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The Beauty of Bacteriophage T4 Research: Lindsay W. Black and the T4 Head Assembly. Viruses 2022; 14:v14040700. [PMID: 35458430 PMCID: PMC9026906 DOI: 10.3390/v14040700] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 02/06/2023] Open
Abstract
Viruses are biochemically complex structures and mainly consist of folded proteins that contain nucleic acids. Bacteriophage T4 is one of most prominent examples, having a tail structure that contracts during the infection process. Intracellular phage multiplication leads to separate self-directed assembly reactions of proheads, tails and tail fibers. The proheads are packaged with concatemeric DNA produced by tandem replication reactions of the parental DNA molecule. Once DNA packaging is completed, the head is joined with the tail and six long fibers are attached. The mature particles are then released from the cell via lysis, another tightly regulated process. These processes have been studied in molecular detail leading to a fascinating view of the protein-folding dynamics that direct the structural interplay of assembled complexes. Lindsay W. Black dedicated his career to identifying and defining the molecular events required to form the T4 virion. He leaves us with rich insights into the astonishingly precise molecular clockwork that co-ordinates all of the players in T4 assembly, both viral and cellular. Here, we summarize Lindsay’s key research contributions that are certain to stimulate our future science for many years to come.
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2
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A Cut above the Rest: Characterization of the Assembly of a Large Viral Icosahedral Capsid. Viruses 2020; 12:v12070725. [PMID: 32635654 PMCID: PMC7411985 DOI: 10.3390/v12070725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 11/17/2022] Open
Abstract
The head of Salmonella virus SPN3US is composed of ~50 different proteins and is unusual because within its packaged genome there is a mass (>40 MDa) of ejection or E proteins that enter the Salmonella cell. The assembly mechanisms of this complex structure are poorly understood. Previous studies showed that eight proteins in the mature SPN3US head had been cleaved by the prohead protease. In this study, we present the characterization of SPN3US prohead protease mutants using transmission electron microscopy and mass spectrometry. In the absence of the prohead protease, SPN3US head formation was severely impeded and proheads accumulated on the Salmonella inner membrane. This impediment is indicative of proteolysis being necessary for the release and subsequent DNA packaging of proheads in the wild-type phage. Proteomic analyses of gp245- proheads that the normal proteolytic processing of head proteins had not occurred. Assays of a recombinant, truncated form of the protease found it was active, leading us to hypothesize that the C-terminal propeptide has a role in targeting the protease into the prohead core. Our findings provide new evidence regarding the essential role of proteolysis for correct head assembly in this remarkable parasite.
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3
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Abstract
Assembly of the bacteriophage T4 head structure occurs at the cytoplasmic face of the inner membrane of Escherichia coli with the formation of proheads. The proheads contain an internal scaffolding core that determines the size and the structure of the capsid. In a mutant where the major shell protein gp23 was compromised, core structures without a shell had been detected. Such core structures were also found in the mutant T4am20am23. Since the mutation in gene 20 is at the N terminus of gp20, it was assumed that these core structures assemble in the absence of gp20. However, sequencing showed that the mutation introduces a new ribosome binding site that leads to a restart at codon 15. Although the mutant protein gp20s lacks the very N-terminal sequence, we found that it still binds to the membrane of the host cell and can initiate prohead assembly. This explains its activity to allow the assembly of core structures and proheads at the membrane surface. With a cross-linking approach, we show here that gp20 and gp20s are escorted by the chaperones DnaK, trigger factor, and GroEL and dock on the membrane at the membrane protein YidC.
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4
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Miller ES, Kutter E, Mosig G, Arisaka F, Kunisawa T, Rüger W. Bacteriophage T4 genome. Microbiol Mol Biol Rev 2003; 67:86-156, table of contents. [PMID: 12626685 PMCID: PMC150520 DOI: 10.1128/mmbr.67.1.86-156.2003] [Citation(s) in RCA: 551] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phage T4 has provided countless contributions to the paradigms of genetics and biochemistry. Its complete genome sequence of 168,903 bp encodes about 300 gene products. T4 biology and its genomic sequence provide the best-understood model for modern functional genomics and proteomics. Variations on gene expression, including overlapping genes, internal translation initiation, spliced genes, translational bypassing, and RNA processing, alert us to the caveats of purely computational methods. The T4 transcriptional pattern reflects its dependence on the host RNA polymerase and the use of phage-encoded proteins that sequentially modify RNA polymerase; transcriptional activator proteins, a phage sigma factor, anti-sigma, and sigma decoy proteins also act to specify early, middle, and late promoter recognition. Posttranscriptional controls by T4 provide excellent systems for the study of RNA-dependent processes, particularly at the structural level. The redundancy of DNA replication and recombination systems of T4 reveals how phage and other genomes are stably replicated and repaired in different environments, providing insight into genome evolution and adaptations to new hosts and growth environments. Moreover, genomic sequence analysis has provided new insights into tail fiber variation, lysis, gene duplications, and membrane localization of proteins, while high-resolution structural determination of the "cell-puncturing device," combined with the three-dimensional image reconstruction of the baseplate, has revealed the mechanism of penetration during infection. Despite these advances, nearly 130 potential T4 genes remain uncharacterized. Current phage-sequencing initiatives are now revealing the similarities and differences among members of the T4 family, including those that infect bacteria other than Escherichia coli. T4 functional genomics will aid in the interpretation of these newly sequenced T4-related genomes and in broadening our understanding of the complex evolution and ecology of phages-the most abundant and among the most ancient biological entities on Earth.
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Affiliation(s)
- Eric S Miller
- Department of Microbiology, North Carolina State University, Raleigh, North Carolina 27695-7615, USA.
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5
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Iwasaki K, Trus BL, Wingfield PT, Cheng N, Campusano G, Rao VB, Steven AC. Molecular architecture of bacteriophage T4 capsid: vertex structure and bimodal binding of the stabilizing accessory protein, Soc. Virology 2000; 271:321-33. [PMID: 10860886 DOI: 10.1006/viro.2000.0321] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
T4 encodes two dispensable proteins that bind to the outer surface of the mature capsid. Soc (9 kDa) stabilizes the capsid against extremes of alkaline pH and temperature, but Hoc (40 kDa) has no perceptible effect. Both proteins have been developed as display platforms. Their positions on the hexagonal surface lattice of gp23*, the major capsid protein, were previously defined by two-dimensional image averaging of negatively stained electron micrographs of elongated variant capsids. We have extended these observations by reconstructing cryo-electron micrographs of isometric capsids produced by a point mutant in gene 23, for both Hoc+.Soc+ and Hoc+.Soc- phages. The expected T = 13 lattice was observed, with a single Hoc molecule at the center of each gp23* hexamer. The vertices are occupied by pentamers of gp24*: despite limited sequence similarity with gp23*, the respective monomers are similar in size and shape, suggesting they may have the same fold. However, gp24* binds neither Hoc nor Soc; in situ, Soc is visualized as trimers at the trigonal points of the gp23* lattice and as monomers at the sites closest to the vertices. In solution, Soc is a folded protein ( approximately 10% alpha-helix and 50-60% beta sheet) that is monomeric as determined by analytic ultracentrifugation. Thus its trimerization on the capsid surface is imposed by a template of three symmetry-related binding sites. The observed mode of Soc binding suggests that it stabilizes the capsid by a clamping mechanism and offers a possible explanation for the phenotype of osmotic shock resistance.
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Affiliation(s)
- K Iwasaki
- Laboratory of Structural Biology, National Institutes of Health, Bethesda, MD 20892, USA
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6
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Zhang Z, Greene B, Thuman-Commike PA, Jakana J, Prevelige PE, King J, Chiu W. Visualization of the maturation transition in bacteriophage P22 by electron cryomicroscopy. J Mol Biol 2000; 297:615-26. [PMID: 10731416 DOI: 10.1006/jmbi.2000.3601] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Large-scale conformational transitions are involved in the life-cycle of many types of virus. The dsDNA phages, herpesviruses, and adenoviruses must undergo a maturation transition in the course of DNA packaging to convert a scaffolding-containing precursor capsid to the DNA-containing mature virion. This conformational transition converts the procapsid, which is smaller, rounder, and displays a distinctive skewing of the hexameric capsomeres, to the mature virion, which is larger and more angular, with regular hexons. We have used electron cryomicroscopy and image reconstruction to obtain 15 A structures of both bacteriophage P22 procapsids and mature phage. The maturation transition from the procapsid to the phage results in several changes in both the conformations of the individual coat protein subunits and the interactions between neighboring subunits. The most extensive conformational transformation among these is the outward movement of the trimer clusters present at all strict and local 3-fold axes on the procapsid inner surface. As the trimer tips are the sites of scaffolding binding, this helps to explain the role of scaffolding protein in regulating assembly and maturation. We also observe DNA within the capsid packed in a manner consistent with the spool model. These structures allow us to suggest how the binding interactions of scaffolding and DNA with the coat shell may act to control the packaging of the DNA into the expanding procapsids.
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Affiliation(s)
- Z Zhang
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
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7
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Parker MH, Stafford WF, Prevelige PE. Bacteriophage P22 scaffolding protein forms oligomers in solution. J Mol Biol 1997; 268:655-65. [PMID: 9171289 DOI: 10.1006/jmbi.1997.0995] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The scaffolding protein of Salmonella typhimurium bacteriophage P22 is a 33.6 kDa protein required both in vivo and in vitro for the polymerization of the viral coat protein into closed T = 7 icosahedral procapsids. In vitro assembly reaction kinetics have previously been found to vary between second and third order with respect to scaffolding protein concentration, suggesting that dimers and/or higher-order oligomers may be the active species in assembly. Analytical ultracentrifugation experiments suggest that scaffolding protein undergoes a rapidly-reversible monomer/dimer/tetramer equilibrium, with higher association constants at 4 degrees C than at 20 degrees C. Under conditions in which in vitro assembly reactions are carried out (30 to 1000 microg/ml scaffolding protein, 20 degrees C), monomers are the predominant species, but the concentration of dimers is significant. A mutant scaffolding protein, R74C/L177I, which forms disulfide-linked dimers, catalyzed procapsid assembly at a higher rate than did the wild-type scaffolding protein; preincubation in dithiothreitol had little effect on the wild-type protein, but greatly reduced the activity of the mutant. These findings suggest that dimers and/or higher-order oligomers of scaffolding protein are active species in the assembly of P22.
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Affiliation(s)
- M H Parker
- Dept. of Microbiology, Univ. of Alabama at Birmingham, 35294, USA
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8
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Abstract
The T4 prohead protease (T4 PPase) is the key enzyme in the morphopoietic pathway of the T4 phage head. It is responsible for the proteolytic processing of all head proteins allowing protein rearrangement and head expansion. To study its biochemistry and gene regulation, T4 gene 21 was cloned into an expression vector under the control of the inducible tac promoter. Two proteins of apparent molecular weights of 21.5 and 27.5 kDa were detected after induction. These proteins are synthesized using two different start codons in the same reading frame. Destruction of either start codon resulted in the loss of the respective protein. Complementation experiments with bacteriophage T4 21(-)-infected cells showed that both proteins are functional in vivo and essential for T4 phage assembly.
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Affiliation(s)
- E Hintermann
- Department of Microbiology, Biozentrum, University of Basal, Switzerland
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9
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Mooney DT, Stockard J, Parker ML, Doermann AH. Genetic control of capsid length in bacteriophage T4: DNA sequence analysis of petite and petite/giant mutants. J Virol 1987; 61:2828-34. [PMID: 3612953 PMCID: PMC255798 DOI: 10.1128/jvi.61.9.2828-2834.1987] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The T4 gene 23 product (gp23) encodes the major structural protein of the mature capsid. Mutations in this gene have been described which disrupt the normal length-determining mechanism (A.H. Doermann, F.A. Eiserling, and L. Boehner, J. Virol. 12:374-385, 1973). Mutants which produce high levels of petite and giant phage (ptg) are restricted to three tight clusters in gene 23 (A.H. Doermann, A. Pao, and P. Jackson, J. Virol. 61:2823-2827, 1987). Twenty-six of these ptg mutations were cloned, and their DNA sequence alterations were determined. Each member of this set of ptg mutants arose from a single mutation, and the set defined 10 different sites at which ptg mutations can occur in gene 23. Two petite (pt) mutations in gene 23 (pt21-34 and ptE920g), which produce high frequencies of petite particles but no giants, were also sequenced. Both pt21-34 and ptE920g were shown to include multiple mutations. The phenotypes attributed to both pt and ptg mutations are discussed relative to the mechanism of capsid morphogenesis. A site-directed mutation (SD-1E) was created at the ptgNg191 site, and its phenotypic consequences were examined. Plaque morphology revertants arising from a gene 23 mutant derivative of pt21-34 and from SD-1E were isolated. A preliminary mapping of the mutation(s) responsible for their revertant phenotypes suggested that both intra- and extragenic suppressors of the petite phenotype can be isolated by this method.
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10
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Traub F, Keller B, Kuhn A, Maeder M. Isolation of the prohead core of bacteriophage T4 after cross-linking and determination of protein composition. J Virol 1984; 49:902-8. [PMID: 6422052 PMCID: PMC255552 DOI: 10.1128/jvi.49.3.902-908.1984] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The naked core of bacteriophage T4 was isolated ex vivo after cross-linking with either glutaraldehyde or dithiobis(succinimidyl propionate). The isolated particles appeared to be morphologically identical to the cores found in thin sections, to those demonstrated in in situ lysis preparations, and to core structures assembled in vitro. Treatment with glutaraldehyde provided core particles which were morphologically well preserved, whereas dithiobis(succinimidyl propionate)-induced cross-linking was reversible and allowed analysis of the protein composition of the isolated particles. The identity of the reversibly cross-linked particles with those obtained after irreversible cross-linking was suggested by their morphology and their similar sedimentation behavior. Immunolabeling confirmed the structural presence of the main core protein in both structures. Gel electrophoresis of reversibly cross-linked cores revealed the essential head proteins gp22, gp67, and gp21, the three internal proteins IPI, IPII, and IPIII, and a 17K protein.
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11
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Abstract
Formation of the prohead core of bacteriophage T4 was not dependent on shell assembly. In mutant infections, where the production or assembly of active shell protein was not possible, naked core structures were formed. The particles were generally attached to the bacterial inner membrane and possessed defined prolate dimensions. The intracellular yield varied between 15 and 71% of a corresponding prohead yield and was dependent on the temperature of incubation. The products of genes 21 and 22 were found to be essential for in vivo core formation, whereas those of genes 20, 23, 24, 31, and 40, as well as the internal proteins I to III, were dispensable.
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12
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Abstract
We used electron microscopy and serum blocking power tests to determine the phenotypes of 47 phage P1 amber mutants that have defects in particle morphogenesis. Eleven mutants showed head defects, 30 showed tail defects, and 6 had a defect in particle maturation (which could be either in the head or in the tail). Consideration of previous complementation test results, genetic and physical positions of the mutations, and phenotypes of the mutants allowed assignment of most of the 47 mutations to genes. Thus, a minimum of 12 tail genes, 4 head genes, and 1 particle maturation gene are now known for P1. Of the 12 tail genes, 1 (gene 19, located within the invertible C loop) codes for tail fibers, 6 (genes 3, 5, 16, 20, 21, and 26) code for baseplate components (although one of these genes could code for the tail tube), 1 (gene 22) codes for the sheath, 1 (gene 6) affects tail length, 2 (genes 7 and 25) are involved in tail stability, and 1 (gene 24) either codes for a baseplate component or is involved in tail stability. Of the four head genes, gene 9 codes for a protein required for DNA packaging. The function of head gene 4 is unclear. Head gene 8 probably codes for a minor head protein, whereas head gene 23 could code for either a minor head protein or the major head protein. Excluding the particle maturation gene (gene 1), the 12 tail genes are clustered in three regions of the P1 physical genome. The four head genes are at four separate locations. However, some P1 head genes have not yet been detected and could be located in two regions (for which there are no known genes) adjacent to genes 4 and 8. The P1 morphogenetic gene clusters are interrupted by many genes that are expressed in the prophage.
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13
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Völker TA, Gafner J, Bickle TA, Showe MK. Gene 67, a new, essential bacteriophage T4 head gene codes for a prehead core component, PIP. I. Genetic mapping and DNA sequence. J Mol Biol 1982; 161:479-89. [PMID: 7154087 DOI: 10.1016/0022-2836(82)90402-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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14
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15
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Doherty DH. Genetic studies on capsid-length determination in bacteriophage T4. I. Isolation and partial characterization of second-site revertants of a gene 23 mutation affecting capsid length. J Virol 1982; 43:641-54. [PMID: 7109034 PMCID: PMC256166 DOI: 10.1128/jvi.43.2.641-654.1982] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The T4 mutation ptg19-80 affects the mechanism of capsid-length determination. It is located in gene 23, which encodes the major structural protein of the capsid. The mutation results in the production of abnormal-length capsids in high frequencies. This paper describes the isolation and partial characterization of second-site revertants of ptg19-80. In the course of their analysis, it was discovered that ptg19-80 is itself a double mutation consisting of a gene 23 mutation (ptg19-80c), which causes the morphogenetic defect, and a suppressor mutation located near the lysozyme gene. Phenotypic characterization of nine pseudo-wild-type revertants of this double-mutation revealed that these revertants all produced lower frequencies of abnormal capsids than did ptg19-80. Seven of these revertants were shown to contain two suppressor mutations, one mapping in or near gene 22 and done mapping in or near gene 24. Both mutations were required for suppression. These suppressors displayed no discernible phenotype in the absence of ptg19-80c.
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16
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Tsugita A, van den Broek R, Gregor I. Protein chemical approaches for the investigation of T4-head morphogenesis. Biosystems 1980; 12:225-38. [PMID: 6994830 DOI: 10.1016/0303-2647(80)90019-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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17
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Aron GM, Battreall CM. Production of infectious particles at the nonpermissive temperature by a temperature-sensitive mutant of bacteriophage SH-133 specific forPseudomonas facilis. Curr Microbiol 1979. [DOI: 10.1007/bf02603057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Isobe T, Yanagida M, Boosman A, Tsugita A. Characterization of the morphogenesis-dependent cleavage region of the major capsid protein (P23) of bacteriophage T4; sequence of an amber fragment of P23. J Mol Biol 1978; 125:339-56. [PMID: 366157 DOI: 10.1016/0022-2836(78)90407-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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Abstract
To determine the function of individual gene products in the assembly and maturation of the T4 prehead, we have isolated and characterized aberrant preheads produced by mutations in three of the T4 head genes. Mutants in gene 21, which codes for the T4 maturation proteases, produce rather stable preheads whose morphology and protein composition are consistent with a wild-type prehead blocked in the maturation cleavages. Mutants in gene 24 produce similar structures which are unstable because they have gaps at all of their icosahedral vertices except the membrane attachment site. In addition, greatly elongated "giant preheads" are produced, suggesting that in the absence of P24 at the vertices, the distal cap of the prehead is unstable, allowing abnormal elongation of broth the prehead core and its shell. Vertex completion by P24 is required to allow the maturation cleavages to occur, and 24- preheads can be matured to capsids in vitro by the addition of P24. Preheads produced by a temperature-sensitive mutant in gene 23 are deficient in core proteins. We show that the shell of these preheads has the expanded lattice characteristic of the mature capsid as well as the binding sites for the proteins hoc and soc, even though none of the maturation cleavage takes place. We also show that 21- preheads composed of wild-type P23 can be expanded in vitro without cleavage.
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20
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McNicol LA, Simon LE. A mutation which bypasses the requirement for p24 in bacteriophage T4 capsid morphogenesis. J Mol Biol 1977; 116:261-83. [PMID: 599558 DOI: 10.1016/0022-2836(77)90216-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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21
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Müller-Salamin L, Onorato L, Showe MK. Localization of minor protein components of the head of bacteriophage T4. J Virol 1977; 24:121-34. [PMID: 904022 PMCID: PMC515916 DOI: 10.1128/jvi.24.1.121-134.1977] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The bacteriophage T4 capsid contains a number of minor proteins that are required for head assembly but whose detailed function and position in the head are unknown. We have found that by systematically varying the conditions of extraction, some of these minor proteins can be removed while the main capsid structure is left substantially intact. Electron microscopic examination of the residual capsids showed that the extraction of the product of gene 20 is correlated with the loss of a plug that distinguishes one vertex position (presumably the tail attachment site) from the others. Extraction of the product of gene 24 is correlated with the loss of the other 11 (nonproximal) vertexes of the capsid. We further show that antibody to P24 binds specifically to the nonproximal vertexes of both T4 preheads and T4 phages. On the basis of our findings, we suggest that P20 is located at or near the tail attachment site of the capsid, whereas P24 forms the 11 nonproximal vertexes of preheads and P24 forms the nonproximal vertexes of the mature head.
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22
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Choy WN, Champe SP. Proteolysis during T4 head maturation: evidence against the involvement of a phage-induced trypsin-like enzyme. Virology 1977; 80:229-31. [PMID: 327685 DOI: 10.1016/0042-6822(77)90398-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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van Driel R. Assembly of bacteriophage T4 head-related structures. Assembly of polyheads in vitro. J Mol Biol 1977; 114:61-72. [PMID: 20510 DOI: 10.1016/0022-2836(77)90283-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Abstract
The precursors of the two T4 internal peptides have been identified by in vitro cleavage of individual phage proteins eluted from sodium dodecyl sulfate-acrylamide gels. The precursor of internal peptide VII is p22, the product of T4 gene 22 and an essential component of the morphogenic core. The precursor of peptide II is a protein with a molecular weight of approximately 13,000, whose gene has yet to be defined by mutation. A newly detected protein of approximately 15,000 molecular weight is found to be cleaved and is, therefore, likely to be a component of precursor head structures.
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25
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Castillo CJ, Hsiao CL, Coon P, Black LW. Identification and perperties of bacteriophage T4 capsid-formation gene products. J Mol Biol 1977; 110:585-601. [PMID: 845961 DOI: 10.1016/s0022-2836(77)80113-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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26
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27
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Purification and properties of a specific proteolytic enzyme present in spores of Bacillus magaterium. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(19)57013-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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28
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Isobe T, Black LW, Tsugita A. Protein cleavage during virus assembly: a novel specificity of assembly dependent cleavage in bacteriophage T4. Proc Natl Acad Sci U S A 1976; 73:4205-9. [PMID: 1069310 PMCID: PMC431386 DOI: 10.1073/pnas.73.11.4205] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cleavage of precursor proteins occurs during assembly of numerous viruses. Seven bacteriophage T4 head-related proteins areknown to be cleaved during morphogenesis. Sequences surrounding the cleavage sites in T4 head precursors P23 and IPIII are reported here. We previously determined the sequences of precursor and processed forms of IPII and IPI. Cleavage occurs at a glutamyl-alanyl bond in each protein. By comparison of sequences around five cleaved and four uncleaved Glu-Ala bonds in head precursors, it appears that cleavage is limited to the Thr or Ala, and X2 to hydrophilic residues. The results suggest the viral-induced assembly protease recognizes and cleaves an extended primary structure in the structurally dissimilar precursors.
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29
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Showe MK, Isobe E, Onorato L. Bacteriophage T4 prehead proteinase. I. Purification and properties of a bacteriophage enzyme which cleaves the capsid precursor proteins. J Mol Biol 1976; 107:35-54. [PMID: 12371 DOI: 10.1016/s0022-2836(76)80016-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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30
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Showe MK, Isobe E, Onorato L. Bacteriophage T4 prehead proteinase. II. Its cleavage from the product of gene 21 and regulation in phage-infected cells. J Mol Biol 1976; 107:55-69. [PMID: 1003460 DOI: 10.1016/s0022-2836(76)80017-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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31
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Steven AC, Couture E, Aebi U, Showe MK. Structure of T4 polyheads. II. A pathway of polyhead transformation as a model for T4 capsid maturation. J Mol Biol 1976; 106:187-221. [PMID: 972397 DOI: 10.1016/0022-2836(76)90307-7] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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32
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33
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34
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Giri JG, McCullough JE, Champe SP. Identification of gene products required for in vitro formation of the internal peptides of bacteriophage T4. J Virol 1976; 18:894-903. [PMID: 1271534 PMCID: PMC354788 DOI: 10.1128/jvi.18.3.894-903.1976] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In vitro formation of both bacteriophage T4 internal peptides (II and VII) from preexisting precursor protein was shown to require the product of T4 gene 21. The proteolytic factor was detectable in extracts of cells infected with certain phage mutants blocked in early steps of head assembly but could not be demonstrated in extracts of T4 wild-type infected cells. This finding suggests that the proteolytic factor is inactivated during normal phage assembly. The product of T4 gene 22 appears to be the precursor of peptide VII but not of peptide II.
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35
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Kemper B, Brown DT. Function of gene 49 of bacteriophage T4. II. Analysis of intracellular development and the structure of very fast-sedimenting DNA. J Virol 1976; 18:1000-15. [PMID: 775128 PMCID: PMC354800 DOI: 10.1128/jvi.18.3.1000-1015.1976] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
With the exception of mutants in gene 49, all mutants in phage T4 defective in the process of head filling accumulate a normal replicative DNA intermediate of 200S. Mutants in gene 49 produce a very fast-sedimenting (VFS) DNA with s values of greater than 1,000S. The intracellular development of the VFS-DNA generated in gene 49-defective phage-infected cells was followed by sedimentation analysis of crude lysates on neutral sucrose gradients. It was observed that the production of a 200S replicative intermediate is one step in the development of VFS-DNA. After restoring permissive conditions the development of the VFS-DNA can be reversed, but the 200S form is not regenerated under these conditions. The process of head filling can take place from the VFS-DNA under permissive conditions. From the absence of other components in the VFS-DNA complexes, its high resistance to shearing, its resistance against the attack of the single-strand-specific nuclease S1, and from its appearance in the electron microscope, a complex structure of tightly packed DNA is inferred. The demonstration by the electron microscope of branched DNA structures sometimes closely related to partially filled heads is taken in support of the idea that the process of head filling in gene 49-defective phage-infected cells is blocked by some steric hindrance in the DNA. In light of these results, the role of gene 49 is discussed as a control function for the clearance of these structures. A fixation procedure for cross-linking of gene 49-defective heads to the VFS-DNA allowed us to study progressive stages in the process of head filling. Electron microscopic evidence is presented which suggests that during the initial events the DNA accumulates in the vertexes of the head.
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36
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Benchetrit L, Bachrach U. Purification of a proteolytic enzyme from T4-infected Escherichia coli cells. Virology 1976; 71:602-4. [PMID: 779237 DOI: 10.1016/0042-6822(76)90386-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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37
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Cummings DJ, Bolin RW. Head length control in T4 bacteriophage morphogenesis: effect of canavanine on assembly. BACTERIOLOGICAL REVIEWS 1976; 40:314-59. [PMID: 786254 PMCID: PMC413960 DOI: 10.1128/br.40.2.314-359.1976] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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38
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Isobe T, Black LW, Tsugita A. Primary structure of bacteriophage T4 internal protein II and characterization of the cleavage upon phage maturation. J Mol Biol 1976; 102:349-65. [PMID: 1271467 DOI: 10.1016/s0022-2836(76)80059-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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39
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Abstract
Limited hydrolysis of gene 32 protein by various proteinases results in the production of three stable cleavage products. Two of these products show an affinity for native T4 DNA cellulose that the uncleaved protein does not exhibit. A model for proteolytic cleavage and for the total unwinding of DNA in advance of the replication fork is discussed in terms of this unusual binding affinity.
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40
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Bolin RW, Cummings DJ. Structural aberrations in T-even bacteriophage. VII. In vitro analysis of the canavanine-mediated inhibition of proteolytic cleavage. J Virol 1975; 16:1273-81. [PMID: 1185853 PMCID: PMC355727 DOI: 10.1128/jvi.16.5.1273-1281.1975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Canavanine arrests a critical function in head morphogenesis and the potential for forming giant T-even phage particles termed lollipops is induced. Formation of the particles requires the addition of arginine and the restoration of normal functions. We now report on an investigation into the effects of canavanine on both the T4-induced proteolytic activity and on the substrate proteins. Using an in vitro cleavage assay we have shown that the gene 21-dependent proteolytic activity from canavanine-treated extracts is markedly inhibited, whereas the substrate proteins retain a high susceptibility for cleavage. The proteolytic activity in extracts treated with canavanine followed by arginine is readily detectable, and proteins previously synthesized in the presence of canavanine can be cleaved. Protein synthesis is apparently required for the appearance of the proteolytic activity after the canavanine-arginine treatment. Mixing experiments suggest the requirement for a component of the gene 21-dependent proteolytic activity that is not coded for by gene 21.
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41
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Tsugita A, Black LW, Showe MK. Protein cleavage during virus assembly: characterization of cleavage in T4 phage. J Mol Biol 1975; 98:217-5. [PMID: 1195380 DOI: 10.1016/s0022-2836(75)80116-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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42
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Hohn T, Flick H, Hohn B. Petit lambda, a family of particles from coliphage lambda infected cells. J Mol Biol 1975; 98:107-20. [PMID: 1104865 DOI: 10.1016/s0022-2836(75)80104-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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