scholarly journals Survival Strategies of Streptococcus pyogenes in Response to Phage Infection

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 612
Author(s):  
Dior Beerens ◽  
Sandra Franch-Arroyo ◽  
Timothy J. Sullivan ◽  
Christian Goosmann ◽  
Volker Brinkmann ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Membrane Vesicles ◽  
Phage Infection ◽  
Survival Strategies ◽  
Modular Organization ◽  
Lytic Phage ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Double Stranded Dna ◽  
Insight Into

Bacteriophages exert strong evolutionary pressure on their microbial hosts. In their lytic lifecycle, complete bacterial subpopulations are utilized as hosts for bacteriophage replication. However, during their lysogenic lifecycle, bacteriophages can integrate into the host chromosome and alter the host’s genomic make-up, possibly resulting in evolutionary important adjustments. Not surprisingly, bacteria have evolved sophisticated immune systems to protect against phage infection. Streptococcus pyogenes isolates are frequently lysogenic and their prophages have been shown to be major contributors to the virulence of this pathogen. Most S. pyogenes phage research has focused on genomic prophages in relation to virulence, but little is known about the defensive arsenal of S. pyogenes against lytic phage infection. Here, we characterized Phage A1, an S. pyogenes bacteriophage, and investigated several mechanisms that S. pyogenes utilizes to protect itself against phage predation. We show that Phage A1 belongs to the Siphoviridae family and contains a circular double-stranded DNA genome that follows a modular organization described for other streptococcal phages. After infection, the Phage A1 genome can be detected in isolated S. pyogenes survivor strains, which enables the survival of the bacterial host and Phage A1 resistance. Furthermore, we demonstrate that the type II-A CRISPR-Cas system of S. pyogenes acquires new spacers upon phage infection, which are increasingly detectable in the absence of a capsule. Lastly, we show that S. pyogenes produces membrane vesicles that bind to phages, thereby limiting the pool of phages available for infection. Altogether, this work provides novel insight into survival strategies employed by S. pyogenes to combat phage predation.

scholarly journals Viral satellites exploit phage proteins to escape degradation of the bacterial host chromosome

2019 ◽  
Author(s):  
Amelia C. McKitterick ◽  
Stephanie G. Hays ◽  
Munirul Alam ◽  
Kimberley D. Seed
Keyword(s):  
Vibrio Cholerae ◽  
Bacterial Genome ◽  
Lytic Phage ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Defense Systems ◽  
Phage Production ◽  
Phage Proteins ◽  
Insight Into ◽  
Phage Activity

SummaryPhage defense systems are often found on mobile genetic elements (MGEs), where they constitutively defend against invaders or are induced to respond to new assaults. Some MGEs, the phage satellites, exploit phages for their own transmission after induction, reducing phage production and protecting their hosts in the process. One such satellite inVibrio cholerae, PLE, is triggered by the lytic phage ICP1 to excise from the chromosome, replicate, and transduce to neighboring cells, completely sabotaging phage production. Here, we found that ICP1 has evolved to possess one of two syntenic loci encoding an SF1B-type helicase, either of which PLE can exploit to directly drive PLE replication. Further, loss of PLE mobilization limits anti-phage activity due to phage-mediated degradation of the bacterial genome. Our work provides insight into the unique challenges imposed on the parasites of lytic phages and underscores the adaptions of these satellites to their ever-evolving target phage.

scholarly journals Cryptic-Prophage-Encoded Small Protein DicB Protects Escherichia coli from Phage Infection by Inhibiting Inner Membrane Receptor Proteins

2019 ◽  
Vol 201 (23) ◽  
Author(s):  
Preethi T. Ragunathan ◽  
Carin K. Vanderpool
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Phage Infection ◽  
Gene Products ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Small Protein ◽  
Content Type ◽  
Bacterial Physiology ◽  
K 12

ABSTRACT Bacterial genomes harbor cryptic prophages that have lost genes required for induction, excision from host chromosomes, or production of phage progeny. Escherichia coli K-12 strains contain a cryptic prophage, Qin, that encodes a small RNA, DicF, and a small protein, DicB, that have been implicated in control of bacterial metabolism and cell division. Since DicB and DicF are encoded in the Qin immunity region, we tested whether these gene products could protect the E. coli host from bacteriophage infection. Transient expression of the dicBF operon yielded cells that were ∼100-fold more resistant to infection by λ phage than control cells, and the phenotype was DicB dependent. DicB specifically inhibited infection by λ and other phages that use ManYZ membrane proteins for cytoplasmic entry of phage DNA. In addition to blocking ManYZ-dependent phage infection, DicB also inhibited the canonical sugar transport activity of ManYZ. Previous studies demonstrated that DicB interacts with MinC, an FtsZ polymerization inhibitor, causing MinC localization to midcell and preventing Z ring formation and cell division. In strains producing mutant MinC proteins that do not interact with DicB, both DicB-dependent phenotypes involving ManYZ were lost. These results suggest that DicB is a pleiotropic regulator of bacterial physiology and cell division and that these effects are mediated by a key molecular interaction with the cell division protein MinC. IMPORTANCE Temperate bacteriophages can integrate their genomes into the bacterial host chromosome and exist as prophages whose gene products play key roles in bacterial fitness and interactions with eukaryotic host organisms. Most bacterial chromosomes contain “cryptic” prophages that have lost genes required for production of phage progeny but retain genes of unknown function that may be important for regulating bacterial host physiology. This study provides such an example, where a cryptic-prophage-encoded product can perform multiple roles in the bacterial host and influence processes, including metabolism, cell division, and susceptibility to phage infection. Further functional characterization of cryptic-prophage-encoded functions will shed new light on host-phage interactions and their cellular physiological implications.

scholarly journals Cryptic prophage-encoded small protein DicB protects Escherichia coli from phage infection by inhibiting inner membrane receptor proteins

2019 ◽  
Author(s):  
Preethi T. Ragunathan ◽  
Carin K. Vanderpool
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Functional Characterization ◽  
Phage Infection ◽  
Gene Products ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Small Protein ◽  
Bacterial Physiology ◽  
Bacteriophage Infection

AbstractBacterial genomes harbor cryptic prophages that have lost genes required for induction, excision from host chromosomes, or production of phage progeny. Escherichia coli K12 strains contain a cryptic prophage Qin that encodes a small RNA, DicF, and small protein, DicB, that have been implicated in control of bacterial metabolism and cell division. Since DicB and DicF are encoded in the Qin immunity region, we tested whether these gene products could protect the E. coli host from bacteriophage infection. Transient expression of the dicBF operon yielded cells that were ~100-fold more resistant to infection by λ phage than control cells, and the phenotype was DicB-dependent. DicB specifically inhibited infection by λ and other phages that use ManYZ membrane proteins for cytoplasmic entry of phage DNA. In addition to blocking ManYZ-dependent phage infection, DicB also inhibited the canonical sugar transport activity of ManYZ. Previous studies demonstrated that DicB interacts with MinC, an FtsZ polymerization inhibitor, causing MinC localization to mid-cell and preventing Z ring formation and cell division. In strains producing mutant MinC proteins that do not interact with DicB, both DicB-dependent phenotypes involving ManYZ were lost. These results suggest that DicB is a pleiotropic regulator of bacterial physiology and cell division, and that these effects are mediated by a key molecular interaction with the cell division protein MinC.ImportanceTemperate bacteriophages can integrate their genomes into the bacterial host chromosome and exist as prophages whose gene products play key roles in bacterial fitness and interactions with eukaryotic host organisms. Most bacterial chromosomes contain “cryptic” prophages that have lost genes required for production of phage progeny but retain genes of unknown function that may be important for regulating bacterial host physiology. This study provides such an example – where a cryptic prophage-encoded product can perform multiple roles in the bacterial host and influence processes including metabolism, cell division, and susceptibility to phage infection. Further functional characterization of cryptic prophage-encoded functions will shed new light on host-phage interactions and their cellular physiological implications.

Mechanistic insight into the recognition of single-stranded and double-stranded DNA substrates by ABH2 and ABH3

2010 ◽  
Vol 6 (11) ◽  
pp. 2143 ◽  
Author(s):  
Baoen Chen ◽  
Hongchuan Liu ◽  
Xiaoxu Sun ◽  
Cai-Guang Yang
Keyword(s):  
Double Stranded Dna ◽  
Mechanistic Insight ◽  
Dna Substrates ◽  
Insight Into

scholarly journals Mechanism of riboregulation of p62 protein oligomerisation by vault RNA1-1 in selective autophagy

2021 ◽  
Author(s):  
Magdalena Buescher ◽  
Rastislav Horos ◽  
Kevin Haubrich ◽  
Nikolay Dobrev ◽  
Florence Baudin ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Membrane Vesicles ◽  
Underlying Mechanism ◽  
Selective Autophagy ◽  
Ubiquitinated Proteins ◽  
Flexible Loop ◽  
Structure Probing ◽  
Molecular Determinants ◽  
Necessary And Sufficient ◽  
Insight Into

Macroautophagy ensures the clearance of intracellular substrates ranging from single ubiquitinated proteins to large proteotoxic aggregates and defective organelles. The selective autophagy receptor p62 binds these targets and recruits them to double-membrane vesicles, which fuse with lysosomes to degrade their content. We recently uncovered that p62 function is riboregulated by the small non-coding vault RNA1-1. Here, we present detailed insight into the underlying mechanism. We show that the PB1 domain and adjacent linker region of p62 (aa 1-122) are necessary and sufficient for specific vault RNA1-1 binding, and identify lysine 7 and arginine 21 as key hinges for p62 riboregulation. Chemical structure probing of vault RNA1-1 further reveals a central flexible loop within the RNA that mediates the specific p62 interaction. Our data define molecular determinants that govern mammalian autophagy via the p62-vault RNA1-1 riboregulatory pair.

scholarly journals A Novel Benthic Phage Infecting Shewanella with Strong Replication Ability

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1081 ◽  
Author(s):  
Zengmeng Wang ◽  
Jiulong Zhao ◽  
Long Wang ◽  
Chengcheng Li ◽  
Jianhui Liu ◽  
...  
Keyword(s):  
Burst Size ◽  
Coastal Sediments ◽  
The Yellow Sea ◽  
Comparative Genomic ◽  
Lytic Phage ◽  
Host Interactions ◽  
Metabolic Genes ◽  
Double Stranded Dna ◽  
Auxiliary Metabolic Genes ◽  
Structure Assembly

The coastal sediments were considered to contain diverse phages playing important roles in driving biogeochemical cycles based on genetic analysis. However, till now, benthic phages in coastal sediments were very rarely isolated, which largely limits our understanding of their biological characteristics. Here, we describe a novel lytic phage (named Shewanella phage S0112) isolated from the coastal sediments of the Yellow Sea infecting a sediment bacterium of the genus Shewanella. The phage has a very high replication capability, with the burst size of ca. 1170 phage particles per infected cell, which is 5–10 times higher than that of most phages isolated before. Meanwhile, the latent period of this phage is relatively longer, which might ensure adequate time for phage replication. The phage has a double-stranded DNA genome comprising 62,286 bp with 102 ORFs, ca. 60% of which are functionally unknown. The expression products of 16 ORF genes, mainly structural proteins, were identified by LC-MS/MS analysis. Besides the general DNA metabolism and structure assembly genes in the phage genome, there is a cluster of auxiliary metabolic genes that may be involved in 7-cyano-7-deazaguanine (preQ0) biosynthesis. Meanwhile, a pyrophosphohydrolase (MazG) gene being considered as a regulator of programmed cell death or involving in host stringer responses is inserted in this gene cluster. Comparative genomic and phylogenetic analysis both revealed a great novelty of phage S0112. This study represents the first report of a benthic phage infecting Shewanella, which also sheds light on the phage–host interactions in coastal sediments.

scholarly journals Complete Genome Sequence of Mycobacteriophage Faze9

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
John Grossi ◽  
John Shebby ◽  
Christopher W. Brey
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Mycobacterium Smegmatis ◽  
Complete Genome ◽  
Lytic Phage ◽  
Content Type ◽  
Double Stranded Dna

Mycobacteriophage Faze9 is a novel lytic phage that was isolated from soil collected in Scranton, PA, using the host Mycobacterium smegmatis mc2155. Faze9 has a double-stranded DNA genome composed of 67,503 kbp, has a G+C content of 68.9%, encodes 91 predicted proteins, and is closely related to mycobacteriophages in the B2 subcluster. 

The genome of Oryctes rhinoceros nudivirus provides novel insight into the evolution of nuclear arthropod-specific large circular double-stranded DNA viruses

Virus Genes ◽  
2011 ◽  
Vol 42 (3) ◽  
pp. 444-456 ◽  
Author(s):  
Yongjie Wang ◽  
Olaf R. P. Bininda-Emonds ◽  
Monique M. van Oers ◽  
Just M. Vlak ◽  
Johannes A. Jehle
Keyword(s):  
Dna Viruses ◽  
Oryctes Rhinoceros ◽  
Double Stranded Dna ◽  
Insight Into

scholarly journals Insight into DNA and Protein Transport in Double-Stranded DNA Viruses: The Structure of Bacteriophage N4

2008 ◽  
Vol 378 (3) ◽  
pp. 726-736 ◽  
Author(s):  
Kyung H. Choi ◽  
Jennifer McPartland ◽  
Irene Kaganman ◽  
Valorie D. Bowman ◽  
Lucia B. Rothman-Denes ◽  
...  
Keyword(s):  
Protein Transport ◽  
Dna Viruses ◽  
Double Stranded Dna ◽  
Bacteriophage N4 ◽  
Insight Into
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