Escherichia coli phage SU10 belongs to the genus Kuravirus from the class Caudoviricetes of phages with short non-contractile tails. In contrast to other short-tailed phages, the tails of Kuraviruses elongate upon cell attachment. Here we show that the virion of SU10 has a prolate head, containing genome and ejection proteins, and a tail, which is formed of portal, adaptor, nozzle, and tail needle proteins and decorated with long and short fibers. The binding of the long tail fibers to the receptors in the outer bacterial membrane induces the straightening of nozzle proteins and rotation of short tail fibers. After the re-arrangement, the nozzle proteins and short tail fibers alternate to form a nozzle that extends the tail by 28 nm. Subsequently, the tail needle detaches from the nozzle proteins and five types of ejection proteins are released from the SU10 head. The nozzle with the putative extension formed by the ejection proteins enables the delivery of the SU10 genome into the bacterial cytoplasm. It is likely that this mechanism of genome delivery, involving the formation of the tail nozzle, is employed by all Kuraviruses.
- MeSH
- bakteriofágy * genetika metabolismus MeSH
- DNA virů genetika MeSH
- fosmet * MeSH
- genom virový genetika MeSH
- Podoviridae * genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA virů MeSH
- fosmet * MeSH
Staphylococcus aureus is a serious human and veterinary pathogen in which new strains with increasing virulence and antimicrobial resistance occur due to acquiring new genes by horizontal transfer. It is generally accepted that temperate bacteriophages play a major role in gene transfer. In this study, we proved the presence of various bacterial genes of the S. aureus COL strain directly within the phage particles via qPCR and quantified their packaging frequency. Non-parametric statistical analysis showed that transducing bacteriophages φ11, φ80 and φ80α of serogroup B, in contrast to serogroup A bacteriophage φ81, efficiently package selected chromosomal genes localized in 4 various loci of the chromosome and 8 genes carried on variable elements, such as staphylococcal cassette chromosome SCCmec, staphylococcal pathogenicity island SaPI1, genomic islands vSaα and vSaβ, and plasmids with various frequency. Bacterial gene copy number per ng of DNA isolated from phage particles ranged between 1.05 × 10(2) for the tetK plasmid gene and 3.86 × 10(5) for the SaPI1 integrase gene. The new and crucial finding that serogroup B bacteriophages can package concurrently ccrA1 (1.16 × 10(4)) and mecA (1.26 × 10(4)) located at SCCmec type I into their capsids indicates that generalized transduction plays an important role in the evolution and emergence of new methicillin-resistant clones.
- MeSH
- bakteriální chromozomy genetika MeSH
- bakteriální geny * MeSH
- bakteriální proteiny genetika MeSH
- bakteriofágy genetika metabolismus MeSH
- DNA bakterií genetika MeSH
- frekvence genu MeSH
- genetické lokusy MeSH
- klonování DNA MeSH
- penicilinasa genetika MeSH
- plazmidy genetika MeSH
- polymerázová řetězová reakce MeSH
- přenos genů horizontální MeSH
- proteiny vázající penicilin MeSH
- rezistence na methicilin genetika MeSH
- rozptýlené repetitivní sekvence * MeSH
- sekvenční analýza DNA MeSH
- sestavení viru MeSH
- Staphylococcus aureus genetika fyziologie virologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bakteriální proteiny MeSH
- DNA bakterií MeSH
- mecA protein, Staphylococcus aureus MeSH Prohlížeč
- penicilinasa MeSH
- proteiny vázající penicilin MeSH
The current incidence of Escherichia coli strains in healthy humans capable of producing the inhibitory exoproducts, such as temperate bacteriophages, corpuscular or HMW (high-molar mass) and proteinaceous or LMW (low-molar mass) colicins and siderophores was determined. Fifty-three E. coli strains were collected from the colons of 53 healthy human volunteers in Brno (Czechia) and tested for spontaneous and induced production of inhibitory exoproducts in a cross-test against each other. Of the strains tested, 37.7% produced bacteriophages, 41.5% produced from one to several LMW colicins, 11.3% formed HMW colicins and 15.1% (eight strains) produced exocellular siderophores different from enterochelin. Of these, seven strains formed aerobactin and one strain formed an untyped siderophore. E. coli strains differ greatly in the incidence of colicinogeny and lysogeny from its closest systemic relatives in the genus Escherichia and therefore should not be regarded as a model bacterium in this respect.
- MeSH
- antibióza fyziologie MeSH
- bakteriofágy metabolismus MeSH
- Escherichia coli metabolismus MeSH
- feces mikrobiologie MeSH
- koliciny metabolismus farmakologie MeSH
- kolon mikrobiologie MeSH
- lidé MeSH
- lyzogenie fyziologie MeSH
- siderofory metabolismus farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- koliciny MeSH
- siderofory MeSH
An open reading frame encoding an 88 amino acid protein was present downstream of the previously characterized endolysin of Streptomyces aureofaciens phage micro1/6. Structural analysis of its sequence revealed features characteristic for holin. This open reading frame encoding the putative holin was amplified by polymerase chain reaction and cloned into the expression vector pET-21d(+). Synthesis of the holin-like protein resulted in bacterial cell death but not lysis. The holmicro1/6 gene was able to complement the defective lambda S allele in the nonsuppressing Escherichia coli HB101 strain to produce phage progeny, This fact suggests that the proteins encoded by both phage genes have analogous function, i.e. the streptomycete holin induces nonspecific lesions in the cytoplasmic membrane, through which the lambda endolysin gains an access to its substrate, the cell wall. The concomitant expression of both S. aureofaciens holmicro 1/6 and lambda endolysin in E. coli resulted in abrupt cell lysis. This result provided further evidence that the product of holmicro 1/6 gene is a holin.
- MeSH
- bakteriofágy chemie genetika metabolismus MeSH
- bakteriolýza MeSH
- endopeptidasy genetika metabolismus MeSH
- Escherichia coli genetika růst a vývoj metabolismus MeSH
- klonování DNA MeSH
- molekulární sekvence - údaje MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- Streptomyces aureofaciens virologie MeSH
- virové proteiny chemie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- endolysin MeSH Prohlížeč
- endopeptidasy MeSH
- virové proteiny MeSH
Bacteriophage BFK20 was isolated from a Brevibacterium flavum strain that had become contaminated during industrial fermentation. BFK20 has a polyhedral head 50 nm wide and a non-contractile tail 200 nm long and 10 nm in diameter. The genome of this bacteriophage consists of a linear double stranded DNA molecule of 44-45 kb with cohesive ends. The capsid of phage BFK20 contains nine polypeptides with molecular masses from 22.0-108.0 kDa. BFK20 DNA was used as a donor for fragments carrying promoters and transcription-terminators.
The role of the HCR system in the repair of prelethal lesions induced by UV-light, gamma-rays and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its thermosensitive mutants (N3, N73 and ts1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce the survival in hcr+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr+ cells but has no effect on its survival in competent hcr+ cells; acriflavin and ethidium bromide decrease the survival of UV-irradiated SPP1 phage in both exponentially growing and competent hcr+ cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres in hcr+ cells of UV-irradiated DNA of the SPP1 phage. Repair inhibitors do not lower the survival of UV-irradiated phages or their DNA in hcr cells. The repair mechanism under study repairs also lesions induced by polyfunctional alkylating agents in transfecting DNA's of B. subtilis phages but is not functional with lesions induced by these agents in free phages and lesions caused in phages and their DNA by ethyl methanesulphonate or gamma-rays.
- MeSH
- alkylační látky farmakologie MeSH
- Bacillus subtilis metabolismus MeSH
- bakteriofágy účinky léků metabolismus účinky záření MeSH
- DNA virů biosyntéza účinky záření MeSH
- mutace MeSH
- oprava DNA * MeSH
- teplota MeSH
- transfekce MeSH
- ultrafialové záření MeSH
- záření gama MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- alkylační látky MeSH
- DNA virů MeSH
DNA was isolated from lytic phages of two strains, Bacillus licheniformis, a producer of bacitracin, and Bacillus thuringiensis forming protein paracrystals with pronounced insecticidal effects. Its sensitivity to Eco R1 restriction endonuclease was determined. It was the aim of the work to find out whether these phages could serve as vectors in the transfer and possible amplification of genes of the two important industrial species of bacilli. Approximate values of the molecular weight of DNA of the two phages were determined after degradation of the phage DNA by Eco R1, followed by comparison of electrophoretic mobility of individual fragments with that of the Eco R1-degraded DNA of phage lambdab2.
- MeSH
- Bacillus thuringiensis MeSH
- Bacillus MeSH
- bakteriofágy analýza metabolismus MeSH
- DNA virů izolace a purifikace metabolismus MeSH
- restrikční enzymy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA virů MeSH
- restrikční enzymy MeSH
