High Resolution Structure of the Mature Capsid of Bacteriophage Ï•RSA1 by Cryo-Electron Microscopy.

The Ï•RSA1 bacteriophage has been isolated from , a gram negative bacteria having a significant economic impact on many important crops. We solved the three-dimensional structure of the Ï•RSA1 mature capsid to 3.9 Ã… resolution by cryo-electron microscopy.

In vitro characterization of the site-specific recombination system based on genus Habenivirus Ï•RSM small serine integrase.

The genus Habenivirus which includes Ralstonia virus Ï•RSM encodes a site-specific integrase of a small serine recombinase belonging to the resolvase/invertase family. Here we describe the integrative/excisive recombination reactions mediated by Ï•RSM integrase using in vitro assays. The products of attP/attB recombination, i.

The complete genomic sequence of the novel myovirus RP13 infecting Ralstonia solanacearum, the causative agent of bacterial wilt.

A novel lytic bacteriophage, Ralstonia phage RP13, was isolated from tomato fields in Pang Nga, Thailand. Electron microscopic observation showed it to have the features of a myovirus with a novel triangulation number (T = 21, dextro). The RP13 DNA appeared to be heavily modified.

3D structure of three jumbo phage heads.

Jumbo phages are bacteriophages that carry more than 200 kbp of DNA. In this study we characterized two jumbo phages (ΦRSL2 and ΦXacN1) and one semi-jumbo phage (ΦRP13) at the structural level by cryo-electron microscopy. Focusing on their capsids, three-dimensional structures of the heads at resolutions ranging from 16 to 9 Å were calculated.

Correction to: Full genome sequence of a polyvalent bacteriophage infecting strains of Shigella, Salmonella, and Escherichia.

The original version of this article unfortunately contained a mistake.

Full genome sequence of a polyvalent bacteriophage infecting strains of Shigella, Salmonella, and Escherichia.

A novel lytic bacteriophage, Escherichia phage EcS1, was isolated from sewage samples collected in Higashi-Hiroshima, Japan. The complete genome sequence of EcS1 was determined using the Illumina Miseq System. The whole genome of EcS1 was found to be 175,437 bp in length with a mean G+C content of 37.

Systemic method to isolate large bacteriophages for use in biocontrol of a wide-range of pathogenic bacteria.

Large phages are characterized by genomes around 200 kbp or more. They can infect wide host ranges of bacteria and maintain long-lasting infection. There is no standard method for selective isolation of large phages.

Xanthomonas citri jumbo phage XacN1 exhibits a wide host range and high complement of tRNA genes.

Xanthomonas virus (phage) XacN1 is a novel jumbo myovirus infecting Xanthomonas citri, the causative agent of Asian citrus canker. Its linear 384,670 bp double-stranded DNA genome encodes 592 proteins and presents the longest (66 kbp) direct terminal repeats (DTRs) among sequenced viral genomes. The DTRs harbor 56 tRNA genes, which correspond to all 20 amino acids and represent the largest number of tRNA genes reported in a viral genome.

Lysogenic Conversion of the Phytopathogen by the P2virus Ï•RSY1.

A P2-like phage Ï•RSY1 infecting the phytopathogen was isolated and characterized. The 40-kb genome of Ï•RSY1 showed high sequence similarity to the phage Ï•RSA1 and the GMI1000 prophage Ï•RSX. The major genomic differences between these phages were the different orientation of the gene and the gene content close to the L.

Dynamic integration and excision of filamentous phage XacF1 in pv. , the causative agent of citrus canker disease.

Inovirus XacF1 (7325 nucleotides) is integrated into the genome of pv. () strains at the host site (B) by the host XerC/D recombination system. The XacF1 P sequence is located within the coding region of ORF12, a possible phage regulator.

Chitin synthesis by Chlorella cells infected by chloroviruses: Enhancement by adopting a slow-growing virus and treatment with aphidicolin.

Chlorella viruses or chloroviruses contain a gene that encodes an enzyme that catalyzes chitin synthesis. This gene is expressed early in viral infections to produce chitin on the outside of the Chlorella cell wall. Interestingly, chitin synthesis by microalgal Chlorella cells in combination with chloroviruses represents a unique eco-friendly process for converting solar energy and CO into useful materials.

Replications of Two Closely Related Groups of Jumbo Phages Show Different Level of Dependence on Host-encoded RNA Polymerase.

phages ΦRP12 and ΦRP31 are jumbo phages isolated in Thailand. Here we show that they exhibit similar virion morphology, genome organization and host range. Genome comparisons as well as phylogenetic and proteomic tree analyses support that they belong to the group of ΦKZ-related phages, with their closest relatives being phages ΦRSL2 and ΦRSF1.

Two asian jumbo phages, Ï•RSL2 and Ï•RSF1, infect Ralstonia solanacearum and show common features of Ï•KZ-related phages.

Jumbo phages infecting Ralstonia solanacearum were isolated in Thailand (Ï•RSL2) and Japan (Ï•RSF1). They were similar regarding virion morphology, genomic arrangement, and host range. Phylogenetic and proteomic tree analyses demonstrate that the Ï•RSL2 and Ï•RSF1 belong to a group of evolutionary related phages, including Pseudomonas phages Ï•KZ, 201Ï•2-1 and all previously described Ï•KZ-related phages.

Genomic diversity of large-plaque-forming podoviruses infecting the phytopathogen Ralstonia solanacearum.

The genome organization, gene structure, and host range of five podoviruses that infect Ralstonia solanacearum, the causative agent of bacterial wilt disease were characterized. The phages fell into two distinctive groups based on the genome position of the RNA polymerase gene (i.e.

The involvement of the PilQ secretin of type IV pili in phage infection in Ralstonia solanacearum.

PilQ is a member of the secretin family of outer membrane proteins and specifically involved in type IV secretion. Here we report the effects of pilQ mutation in Ralstonia solanacearum on the host physiology including susceptibility to several phage types (Inoviridae, Podoviridae and Myoviridae). With three lines of cells, namely wild type, ΔpilQ and pilQ-complemented cells, the cell surface proteins, twitching motility and sensitivity to phages were compared.

Identification of the mcpA and mcpM genes, encoding methyl-accepting proteins involved in amino acid and l-malate chemotaxis, and involvement of McpM-mediated chemotaxis in plant infection by Ralstonia pseudosolanacearum (formerly Ralstonia solanacearum phylotypes I and III).

Sequence analysis has revealed the presence of 22 putative methyl-accepting chemotaxis protein (mcp) genes in the Ralstonia pseudosolanacearum GMI1000 genome. PCR analysis and DNA sequencing showed that the highly motile R. pseudosolanacearum strain Ps29 possesses homologs of all 22 R.

The filamentous phage XacF1 causes loss of virulence in Xanthomonas axonopodis pv. citri, the causative agent of citrus canker disease.

In this study, filamentous phage XacF1, which can infect Xanthomonas axonopodis pv. citri (Xac) strains, was isolated and characterized. Electron microscopy showed that XacF1 is a member of the family Inoviridae and is about 600 nm long.

Insights into the diversity of φRSM phages infecting strains of the phytopathogen Ralstonia solanacearum complex: regulation and evolution.

The filamentous φRSM phages (φRSM1 and φRSM3) have integration/excision capabilities in the phytopathogenic bacterium Ralstonia solanacearum. In the present study, we further investigated φRSM-like sequences present in the genomes of R. solanacearum strains belonging to the four major evolutionary lineages (phylotypes I-IV).

Characterization of bacteriophages Cp1 and Cp2, the strain-typing agents for Xanthomonas axonopodis pv. citri.

The strains of Xanthomonas axonopodis pv. citri, the causative agent of citrus canker, are historically classified based on bacteriophage (phage) sensitivity. Nearly all X.

Hyaluronan synthesis in cultured tobacco cells (BY-2) expressing a chlorovirus enzyme: cytological studies.

Extraction of hyaluronan from animals or microbial fermentation has risks including contamination with pathogens and microbial toxins. In this work, tobacco cultured-cells (BY-2) were successfully transformed with a chloroviral hyaluronan synthase (cvHAS) gene to produce hyaluronan. Cytological studies revealed accumulation of HA on the cells, and also in subcellular fractions (protoplasts, miniplasts, vacuoplasts, and vacuoles).

Cryo-electron microscopy three-dimensional structure of the jumbo phage ΦRSL1 infecting the phytopathogen Ralstonia solanacearum.

ϕRSL1 jumbo phage belongs to a new class of viruses within the Myoviridae family. Here, we report its three-dimensional structure determined by electron cryo microscopy. The icosahedral capsid, the tail helical portion, and the complete tail appendage were reconstructed separately to resolutions of 9 Å, 9 Å, and 28 Å, respectively.

Prolonged synthesis of hyaluronan by Chlorella cells infected with chloroviruses.

Hyaluronan (HA) synthesis by microalgal Chlorella cells in combination with chloroviruses represents a unique eco-friendly process for converting solar energy and CO2 into useful materials. However, at the final stage of viral infection, infected host cells are completely lysed, and thus HA should be harvested before cell lysis. In the current study, two methods were investigated to improve the yield of HA: (i) adopting slow-growing chlorovirus isolates and (ii) modification of the virus replication process using an inhibitor of DNA synthesis, aphidicolin.

Utilization of Filamentous Phage Ï•RSM3 to Control Bacterial Wilt Caused by Ralstonia solanacearum.

The wide host range of Ralstonia solanacearum, causal agent of bacterial wilt, and its ability to survive for long periods in the environment restrict the effectiveness of cultural and chemical control measures. The use of phages for disease control is a fast-expanding trend of plant protection with great potential to replace chemical measures. The filamentous phage Ï•RSM3 that infects R.

Loss of virulence of the phytopathogen Ralstonia solanacearum through infection by φRSM filamentous phages.

φRSM1 and φRSM3 (φRSM phages) are filamentous phages (inoviruses) that infect Ralstonia solanacearum, the causative agent of bacterial wilt. Infection by φRSM phages causes several cultural and physiological changes to host cells, especially loss of virulence. In this study, we characterized changes related to the virulence in φRSM3-infected cells, including (i) reduced twitching motility and reduced amounts of type IV pili (Tfp), (ii) lower levels of β-1,4-endoglucanase (Egl) activity and extracellular polysaccharides (EPS) production, and (iii) reduced expression of certain genes (egl, pehC, phcA, phcB, pilT, and hrpB).

The filamentous phage Ï•RSS1 enhances virulence of phytopathogenic Ralstonia solanacearum on tomato.

Ralstonia solanacearum is the causative agent of bacterial wilt in many important crops. Ï•RSS1 is a filamentous phage that infects R. solanacearum strains.