Bacteriophage phi29 terminal protein: its association with the 5' termini of the phi29 genome

Ito, Junetsu

doi:10.1128/jvi.28.3.895-904.1978

Cited by 112 publications

(22 citation statements)

References 39 publications

(65 reference statements)

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“…Since it was not possible to identify the sites of phage DNA replication using DAPI, we examined the localization of the phage‐encoded TP. Linear φ29 DNA molecules contain a TP molecule covalently linked at each DNA 5′ end (Ito, 1978; Salas et al ., 1978; Yehle, 1978). There fore, the localization of phage DNA can be determined indirectly by studying the cellular distribution of TP throughout the infection cycle.…”

Section: Resultsmentioning

confidence: 99%

Dynamic relocalization of phage φ29 DNA during replication and the role of the viral protein p16.7

et al. 2000

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We have examined the localization of DNA replication of the Bacillus subtilis phage f29 by immuno¯uores-cence. To determine where phage replication was localized within infected cells, we examined the distribution of phage replication proteins and the sites of incorporation of nucleotide analogues into phage DNA. On initiation of replication, the phage DNA localized to a single focus within the cell, nearly always towards one end of the host cell nucleoid. At later stages of the infection cycle, phage replication was found to have redistributed to multiple sites around the periphery of the nucleoid, just under the cell membrane. Towards the end of the cycle, phage DNA was once again redistributed to become located within the bulk of the nucleoid. Ef®cient redistribution of replicating phage DNA from the initial replication site to various sites surrounding the nucleoid was found to be dependent on the phage protein p16.7. Keywords: Bacillus subtilis/bacteriophage f29/ immuno¯uorescence/in vivo DNA replication IntroductionThe Bacillus subtilis phage f29 is one of the best characterized phages and serves as a paradigm for the study of double-stranded DNA viruses in Gram-positive bacteria (Salas, 1991;Salas and Rojo, 1993;Salas et al., 1996). The genome of f29 is a linear double-stranded DNA molecule of 19 285 bp, whose sequence is completely known (Yoshikawa and Ito, 1982;Garvey et al., 1985;Vlcek and Paces, 1986). Regulation of f29 DNA transcription, divided into an early and a late stage, has been studied extensively in vivo as well as in vitro (for reviews see Salas and Rojo, 1993;Rojo et al., 1998). The late expressed genes, all transcribed from a single operon present in the central part of the phage genome, encode the phage structural proteins, proteins involved in phage morphogenesis and those required for lysis of the infected cell ( Figure 1A). The early expressed genes are present in two operons that¯ank the late operon ( Figure 1A). The operon located at the right side of the f29 genome encodes, in addition to protein p17 (Crucitti et al., 1998) and p16.7 (W.J.J.Meijer, A.Serna-Rico and M.Salas, submitted), four proteins of unknown function. The early operon located at the left side of the f29 genome encodes the transcriptional regulator protein p4 and various proteins that are directly involved in phage DNA replication, such as the DNA polymerase, terminal protein (TP), single-stranded DNA-binding protein (SSB), doublestranded DNA-binding protein (DBP) and protein p1 (see Discussion).A schematic overview of the in vitro f29 DNA replication mechanism is shown in Figure 1B. Initiation of f29 DNA replication occurs via a so-called proteinprimed mechanism (reviewed in Salas, 1991;Salas et al., 1996). The linear f29 genome contains a TP molecule covalently linked at each of its 5¢ DNA ends, which constitute the origins of replication. Initiation of DNA replication starts by recognition of the origin by a heterodimer formed by the f29 DNA polymerase and the primer TP. The DNA polymerase then catalyses the ad...

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Section: Resultsmentioning

confidence: 99%

Dynamic relocalization of phage φ29 DNA during replication and the role of the viral protein p16.7

et al. 2000

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“…Both phages presented 24 bp inverted repeats at their ends, with no reads extending past the contig ends. This arrangement is reminiscent of φ29-like phages, which are typically packaged with covalently-linked terminal proteins [66]. In spite of their distant collection sites, the WheeHeim and Forthebois chromosomes present an average nucleotide identity (ANI) of 88.5% [67] and a very similar GC content (54.6% and 53.6%, respectively).…”

Section: Genome Sequencing and Annotationmentioning

confidence: 99%

A Novel Genus of Actinobacterial Tectiviridae

Caruso

deCarvalho

Huynh

et al. 2019

Viruses

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Streptomyces phages WheeHeim and Forthebois are two novel members of the Tectiviridae family. These phages were isolated on cultures of the plant pathogen Streptomyces scabiei, known for its worldwide economic impact on potato crops. Transmission electron microscopy showed viral particles with double-layered icosahedral capsids, and frequent instances of protruding nanotubes harboring a collar-like structure. Mass-spectrometry confirmed the presence of lipids in the virion, and serial purification of colonies from turbid plaques and immunity testing revealed that both phages are temperate. Streptomyces phages WheeHeim and Forthebois have linear dsDNA chromosomes (18,266 bp and 18,251 bp long, respectively) with the characteristic two-segment architecture of the Tectiviridae. Both genomes encode homologs of the canonical tectiviral proteins (major capsid protein, packaging ATPase and DNA polymerase), as well as PRD1-type virion-associated transglycosylase and membrane DNA delivery proteins. Comparative genomics and phylogenetic analyses firmly establish that these two phages, together with Rhodococcus phage Toil, form a new genus within the Tectiviridae, which we have tentatively named Deltatectivirus. The identification of a cohesive clade of Actinobacteria-infecting tectiviruses with conserved genome structure but with scant sequence similarity to members of other tectiviral genera confirms that the Tectiviridae are an ancient lineage infecting a broad range of bacterial hosts.

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“…It is therefore not widely appreciated that most, if not all, phages do eject proteins into the cell. Ejection may take place before DNA, as is the case with T7 [58], attached to the ends of the genome as, e.g., T4 and ø29 [65,66], or in principle after complete DNA ejection. It is not likely that the channel from the phage head into the cell cytoplasm can accommodate DNA and protein simultaneously.…”

Section: Transport By Specific Proteinsmentioning

confidence: 99%

Is phage DNA ‘injected’ into cells—biologists and physicists can agree

Grayson

Molineux

2007

Current Opinion in Microbiology

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The double-stranded DNA inside bacteriophages is packaged at a density of approximately 500 mg/ml and exerts an osmotic pressure of tens of atmospheres. This pressure is commonly assumed to cause genome ejection during infection. Indeed, by the addition of their natural receptors, some phages can be induced in vitro to completely expel their genome from the virion. However, the osmotic pressure of the bacterial cytoplasm exerts an opposing force, making it impossible for the pressure of packaged DNA to cause complete genome ejection in vivo. Various processes for complete genome ejection are discussed, but we focus on a novel proposal suggesting that the osmotic gradient between the extracellular environment and the cytoplasm results in fluid flow through the phage virion at the initiation of infection. The phage genome is thereby sucked into the cell by hydrodynamic drag.

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Bacteriophage phi29 terminal protein: its association with the 5' termini of the phi29 genome

Cited by 112 publications

References 39 publications

Dynamic relocalization of phage φ29 DNA during replication and the role of the viral protein p16.7

Dynamic relocalization of phage φ29 DNA during replication and the role of the viral protein p16.7

A Novel Genus of Actinobacterial Tectiviridae

Is phage DNA ‘injected’ into cells—biologists and physicists can agree

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