1
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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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2
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Huang Y, Sun H, Wei S, Cai L, Liu L, Jiang Y, Xin J, Chen Z, Que Y, Kong Z, Li T, Yu H, Zhang J, Gu Y, Zheng Q, Li S, Zhang R, Xia N. Structure and proposed DNA delivery mechanism of a marine roseophage. Nat Commun 2023; 14:3609. [PMID: 37330604 PMCID: PMC10276861 DOI: 10.1038/s41467-023-39220-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 06/02/2023] [Indexed: 06/19/2023] Open
Abstract
Tailed bacteriophages (order, Caudovirales) account for the majority of all phages. However, the long flexible tail of siphophages hinders comprehensive investigation of the mechanism of viral gene delivery. Here, we report the atomic capsid and in-situ structures of the tail machine of the marine siphophage, vB_DshS-R4C (R4C), which infects Roseobacter. The R4C virion, comprising 12 distinct structural protein components, has a unique five-fold vertex of the icosahedral capsid that allows genome delivery. The specific position and interaction pattern of the tail tube proteins determine the atypical long rigid tail of R4C, and further provide negative charge distribution within the tail tube. A ratchet mechanism assists in DNA transmission, which is initiated by an absorption device that structurally resembles the phage-like particle, RcGTA. Overall, these results provide in-depth knowledge into the intact structure and underlining DNA delivery mechanism for the ecologically important siphophages.
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Affiliation(s)
- Yang Huang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Hui Sun
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Shuzhen Wei
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Lanlan Cai
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Liqin Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Yanan Jiang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Jiabao Xin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Zhenqin Chen
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Yuqiong Que
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Zhibo Kong
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Tingting Li
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Hai Yu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Jun Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Ying Gu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China
| | - Qingbing Zheng
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China.
| | - Shaowei Li
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China.
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
| | - Ningshao Xia
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, School of Life Sciences, Xiamen University, Xiamen, 361102, China.
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, 361102, China.
- Research Unit of Frontier Technology of Structural Vaccinology, Chinese Academy of Medical Sciences, Xiamen, 361102, China.
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Vitt AR, Sørensen MCH, Bortolaia V, Brøndsted L. A Representative Collection of Commensal Extended-Spectrum- and AmpC-β-Lactamase-Producing Escherichia coli of Animal Origin for Phage Sensitivity Studies. PHAGE (NEW ROCHELLE, N.Y.) 2023; 4:35-45. [PMID: 37214655 PMCID: PMC10196081 DOI: 10.1089/phage.2023.0002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Introduction Extended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase (AmpC)-producing Escherichia coli from livestock and meat represent a zoonotic risk and biocontrol solutions are needed to prevent transmission to humans. Methods In this study, we established a representative collection of animal-origin ESBL/AmpC E. coli as target to test the antimicrobial potential of bacteriophages. Results Bioinformatic analysis of whole-genome sequence data of 198 ESBL/AmpC E. coli from pigs, broilers, and broiler meat identified strains belonging to all known E. coli phylogroups and 65 multilocus sequence types. Various ESBL/AmpC genes and plasmid types were detected with expected source-specific patterns. Plaque assay using 15 phages previously isolated using the E. coli reference collection demonstrated that Warwickvirus phages showed the broadest host range, killing up to 26 strains. Conclusions 154/198 strains were resistant to infection by all phages tested, suggesting a need for isolating phages specific for ESBL/AmpC E. coli. The strain collection described in this study is a useful resource fulfilling such need.
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Affiliation(s)
- Amira R. Vitt
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | | | - Valeria Bortolaia
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen S, Denmark
| | - Lone Brøndsted
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
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4
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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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5
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Intravirion DNA Can Access the Space Occupied by the Bacteriophage P22 Ejection Proteins. Viruses 2021; 13:v13081504. [PMID: 34452369 PMCID: PMC8402733 DOI: 10.3390/v13081504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/16/2022] Open
Abstract
Tailed double-stranded DNA bacteriophages inject some proteins with their dsDNA during infection. Phage P22 injects about 12, 12, and 30 molecules of the proteins encoded by genes 7, 16 and 20, respectively. After their ejection from the virion, they assemble into a trans-periplasmic conduit through which the DNA passes to enter the cytoplasm. The location of these proteins in the virion before injection is not well understood, although we recently showed they reside near the portal protein barrel in DNA-filled heads. In this report we show that when these proteins are missing from the virion, a longer than normal DNA molecule is encapsidated by the P22 headful DNA packaging machinery. Thus, the ejection proteins occupy positions within the virion that can be occupied by packaged DNA when they are absent.
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6
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Baxa U, Weintraub A, Seckler R. Self-Competitive Inhibition of the Bacteriophage P22 Tailspike Endorhamnosidase by O-Antigen Oligosaccharides. Biochemistry 2020; 59:4845-4855. [PMID: 33326210 DOI: 10.1021/acs.biochem.0c00872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The P22 tailspike endorhamnosidase confers the high specificity of bacteriophage P22 for some serogroups of Salmonella differing only slightly in their O-antigen polysaccharide. We used several biophysical methods to study the binding and hydrolysis of O-antigen fragments of different lengths by P22 tailspike protein. O-Antigen saccharides of defined length labeled with fluorophors could be purified with higher resolution than previously possible. Small amounts of naturally occurring variations of O-antigen fragments missing the nonreducing terminal galactose could be used to determine the contribution of this part to the free energy of binding to be ∼7 kJ/mol. We were able to show via several independent lines of evidence that an unproductive binding mode is highly favored in binding over all other possible binding modes leading to hydrolysis. This is true even under circumstances under which the O-antigen fragment is long enough to be cleaved efficiently by the enzyme. The high-affinity unproductive binding mode results in a strong self-competitive inhibition in addition to product inhibition observed for this system. Self-competitive inhibition is observed for all substrates that have a free reducing end rhamnose. Naturally occurring O-antigen, while still attached to the bacterial outer membrane, does not have a free reducing end and therefore does not perform self-competitive inhibition.
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Affiliation(s)
- Ulrich Baxa
- Physikalische Biochemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Golm, Germany
| | - Andrej Weintraub
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska University Hospital, S-14186 Stockholm, Sweden
| | - Robert Seckler
- Physikalische Biochemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Golm, Germany
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7
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Lokareddy RK, Ko YH, Hong N, Doll SG, Paduch M, Niederweis M, Kossiakoff AA, Cingolani G. Recognition of an α-helical hairpin in P22 large terminase by a synthetic antibody fragment. Acta Crystallogr D Struct Biol 2020; 76:876-888. [PMID: 32876063 PMCID: PMC7466751 DOI: 10.1107/s2059798320009912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 07/20/2020] [Indexed: 11/10/2022] Open
Abstract
The genome-packaging motor of tailed bacteriophages and herpesviruses is a multisubunit protein complex formed by several copies of a large (TerL) and a small (TerS) terminase subunit. The motor assembles transiently at the portal protein vertex of an empty precursor capsid to power the energy-dependent packaging of viral DNA. Both the ATPase and nuclease activities associated with genome packaging reside in TerL. Structural studies of TerL from bacteriophage P22 have been hindered by the conformational flexibility of this enzyme and its susceptibility to proteolysis. Here, an unbiased, synthetic phage-display Fab library was screened and a panel of high-affinity Fabs against P22 TerL were identified. This led to the discovery of a recombinant antibody fragment, Fab4, that binds a 33-amino-acid α-helical hairpin at the N-terminus of TerL with an equilibrium dissociation constant Kd of 71.5 nM. A 1.51 Å resolution crystal structure of Fab4 bound to the TerL epitope (TLE) together with a 1.15 Å resolution crystal structure of the unliganded Fab4, which is the highest resolution ever achieved for a Fab, elucidate the principles governing the recognition of this novel helical epitope. TLE adopts two different conformations in the asymmetric unit and buries as much as 1250 Å2 of solvent-accessible surface in Fab4. TLE recognition is primarily mediated by conformational changes in the third complementarity-determining region of the Fab4 heavy chain (CDR H3) that take place upon epitope binding. It is demonstrated that TLE can be introduced genetically at the N-terminus of a target protein, where it retains high-affinity binding to Fab4.
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Affiliation(s)
- Ravi K. Lokareddy
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, JAH-4E, Philadelphia, PA 19107, USA
| | - Ying-Hui Ko
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, JAH-4E, Philadelphia, PA 19107, USA
| | - Nathaniel Hong
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, JAH-4E, Philadelphia, PA 19107, USA
| | - Steven G. Doll
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, JAH-4E, Philadelphia, PA 19107, USA
| | - Marcin Paduch
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anthony A. Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, JAH-4E, Philadelphia, PA 19107, USA
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8
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Hrebík D, Štveráková D, Škubník K, Füzik T, Pantůček R, Plevka P. Structure and genome ejection mechanism of Staphylococcus aureus phage P68. SCIENCE ADVANCES 2019; 5:eaaw7414. [PMID: 31663016 PMCID: PMC6795507 DOI: 10.1126/sciadv.aaw7414] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 09/23/2019] [Indexed: 06/01/2023]
Abstract
Phages infecting Staphylococcus aureus can be used as therapeutics against antibiotic-resistant bacterial infections. However, there is limited information about the mechanism of genome delivery of phages that infect Gram-positive bacteria. Here, we present the structures of native S. aureus phage P68, genome ejection intermediate, and empty particle. The P68 head contains 72 subunits of inner core protein, 15 of which bind to and alter the structure of adjacent major capsid proteins and thus specify attachment sites for head fibers. Unlike in the previously studied phages, the head fibers of P68 enable its virion to position itself at the cell surface for genome delivery. The unique interaction of one end of P68 DNA with one of the 12 portal protein subunits is disrupted before the genome ejection. The inner core proteins are released together with the DNA and enable the translocation of phage genome across the bacterial membrane into the cytoplasm.
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Affiliation(s)
- Dominik Hrebík
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Dana Štveráková
- Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Karel Škubník
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Tibor Füzik
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Roman Pantůček
- Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Plevka
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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9
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McNulty R, Cardone G, Gilcrease EB, Baker TS, Casjens SR, Johnson JE. Cryo-EM Elucidation of the Structure of Bacteriophage P22 Virions after Genome Release. Biophys J 2019; 114:1295-1301. [PMID: 29590587 DOI: 10.1016/j.bpj.2018.01.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/24/2017] [Accepted: 01/17/2018] [Indexed: 11/19/2022] Open
Abstract
Genome ejection proteins are required to facilitate transport of bacteriophage P22 double-stranded DNA safely through membranes of Salmonella. The structures and locations of all proteins in the context of the mature virion are known, with the exception of three ejection proteins. Furthermore, the changes that occur to the proteins residing in the mature virion upon DNA release are not fully understood. We used cryogenic electron microscopy to obtain what is, to our knowledge, the first asymmetric reconstruction of mature bacteriophage P22 after double-stranded DNA has been extruded from the capsid-a state representative of one step during viral infection. Results of icosahedral and asymmetric reconstructions at estimated resolutions of 7.8 and 12.5 Å resolutions, respectively, are presented. The reconstruction shows tube-like protein density extending from the center of the tail assembly. The portal protein does not revert to the more contracted, procapsid state, but instead maintains an extended and splayed barrel structure. These structural details contribute to our understanding of the molecular mechanism of P22 phage infection and also set the foundation for future exploitation serving engineering purposes.
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Affiliation(s)
- Reginald McNulty
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California.
| | - Giovanni Cardone
- Department of Chemistry and BiochemistryUniversity of California, San Diego, La Jolla, California
| | - Eddie B Gilcrease
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah
| | - Timothy S Baker
- Department of Chemistry and BiochemistryUniversity of California, San Diego, La Jolla, California; Division of Biological Sciences, University of California, San Diego, La Jolla, California
| | - Sherwood R Casjens
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah
| | - John E Johnson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California.
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10
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Afonine PV, Poon BK, Read RJ, Sobolev OV, Terwilliger TC, Urzhumtsev A, Adams PD. Real-space refinement in PHENIX for cryo-EM and crystallography. Acta Crystallogr D Struct Biol 2018; 74:531-544. [PMID: 29872004 PMCID: PMC6096492 DOI: 10.1107/s2059798318006551] [Citation(s) in RCA: 1668] [Impact Index Per Article: 278.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 04/27/2018] [Indexed: 02/23/2023] Open
Abstract
This article describes the implementation of real-space refinement in the phenix.real_space_refine program from the PHENIX suite. The use of a simplified refinement target function enables very fast calculation, which in turn makes it possible to identify optimal data-restraint weights as part of routine refinements with little runtime cost. Refinement of atomic models against low-resolution data benefits from the inclusion of as much additional information as is available. In addition to standard restraints on covalent geometry, phenix.real_space_refine makes use of extra information such as secondary-structure and rotamer-specific restraints, as well as restraints or constraints on internal molecular symmetry. The re-refinement of 385 cryo-EM-derived models available in the Protein Data Bank at resolutions of 6 Å or better shows significant improvement of the models and of the fit of these models to the target maps.
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Affiliation(s)
- Pavel V. Afonine
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Physics and International Centre for Quantum and Molecular Structures, Shanghai University, Shanghai 200444, People’s Republic of China
| | - Billy K. Poon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Randy J. Read
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, England
| | - Oleg V. Sobolev
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Thomas C. Terwilliger
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- New Mexico Consortium, Los Alamos, NM 87545, USA
| | - Alexandre Urzhumtsev
- Faculté des Sciences et Technologies, Université de Lorraine, BP 239, 54506 Vandoeuvre-les-Nancy, France
- Centre for Integrative Biology, IGBMC, CNRS–INSERM–UdS, 1 Rue Laurent Fries, BP 10142, 67404 Illkirch, France
| | - Paul D. Adams
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Bioengineering, University of California Berkeley, Berkeley, California, USA
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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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Localization of the Houdinisome (Ejection Proteins) inside the Bacteriophage P22 Virion by Bubblegram Imaging. mBio 2016; 7:mBio.01152-16. [PMID: 27507825 PMCID: PMC4992974 DOI: 10.1128/mbio.01152-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The P22 capsid is a T=7 icosahedrally symmetric protein shell with a portal protein dodecamer at one 5-fold vertex. Extending outwards from that vertex is a short tail, and putatively extending inwards is a 15-nm-long α-helical barrel formed by the C-terminal domains of portal protein subunits. In addition to the densely packed genome, the capsid contains three “ejection proteins” (E-proteins [gp7, gp16, and gp20]) destined to exit from the tightly sealed capsid during the process of DNA delivery into target cells. We estimated their copy numbers by quantitative SDS-PAGE as approximately 12 molecules per virion of gp16 and gp7 and 30 copies of gp20. To localize them, we used bubblegram imaging, an adaptation of cryo-electron microscopy in which gaseous bubbles induced in proteins by prolonged irradiation are used to map the proteins’ locations. We applied this technique to wild-type P22, a triple mutant lacking all three E-proteins, and three mutants each lacking one E-protein. We conclude that all three E-proteins are loosely clustered around the portal axis, in the region displaced radially inwards from the portal crown. The bubblegram data imply that approximately half of the α-helical barrel seen in the portal crystal structure is disordered in the mature virion, and parts of the disordered region present binding sites for E-proteins. Thus positioned, the E-proteins are strategically placed to pass down the shortened barrel and through the portal ring and the tail, as they exit from the capsid during an infection. While it has long been appreciated that capsids serve as delivery vehicles for viral genomes, there is now growing awareness that viruses also deliver proteins into their host cells. P22 has three such proteins (ejection proteins [E-proteins]), whose initial locations in the virion have remained unknown despite their copious amounts (total of 2.5 MDa). This study succeeded in localizing them by the novel technique of bubblegram imaging. The P22 E-proteins are seen to be distributed around the orifice of the portal barrel. Interestingly, this barrel, 15 nm long in a crystal structure, is only about half as long in situ: the remaining, disordered, portion appears to present binding sites for E-proteins. These observations document a spectacular example of a regulatory order-disorder transition in a supramolecular system and demonstrate the potential of bubblegram imaging to map the components of other viruses as well as cellular complexes.
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