Salmonella virus P22

Last updated
Bacteriophage P22.tif
Salmonella virus P22
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Duplodnaviria
Kingdom: Heunggongvirae
Phylum: Uroviricota
Class: Caudoviricetes
Order: Caudovirales
Family: Podoviridae
Genus: Lederbergvirus
Species:
Salmonella virus P22

Salmonella virus P22 is a bacteriophage in the Podoviridae family that infects Salmonella typhimurium . [1] Like many phages, it has been used in molecular biology to induce mutations in cultured bacteria and to introduce foreign genetic material. [2] P22 has been used in generalized transduction and is an important tool for investigating Salmonella genetics. [1]

Contents

Morphology, classification and relatives

Schematic drawing of an Enterobacteria phage P22 virion (cross section and side view) P22likevirus virion.jpg
Schematic drawing of an Entero­bacteria phage P22 virion (cross section and side view)

P22 shares many similarities in genetic structure and regulation with bacteriophage λ. [1] It is a temperate double stranded DNA phage as well as a lambdoid phage since it carries control of gene expression regions and early operons similar to those of bacteriophage λ. [3] However, the genes which encode proteins that build the virion are different from those of bacteriophage λ. [3] P22 has a 60 nm diameter icosahedral (T=7) virion head and a short tail. [3] This virion morphology puts P22 in the formal Podoviridae group. [3] Traditionally, P22 is associated with viruses with similar genomic transcription patterns and life cycles including bacteriophage λ and all the other lambdoid phages. However, this relatedness seems to be overestimated. [4] Other relatives with similar short-tailed morphology and DNA homology in the protein genes of the virion include bacteriophages λ and Ε34. [3] Many Podoviridae, for example phages T7 and Φ29, share few DNA similarities with P22, even though their virion morphologies are similar. [3]

Genomics

P22 tail accessory factor
Identifiers
SymbolP22_Tail-4
Pfam PF11650
InterPro IPR020362
Available protein structures:
Pfam   structures / ECOD  
PDB RCSB PDB; PDBe; PDBj
PDBsum structure summary

P22 has a linear, double-stranded DNA chromosome within its virion that is about 44 kilobases long with blunt ends and a circular genetic map. [3] However, its "wild type" nucleotide sequence is about 42 kilobases long. [3] The genome of P22 has been sequenced and sixty five genes have been annotated. [1] The sequencing results support the hypothesis that phage P22 is a virus that has evolved through extensive recombination with other viruses. [1]

P22 research has focused on its differences from bacteriophage λ including the mechanisms by which it circularizes DNA upon infection and packages DNA into the virion. [3] Prior to leaving the host cell, virion chromosomes are packaged into capsids from concatemers of the sequence that result from rolling circle DNA replication. [3] The P22 packaged DNA carries a direct duplication of about 4% at both ends since the inside of the virion has more space than is filled by 100% of the sequence. [3] This process is called "headful packaging" since replicated DNA is "stuffed" into the virion until it is full, rather than filling each virion with a single copy of the sequence. [3] This usually encompasses 48Kb, so part of the host DNA is transferred along with the phage.

After host infection, the linear P22 virion DNA is circularized by a homologous recombination event between the direct repeats at both ends of the chromosome. [3] This can be done by host rec gene products, but also by P22 recombination function genes in the absence of host enzymes. [3] The circularized DNA containing one copy of the P22 nucleotide sequence is the substrate for gene expression and DNA replication. [3]

Life cycle

The P22 tailspike protein is anchored in the viral coat and used to aid in penetrating the membranes of host cells. P22's tailspike has an unusual beta helix fold. Infection begins when the gp9 tailspike of the P22 phage binds to the O-antigen lipopolysaccharide on the surface of Salmonella typhimurium host. [1] The virion's tail fiber protein has endorhamnosidase activity, which cleaves the O-antigen chain. [3] Upon infection, P22 can enter either a lytic or lysogenic growth pathway. [1] In the lytic pathway, viral replication proceeds immediately following infection and releases approximately 300–500 phage progeny via cell lysis within an hour. [1] However, in the lysogenic pathway, the phage chromosome integrates into the host chromosome and is passed to daughter cells through cell division. [1] The primary factor controlling the growth pathway is the multiplicity of infection (moi); high moi favors lysogenic pathway and low moi favors lytic pathway. [1]

Assembly pathway

The viral capsid has been the subject of studies in P22 virus assembly. Like other large dsDNA viruses, P22 first builds a protein "procapsid" structure and then packages it with the DNA chromosome. [3] P22 procapsid is assembled by a well-studied protein. [3] About 250 molecules of scaffolding protein are present in the procapsid during assembly, but during DNA packaging, the scaffolding protein is released. [3] The released scaffolding protein is not damaged and can re-assemble with newly synthesized coat protein to make more procapsids. [3]

In laboratory infections, scaffolding protein molecules participate in 5 rounds of procapsid assembly on average. [3] Since P22 scaffolding protein mediates the assembly of other proteins without becoming part of the finished structure, it is acting catalytically. [3] The action scaffolding protein in procapsid assembly is common in other large icosahedral viruses including the herpes viruses of eukaryotes, but in some cases the scaffold is proteolytically removed instead of being reused. [3] In addition, P22 scaffolding protein may represses the synthesis of additional scaffolding protein when not assembled into procapsids. [3]

The products of three adjacent genes are required for the stabilization of the condensed DNA within P22 phage capsids: Gp4, Gp10 and Gp26. [5] These proteins act by plugging the hole through which the DNA enters. [6] These three proteins appear to polymerise onto the newly filled capsids to form the neck of the mature phage through which DNA will be injected into a cell. Gp4 (P22 tail accessory factor) is the first tail accessory factor to be added to newly DNA-filled capsids during P22-morphogenesis. In solution, the protein acts as a monomer and has low structural stability. The interaction of gp4 with the portal protein involves the binding of two non-equivalent sets of six gp4 proteins. Gp4 acts as a structural adaptor for gp10 and gp26, the other tail accessory factors. [7]

Application to Salmonella genetic research

Transduction has been used extensively in bacterial genetics and is useful in strain construction. [8] In general, transduction within each bacterial species requires use of a specific phage; for example, P22 has been used for transduction in S. enterica sv. Typhimurium. [8] A significant factor in the development of the genetics of S. enterica has been the ease of use of P22 for transductional crosses. [8] In particular, P22 is stable in storage, high-titer stocks are easily obtained, and high-frequency transduction (HT) and integration-deficient mutants have been isolated. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Lambda phage</span> Bacteriophage that infects Escherichia coli

Enterobacteria phage λ is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli. It was discovered by Esther Lederberg in 1950. The wild type of this virus has a temperate life cycle that allows it to either reside within the genome of its host through lysogeny or enter into a lytic phase, during which it kills and lyses the cell to produce offspring. Lambda strains, mutated at specific sites, are unable to lysogenize cells; instead, they grow and enter the lytic cycle after superinfecting an already lysogenized cell.

<span class="mw-page-title-main">Prophage</span> Bacteriophage genome that is integrated into a bacterial cell

A prophage is a bacteriophage genome that is integrated into the circular bacterial chromosome or exists as an extrachromosomal plasmid within the bacterial cell. Integration of prophages into the bacterial host is the characteristic step of the lysogenic cycle of temperate phages. Prophages remain latent in the genome through multiple cell divisions until activation by an external factor, such as UV light, leading to production of new phage particles that will lyse the cell and spread. As ubiquitous mobile genetic elements, prophages play important roles in bacterial genetics and evolution, such as in the acquisition of virulence factors.

<span class="mw-page-title-main">Transduction (genetics)</span> Transfer process in genetics

Transduction is the process by which foreign DNA is introduced into a cell by a virus or viral vector. An example is the viral transfer of DNA from one bacterium to another and hence an example of horizontal gene transfer. Transduction does not require physical contact between the cell donating the DNA and the cell receiving the DNA, and it is DNase resistant. Transduction is a common tool used by molecular biologists to stably introduce a foreign gene into a host cell's genome.

<span class="mw-page-title-main">Lytic cycle</span> Cycle of viral reproduction

The lytic cycle is one of the two cycles of viral reproduction, the other being the lysogenic cycle. The lytic cycle results in the destruction of the infected cell and its membrane. Bacteriophages that only use the lytic cycle are called virulent phages.

<i>Escherichia virus T4</i> Species of bacteriophage

Escherichia virus T4 is a species of bacteriophages that infect Escherichia coli bacteria. It is a double-stranded DNA virus in the subfamily Tevenvirinae from the family Myoviridae. T4 is capable of undergoing only a lytic life cycle and not the lysogenic life cycle. The species was formerly named T-even bacteriophage, a name which also encompasses, among other strains, Enterobacteria phage T2, Enterobacteria phage T4 and Enterobacteria phage T6.

Microviridae is a family of bacteriophages with a single-stranded DNA genome. The name of this family is derived from the ancient Greek word μικρός (mikrós), meaning "small". This refers to the size of their genomes, which are among the smallest of the DNA viruses. Enterobacteria, intracellular parasitic bacteria, and spiroplasma serve as natural hosts. There are 22 species in this family, divided among seven genera and two subfamilies.

<span class="mw-page-title-main">Viral replication</span> Formation of biological viruses during the infection process

Viral replication is the formation of biological viruses during the infection process in the target host cells. Viruses must first get into the cell before viral replication can occur. Through the generation of abundant copies of its genome and packaging these copies, the virus continues infecting new hosts. Replication between viruses is greatly varied and depends on the type of genes involved in them. Most DNA viruses assemble in the nucleus while most RNA viruses develop solely in cytoplasm.

<span class="mw-page-title-main">T7 phage</span> Species of virus

Bacteriophage T7 is a bacteriophage, a virus that infects bacteria. It infects most strains of Escherichia coli and relies on these hosts to propagate. Bacteriophage T7 has a lytic life cycle, meaning that it destroys the cell it infects. It also possesses several properties that make it an ideal phage for experimentation: its purification and concentration have produced consistent values in chemical analyses; it can be rendered noninfectious by exposure to UV light; and it can be used in phage display to clone RNA binding proteins.

Escherichia virus HK97, often shortened to HK97, is a species of virus that infects Escherichia coli and related bacteria. It is named after Hong Kong (HK), where it was first located. HK97 has a double-stranded DNA genome.

P1 is a temperate bacteriophage that infects Escherichia coli and some other bacteria. When undergoing a lysogenic cycle the phage genome exists as a plasmid in the bacterium unlike other phages that integrate into the host DNA. P1 has an icosahedral head containing the DNA attached to a contractile tail with six tail fibers. The P1 phage has gained research interest because it can be used to transfer DNA from one bacterial cell to another in a process known as transduction. As it replicates during its lytic cycle it captures fragments of the host chromosome. If the resulting viral particles are used to infect a different host the captured DNA fragments can be integrated into the new host's genome. This method of in vivo genetic engineering was widely used for many years and is still used today, though to a lesser extent. P1 can also be used to create the P1-derived artificial chromosome cloning vector which can carry relatively large fragments of DNA. P1 encodes a site-specific recombinase, Cre, that is widely used to carry out cell-specific or time-specific DNA recombination by flanking the target DNA with loxP sites.

<i>Escherichia virus T5</i> Species of virus

Escherichia virus T5, sometimes called Bacteriophage T5 is a caudal virus within the family Demerecviridae. This bacteriophage specifically infects E. coli bacterial cells and follows a lytic life cycle.

<span class="mw-page-title-main">Bacteriophage P2</span> Species of virus

Bacteriophage P2, scientific name Escherichia virus P2, is a temperate phage that infects E. coli. It is a tailed virus with a contractile sheath and is thus classified in the genus Peduovirus, subfamily Peduovirinae, family Myoviridae within order Caudovirales. This genus of viruses includes many P2-like phages as well as the satellite phage P4.

A prohead or procapsid is an immature viral capsid structure formed in the early stages of self-assembly of some bacteriophages, including the Caudovirales or tailed bacteriophages. Production and assembly of stable proheads is an essential precursor to bacteriophage genome packaging; this packaging activity can be replicated in vitro. The prohead structure may take a different shape from the head of a mature virion, as seen with the prohead of Bacillus subtilis phage φ29.

<i>Spiroplasma phage 1-R8A2B</i> Species of virus

Spiroplasma phage 1-R8A2B is a filamentous bacteriophage in the genus Vespertiliovirus of the family Plectroviridae, part of the group of single-stranded DNA viruses. The virus has many synonyms, such as SpV1-R8A2 B, Spiroplasma phage 1, and Spiroplasma virus 1, SpV1. SpV1-R8A2 B infects Spiroplasma citri. Its host itself is a prokaryotic pathogen for citrus plants, causing Citrus stubborn disease.

<i>Teseptimavirus</i> Genus of viruses

Teseptimavirus is a genus of viruses in the order Caudovirales, in the family Autographiviridae, in the subfamily Studiervirinae. Bacteria serve as the natural host, with transmission achieved through passive diffusion. There are currently 17 species in this genus, including the type species Escherichia virus T7.

Lederbergvirus is a genus of viruses in the order Caudovirales, in the family Podoviridae. Bacteria serve as natural hosts, with transmission achieved through passive diffusion. There are six species in this genus.

Escherichia virus CC31, formerly known as Enterobacter virus CC31, is a dsDNA bacteriophage of the subfamily Tevenvirinae responsible for infecting the bacteria family of Enterobacteriaceae. It is one of two discovered viruses of the genus Karamvirus, diverging away from the previously discovered T4virus, as a clonal complex (CC). CC31 was first isolated from Escherichia coli B strain S/6/4 and is primarily associated with Escherichia, even though is named after Enterobacter.

Arbitrium is a viral peptide produced by bacteriophages to communicate with each other and decide host cell fate. It is six amino acids(aa) long, and so is also referred to as a hexapeptide. It is produced when a phage infects a bacterial host. and signals to other phages that the host has been infected.

<i>Duplodnaviria</i> Realm of viruses

Duplodnaviria is a realm of viruses that includes all double-stranded DNA viruses that encode the HK97 fold major capsid protein. The HK97 fold major capsid protein is the primary component of the viral capsid, which stores the viral deoxyribonucleic acid (DNA). Viruses in the realm also share a number of other characteristics, such as an icosahedral capsid, an opening in the viral capsid called a portal, a protease enzyme that empties the inside of the capsid prior to DNA packaging, and a terminase enzyme that packages viral DNA into the capsid.

<span class="mw-page-title-main">Integration host factor</span>

The integration host factor (IHF) is a bacterial DNA binding protein complex that facilitates genetic recombination, replication, and transcription by binding to specific DNA sequences and bending the DNA. It also facilitates the integration of foreign DNA into the host genome. It is a heterodimeric complex composed of two homologous subunits IHFalpha and IHFbeta.

References

  1. 1 2 3 4 5 6 7 8 9 10 Peter E. Prevelige Jr. (2006). Richard Calender (ed.). The Bacteriophages (2nd ed.). New York, New York: Oxford University Press. pp. 457–468. ISBN   978-0-19-514850-3.
  2. ↑ Snyder L, Champness W (2007). Molecular Genetics of Bacteria (3rd ed.). ASM Press. ISBN   978-1-55581-399-4.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Casjens, Sherwood. "Information about bacteriophage P22". ASM Division M: Bacteriophage P22. American Society for Microbiology. Archived from the original on 26 December 2010. Retrieved 15 April 2012.
  4. ↑ Ackermann, H. W. (2015). "The lambda - P22 problem". Bacteriophage. 5 (1): e1017084. doi:10.1080/21597081.2015.1017084. PMC   4422791 . PMID   26442187.
  5. ↑ Strauss H, King J (February 1984). "Steps in the stabilization of newly packaged DNA during phage P22 morphogenesis". J. Mol. Biol. 172 (4): 523–43. doi:10.1016/S0022-2836(84)80021-2. PMID   6363718.
  6. ↑ Eppler K, Wyckoff E, Goates J, Parr R, Casjens S (August 1991). "Nucleotide sequence of the bacteriophage P22 genes required for DNA packaging". Virology. 183 (2): 519–38. doi:10.1016/0042-6822(91)90981-G. PMID   1853558.
  7. ↑ Olia AS, Al-Bassam J, Winn-Stapley DA, Joss L, Casjens SR, Cingolani G (2006). "Binding-induced stabilization and assembly of the phage P22 tail accessory factor gp4". J Mol Biol. 363 (2): 558–76. doi:10.1016/j.jmb.2006.08.014. PMID   16970964.
  8. 1 2 3 4 Neal, B. L.; P. K. Brown; P. R. Reeves (November 1993). "Use of Salmonella Phage P22 for Transduction in Escherichia coli". Journal of Bacteriology. 175 (21): 7115–7118. doi:10.1128/jb.175.21.7115-7118.1993. PMC   206843 . PMID   8226656.
This article incorporates text from the public domain Pfam and InterPro: IPR020362

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.