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Cingolani G, Lokareddy R, Hou CF, Forti F, Iglesias S, Li F, Pavlenok M, Niederweis M, Briani F. Integrative structural analysis of Pseudomonas phage DEV reveals a genome ejection motor. RESEARCH SQUARE 2024:rs.3.rs-3941185. [PMID: 38463957 PMCID: PMC10925440 DOI: 10.21203/rs.3.rs-3941185/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
DEV is an obligatory lytic Pseudomonas phage of the N4-like genus, recently reclassified as Schitoviridae. The DEV genome encodes 91 ORFs, including a 3,398 amino acid virion-associated RNA polymerase. Here, we describe the complete architecture of DEV, determined using a combination of cryo-electron microscopy localized reconstruction, biochemical methods, and genetic knockouts. We built de novo structures of all capsid factors and tail components involved in host attachment. We demonstrate that DEV long tail fibers are essential for infection of Pseudomonas aeruginosa and dispensable for infecting mutants with a truncated lipopolysaccharide devoid of the O-antigen. We identified DEV ejection proteins and, unexpectedly, found that the giant DEV RNA polymerase, the hallmark of the Schitoviridae family, is an ejection protein. We propose that DEV ejection proteins form a genome ejection motor across the host cell envelope and that these structural principles are conserved in all Schitoviridae.
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2
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Iglesias SM, Lokareddy RK, Yang R, Li F, Yeggoni DP, David Hou CF, Leroux MN, Cortines JR, Leavitt JC, Bird M, Casjens SR, White S, Teschke CM, Cingolani G. Molecular Architecture of Salmonella Typhimurium Virus P22 Genome Ejection Machinery. J Mol Biol 2023; 435:168365. [PMID: 37952769 PMCID: PMC10842050 DOI: 10.1016/j.jmb.2023.168365] [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: 09/01/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Bacteriophage P22 is a prototypical member of the Podoviridae superfamily. Since its discovery in 1952, P22 has become a paradigm for phage transduction and a model for icosahedral viral capsid assembly. Here, we describe the complete architecture of the P22 tail apparatus (gp1, gp4, gp10, gp9, and gp26) and the potential location and organization of P22 ejection proteins (gp7, gp20, and gp16), determined using cryo-EM localized reconstruction, genetic knockouts, and biochemical analysis. We found that the tail apparatus exists in two equivalent conformations, rotated by ∼6° relative to the capsid. Portal protomers make unique contacts with coat subunits in both conformations, explaining the 12:5 symmetry mismatch. The tail assembles around the hexameric tail hub (gp10), which folds into an interrupted β-propeller characterized by an apical insertion domain. The tail hub connects proximally to the dodecameric portal protein and head-to-tail adapter (gp4), distally to the trimeric tail needle (gp26), and laterally to six trimeric tailspikes (gp9) that attach asymmetrically to gp10 insertion domain. Cryo-EM analysis of P22 mutants lacking the ejection proteins gp7 or gp20 and biochemical analysis of purified recombinant proteins suggest that gp7 and gp20 form a molecular complex associated with the tail apparatus via the portal protein barrel. We identified a putative signal transduction pathway from the tailspike to the tail needle, mediated by three flexible loops in the tail hub, that explains how lipopolysaccharide (LPS) is sufficient to trigger the ejection of the P22 DNA in vitro.
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Affiliation(s)
- Stephano M Iglesias
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Ravi K Lokareddy
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA
| | - Ruoyu Yang
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Fenglin Li
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Daniel P Yeggoni
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Chun-Feng David Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Makayla N Leroux
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Juliana R Cortines
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA; Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Justin C Leavitt
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mary Bird
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Sherwood R Casjens
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Simon White
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA; 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 Locus Street, Philadelphia, PA 19107, USA; Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA.
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3
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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.
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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
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4
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In Vitro Studies of Lipopolysaccharide-Mediated DNA Release of Podovirus HK620. Viruses 2018; 10:v10060289. [PMID: 29843473 PMCID: PMC6024685 DOI: 10.3390/v10060289] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/19/2018] [Accepted: 05/21/2018] [Indexed: 12/17/2022] Open
Abstract
Gram-negative bacteria protect themselves with an outermost layer containing lipopolysaccharide (LPS). O-antigen-specific bacteriophages use tailspike proteins (TSP) to recognize and cleave the O-polysaccharide part of LPS. However, O-antigen composition and structure can be highly variable depending on the environmental conditions. It is important to understand how these changes may influence the early steps of the bacteriophage infection cycle because they can be linked to changes in host range or the occurrence of phage resistance. In this work, we have analyzed how LPS preparations in vitro trigger particle opening and DNA ejection from the E. coli podovirus HK620. Fluorescence-based monitoring of DNA release showed that HK620 phage particles in vitro ejected their genome at velocities comparable to those found for other podoviruses. Moreover, we found that HK620 irreversibly adsorbed to the LPS receptor via its TSP at restrictive low temperatures, without opening the particle but could eject its DNA at permissive temperatures. DNA ejection was solely stimulated by LPS, however, the composition of the O-antigen dictated whether the LPS receptor could start the DNA release from E. coli phage HK620 in vitro. This finding can be significant when optimizing bacteriophage mixtures for therapy, where in natural environments O-antigen structures may rapidly change.
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Abstract
Many icosahedral viruses use a specialized portal vertex for genome encapsidation in the viral capsid (or head). This structure then controls release of the viral genetic information to the host cell at the beginning of infection. In tailed bacteriophages, the portal system is connected to a tail device that delivers their genome to the bacterial cytoplasm. The head-to-tail interface is a multiprotein complex that locks the viral DNA inside the phage capsid correctly positioned for egress and that controls its ejection when the viral particle interacts with the host cell receptor. Here we review the molecular mechanisms how this interface is assembled and how it carries out those two critical steps in the life cycle of tailed phages.
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Affiliation(s)
- Paulo Tavares
- Department of Virology, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.
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Zhao H, Speir JA, Matsui T, Lin Z, Liang L, Lynn AY, Varnado B, Weiss TM, Tang L. Structure of a Bacterial Virus DNA-Injection Protein Complex Reveals a Decameric Assembly with a Constricted Molecular Channel. PLoS One 2016; 11:e0149337. [PMID: 26882199 PMCID: PMC4755594 DOI: 10.1371/journal.pone.0149337] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/29/2016] [Indexed: 12/18/2022] Open
Abstract
The multi-layered cell envelope structure of Gram-negative bacteria represents significant physical and chemical barriers for short-tailed phages to inject phage DNA into the host cytoplasm. Here we show that a DNA-injection protein of bacteriophage Sf6, gp12, forms a 465-kDa, decameric assembly in vitro. The electron microscopic structure of the gp12 assembly shows a ~150-Å, mushroom-like architecture consisting of a crown domain and a tube-like domain, which embraces a 25-Å-wide channel that could precisely accommodate dsDNA. The constricted channel suggests that gp12 mediates rapid, uni-directional injection of phage DNA into host cells by providing a molecular conduit for DNA translocation. The assembly exhibits a 10-fold symmetry, which may be a common feature among DNA-injection proteins of P22-like phages and may suggest a symmetry mismatch with respect to the 6-fold symmetric phage tail. The gp12 monomer is highly flexible in solution, supporting a mechanism for translocation of the protein through the conduit of the phage tail toward the host cell envelope, where it assembles into a DNA-injection device.
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Affiliation(s)
- Haiyan Zhao
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
| | - Jeffrey A. Speir
- National Resource for Automated Molecular Microscopy, The Scripps Research Institute, La Jolla, California, United States of America
| | - Tsutomu Matsui
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, 14 2575 Sand Hill Road, MS69, Menlo Park, California, United States of America
| | - Zihan Lin
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
| | - Lingfei Liang
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
| | - Anna Y. Lynn
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
| | - Brittany Varnado
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
| | - Thomas M. Weiss
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, 14 2575 Sand Hill Road, MS69, Menlo Park, California, United States of America
| | - Liang Tang
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas, United States of America
- * E-mail:
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Bhardwaj A, Sankhala RS, Olia AS, Brooke D, Casjens SR, Taylor DJ, Prevelige PE, Cingolani G. Structural Plasticity of the Protein Plug That Traps Newly Packaged Genomes in Podoviridae Virions. J Biol Chem 2015; 291:215-26. [PMID: 26574546 DOI: 10.1074/jbc.m115.696260] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Indexed: 02/05/2023] Open
Abstract
Bacterial viruses of the P22-like family encode a specialized tail needle essential for genome stabilization after DNA packaging and implicated in Gram-negative cell envelope penetration. The atomic structure of P22 tail needle (gp26) crystallized at acidic pH reveals a slender fiber containing an N-terminal "trimer of hairpins" tip. Although the length and composition of tail needles vary significantly in Podoviridae, unexpectedly, the amino acid sequence of the N-terminal tip is exceptionally conserved in more than 200 genomes of P22-like phages and prophages. In this paper, we used x-ray crystallography and EM to investigate the neutral pH structure of three tail needles from bacteriophage P22, HK620, and Sf6. In all cases, we found that the N-terminal tip is poorly structured, in stark contrast to the compact trimer of hairpins seen in gp26 crystallized at acidic pH. Hydrogen-deuterium exchange mass spectrometry, limited proteolysis, circular dichroism spectroscopy, and gel filtration chromatography revealed that the N-terminal tip is highly dynamic in solution and unlikely to adopt a stable trimeric conformation at physiological pH. This is supported by the cryo-EM reconstruction of P22 mature virion tail, where the density of gp26 N-terminal tip is incompatible with a trimer of hairpins. We propose the tail needle N-terminal tip exists in two conformations: a pre-ejection extended conformation, which seals the portal vertex after genome packaging, and a postejection trimer of hairpins, which forms upon its release from the virion. The conformational plasticity of the tail needle N-terminal tip is built in the amino acid sequence, explaining its extraordinary conservation in nature.
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Affiliation(s)
- Anshul Bhardwaj
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Rajeshwer S Sankhala
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Adam S Olia
- the Department of Biochemistry & Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Dewey Brooke
- the Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Sherwood R Casjens
- the Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Derek J Taylor
- the Department of Pharmacology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, and
| | - Peter E Prevelige
- the Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Gino Cingolani
- From the Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, the Institute of Biomembranes and Bioenergetics, National Research Council, 70126 Bari, Italy
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8
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Bhardwaj A, Casjens SR, Cingolani G. Exploring the atomic structure and conformational flexibility of a 320 Å long engineered viral fiber using X-ray crystallography. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:342-53. [PMID: 24531468 PMCID: PMC3940195 DOI: 10.1107/s1399004713027685] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/09/2013] [Indexed: 11/10/2022]
Abstract
Protein fibers are widespread in nature, but only a limited number of high-resolution structures have been determined experimentally. Unlike globular proteins, fibers are usually recalcitrant to form three-dimensional crystals, preventing single-crystal X-ray diffraction analysis. In the absence of three-dimensional crystals, X-ray fiber diffraction is a powerful tool to determine the internal symmetry of a fiber, but it rarely yields atomic resolution structural information on complex protein fibers. An 85-residue-long minimal coiled-coil repeat unit (MiCRU) was previously identified in the trimeric helical core of tail needle gp26, a fibrous protein emanating from the tail apparatus of the bacteriophage P22 virion. Here, evidence is provided that an MiCRU can be inserted in frame inside the gp26 helical core to generate a rationally extended fiber (gp26-2M) which, like gp26, retains a trimeric quaternary structure in solution. The 2.7 Å resolution crystal structure of this engineered fiber, which measures ∼320 Å in length and is only 20-35 Å wide, was determined. This structure, the longest for a trimeric protein fiber to be determined to such a high resolution, reveals the architecture of 22 consecutive trimerization heptads and provides a framework to decipher the structural determinants for protein fiber assembly, stability and flexibility.
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Affiliation(s)
- Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
| | - Sherwood R. Casjens
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
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Bhardwaj A, Olia AS, Cingolani G. Architecture of viral genome-delivery molecular machines. Curr Opin Struct Biol 2013; 25:1-8. [PMID: 24878339 DOI: 10.1016/j.sbi.2013.10.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/21/2013] [Indexed: 12/27/2022]
Abstract
From the abyss of the ocean to the human gut, bacterial viruses (or bacteriophages) have colonized all ecosystems of the planet earth and evolved in sync with their bacterial hosts. Over 95% of bacteriophages have a tail that varies greatly in length and complexity. The tail complex interrupts the icosahedral capsid symmetry and provides both an entry for viral genome-packaging during replication and an exit for genome-ejection during infection. Here, we review recent progress in deciphering the structure, assembly and conformational dynamics of viral genome-delivery tail machines. We focus on the bacteriophages P22 and T7, two well-studied members of the Podoviridae family that use short, non-contractile tails to infect Gram-negative bacteria. The structure of specialized tail fibers and their putative role in host anchoring, cell-surface penetration and genome-ejection is discussed.
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Affiliation(s)
- Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
| | - Adam S Olia
- Program in Gene Expression and Regulation, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA.
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Leavitt JC, Gogokhia L, Gilcrease EB, Bhardwaj A, Cingolani G, Casjens SR. The tip of the tail needle affects the rate of DNA delivery by bacteriophage P22. PLoS One 2013; 8:e70936. [PMID: 23951045 PMCID: PMC3741392 DOI: 10.1371/journal.pone.0070936] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 06/25/2013] [Indexed: 02/01/2023] Open
Abstract
The P22-like bacteriophages have short tails. Their virions bind to their polysaccharide receptors through six trimeric tailspike proteins that surround the tail tip. These short tails also have a trimeric needle protein that extends beyond the tailspikes from the center of the tail tip, in a position that suggests that it should make first contact with the host’s outer membrane during the infection process. The base of the needle serves as a plug that keeps the DNA in the virion, but role of the needle during adsorption and DNA injection is not well understood. Among the P22-like phages are needle types with two completely different C-terminal distal tip domains. In the phage Sf6-type needle, unlike the other P22-type needle, the distal tip folds into a “knob” with a TNF-like fold, similar to the fiber knobs of bacteriophage PRD1 and Adenovirus. The phage HS1 knob is very similar to that of Sf6, and we report here its crystal structure which, like the Sf6 knob, contains three bound L-glutamate molecules. A chimeric P22 phage with a tail needle that contains the HS1 terminal knob efficiently infects the P22 host, Salmonella enterica, suggesting the knob does not confer host specificity. Likewise, mutations that should abrogate the binding of L-glutamate to the needle do not appear to affect virion function, but several different other genetic changes to the tip of the needle slow down potassium release from the host during infection. These findings suggest that the needle plays a role in phage P22 DNA delivery by controlling the kinetics of DNA ejection into the host.
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Affiliation(s)
- Justin C. Leavitt
- Biology Department, University of Utah, Salt Lake City, Utah, United States of America
| | - Lasha Gogokhia
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Eddie B. Gilcrease
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Sherwood R. Casjens
- Biology Department, University of Utah, Salt Lake City, Utah, United States of America
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail:
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Tavares P, Zinn-Justin S, Orlova EV. Genome gating in tailed bacteriophage capsids. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 726:585-600. [PMID: 22297531 DOI: 10.1007/978-1-4614-0980-9_25] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tailed bacteriophages use a portal system for genome entry and exit from viral capsids. Here, we review the mechanisms how these movements are controlled by the genome gatekeeper that assembles at the portal structure. Phage DNA is packaged at high pressure inside the viral capsid by a powerful motor. The viral genome is translocated through the central channel of the portal protein found at a single vertex of the capsid. Packaging is normally terminated by endonucleolytic cleavage of the substrate DNA followed by disassembly of the packaging motor and closure of the portal system, preventing leakage of the viral genome. This can be achieved either by conformational changes in the portal protein or by sequential addition of proteins that extend the portal channel (adaptors) and physically close it preventing DNA exit (stoppers). The resulting connector structure provides the interface for assembly of short tails (podoviruses) or for attachment of preformed long tails (siphoviruses and myoviruses). The connector maintains the viral DNA correctly positioned for ejection that is triggered by interaction of the phage particle with bacterial receptors. Recent exciting advances are providing new molecular insights on the mechanisms that ensure precise coordination of these critical steps required both for stable viral genome packaging and for its efficient release to initiate infection.
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Affiliation(s)
- Paulo Tavares
- Unité de Virologie Moléculaire et Structurale, Gif-sur-Yvette, France.
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12
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Bhardwaj A, Molineux IJ, Casjens SR, Cingolani G. Atomic structure of bacteriophage Sf6 tail needle knob. J Biol Chem 2011; 286:30867-30877. [PMID: 21705802 PMCID: PMC3162447 DOI: 10.1074/jbc.m111.260877] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 06/22/2011] [Indexed: 11/06/2022] Open
Abstract
Podoviridae are double-stranded DNA bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. Within the tail apparatus of P22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelope-penetrating device to promote ejection of viral DNA inside the host. In Sf6, a P22-like phage that infects Shigella flexneri, the tail needle presents a C-terminal globular knob. This knob, absent in phage P22 but shared in other members of the P22-like genus, represents the outermost exposed tip of the virion that contacts the host cell surface. Here, we report a crystal structure of the Sf6 tail needle knob determined at 1.0 Å resolution. The structure reveals a trimeric globular domain of the TNF fold structurally superimposable with that of the tail-less phage PRD1 spike protein P5 and the adenovirus knob, domains that in both viruses function in receptor binding. However, P22-like phages are not known to utilize a protein receptor and are thought to directly penetrate the host surface. At 1.0 Å resolution, we identified three equivalents of l-glutamic acid (l-Glu) bound to each subunit interface. Although intimately bound to the protein, l-Glu does not increase the structural stability of the trimer nor it affects its ability to self-trimerize in vitro. In analogy to P22 gp26, we suggest the tail needle of phage Sf6 is ejected through the bacterial cell envelope during infection and its C-terminal knob is threaded through peptidoglycan pores formed by glycan strands.
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Affiliation(s)
- Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Ian J Molineux
- Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas 78712
| | - Sherwood R Casjens
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
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13
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Olia AS, Prevelige PE, Johnson JE, Cingolani G. Three-dimensional structure of a viral genome-delivery portal vertex. Nat Struct Mol Biol 2011; 18:597-603. [PMID: 21499245 PMCID: PMC3087855 DOI: 10.1038/nsmb.2023] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 01/31/2011] [Indexed: 12/15/2022]
Abstract
DNA viruses such as bacteriophages and herpesviruses deliver their genome into and out of the capsid through large proteinaceous assemblies, known as portal proteins. Here we report two snapshots of the dodecameric portal protein of bacteriophage P22. The 3.25 Å resolution structure of the portal protein core bound to twelve copies of gp4 reveals a ~1.1 MDa assembly formed by 24 proteins. Unexpectedly, a lower resolution structure of the full length portal protein unveils the unique topology of the C-terminal domain, which forms a ~200 Å long, α-helical barrel. This domain inserts deeply into the virion and is highly conserved in the Podoviridae family. We propose that the barrel domain facilitates genome spooling onto the interior surface of the capsid during genome packaging and, in analogy to a rifle barrel, increases the accuracy of genome ejection into the host cell.
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Affiliation(s)
- Adam S Olia
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
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Casjens SR, Thuman-Commike PA. Evolution of mosaically related tailed bacteriophage genomes seen through the lens of phage P22 virion assembly. Virology 2011; 411:393-415. [PMID: 21310457 DOI: 10.1016/j.virol.2010.12.046] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 01/06/2023]
Abstract
The mosaic composition of the genomes of dsDNA tailed bacteriophages (Caudovirales) is well known. Observations of this mosaicism have generally come from comparisons of small numbers of often rather distantly related phages, and little is known about the frequency or detailed nature of the processes that generate this kind of diversity. Here we review and examine the mosaicism within fifty-seven clusters of virion assembly genes from bacteriophage P22 and its "close" relatives. We compare these orthologous gene clusters, discuss their surprising diversity and document horizontal exchange of genetic information between subgroups of the P22-like phages as well as between these phages and other phage types. We also point out apparent restrictions in the locations of mosaic sequence boundaries in this gene cluster. The relatively large sample size and the fact that phage P22 virion structure and assembly are exceptionally well understood make the conclusions especially informative and convincing.
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Affiliation(s)
- Sherwood R Casjens
- Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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