Polyhedrin

Last updated

For the three dimensional shape, see Polyhedron

Polyhedrin dodekamer, Cypovirus 1. 5exy.jpg
Polyhedrin dodekamer, Cypovirus 1.
Polyhedrin
Jmol2WUX.pdb.jpg
The crystal structure of recombinant baculovirus polyhedra. [1]
Identifiers
SymbolPolyhedrin
Pfam PF00738
InterPro IPR001746

Polyhedrins are proteins that form the Baculovirus occlusion bodies (also known as Polyhedra), large structures that protect the virus particles from the outside environment for extended periods until they are ingested by other susceptible insect population. The structure of polyhedrin comprises multiple beta strands, three alpha helices, and two pi helices, and are often covered in a polysaccharide coat. The polysaccharide coat confers integrity to the structure of the occlusion bodies, allowing it to remain viable in the environment for up to 40–50 years. [2]

They occur in various viruses including Nuclear polyhedrosis virus (NPV) and Granulovirus (GV). GV is singly enveloped and have one virus particle per occlusion. This is while NPVs have the potential to package multiple virus genomes in an occlusion. The occlusion bodies are usually formed in nucleus of virus infected cells approximately 2 days after the infection.

Related Research Articles

Capsid

A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid.

Biomolecule Molecule that is produced by a living organism

A biomolecule or biological molecule is a loosely used term for molecules present in organisms that are essential to one or more typically biological processes, such as cell division, morphogenesis, or development. Biomolecules include large macromolecules such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites and natural products. A more general name for this class of material is biological materials. Biomolecules are an important element of living organisms, those biomolecules are often endogenous, produced within the organism but organisms usually need exogenous biomolecules, for example certain nuts, to survive.

Rabies virus Species of virus

Rabies lyssavirus, formerly Rabies virus (RABV), is a neurotropic virus that causes rabies in humans and animals. Rabies transmission can occur through the saliva of animals and less commonly through contact with human saliva. Rabies lyssavirus, like many rhabdoviruses, has an extremely wide host range. In the wild it has been found infecting many mammalian species, while in the laboratory it has been found that birds can be infected, as well as cell cultures from mammals, birds, reptiles and insects.

Filamentous bacteriophage

Filamentous bacteriophage is a family of viruses (Inoviridae) that infect bacteria. The phages are named for their filamentous shape, a worm-like chain, about 6 nm in diameter and about 1000-2000 nm long. The coat of the virion comprises five types of viral protein, which are located during phage assembly in the inner membrane of the host bacteria, and are added to the nascent virion as it extrudes through the membrane. The simplicity of this family makes it an attractive model system to study fundamental aspects of molecular biology, and it has also proven useful as a tool in immunology and nanotechnology.

Polydnavirus

A polydnavirus (PDV) is a member of the family Polydnaviridae of insect viruses. There are currently 53 species in this family, divided among 2 genera. Polydnaviruses form a symbiotic relationship with parasitoid wasps, but these wasps are themselves parasitic on Lepidoptera. Little or no sequence homology exists between BV and IV, suggesting that the two genera evolved independently for a long time.

<i>Baculoviridae</i>

Baculoviridae is a family of viruses. Arthropods, lepidoptera, hymenoptera, and diptera serve as natural hosts. There are currently 84 species in this family, divided among four genera.

White spot syndrome (WSS) is a viral infection of penaeid shrimp. The disease is highly lethal and contagious, killing shrimp quickly. Outbreaks of this disease have wiped out the entire populations of many shrimp farms within a few days, in places throughout the world.

<i>Cypovirus</i>

Cypovirus, short for cytoplasmic polyhedrosis virus, is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Cypoviruses have only been isolated from insects. Diseases associated with this genus include: larvae chronic disease. There are currently 16 species in this genus including the type species Cypovirus 1.

<i>Escherichia virus MS2</i>

Escherichia virus MS2 is an icosahedral, positive-sense single-stranded RNA virus that infects the bacterium Escherichia coli and other members of the Enterobacteriaceae. MS2 is a member of a family of closely related bacterial viruses that includes bacteriophage f2, bacteriophage Qβ, R17, and GA.

A-DNA

A-DNA is one of the possible double helical structures which DNA can adopt. A-DNA is thought to be one of three biologically active double helical structures along with B-DNA and Z-DNA. It is a right-handed double helix fairly similar to the more common B-DNA form, but with a shorter, more compact helical structure whose base pairs are not perpendicular to the helix-axis as in B-DNA. It was discovered by Rosalind Franklin, who also named the A and B forms. She showed that DNA is driven into the A form when under dehydrating conditions. Such conditions are commonly used to form crystals, and many DNA crystal structures are in the A form. The same helical conformation occurs in double-stranded RNAs, and in DNA-RNA hybrid double helices.

Cydia pomonella granulovirus (CpGV) is a granulovirus belonging to the family Baculoviridae. It has a double-stranded DNA genome that is 123,500 base pairs in length with 143 ORFs. The virus forms small bodies called granules containing a single virion. CpGV is a virus of invertebrates – specifically Cydia pomonella, commonly known as the Codling moth. CpGV is highly pathogenic, it is known as a fast GV – that is, one that will kill its host in the same instar as infection; thus, it is frequently used as a biological pesticide.

Signal recognition particle RNA

The signal recognition particle RNA, is part of the signal recognition particle (SRP) ribonucleoprotein complex. SRP recognizes the signal peptide and binds to the ribosome, halting protein synthesis. SRP-receptor is a protein that is embedded in a membrane, and which contains a transmembrane pore. When the SRP-ribosome complex binds to SRP-receptor, SRP releases the ribosome and drifts away. The ribosome resumes protein synthesis, but now the protein is moving through the SRP-receptor transmembrane pore.

The nuclear polyhedrosis virus (NPV), part of the family of baculoviruses, is a virus affecting insects, predominantly moths and butterflies. It has been used as a pesticide.

E1 (HCV)

E1 is one of two subunits of the envelope glycoprotein found in the hepatitis C virus. The other subunit is E2. This protein is a type 1 transmembrane protein with a highly glycosylated N-terminal ectodomain and a C-terminal hydrophobic anchor. After being synthesized the E1 glycoproteins associates with the E2 glycoprotein as a noncovalent heterodimer.

BacMam

Baculovirus gene transfer into Mammalian cells, known from scientific research articles as BacMam, is the use of baculovirus to deliver genes to mammalian cells. Baculoviruses are insect cell viruses that can be modified to express proteins in mammalian cells. The unmodified baculovirus is able to enter mammalian cells, however its genes are not expressed unless a mammalian recognizable promoter is incorporated upstream of a gene of interest. Both unmodified baculovirus and baculovirus modified with a mammalian promoter (BacMam) are unable to replicate in humans and are thus non infectious.

Lymantria dispar multicapsid nuclear polyhedrosis virus or LdMNPV is a viral infection in gypsy moths that causes infected larvae to die and disintegrate. Infected larvae climb to the top of a tree and die. The larvae then melt or disintegrate, falling onto the foliage below, where they infect more larvae.

V-cath endopeptidase is an enzyme. This enzyme catalyses the following chemical reaction

Early 35 kDa protein

The Early 35 kDa protein, or P35 in short, is a baculoviral protein that inhibits apoptosis in the cells infected by the virus. Although baculoviruses infect only invertebrates in nature, ectopic expression of P35 in vertebrate animals and cells also results in inhibition of apoptosis, thus indicating a universal mechanism. P35 has been shown to be a caspase inhibitor with a very wide spectrum of activity both in regard to inhibited caspase types and to species in which the mechanism is conserved.

Flock House virus (FHV) is in the alphanodavirus genus of the Nodaviridae family of viruses. Flock House virus was isolated from a grass grub at the Flock House research station in Bulls, New Zealand. FHV is an extensively studied virus and is considered a model system for the study of other non-enveloped RNA viruses owing to its small size and genetic tractability, particularly to study the role of the transiently exposed hydrophobic gamma peptide and the metastability of the viral capsid. FHV can be engineered in insect cell culture allowing for the tailored production of native or mutant authentic virions or virus-like-particles. FHV is a platform for nanotechnology and nanomedicine, for example, for epitope display and vaccine development. Viral entry into host cells occurs via receptor-mediated endocytosis. Receptor binding initiates a sequence of events during which the virus exploits the host environment in order to deliver the viral cargo in to the host cytosol. Receptor binding prompts the meta-stability of the capsid–proteins, the coordinated rearrangements of which are crucial for subsequent steps in the infection pathway. In addition, the transient exposure of a covalently-independent hydrophobic γ-peptide is responsible for breaching cellular membranes and is thus essential for the viral entry of FHV into host cells.

Helicoverpa zea nudivirus 2 is an enveloped, rod-shaped, nonoccluded, double stranded DNA (dsDNA) sexually transmitted virus whose natural host is the corn earworm moth. At about 440 by 90 nm, it is the causative agent of the only sexually transmitted viral disease of any insect. It was originally identified in a colony of corn earworm moths established and maintained in Stoneville, Mississippi, U.S. and was found to be responsible for the sterility of those infected.

References

  1. PDB: 2WUX ; Ji X, Sutton G, Evans G, Axford D, Owen R, Stuart DI (January 2010). "How baculovirus polyhedra fit square pegs into round holes to robustly package viruses". EMBO J. 29 (2): 505–14. doi:10.1038/emboj.2009.352. PMC   2824454 . PMID   19959989.
  2. Rohrmann (1986). "Polyhedrin structure". J Gen Virol. 67 (8): 1499–513. doi: 10.1099/0022-1317-67-8-1499 . PMID   3525744.