorporation and analysis of portal structures.
Collapse
Affiliation(s)
- Corynne L Dedeo
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269, USA;
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269, USA;
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, USA
| |
Collapse
|
40
|
Twarock R, Luque A. Structural puzzles in virology solved with an overarching icosahedral design principle. Nat Commun 2019; 10:4414. [PMID: 31562316 PMCID: PMC6765026 DOI: 10.1038/s41467-019-12367-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 09/03/2019] [Indexed: 11/09/2022] Open
Abstract
Viruses have evolved protein containers with a wide spectrum of icosahedral architectures to protect their genetic material. The geometric constraints defining these container designs, and their implications for viral evolution, are open problems in virology. The principle of quasi-equivalence is currently used to predict virus architecture, but improved imaging techniques have revealed increasing numbers of viral outliers. We show that this theory is a special case of an overarching design principle for icosahedral, as well as octahedral, architectures that can be formulated in terms of the Archimedean lattices and their duals. These surface structures encompass different blueprints for capsids with the same number of structural proteins, as well as for capsid architectures formed from a combination of minor and major capsid proteins, and are recurrent within viral lineages. They also apply to other icosahedral structures in nature, and offer alternative designs for man-made materials and nanocontainers in bionanotechnology.
Collapse
Affiliation(s)
- Reidun Twarock
- Departments of Mathematics and Biology, York Cross-disciplinary Centre for Systems Analysis, University of York, York, YO10 5GE, UK.
| | - Antoni Luque
- Department of Mathematics and Statistics, Viral Information Institute, and Computational Science Research Center, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182-7720, USA.
| |
Collapse
|
41
|
Doore SM, Schrad JR, Perrett HR, Schrad KP, Dean WF, Parent KN. A cornucopia of Shigella phages from the Cornhusker State. Virology 2019; 538:45-52. [PMID: 31569014 DOI: 10.1016/j.virol.2019.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/05/2019] [Accepted: 09/16/2019] [Indexed: 01/21/2023]
Abstract
Bacteriophages are abundant in the environment, yet the vast majority have not been discovered or described. Many characterized bacteriophages infect a small subset of Enterobacteriaceae hosts. Despite its similarity to Escherichia coli, the pathogenic Shigella flexneri has relatively few known phages, which exhibit significant differences from many E. coli phages. This suggests that isolating additional Shigella phages is necessary to further explore these differences. To address questions of novelty and prevalence, high school students isolated bacteriophages on non-pathogenic strains of enteric bacteria. Results indicate that Shigella phages are abundant in the environment and continue to differ significantly from E. coli phages. Our findings suggest that Shigella-infecting members of the Ounavirinae subfamily continue to be over-represented and show surprisingly low diversity within and between sampling sites. Additionally, a podophage with distinct genomic and structural properties suggests that continued isolation on non-model species of bacteria is necessary to truly understand bacteriophage diversity.
Collapse
Affiliation(s)
- Sarah M Doore
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA; BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI, 48824, USA
| | - Jason R Schrad
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Hailee R Perrett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Kevin P Schrad
- Department of Science, Lincoln Southwest High School, Lincoln, NE, 68512, USA
| | - William F Dean
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Kristin N Parent
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA; BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
42
|
Cuervo A, Fàbrega-Ferrer M, Machón C, Conesa JJ, Fernández FJ, Pérez-Luque R, Pérez-Ruiz M, Pous J, Vega MC, Carrascosa JL, Coll M. Structures of T7 bacteriophage portal and tail suggest a viral DNA retention and ejection mechanism. Nat Commun 2019; 10:3746. [PMID: 31431626 PMCID: PMC6702177 DOI: 10.1038/s41467-019-11705-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 07/18/2019] [Indexed: 12/31/2022] Open
Abstract
Double-stranded DNA bacteriophages package their genome at high pressure inside a procapsid through the portal, an oligomeric ring protein located at a unique capsid vertex. Once the DNA has been packaged, the tail components assemble on the portal to render the mature infective virion. The tail tightly seals the ejection conduit until infection, when its interaction with the host membrane triggers the opening of the channel and the viral genome is delivered to the host cell. Using high-resolution cryo-electron microscopy and X-ray crystallography, here we describe various structures of the T7 bacteriophage portal and fiber-less tail complex, which suggest a possible mechanism for DNA retention and ejection: a portal closed conformation temporarily retains the genome before the tail is assembled, whereas an open portal is found in the tail. Moreover, a fold including a seven-bladed β-propeller domain is described for the nozzle tail protein.
Collapse
Affiliation(s)
- Ana Cuervo
- Centro Nacional de Biotecnología, (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Montserrat Fàbrega-Ferrer
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain
- Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Baldiri Reixac 10, 08028, Barcelona, Spain
| | - Cristina Machón
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain
- Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Baldiri Reixac 10, 08028, Barcelona, Spain
| | - José Javier Conesa
- Centro Nacional de Biotecnología, (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Francisco J Fernández
- Centro de Investigaciones Biológicas (CIB-CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
- Abvance Biotech srl, Ave. Reina Victoria 32, 28003, Madrid, Spain
| | - Rosa Pérez-Luque
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain
- Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Baldiri Reixac 10, 08028, Barcelona, Spain
| | - Mar Pérez-Ruiz
- Centro Nacional de Biotecnología, (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Joan Pous
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain
| | - M Cristina Vega
- Centro de Investigaciones Biológicas (CIB-CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - José L Carrascosa
- Centro Nacional de Biotecnología, (CNB-CSIC), Darwin 3, 28049, Madrid, Spain.
| | - Miquel Coll
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain.
- Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Baldiri Reixac 10, 08028, Barcelona, Spain.
| |
Collapse
|