Cystoviridae: A family of bacteriophages containing one genus (Cystovirus) with one member (BACTERIOPHAGE PHI 6).Bacteriophage phi 6: Virulent bacteriophage and sole member of the genus Cystovirus that infects Pseudomonas species. The virion has a segmented genome consisting of three pieces of doubled-stranded DNA and also a unique lipid-containing envelope.RNA, Double-Stranded: RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. Most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms.Totiviridae: A family of RNA viruses that infect fungi and protozoa. There are three genera: TOTIVIRUS; GIARDIAVIRUS; and LEISHMANIAVIRUS.Reoviridae: A family of unenveloped RNA viruses with cubic symmetry. The twelve genera include ORTHOREOVIRUS; ORBIVIRUS; COLTIVIRUS; ROTAVIRUS; Aquareovirus, Cypovirus, Phytoreovirus, Fijivirus, Seadornavirus, Idnoreovirus, Mycoreovirus, and Oryzavirus.Birnaviridae: A family of bisegmented, double-stranded RNA viruses causing infection in fish, mollusks, fowl, and Drosophila. There are three genera: AQUABIRNAVIRUS; AVIBIRNAVIRUS; and ENTOMOBIRNAVIRUS. Horizontal and vertical transmission occurs for all viruses.RNA Viruses: Viruses whose genetic material is RNA.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Nucleic Acids: High molecular weight polymers containing a mixture of purine and pyrimidine nucleotides chained together by ribose or deoxyribose linkages.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)Illusions: The misinterpretation of a real external, sensory experience.DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Oligonucleotide Probes: Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.Pseudomonas Phages: Viruses whose host is Pseudomonas. A frequently encountered Pseudomonas phage is BACTERIOPHAGE PHI 6.Tectiviridae: A family of lipid-containing bacteriophages with double capsids which infect both gram-negative and gram-positive bacteria. It has one genus, Tectivirus.Myoviridae: A family of BACTERIOPHAGES and ARCHAEAL VIRUSES which are characterized by complex contractile tails.Pseudomonas: A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.Corticoviridae: A family of icosahedral, lipid-containing, non-enveloped bacteriophages containing one genus (Corticovirus).Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Terminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.GermanyRed Cross: International collective of humanitarian organizations led by volunteers and guided by its Congressional Charter and the Fundamental Principles of the International Red Cross Movement, to provide relief to victims of disaster and help people prevent, prepare for, and respond to emergencies.Classification: The systematic arrangement of entities in any field into categories classes based on common characteristics such as properties, morphology, subject matter, etc.Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Editorial Policies: The guidelines and policy statements set forth by the editor(s) or editorial board of a publication.Indigo Carmine: Indolesulfonic acid used as a dye in renal function testing for the detection of nitrates and chlorates, and in the testing of milk.BooksVanilla: A plant genus of the family ORCHIDACEAE that is the source of the familiar flavoring used in foods and medicines (FLAVORING AGENTS).Paeonia: A plant genus of the family Paeoniaceae, order Dilleniales, subclass Dilleniidae, class Magnoliopsida. These perennial herbs are up to 2 m (6') tall. Leaves are alternate and are divided into three lobes, each lobe being further divided into three smaller lobes. The large flowers are symmetrical, bisexual, have 5 sepals, 5 petals (sometimes 10), and many stamens.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Virus Cultivation: Process of growing viruses in live animals, plants, or cultured cells.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Virus Assembly: The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Coronavirus: A genus of the family CORONAVIRIDAE which causes respiratory or gastrointestinal disease in a variety of vertebrates.Camels: Hoofed mammals with four legs, a big-lipped snout, and a humped back belonging to the family Camelidae.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Coronavirus Infections: Virus diseases caused by the CORONAVIRUS genus. Some specifics include transmissible enteritis of turkeys (ENTERITIS, TRANSMISSIBLE, OF TURKEYS); FELINE INFECTIOUS PERITONITIS; and transmissible gastroenteritis of swine (GASTROENTERITIS, TRANSMISSIBLE, OF SWINE).Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Oligodeoxyribonucleotides: A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.Middle East: The region of southwest Asia and northeastern Africa usually considered as extending from Libya on the west to Afghanistan on the east. (From Webster's New Geographical Dictionary, 1988)Authorship: The profession of writing. Also the identity of the writer as the creator of a literary production.Sinorhizobium: A genus of gram-negative, aerobic, nonsporeforming rods which usually contain granules of poly-beta-hydroxybutyrate. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Click Chemistry: Organic chemistry methodology that mimics the modular nature of various biosynthetic processes. It uses highly reliable and selective reactions designed to "click" i.e., rapidly join small modular units together in high yield, without offensive byproducts. In combination with COMBINATORIAL CHEMISTRY TECHNIQUES, it is used for the synthesis of new compounds and combinatorial libraries.Students: Individuals enrolled in a school or formal educational program.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Students, Medical: Individuals enrolled in a school of medicine or a formal educational program in medicine.SARS Virus: A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Mutation Rate: The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.

Self-assembly of a viral molecular machine from purified protein and RNA constituents. (1/25)

We present the assembly of the polymerase complex (procapsid) of a dsRNA virus from purified recombinant proteins. This molecular machine packages and replicates viral ssRNA genomic precursors in vitro. After addition of an external protein shell, these in vitro self-assembled viral core particles can penetrate the host plasma membrane and initiate a productive infection. Thus, a viral procapsid has been assembled and rendered infectious using purified components. Using this system, we have studied the mechanism of assembly of the common dsRNA virus shell and the incorporation of a symmetry mismatch within an icosahedral capsid. Our work demonstrates that this molecular machine, self-assembled under defined conditions in vitro, can function in its natural environment, the cell cytoplasm.  (+info)

Characterization of phi12, a bacteriophage related to phi6: nucleotide sequence of the large double-stranded RNA. (2/25)

The isolation of additional bacteriophages besides phi6 containing segmented double-stranded RNA genomes (dsRNA) has expanded the Cystoviridae family to nine members. Comparing the genomic sequences of these viruses has allowed evaluation of important genetic as well as structural motifs. These comparative studies are resulting in greater understanding of viral evolution and the role played by genetic and structural variation in the assembly mechanisms of the cystoviruses. In this regard, the large double-stranded RNA genomic segment of bacteriophage phi12 was copied as cDNA and its nucleotide sequence determined. This genome's organization is similar to that of the large segment of bacteriophages phi6, phi8, and phi13. In the amino acid sequence of the viral RNA-dependent RNA polymerase (P2), similarity was found to the comparable proteins of phi6, phi8, and phi13. Amino acid sequence similarity was also noted in the nucleotide triphosphate phosphorylase (P4) to the comparable proteins of phi8 and phi13.  (+info)

Cloning of complete genome sets of six dsRNA viruses using an improved cloning method for large dsRNA genes. (3/25)

Cloning full-length large (>3 kb) dsRNA genome segments from small amounts of dsRNA has thus far remained problematic. Here, a single-primer amplification sequence-independent dsRNA cloning procedure was perfected for large genes and tailored for routine use to clone complete genome sets or individual genes. Nine complete viral genome sets were amplified by PCR, namely those of two human rotaviruses, two African horsesickness viruses (AHSV), two equine encephalosis viruses (EEV), one bluetongue virus (BTV), one reovirus and bacteriophage Phi12. Of these amplified genomes, six complete genome sets were cloned for viruses with genes ranging in size from 0.8 to 6.8 kb. Rotavirus dsRNA was extracted directly from stool samples. Co-expressed EEV VP3 and VP7 assembled into core-like particles that have typical orbivirus capsomeres. This work presents the first EEV sequence data and establishes that EEV genes have the same conserved termini (5' GUU and UAC 3') and coding assignment as AHSV and BTV. To clone complete genome sets, one-tube reactions were developed for oligo-ligation, cDNA synthesis and PCR amplification. The method is simple and efficient compared to other methods. Complete genomes can be cloned from as little as 1 ng dsRNA and a considerably reduced number of PCR cycles (22-30 cycles compared to 30-35 of other methods). This progress with cloning large dsRNA genes is important for recombinant vaccine development and determination of the role of terminal sequences for replication and gene expression.  (+info)

Unique properties of the inner core of bacteriophage phi8, a virus with a segmented dsRNA genome. (4/25)

The inner core of bacteriophage phi8 is capable of packaging and replicating the plus strands of the RNA genomic segments of the virus in vitro. The particles composed of proteins P1, P2, P4, and P7 can be assembled in cells of E. coli that carry plasmids with cDNA copies of genomic segment L. The gene arrangement on segment L was found to differ from that of other cystoviruses in that the gene for the ortholog of protein P7 is located at the 3' end of the plus strand rather than near the 5' end. In place of the normal location of gene 7 is gene H, whose product is necessary for normal phage development, but not necessary for in vitro genomic packaging and replication. Genomic packaging is dependent upon the activity of an NTPase motor protein, P4. P4 was purified from cell extracts and was found to form hexamers with little NTPase activity until associated with inner core particles. Labeling studies of in vitro packaging of phi8 RNA do not show serial dependence; however, studies involving in vitro packaging for the formation of live virus indicate that packaging is stringent. Studies with the acquisition of chimeric segments in live virus indicate that phi8 does package RNA in the order s/m/l. The inner core of bacteriophage phi8 differs from that of its relatives in the Cystoviridae in that the major structural protein P1 is able to interact with the host cell membrane to effect penetration of the inner core into the cell.  (+info)

RNA packaging device of double-stranded RNA bacteriophages, possibly as simple as hexamer of P4 protein. (5/25)

Genomes of complex viruses have been demonstrated, in many cases, to be packaged into preformed empty capsids (procapsids). This reaction is performed by molecular motors translocating nucleic acid against the concentration gradient at the expense of NTP hydrolysis. At present, the molecular mechanisms of packaging remain elusive due to the complex nature of packaging motors. In the case of the double-stranded RNA bacteriophage phi 6 from the Cystoviridae family, packaging of single-stranded genomic precursors requires a hexameric NTPase, P4. In the present study, the purified P4 proteins from two other cystoviruses, phi 8 and phi 13, were characterized and compared with phi 6 P4. All three proteins are hexameric, single-stranded RNA-stimulated NTPases with alpha/beta folds. Using a direct motor assay, we found that phi 8 and phi 13 P4 hexamers translocate 5' to 3' along ssRNA, whereas the analogous activity of phi 6 P4 requires association with the procapsid. This difference is explained by the intrinsically high affinity of phi 8 and phi 13 P4s for nucleic acids. The unidirectional translocation results in RNA helicase activity. Thus, P4 proteins of Cystoviridae exhibit extensive similarity to hexameric helicases and are simple models for studying viral packaging motor mechanisms.  (+info)

Temperature requirements for initiation of RNA-dependent RNA polymerization. (6/25)

To continue the molecular characterization of RNA-dependent RNA polymerases of dsRNA bacteriophages (Cystoviridae), we purified and biochemically characterized the wild-type (wt) and a temperature-sensitive (ts) point mutant of the polymerase subunit (Pol) from bacteriophage phi12. Interestingly, initiation by both wt and the ts phi12 Pol was notably more sensitive to increased temperatures than the elongation step, the absolute value of the nonpermissive temperature being lower for the ts enzyme. Experiments with the Pol subunit of related cystovirus phi6 revealed a similar differential sensitivity of the initiation and elongation steps. This is consistent with the previous result showing that de novo initiation by RdRp from dengue virus is inhibited at elevated temperatures, whereas the elongation phase is relatively thermostable. Overall, these data suggest that de novo RNA-dependent RNA synthesis in many viral systems includes a specialized thermolabile state of the RdRp initiation complex.  (+info)

Construction of carrier state viruses with partial genomes of the segmented dsRNA bacteriophages. (7/25)

The cystoviridae are bacteriophages with genomes of three segments of dsRNA enclosed within a polyhedral capsid. Two members of this family, Phi6 and Phi8, have been shown to form carrier states in which the virus replicates as a stable episome in the host bacterium while expressing reporter genes such as kanamycin resistance or lacalpha. The carrier state does not require the activity of all the genes necessary for phage production. It is possible to generate carrier states by infecting cells with virus or by electroporating nonreplicating plasmids containing cDNA copies of the viral genomes into the host cells. We have found that carrier states in both Phi6 and Phi8 can be formed at high frequency with all three genomic segments or with only the large and small segments. The large genomic segment codes for the proteins that constitute the inner core of the virus, which is the structure responsible for the packaging and replication of the genome. In Phi6, a carrier state can be formed with the large and middle segment if mutations occur in the gene for the major structural protein of the inner core. In Phi8, carrier state formation requires the activity of genes 8 and 12 of segment S.  (+info)

Packaging motor from double-stranded RNA bacteriophage phi12 acts as an obligatory passive conduit during transcription. (8/25)

Double-stranded RNA viruses sequester their genomes within a protein shell, called the polymerase complex. Translocation of ssRNA into (packaging) and out (transcription) of the polymerase complex are essential steps in the life cycle of the dsRNA bacteriophages of the Cystoviridae family (phi6-phi14). Both processes require a viral molecular motor P4, an NTPase, which bears structural and functional similarities to hexameric helicases. In effect, switching between the packaging and the transcription mode requires the translocation direction of the P4 motor to reverse. However, the mechanism of the reversal remains elusive. Here we characterize the P4 protein from bacteriophage phi12 and exploit its purine nucleotide specificity to delineate P4 role in transcription. The results indicate that while P4 actively translocates RNA during packaging it acts as a passive conduit for RNA export. The directionality switching is accomplished via the regulation of P4 NTPase activity within the polymerase core.  (+info)

These pages were created in support of the dsRNA Virus Symposia. The editors also wish to acknowledge continuing support from BBSRC, DEFRA and the Commission of the European Community. ...
The importance of the P3 protein in host switching events in phage ϕ6 has been previously established [36, 45]. This study confirmed this observation, but additionally brought to light the importance of the P12 protein in host switching events. This non-structural protein controls the liberation of mature ϕ6 particles from the host cytoplasmic membrane, but is not incorporated into the virion [46]. Like many eukaryotic viruses, Cystoviridae have envelopes comprised of both viral proteins and host lipids. Different hosts may have different lipid constituents which are contributed to the viral envelope and thus may require slightly altered P12 proteins for efficient envelope assembly. We have already shown that phage ϕ6 maturation in ERA affects fitness when the virion infects PP, and vice versa[25, 36]. We assume this epigenetic effect is mediated by the lipids taken from these very different hosts, and we speculate that our current results may relate to the importance of host lipid ...
Cystovirus is a genus of viruses, in the family Cystoviridae. Pseudomonas syringae pathovar phaseolicola bacteria serve as natural hosts. There is currently only one species in this genus: the type species Pseudomonas phage phi6. Group: dsRNA Order: Unassigned Family: Cystoviridae Genus: Cystovirus Pseudomonas phage phi6 Pseudomonas phage phi8 Pseudomonas phage phi12 Pseudomonas phage phi13 Pseudomonas phage phi2954 Pseudomonas phage phiNN Pseudomonas phage phiYY Cystoviruses are distinguished by their tripartite dsRNA genome, totaling ~14 kb in length and their protein and lipid outer layer. No other bacteriophage has any lipid in its outer coat, though the Tectiviridae and the Corticoviridae have lipids within their capsids. Most identified cystoviruses infect Pseudomonas species, but this is likely biased due to the method of screening and enrichment. The type species is Pseudomonas phage phi6, but there are many other proposed members of this family. Pseudomonas phage φ7, φ8, φ9, φ10, ...
Bacteriophages are perceived to be good models for the study of airborne viruses because they are safe to use, some of them display structural features similar to those of human and animal viruses, and they are relatively easy to produce in large quantities. Yet, only a few studies have investigated them as models. It has previously been demonstrated that aerosolization, environmental conditions, and sampling conditions affect viral infectivity, but viral infectivity is virus dependent. Thus, several virus models are likely needed to study their general behavior in aerosols. The aim of this study was to compare the effects of aerosolization and sampling on the infectivity of five tail-less bacteriophages and two pathogenic viruses: MS2 (a single-stranded RNA [ssRNA] phage of the Leviviridae family), F6 (a segmented double-stranded RNA [dsRNA] phage of the Cystoviridae family), FX174 (a single-stranded DNA [ssDNA] phage of the Microviridae family), PM2 (a double-stranded DNA [dsDNA] phage of the ...
By a genetic approach, a number of mutants affected in quelling, RNAi, or PTGS have been isolated, leading to the identification of eight genes controlling these phenomena (21-23, 26, 27, 29, 33, 43, 44). QDE-1, QDE-2, and QDE-3 genes, required for quelling in the fungus N. crassa, encode proteins similar to tomato RNA-directed RNA polymerase, rabbit translation initiation factor eIF2C, and E. coli RecQ DNA helicase, respectively (21, 29, 44), whereas EGO-1, RDE-1, and MUT-7 genes required for RNAi in the nematode C. elegans encode proteins similar to tomato RNA-directed RNA polymerase, rabbit translation initiation factor eIF2C, and E. coli RNaseD, respectively (23, 26, 27). SGS2 and SGS3 genes, required for PTGS in A. thaliana, encode a protein similar to tomato RNA-directed RNA polymerase and a protein of unknown function, respectively (22). The finding of one set of related proteins shared by PTGS, quelling, and RNAi (SGS2/QDE-1/EGO-1), therefore, suggested that these three mechanisms could ...
Experimental and directed evolution using microbes offer powerful methods for uncovering processes of evolution across the tree of life. The goal of such experiments is to generate mutational diversity, either through propagation of microbes in stressful conditions (experimental evolution) or through artificial introduction of mutations into their genomes (directed evolution). In the case of multiple resulting mutations, each is then reverse engineered into the ancestral genotype individually to determine how it changes the phenotype of interest. This thesis presents the results of one experimental evolution project (evolution of viral thermostability under increasing temperatures) and one directed evolution project (diversification of toxin-antitoxin protein pairs in bacteria), including both evolutionary and single-mutation analyses. In both cases, I found that mutations may persist in a population due to their pleiotropic effects on traits other than the focal one of the study. My thesis ...
I study how sex, social interactions, and ecology shape viral evolution. Viruses frequently infect the same cell, leading to conflicts of interest over cell resources. Viruses can evolve to exploit other co-infecting viruses and increase their reproduction at the expense other viruses. I work with viruses isolated from the environment, using a variety of lab techniques to understand the evolution of sexual strategies and their relationship with ecology.. I currently study genetic exchange among RNA viruses (Cystoviruses) that infect Pseudomonas bacteria. The genome of these phages is divided into three segments. Sex occurs when phages swap their segments while reproducing within a cell (reassortment). Reassortment occurs in other viruses, such as influenza, and is an important factor in determining the capacity to infect new hosts, evade immune responses or vaccines, and adapt to new environments. Some of my research questions using the Pseudomonas-Cystovirus system are: How frequent is genetic ...
RNA-dependent RNA polymerase which is responsible for replication and transcription of virus RNA segments. The transcription of viral mRNAs occurs by a unique mechanism called cap-snatching. 5 methylated caps of cellular mRNAs are cleaved after 10-13 nucleotides by PA. In turn, these short capped RNAs are used as primers by PB1 for transcription of viral mRNAs. During virus replication, PB1 initiates RNA synthesis and copy vRNA into complementary RNA (cRNA) which in turn serves as a template for the production of more vRNAs.
RNA-dependent RNA polymerase which is responsible for replication and transcription of virus RNA segments. The transcription of viral mRNAs occurs by a unique mechanism called cap-snatching. 5 methylated caps of cellular mRNAs are cleaved after 10-13 nucleotides by PA. In turn, these short capped RNAs are used as primers by PB1 for transcription of viral mRNAs. During virus replication, PB1 initiates RNA synthesis and copy vRNA into complementary RNA (cRNA) which in turn serves as a template for the production of more vRNAs.
The PDB archive contains information about experimentally-determined structures of proteins, nucleic acids, and complex assemblies. As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.
Nucleic acid sandwich hybridization assays are provided that incorporate one or a combination of background reduction steps. Those steps include use of a separate capture probe and separation from immobilized capture probes by cleavage and isolation. A very sensitive assay for RNA targets includes both of those steps, plus RNA binary probes, an RNA-directed RNA ligase and amplification by an RNA-directed RNA polymerase. Kits of reagents for performing assays according to this invention are also provided.
According to National Geographic, the inner core of the Earth ranges between 9,000 and 13,000 degrees Fahrenheit. This is approximately as high as the temperature of the suns...
Presence of pathogens without causing disease. Of particular relevance is the potential for these assymptomatic pathogens, or pathogens otherwise acting like organisms, to be transmitted to new hosts where disease in fact may then occur. See more or less equivalently the concept of carriers or, especially, (or ...
Viral structure Virus: poison (Latin); infectious particles consisting of a nucleic acid in a protein coat Capsid; (viral envelopes); DNA or RNA Bacteriophages (phages)
Cystoviridae. Enveloped, spherical. Segmented dsRNA. Fuselloviridae. Nonenveloped, lemon-shaped. Circular dsDNA. Globuloviridae ...
"ICTV Report Cystoviridae". "Viral Zone". ExPASy. Retrieved 15 June 2015. "NCBI Taxonomy Browser: Cystoviridae". NCBI. Retrieved ... Members of the Cystoviridae appear to be most closely related to the Reoviridae, but also share homology with the Totiviridae. ... Cystovirus is a genus of viruses, in the family Cystoviridae. Pseudomonas syringae pathovar phaseolicola bacteria serve as ... Group: dsRNA Order: Unassigned Family: Cystoviridae Genus: Cystovirus Pseudomonas phage phi6 Pseudomonas phage phi8 Pseudomonas ...
Familie Cystoviridae. *Genus Cystovirus. *Familie Megabirnaviridae. *Genus Megabirnavirus. *Familie Partitiviridae. *Genus ...
囊状噬菌体科 Cystoviridae. *低毒性病毒科 Hypoviridae ...
囊状噬菌体科 Cystoviridae. *低毒性病毒科 Hypoviridae ...
Bacteriophage Φ6, is a member of the Cystoviridae family. It infects Pseudomonas bacteria (typically plant-pathogenic P. ... Families Amalgaviridae Birnaviridae Chrysoviridae Cystoviridae Endornaviridae Hypoviridae Megabirnaviridae Partitiviridae ... Cystoviridae, and Totiviridae. The IBDV capsid protein exhibits structural domains that show homology to those of the capsid ...
Φ6 (Phi 6) is the best-studied bacteriophage of the virus family Cystoviridae. It infects Pseudomonas bacteria (typically plant ...
... a family of double-stranded RNA viruses called the Cystoviridae. However, metagenomics has led to the identification of ...
... the best-studied bacteriophage of the family Cystoviridae T7 phage, phage capable of infecting susceptible bacterial cells In ...
Cystoviridae Genus: Cystovirus Pseudomonas phage phi6 Family: Endornaviridae Genus: Endornavirus Bell pepper endornavirus ...
... cystoviridae MeSH B04.123.691.230.070 --- bacteriophage phi 6 MeSH B04.123.691.600 --- leviviridae MeSH B04.123.691.600.050 ...
Family Amalgaviridae Family Birnaviridae Family Chrysoviridae Family Cystoviridae Family Endornaviridae Family Hypoviridae ... Cystoviridae, Partitiviridae, and Reoviridae - and one additional order (Totiviridae) of one of the classes of positive ssRNA ... Birnaviridae and Cystoviridae, Nodaviridae, and Permutotretraviridae families. A number of satellite viruses - viruses that ...
... and Cystoviridae (dsRNA phages) Reoviridae family of dsRNA viruses. RNA transcription is similar to but not the same as DNA ... and the Cystoviridae, Reoviridae, Hypoviridae, Partitiviridae, Totiviridae families Mononegavirales (negative-strand RNA ...
Chrysoviridae Circoviridae Clavaviridae Closteroviridae Comovirinae Coronaviridae Coronavirinae Corticoviridae Cystoviridae ...
When retroviruses have integrated their own genome into the germ line, their genome is passed on to a following generation. These endogenous retroviruses (ERVs), contrasted with exogenous ones, now make up 5-8% of the human genome.[7] Most insertions have no known function and are often referred to as "junk DNA". However, many endogenous retroviruses play important roles in host biology, such as control of gene transcription, cell fusion during placental development in the course of the germination of an embryo, and resistance to exogenous retroviral infection. Endogenous retroviruses have also received special attention in the research of immunology-related pathologies, such as autoimmune diseases like multiple sclerosis, although endogenous retroviruses have not yet been proven to play any causal role in this class of disease.[8] While transcription was classically thought to occur only from DNA to RNA, reverse transcriptase transcribes RNA into DNA. The term "retro" in retrovirus refers to ...
The hepatitis envelope proteins are composed of subunits made from the viral preS1, preS2, and S genes. The L (for "large") envelope protein contains all three subunits. The M (for "medium") protein contains only preS2 and S. The S (for "small") protein contains only S. The genome portions encoding these envelope protein subuntis share both the same frame and the same stop codon (generating nested transcripts on a single open reading frame. The pre-S1 is encoded first (closest to the 5' end), followed directly by the pre-S2 and the S. When a transcript is made from the beginning of the pre-S1 region, all three genes are included in the transcript and the L protein is produced. When the transcript starts after the pro-S1 at the beginning of the pre-S2 the final protein contains the pre-S2 and S subunits only and therefore is an M protein. The smallest envelope protein containing just the S subunit is made most because it is encoded closest to the 3' end and comes from the shortest transcript. ...
Viruses in Betanodavirus are non-enveloped, with icosahedral geometries, and T=3 symmetry. The diameter is around 30 nm. Genomes are linear and segmented, bipartite, around 21.4kb in length.[8]. The crystal structure of a betanodavirus- T=3 Grouper nervous necrosis virus (GNNV)-like particle has been determined by X-ray crystallography. The virus-like particle contains 180 subunits of the capsid protein, and each capsid protein (CP) shows three major domains: (i) the N-terminal arm, an inter-subunit extension at the inner surface; (ii) the shell domain (S-domain), a jelly-roll structure; and (iii) the protrusion domain (P-domain) formed by three-fold trimeric protrusions. [10]. ...
Nucleic acid analysis suggests a very long association of the viruses with the wasps (greater than 70 million years).. Two proposals have been advanced for how the wasp/virus association developed. The first suggests that the virus is derived from wasp genes. Many parasitoids that do not use PDVs inject proteins that provide many of the same functions, that is, a suppression of the immune response to the parasite egg. In this model, the braconid and ichneumonid wasps packaged genes for these functions into the viruses-essentially creating a gene-transfer system that results in the caterpillar producing the immune-suppressing factors. In this scenario, the PDV structural proteins (capsids) were probably "borrowed" from existing viruses.. The alternative proposal suggests that ancestral wasps developed a beneficial association with an existing virus that eventually led to the integration of the virus into the wasp's genome. Following integration, the genes responsible for virus replication and the ...
Louis Pasteur was unable to find a causative agent for rabies and speculated about a pathogen too small to be detected using a microscope.[21] In 1884, the French microbiologist Charles Chamberland invented a filter (known today as the Chamberland filter or the Pasteur-Chamberland filter) with pores smaller than bacteria. Thus, he could pass a solution containing bacteria through the filter and completely remove them from the solution.[22] In 1892, the Russian biologist Dmitri Ivanovsky used this filter to study what is now known as the tobacco mosaic virus. His experiments showed that crushed leaf extracts from infected tobacco plants remain infectious after filtration. Ivanovsky suggested the infection might be caused by a toxin produced by bacteria, but did not pursue the idea.[23] At the time it was thought that all infectious agents could be retained by filters and grown on a nutrient medium - this was part of the germ theory of disease.[2] In 1898, the Dutch microbiologist Martinus ...
The Herpesvirales naming system originated in 1973 and has been elaborated considerably since. All herpesviruses described since this system was adopted have been named in accordance with it. The recommended naming system specifies that each species name consists of three parts: a first word, a second word, and finally a number. The first word should be derived from the taxon (family or subfamily) to which its primary natural host belongs. The subfamily name is used for viruses from members of the family Bovidae or from primates (the virus name ending in -ine, e.g. bovine), and the host family name for other viruses (ending in -id, e.g. equid). Human herpesviruses have been treated as an exception (human rather than hominid). Following the host-derived term, species in the family Herpesviridae, which are divided into subfamilies Alphaherpesvirinae, Betaherpesvirinae, and Gammaherpesvirinae, will have the word alphaherpesvirus, betaherpesvirus, or gammaherpesvirus added, respectively. Species in ...
Despite his other successes, Louis Pasteur (1822-1895) was unable to find a causative agent for rabies and speculated about a pathogen too small to be detected using a microscope.[1] In 1884, the French microbiologist Charles Chamberland (1851-1931) invented a filter - known today as the Chamberland filter - that had pores smaller than bacteria. Thus, he could pass a solution containing bacteria through the filter and completely remove them from the solution.[2] In 1876, Adolf Mayer, who directed the Agricultural Experimental Station in Wageningen was the first to show that what he called "Tobacco Mosaic Disease" was infectious, he thought that it was caused by either a toxin or a very small bacterium. Later, in 1892, the Russian biologist Dmitry Ivanovsky (1864-1920) used a Chamberland filter to study what is now known as the tobacco mosaic virus. His experiments showed that crushed leaf extracts from infected tobacco plants remain infectious after filtration. Ivanovsky suggested the infection ...
The Birnaviridae genome encodes several proteins: Birnaviridae RNA-directed RNA polymerase (VP1), which lacks the highly conserved Gly-Asp-Asp (GDD) sequence, a component of the proposed catalytic site of this enzyme family that exists in the conserved motif VI of the palm domain of other RNA-directed RNA polymerases.[3] The large RNA segment, segment A, of birnaviruses codes for a polyprotein (N-VP2-VP4-VP3-C) [4] that is processed into the major structural proteins of the virion: VP2, VP3 (a minor structural component of the virus), and into the putative protease VP4.[4] VP4 protein is involved in generating VP2 and VP3.[4] recombinant VP3 is more immunogenic than recombinant VP2.[5] Infectious pancreatic necrosis virus (IPNV), a birnavirus, is an important pathogen in fish farms. Analyses of viral proteins showed that VP2 is the major structural and immunogenic polypeptide of the virus.[6][7] All neutralizing monoclonal antibodies are specific to VP2 and bind to continuous or discontinuous ...
Mononegavirales adalah ordo virus RNA yang berada dalam filum Negarnaviricota dan kelas Monjiviricetes.[1] Nama Mononegavirales berasa dari bahasa Yunani μóνος [monos] yang merujuk pada genom untai tunggal pada sebagian besar ordo ini, bahasa Latin negare yang merujuk pada sifat sense-negatif genom virus, serta akhiran -virales yang menunjukkan ordo virus.[2] Anggota ordo ini yang dikenal di antaranya virus rabies dan virus Ebola yang dapat menyebabkan penyakit, baik pada manusia maupun hewan. ...
Birnaviridae · Chrysoviridae · Cystoviridae · Hypoviridae · Partitiviridae · Reoviridae (Rotavirus) · Totiviridae. IV: (+)ssRNA ...
"ICTV Report Cystoviridae". "Viral Zone". ExPASy. Retrieved 15 June 2015. "NCBI Taxonomy Browser: Cystoviridae". NCBI. Retrieved ... Members of the Cystoviridae appear to be most closely related to the Reoviridae, but also share homology with the Totiviridae. ... Cystovirus is a genus of viruses, in the family Cystoviridae. Pseudomonas syringae pathovar phaseolicola bacteria serve as ... Group: dsRNA Order: Unassigned Family: Cystoviridae Genus: Cystovirus Pseudomonas phage phi6 Pseudomonas phage phi8 Pseudomonas ...
Cystoviridae CHAPTER UNDER CONSTRUCTION. Chapter Contents. Cystoviridae: The Family. *Citation. *Summary, properties, and ... Cystoviridae: The Genera. *Genus: Cystovirus. Cystoviridae: Supporting Information. *Authors - Corresponding author: Minna M. ... The viral genome (Figure 2.Cystoviridae) encodes structural (Figure 1.Cystoviridae) and non-structural proteins. The envelope ... The family Cystoviridae includes enveloped viruses with a tri-segmented dsRNA genome and a double-layered protein capsid. The ...
The genome segments and proteins of Pseudomonas phage Phi 6 (genus Cystovirus : family Cystoviridae) (updated 11/09/2002) ...
Cystoviridae. Enveloped, spherical. Segmented dsRNA. Fuselloviridae. Nonenveloped, lemon-shaped. Circular dsDNA. Globuloviridae ...
Cystoviridae. segmented. nonenveloped. Birnaviridae. Reoviridae. ss. nonsegmented. enveloped. Coronaviridae. Flaviviridae. ...
Familie Cystoviridae. *Genus Cystovirus. *Familie Megabirnaviridae. *Genus Megabirnavirus. *Familie Partitiviridae. *Genus ...
Cystoviridae. Genus. Cystovirus. Family. Endornaviridae. Genus. Endornavirus. Family. Partitiviridae. Genus. Partitivirus. ...
Cystoviridae. Plant Virus Groups. *Cryptoviruses. *Plant reoviruses (e.g. fujivirus and phytoreovirus groups) ...
Cystoviridae. Cystovirus. Pseudomonas phage ¯6. Bacteria. Hypoviridae:. Hypovirus. Cryphonectria hypovirus 1-EP713. Fungi. ...
囊状噬菌体科 Cystoviridae. *低毒性病毒科 Hypoviridae ...
囊状噬菌体科 Cystoviridae. *低毒性病毒科 Hypoviridae ...
Cystoviridae. Enterovirus. Filoviridae. Flaviviridae. Fuselloviridae. Geminiviridae. Globuloviridae. Guttaviridae. Hantavirus. ...
Family Cystoviridae. *Family Hypoviridae. *Family Partitiviridae. *Family Reoviridae - includes Rotavirus. *Family Totiviridae ...
Bacteriophage Φ6, is a member of the Cystoviridae family. It infects Pseudomonas bacteria (typically plant-pathogenic P. ... Families Amalgaviridae Birnaviridae Chrysoviridae Cystoviridae Endornaviridae Hypoviridae Megabirnaviridae Partitiviridae ... Cystoviridae, and Totiviridae. The IBDV capsid protein exhibits structural domains that show homology to those of the capsid ...
Outer capsids are part of reoviridae and cystoviridae virions. [UniProtKB-KW:KW-1152] ... Outer capsids are part of reoviridae and cystoviridae virions. [UniProtKB-KW:KW… (More) ...
Cystoviridae, Deltavirus, Dianthovirus, Enamovirus, Filoviridae, Flaviviridae, Furovirus, Fuselloviridae, Geminiviridae, ...
Recognition of six additional cystoviruses: Pseudomonas virus phi6 is no longer the sole species of the family Cystoviridae. ...
The fingers subdomains of λ3 and VP1 resemble those of RdRps from Flaviviridae and Cystoviridae families (HCV NS5B and ϕ6 P2) [ ... three-tunneled enzymes of the Cystoviridae family of dsRNA viruses (such as ϕ6 P2) only extrude dsRNA products. The (+)RNA ...
Pseudomonas phage φ6 of the Cystoviridae (16) appears unequivocally related to the reoviruses (52) of plant and animal hosts, ...
Family Cystoviridae (organism) {423847002 , SNOMED-CT } Parent/Child (Relationship Type) Genus Cystovirus (organism) {424604005 ...
Cystoviridae Enveloped, spherical Segmented dsRNA Fuselloviridae Nonenveloped, lemon-shaped Circular dsDNA Globuloviridae ...
... although RNA viral representation is low because only RefSeq-curated families Cystoviridae and Leviviridae were available (no ...
Family Cystoviridae (organism) {423847002 , SNOMED-CT } Other Relationships No other relationships present. ...
... ɸ6 of the Cystoviridae family, we show that dsRNA viruses can adopt a dsDNA-like single-spooled genome organization. We find ...
Cystoviridae Cystovirus Φ6 Other designations phi 6 ATCC21781-B1 phi6 Electron Micrograph ...
  • Accessed 27 Nov of which 19 are genome sequences of phages infecting Aeromonas (phages belonging to Myoviridae, Podoviridae, and Siphovirida e families) and 144 infecting Pseudomonas (phages belonging to Myoviridae, Podoviridae, Siphoviridae, Cystoviridae, Leviviridae, Inoviridae families and 5 unclassified). (biomedcentral.com)
  • The viral genome (Figure 2 .Cystoviridae ) encodes structural (Figure 1 .Cystoviridae ) and non-structural proteins. (ictvonline.org)
  • Twenty five new isolates of members of the Cystoviridae were obtained from the leaves of radish, carrot and onion plants. (beds.ac.uk)