Two clades of dsRNA viruses exist: the phylum "Duplornaviricota" and the class "Duplopiviricetes", which is in the phylum "Pisuviricota". Both are included in the kingdom "Orthornavirae" in the realm "Riboviria". Based on phylogenetic analysis of RdRp, the two clades do not share a common dsRNA ancestor but are instead separately descended from different positive-sense, single-stranded RNA viruses. In the Baltimore classification system, which groups viruses together based on their manner of mRNA synthesis, dsRNA viruses are group III.
Classification
Double-stranded RNA viruses
Double-stranded RNA viruses | Classification
The phylum "Duplornaviricota" and the class "Duplopiviricetes", which is in the phylum "Pisuviricota" viral RNA or siRNA The phylum "Duplornaviricota" and the class "Duplopiviricetes", which is in the phylum "Pisuviricota". Double-stranded RNA viruses are classified in two separate phyla "Duplornaviricota" and "Pisuviricota".
rna consists of how many chains of subunits
user
Small RNAs mainly include 5.8S ribosomal RNA (rRNA), 5S rRNA, transfer RNA (tRNA), microRNA (miRNA), small interfering RNA (siRNA), small nucleolar RNA (snoRNAs), Piwi-interacting RNA (piRNA), tRNA-derived small RNA (tsRNA) and small rDNA-derived RNA (srRNA)
assistant
are they also double-stranded?
user
Yes, Double-stranded RNA is RNA with two complementary strands
assistant
how is it different from dna?
user
Analysis of mRNA, tRNA, rRNA, snRNAs, and other non-coding RNAs  has revealed that self-complementary sequences that allow parts of the RNA to fold and pair with itself to form double helices and they are highly structured. Unlike DNA, their structures do not consist of long double helices, but rather collections of short helices packed together into structures akin to proteins
assistant
what is the function of the non-coding ones?
user
Silencing of blocks of chromatin via recruitment of Polycomb complex so that messenger RNA could not be transcribed from them
assistant
who discovered it?
user
Friedrich Miescher
assistant
what is its role in alzheimer?
user
Sorry. I cannot find the answer based on the context.
assistant
what is its double-stranded virus classified into?
user
The class "Duplopiviricetes" is the second clade of dsRNA viruses and is in the phylum "Pisuviricota", which also contains positive-sense single-stranded RNA viruses. "Duplopiviricetes" mostly contains plant and fungal viruses and includes the following four families: "Amalgaviridae", "Hypoviridae", "Partitiviridae", and "Picobirnaviridae".
Double-stranded RNA viruses | "Duplopiviricetes"
This small group of viruses, exemplified by the Hepatitis B virus, have a double-stranded, gapped genome that is subsequently filled in to form a covalently closed circle (cccDNA) that serves as a template for production of viral mRNAs and a subgenomic RNA. The pregenome RNA serves as template for the viral reverse transcriptase and for production of the DNA genome.
Viral replication | Class 7: Double-stranded DNA viruses that replicate through a single-stranded RNA intermediate
Moreover, the structural and functional similarities with dsRNA viruses of mammals has made it useful to consider these entities as viruses.
Double-stranded RNA viruses | "Saccharomyces cerevisiae" virus L-A
Double-stranded RNA viruses (dsRNA viruses) are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA polymerase (RdRp). The positive-strand RNA may be used as messenger RNA (mRNA) which can be translated into viral proteins by the host cell's ribosomes. The positive-strand RNA can also be replicated by the RdRp to create a new double-stranded viral genome. Double-stranded RNA viruses are classified in two separate phyla "Duplornaviricota" and "Pisuviricota" (specifically class "Duplopiviricetes"), which are in the kingdom "Orthornavirae" and realm "Riboviria". The two groups do not share a common dsRNA virus ancestor.
Double-stranded RNA viruses | Introduction
Like most viruses with RNA genomes, double-stranded RNA viruses do not rely on host polymerases for replication to the extent that viruses with DNA genomes do. Double-stranded RNA viruses are not as well-studied as other classes. This class includes two major families, the Reoviridae and Birnaviridae. Replication is monocistronic and includes individual, segmented genomes, meaning that each of the genes codes for only one protein, unlike other viruses, which exhibit more complex translation.
Viral replication | Class 3: Double-stranded RNA viruses
Double-stranded RNA viruses evolved two separate times from positive-strand RNA viruses. In the Baltimore classification system, dsRNA viruses belong to Group III. Virus group members vary widely in host range (animals, plants, fungi, and bacteria), genome segment number (one to twelve), and virion organization (T-number, capsid layers, or turrets). Double-stranded RNA viruses include the rotaviruses, known globally as a common cause of gastroenteritis in young children, and bluetongue virus, an economically significant pathogen of cattle and sheep. The family "Reoviridae" is the largest and most diverse dsRNA virus family in terms of host range.
Double-stranded RNA viruses | Introduction
After replication, the dsDNA genome may be packed or sent to the nucleus for further rounds of transcription. dsDNA-RT viruses are, like ssRNA-RT, all included in the class "Revtraviricetes". Two families of dsDNA-RT viruses are recognized: "Caulimoviridae", which belongs to the order "Ortervirales", and "Hepadnaviridae", which is the sole family in the order "Blubervirales".
Baltimore classification | Group VII: double-stranded DNA viruses with an RNA intermediate
Two clades of dsRNA viruses exist: the phylum "Duplornaviricota" and the class "Duplopiviricetes", which is in the phylum "Pisuviricota". Both are included in the kingdom "Orthornavirae" in the realm "Riboviria". Based on phylogenetic analysis of RdRp, the two clades do not share a common dsRNA ancestor but are instead separately descended from different positive-sense, single-stranded RNA viruses. In the Baltimore classification system, which groups viruses together based on their manner of mRNA synthesis, dsRNA viruses are group III.
Double-stranded RNA viruses | Classification
RNA tends to be single stranded but in special cases it is double. Unusually for a virus, its genome is not a single piece of nucleic acid; instead, it contains seven or eight pieces of segmented negative-sense RNA, each piece of RNA containing either one or two genes, which code for a gene product (protein). For example, the influenza A genome contains 11 genes on eight pieces of RNA, encoding for 11 proteins: hemagglutinin (HA), neuraminidase (NA), nucleoprotein (NP), M1 (matrix 1 protein), M2, NS1 (non-structural protein 1), NS2 (other name is NEP, nuclear export protein), PA, PB1 (polymerase basic 1), PB1-F2 and PB2.
Influenza | Structure, properties, and subtype nomenclature
With the exception of the Hepatitis D virus, this group of viruses has been placed into a single phylum—Negarnaviricota. This phylum has been divided into two subphyla—Haploviricotina and Polyploviricotina. Within the subphylum Haploviricotina four classes are currently recognised: Chunqiuviricetes, Milneviricetes, Monjiviricetes and Yunchangviricetes. In the subphylum Polyploviricotina two classes are recognised: Ellioviricetes and Insthoviricetes. Six classes, seven orders and twenty four families are currently recognised in this group. A number of unassigned species and genera are yet to be classified.
RNA virus | Group V – negative-sense ssRNA viruses
Ghabrivirales is an order of double-stranded RNA viruses. It is the only order in the class Chrysmotiviricetes. The name of the order derives from Said "Ghabri"al, a pioneering researcher who studied viruses in this order, and -"virales" which is the suffix for a virus order. The name of the class is a portmanteau of member viruses ("chrys"ovirus, "m"egabirnavirus, and "toti"virus), and -"viricetes" which is the suffix for a virus class.
Ghabrivirales | Introduction
Classification of the RNA viruses is difficult. This is in part due to the high mutation rates these genomes undergo. Classification is based principally on the type of genome (double-stranded, negative- or positive-single-strand) and gene number and organisation. Currently, there are 5 orders and 47 families of RNA viruses recognised. There are also many unassigned species and genera. Related to but distinct from the RNA viruses are the viroids and the RNA satellite viruses. These are not currently classified as RNA viruses and are described on their own pages. A study of several thousand RNA viruses has shown the presence of at least five main taxa: a levivirus and relatives group; a picornavirus supergroup; an alphavirus supergroup plus a flavivirus supergroup; the dsRNA viruses; and the -ve strand viruses.
RNA virus | Classification
The members of genus "Orbivirus" within the "Reoviridae" family are arthropod borne viruses and are responsible for high morbidity and mortality in ruminants. Bluetongue virus (BTV) which causes disease in livestock (sheep, goat, cattle) has been in the forefront of molecular studies for the last three decades and now represents the best understood orbivirus at the molecular and structural levels. BTV, like other members of the family, is a complex non-enveloped virus with seven structural proteins and a RNA genome consisting of 10 variously sized dsRNA segments.
Double-stranded RNA viruses | Bluetongue virus
RCN is a double-stranded DNA virus. It is an orthopoxvirus in the family Poxviridae and subfamily Chordopoxvirinae.
Raccoonpox virus | Viral classification
Viruses with a DNA genome, except for the DNA reverse transcribing viruses, are members of three of the four recognized viral realms: "Duplodnaviria", "Monodnaviria", and "Varidnaviria". But the "incertae sedis" order "Ligamenvirales", and many other "incertae sedis" families and genera, are also used to classify DNA viruses. The domains "Duplodnaviria" and "Varidnaviria" consist of double-stranded DNA viruses; other double-stranded DNA viruses are "incertae sedis". The domain "Monodnaviria" consists of single-stranded DNA viruses that generally encode a HUH endonuclease; other single-stranded DNA viruses are "incertae sedis".
Virus classification | DNA viruses
RHBV is a single stranded, negative-sense RNA virus of the genus "Tenuivirus", derived from the Latin ""tenui"", meaning thin or weak. This comes from the nature of "Tenuiviruses" to form thin, filamentous viral particles. Other viruses in the genus "Tenuivirus" include maize stripe virus (MSV), rice stripe virus (RSV), and rice grassy stunt virus (RGSV). While RHBV and other "Tenuiviruses" have single stranded RNA genomes, it is interesting to note that examination of non-denaturing gel electrophoresis performed with "Tenuiviruses" has yielded both single stranded and double stranded RNA. Because it is unlikely that both single stranded and double stranded RNA's are encapsidated within the viral ribonucleoprotein, it is theorized that the double stranded RNA sometimes present in gel electrophoresis results comes from the annealing in vitro of single stranded RNA's that possess opposite polarities.
Rice hoja blanca tenuivirus | Viral Classification
The lentivirus group appears to be basal to all the remaining RNA viruses. The next major division lies between the picornasupragroup and the remaining viruses. The dsRNA viruses appear to have evolved from a +ve RNA ancestor and the -ve RNA viruses from within the dsRNA viruses. The closest relation to the -ve stranded RNA viruses is the Reoviridae.
RNA virus | Classification
It also demonstrates that these RNA forms are likely to be implicated on complex traits including Alzheimer disease will help to understand the biological events that leads to disease.
Circular RNA | Circular RNAs play a role in Alzheimer disease pathogenesis
"Reoviridae" are currently classified into nine genera. The genomes of these viruses consist of 10 to 12 segments of dsRNA, each generally encoding one protein. The mature virions are non-enveloped. Their capsids, formed by multiple proteins, have icosahedral symmetry and are arranged generally in concentric layers. A distinguishing feature of the dsRNA viruses, irrespective of their family association, is their ability to carry out transcription of the dsRNA segments, under appropriate conditions, within the capsid. In all these viruses, the enzymes required for endogenous transcription are thus part of the virion structure.
Double-stranded RNA viruses | Reoviridae
This analysis also suggests that the dsRNA viruses are not closely related to each other but instead belong to four additional classes—Birnaviridae, Cystoviridae, Partitiviridae, and Reoviridae—and one additional order (Totiviridae) of one of the classes of positive ssRNA viruses in the same subphylum as the positive-strand RNA viruses. One study has suggested that there are two large clades: One includes the families "Caliciviridae", "Flaviviridae", and "Picornaviridae" and a second that includes the families "Alphatetraviridae", "Birnaviridae", "Cystoviridae", Nodaviridae", and "Permutotretraviridae".
RNA virus | Double-stranded RNA viruses
"Negarnaviricota" is divided into two subphyla: "Haploviricotina", whose members synthesize a cap structure on viral mRNA required for protein synthesis, and "Polyploviricotina", whose members instead obtain caps on mRNA via cap snatching.
Baltimore classification | Group V: negative sense single-stranded RNA viruses
The negative-sense RNA viruses and indeed all genes defined as negative-sense cannot be directly accessed by host ribosomes to immediately form proteins. Instead, they must be transcribed by viral polymerases into the "readable" complementary positive-sense. These can also be divided into two groups: Examples in this class include the families Orthomyxoviridae, Paramyxoviridae, Bunyaviridae, Filoviridae, and Rhabdoviridae (which includes rabies).
Viral replication | Class 5: Single-stranded RNA viruses - negative-sense
The second Baltimore group contains viruses that have a single-stranded DNA (ssDNA) genome. ssDNA viruses have the same manner of transcription as dsDNA viruses. However, because the genome is single-stranded, it is first made into a double-stranded form by a DNA polymerase upon entering a host cell. mRNA is then synthesized from the double-stranded form. The double-stranded form of ssDNA viruses may be produced either directly after entry into a cell or as a consequence of replication of the viral genome. Eukaryotic ssDNA viruses are replicated in the nucleus. Most ssDNA viruses contain circular genomes that are replicated via rolling circle replication (RCR).
Baltimore classification | Group II: single-stranded DNA viruses
All viruses that encode a reverse transcriptase (also known as RT or RNA-dependent DNA polymerase) are members of the class "Revtraviricetes", within the phylum "Arterviricota", kingdom "Pararnavirae", and realm "Riboviria". The class "Blubervirales" contains the single family "Hepadnaviridae" of DNA RT (reverse transcribing) viruses; all other RT viruses are members of the class Ortervirales.
Virus classification | Reverse transcribing viruses
mRNA is forced out from the capsid in order to be translated or to be translocated from a mature capsid to a progeny capsid. While dsRNA viruses typically have capsids, viruses in the families "Amalgaviridae" and "Endornaviridae" have not been observed to form virions and as such apparently lack capsids. Endornaviruses are also unusual in that unlike other RNA viruses, they possess a single, long open reading frame (ORF), or translatable portion, and a site-specific nick in the 5' region of the positive strand. dsRNA viruses are classified into two phyla within the kingdom "Orthornavirae" of the realm "Riboviria":
Baltimore classification | Group III: double-stranded RNA viruses
"Duplornaviricota" contains most dsRNA viruses, including reoviruses, which infect a diverse range of eukaryotes, and cystoviruses, which are the only dsRNA viruses known to infect prokaryotes. Apart from RdRp, viruses in "Duplornaviricota" also share icosahedral capsids that contain 60 homo- or heterodimers of the capsid protein organized on a pseudo T=2 lattice. The phylum is divided into three classes: "Chrymotiviricetes", which primarily contains fungal and protozoan viruses, "Resentoviricetes", which contains reoviruses, and "Vidaverviricetes", which contains cystoviruses.
Double-stranded RNA viruses | "Duplornaviricota"
RNA viruses have genomes made of ribonucleic acid (RNA) and comprise three groups: double-stranded RNA (dsRNA) viruses, positive sense single-stranded RNA (+ssRNA) viruses, and negative sense single-stranded RNA (-ssRNA) viruses. RNA viruses are classified in the kingdom "Orthornavirae" in the realm "Riboviria".
Baltimore classification | RNA viruses
Durnavirales is an order of double-stranded RNA viruses which infect eukaryotes. The name of the group derives from Italian "duplo" which means double (a reference to double-stranded), "rna" for the type of virus, and -"virales" which is the suffix for a virus order.
Durnavirales | Introduction
This is in contrast to a normal aging brain where a steady decrease of this RNA is observed between the ages of 49 and 86.
BC200 lncRNA | Alzheimer's disease
Many RNAs are shipped to the cytoplasm where the proteins are assembled, including a large number of empty capsids. Reverse transcription by the viral polymerase protein re-creates the relaxed, partially double-stranded circular DNA genome.
Woolly monkey hepatitis B virus | Replication and transcription
The precise role of double-stranded (ds)RNA is still widely investigated as a central player in the Interferon System. Groups have found that positive-strand RNA viruses and dsRNA viruses produced significant amounts of dsRNA, but the precise methods mammalian cells leverage to distinguish between self vs. non-self dsRNA have yet to be uncovered. Studies suggest that recognition must extend beyond simple identification of dsRNA structure and likely relies on other epigenetic markers.
Viral strategies for immune response evasion | Double-stranded RNA mediated immune response
Two groups of viruses use reverse transcription as part of their life cycles: retroviruses, which encode their genomes in single-stranded RNA and replicate through a double-stranded DNA intermediate; and dsDNA-RT viruses, which replicate their double-stranded DNA genomes through an RNA "pregenome" intermediate. Pathogenic examples include human immunodeficiency virus and hepatitis B virus, respectively. Both encode large multifunctional reverse transcriptase (RT) proteins containing RNase H domains. Retroviral RT proteins from HIV-1 and murine leukemia virus are the best-studied members of the family. Retroviral RT is responsible for converting the virus' single-stranded RNA genome into double-stranded DNA. This process requires three steps: first, RNA-dependent DNA polymerase activity produces minus-strand DNA from the plus-strand RNA template, generating an RNA:DNA hybrid intermediate; second, the RNA strand is destroyed; and third, DNA-dependent DNA polymerase activity synthesizes plus-strand DNA, generating double-stranded DNA as the final product.
Ribonuclease H | In viruses
DNA viruses have genomes made of deoxyribonucleic acid (DNA) and are organized into two groups: double-stranded DNA (dsDNA) viruses, and single-stranded DNA (ssDNA) viruses. They are assigned to three separate realms: "Duplodnaviria", "Monodnaviria", and "Varidnaviria".
Baltimore classification | DNA viruses
The host cell's RNA polymerase II then transcribes RNA in the nucleus from the proviral DNA. Some of this RNA may become mRNA whereas other strands will become copies of the viral genome for replication. ssRNA-RT viruses are all included in the class "Revtraviricetes", phylum "Arterviricota", kingdom "Pararnavirae" of the realm "Riboviria". Excluding "Caulimoviridae", which belongs to Group VII, all members of the "Revtraviricetes" order "Ortervirales" are ssRNA-RT viruses.
Baltimore classification | Group VI: single-stranded RNA viruses with a DNA intermediate
Viruses that fall under this category include ones that are not as well-studied, but still do pertain highly to vertebrates. Two examples include the Circoviridae and Parvoviridae. They replicate within the nucleus, and form a double-stranded DNA intermediate during replication. A human Anellovirus called TTV is included within this classification and is found in almost all humans, infecting them asymptomatically in nearly every major organ.
Viral replication | Class 2: Single-stranded DNA viruses
Since cells do not produce double-stranded RNA during normal nucleic acid metabolism, natural selection has favored the evolution of enzymes that destroy dsRNA on contact. The best known class of this type of enzymes is Dicer. It is hoped that broad-spectrum anti-virals could be synthesized that take advantage of this vulnerability of double-stranded RNA viruses.
Double-stranded RNA viruses | Anti-virals
The eleven dsRNA strands remain within the protection of the two protein shells and the viral RNA-dependent RNA polymerasecreates mRNA transcripts of the double-stranded viral genome. By remaining in the core, the viral RNA evades innate host immune responses called RNA interference that are triggered by the presence of double-stranded RNA.
Rotaviral gastroenteritis | Replication
Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells, but with the replacement of thymine by uracil. dsRNA forms the genetic material of some viruses (double-stranded RNA viruses). Double-stranded RNA, such as viral RNA or siRNA, can trigger RNA interference in eukaryotes, as well as interferon response in vertebrates.
RNA | Double-stranded RNA
The seventh Baltimore group contains viruses that have a double-stranded DNA genome that has an RNA intermediate (dsDNA-RT) in its replication cycle. dsDNA-RT viruses have a gap in one strand, which is repaired to create a complete dsDNA genome prior to transcription. dsDNA-RT viruses are transcribed in the same manner as dsDNA viruses, but make use of reverse transcription to replicate their circular genome while it is still in the capsid. The host cell's RNA polymerase II transcribes RNA strands from the genome in the cytoplasm, and the genome is replicated from these RNA strands. The dsDNA genome is produced from pregenomic RNA strands via the same general mechanism as ssRNA-RT viruses, but with replication occurring in a loop around the circular genome.
Baltimore classification | Group VII: double-stranded DNA viruses with an RNA intermediate
The third Baltimore group contains viruses that have a double-stranded RNA (dsRNA) genome. After entering a host cell, the dsRNA genome is transcribed to mRNA from the negative strand by the viral RNA-dependent RNA polymerase (RdRp). The mRNA may be used for translation or replication. Single-stranded mRNA is replicated to form the dsRNA genome. The 5'-end of the genome may be naked, capped, or covalently bound to a viral protein. dsRNA is not a molecule made by cells, so cellular life has evolved antiviral systems to detect and inactivate viral dsRNA. To counteract this, many dsRNA genomes are constructed inside of capsids, thereby avoiding detection inside of the host cell's cytoplasm.
Baltimore classification | Group III: double-stranded RNA viruses
All viruses that have an RNA genome, and that encode an RNA-dependent RNA polymerase (RdRp), are members of the kingdom "Orthornavirae", within the realm "Riboviria".
Virus classification | RNA viruses
This is the Poxvirus family, which comprises highly pathogenic viruses that infect vertebrates.
Viral replication | Class 1: Double-stranded DNA viruses
The majority of fungal viruses are double-stranded RNA viruses. A small number of positive-strand RNA viruses have been described. One report has suggested the possibility of a negative stranded virus.
RNA virus | Notes
Based upon the Baltimore classification scheme, the Mammalian orthoreovirus is a Group III virus. This is because the Mammalian orthoreovirus is a double stranded RNA virus, and as stated previously, apart of the Reovirus family. The name “Reo-“is derived from "respiratory enteric orphan diseases". The term “orphan diseases” makes reference to the fact that some Reoviruses were not known to be associated with any diseases at the time of their discovery. The Reoviridae family is also characterized with "naked", icosahedral capsids and 10-12 segments of linear double stranded RNA. “Naked” meaning the icosahedral capsid is not surrounded by a viral envelope.
Mammalian orthoreovirus | Viral classification
These viruses have double-stranded RNA genomes, so are classified as Class III viruses. Their genome is linear and is segmented into 10 segments of various lengths. One copy of each gene segment is packaged per virion. In most cases, each gene segment encodes a single open reading frame (ORF). The genome encodes seven major structural proteins (VP1–VP7) and three major nonstructural proteins (NS1-NS3). Exceptions to the one gene-one protein rule are segment 9 (Seg-9) and segment 10 (Seg-10), both of which encode two nearly identical proteins initiated from in-phase AUG codons close together near the upstream termini (VP6 and VP6a encoded by Seg-9: NS3 and NS3a encoded by Seg-10) An ORF spans almost the entire length of genome segment 9 and encodes VP6 (the viral helicase).
Orbivirus | Genome
An RNA virus is a virus that has RNA (ribonucleic acid) as its genetic material. This nucleic acid is usually single-stranded RNA (ssRNA) but may be double-stranded RNA (dsRNA). Notable human diseases caused by RNA viruses include the common cold, influenza, SARS, COVID-19, Dengue Virus, hepatitis C, hepatitis E, West Nile fever, Ebola virus disease, rabies, polio and measles. The International Committee on Taxonomy of Viruses (ICTV) classifies RNA viruses as those that belong to "Group III", "Group IV" or "Group V" of the Baltimore classification system of classifying viruses and does not consider viruses with DNA intermediates in their life cycle as RNA viruses.
RNA virus | Introduction
The L-A dsRNA virus of the yeast "Saccharomyces cerevisiae" has a single 4.6 kb genomic segment that encodes its major coat protein, Gag (76 kDa) and a Gag-Pol fusion protein (180 kDa) formed by a -1 ribosomal frameshift. L-A can support the replication and encapsidation in separate viral particles of any of several satellite dsRNAs, called M dsRNAs, each of which encodes a secreted protein toxin (the killer toxin) and immunity to that toxin. L-A and M are transmitted from cell to cell by the cytoplasmic mixing that occurs in the process of mating. Neither is naturally released from the cell or enters cells by other mechanisms, but the high frequency of yeast mating in nature results in the wide distribution of these viruses in natural isolates.
Double-stranded RNA viruses | "Saccharomyces cerevisiae" virus L-A
"Bwamba orthobunyavirus" has a negative sense single stranded RNA (ssRNA) genome, and so is classified as a class V virus under the Baltimore classification system. The genome is segmented into three pieces, Large (L), Medium (M) and Small (S), which have a combined length of approximately 12,000nt. The S RNA encodes a nucleocapsid and non structural proteins, the M RNA encodes envelope glycoproteins and a non structural membrane polypeptide and the L RNA encodes an RNA dependent RNA polymerase. The segmented RNAs are surrounded by nucleocapsid proteins that form a Ribonucleoprotein complex, that associates with RNA dependent RNA polymerase. The complex is surrounded by a lipid layer, into which the nuclear complex interacts.
Bwamba orthobunyavirus | Virus structure
"Negarnaviricota" belongs to the kingdom "Orthornavirae", which encompasses all RNA viruses that encode RdRp, and the realm "Riboviria", which includes "Orthornavirae" as well as all viruses that encode reverse transcriptase in the kingdom "Pararnavirae". "Negarnaviricota" contains two subphyla, which contain a combined six classes, five of which are monotypic down to lower taxa: Negative-strand RNA viruses are classified as Group V in the Baltimore classification system, which groups viruses together based on their manner of mRNA production and which is often used alongside standard virus taxonomy, which is based on evolutionary history. Therefore, Group V and "Negarnaviricota" are synonymous.
Negative-strand RNA virus | Classification
RHR is similar to RCR but each end of the linear genome contains an inverted terminal repeat in a hairpin loop structure. After the genome has been repaired by a DNA polymerase to form dsDNA, the endonuclease unbinds the hairpin loops, which are replicated with the rest of the genome. The dsDNA genome is then cleaved in two, and the hairpin loops at both ends of both strands are formed. For parvoviruses, either the positive or negative sense strand may be packaged into capsids.
Baltimore classification | Group II: single-stranded DNA viruses
The "T" = 13 shell of the IBDV capsid is formed by trimers of VP2, a protein generated by removal of the C-terminal domain from its precursor, pVP2. The trimming of pVP2 is performed on immature particles as part of the maturation process. The other major structural protein, VP3, is a multifunctional component lying under the "T" = 13 shell that influences the inherent structural polymorphism of pVP2. The virus-encoded RNA-dependent RNA polymerase, VP1, is incorporated into the capsid through its association with VP3. VP3 also interacts extensively with the viral dsRNA genome.
Double-stranded RNA viruses | Infectious bursal disease virus
SBPV is a non-enveloped Positive-sense single-stranded RNA virus, and is 9470 nucleotides long. The virus has approximately 300 nucleotides of 5' untranslated region and approximately 270 nucleotides of 3' untranslated region and is terminated by a poly(A) tail. The RNA has a coding region which codes for RNA-dependent RNA polymerase. Though it was not identified, it is expected that a viral genome-linked protein, involved in stability, replication, and translation, would be bound to the 5' end. There are two strains of the virus, named "Rothamsted" and "Harpenden" which are 83% identical at the nucleotide level, and 94% identical at the amino acid level.
Slow bee paralysis virus | Genome
These viruses have double stranded DNA genomes with no RNA intermediate.
Mardivirus | Introduction
Bacteriophage Φ6, is a member of the "Cystoviridae" family. It infects "Pseudomonas" bacteria (typically plant-pathogenic "P. syringae"). It has a three-part, segmented, double-stranded RNA genome, totalling ~13.5 kb in length. Φ6 and its relatives have a lipid membrane around their nucleocapsid, a rare trait among bacteriophages. It is a lytic phage, though under certain circumstances has been observed to display a delay in lysis which may be described as a "carrier state".
Double-stranded RNA viruses | Bacteriophage Φ6
DcPV's 10,138 nucleotide linear RNA has a single large open reading frame, predicted to encode a 3007 residue polyprotein with non-structural helicase, protease and RNA-dependent RNA polymerase functions in the C-terminal portion and four structural proteins (VP1–4) in the N-terminal portion. The 5′ non-translated region contains cloverleaf and hairpin structures similar to those present in picornaviruses and other picorna-like viruses. The virus particle is around 27 nm in diameter.
Dinocampus coccinellae paralysis virus | Structure
Single-stranded RNA virus refers to RNA viruses with single-stranded RNA genomes. There are two kinds:
Single-stranded RNA virus | Introduction
In bidirectional replication, a circular genome is cleaved to separate the two strands, creating a fork from which replication of both strands progresses around the genome at the same time, going in two opposite directions until the opposite end is reached. A rolling circle mechanism that produces linear strands while progressing in a loop around the circular genome is also used that likewise replicates both strands simultaneously. Instead of replicating both strands at once, some dsDNA viruses use a strand displacement method whereby one strand is synthesized from a template strand, and a complementary strand is then synthesized from the prior synthesized strand, forming a dsDNA genome.
Baltimore classification | Group I: double-stranded DNA viruses
The double stranded RNA viral core, which plays an important role in packaging the genome and the transcription of mRNA as well as maturation, contain proteins which are present across the entire Type 3 double stranded RNA group. In the outer capsid layer, the proteins take part in the role of environmental stability, and cell attachment to a number of hosts, which are quite variable even within the same Orthoreovirus genus.
Mammalian orthoreovirus | Structure and genome
The genome of viruses from this family is unsegmented, -RT, positive-sense, single-stranded RNA and is 4200–9700 nucleotides long. The genome encodes structural proteins and non-structural proteins which codes for an RNA-dependent DNA polymerase, replicase, and reverse transcriptase for the reverse transcription step during replication.
Pseudoviridae | Genome
These viruses consist of two types, however both share the fact that replication is primarily in the cytoplasm, and that replication is not as dependent on the cell cycle as that of DNA viruses. This class of viruses is also one of the most-studied types of viruses, alongside the double-stranded DNA viruses.
Viral replication | Classes 4 & 5: Single-stranded RNA viruses
Using his pipeline, they found 3,547 circRNA that passed stringent QC in the Knight ADRC cohort that includes RNA-seq from 13 controls and 83 Alzheimer cases, and 3,924 circRNA passed stringent QC in the MSBB dataset. A meta-analysis of the discovery and replication results revealed a total of 148 circRNAs that were significantly correlated with CDR after FDR correction. In addition, 33 circRNA passed the stringent gene-based, Bonferroni multiple test correction of 5×10-6, including circHOMER1 (P =2.21×10) and circCDR1-AS (P = 2.83 × 10), among others. They also performed additional analyses to demonstrate that the expression of circRNA were independent of the lineal form as well as the cell proportion that can confound the brain RNA-seq analyses in Alzheimer disease studies.
Circular RNA | Circular RNAs play a role in Alzheimer disease pathogenesis
The genetic structure of "Bunyamwera orthobunyavirus" is typical for "Bunyavirales" viruses, which are an order of enveloped negative-sense, single-stranded RNA viruses with a genome split into three parts—Small (S), Middle (M), and Large (L). The L RNA segment encodes an RNA-dependent RNA polymerase (L protein), the M RNA segment encodes two surface glycoproteins (Gc and Gn) and a nonstructural protein (NSm), while the S RNA segment encodes a nucleocapsid protein (N) and, in an alternative overlapping reading frame, a second nonstructural protein (NSs). The genomic RNA segments are encapsidated by copies of the N protein in the form of ribonucleoprotein (RNP) complexes.
Bunyamwera orthobunyavirus | Molecular biology
Reverse transcribing (RT) viruses have genomes made of either DNA or RNA and replicate via reverse transcription. Two groups of reverse transcribing viruses exist: single-stranded RNA-RT (ssRNA-RT) viruses, and double-stranded DNA-RT (dsDNA-RT) viruses. Reverse transcribing viruses are classified in the kingdom "Pararnavirae" in the realm "Riboviria".
Baltimore classification | Reverse transcribing viruses
RDPV was classified as a separate species due to its unique patterns of restriction enzymes. Parapoxviruses belongs to the family of viruses named "Poxviridae", family of double-stranded DNA viruses. "Parapoxvirus" is classified into the subfamily of "Chordopoxvirinae".
Red deerpox virus | Viral classification
Animal RNA viruses are classified by the ICTV. There are three distinct groups of RNA viruses depending on their genome and mode of replication: Retroviruses (Group VI) have a single-stranded RNA genome but, in general, are not considered RNA viruses because they use DNA intermediates to replicate. Reverse transcriptase, a viral enzyme that comes from the virus itself after it is uncoated, converts the viral RNA into a complementary strand of DNA, which is copied to produce a double-stranded molecule of viral DNA. After this DNA is integrated into the host genome using the viral enzyme integrase, expression of the encoded genes may lead to the formation of new virions.
RNA virus | Replication
The double-stranded RNA genome of Avibirnavirus is linear and segmented into two segments (A and B). The combined lengths of the two segments is around 6,000 nucleotides, almost entirely composed of reading-frames. The genome codes for 4-5 proteins depending on the strain. The high degree of antigenic variation is due to a combination of high mutation rate and inter-strain homologous recombination within a hypervariable region that is located in the "vp2" gene. At approximately 3,200 bp in length, segment A is the larger of the two segments. It contains two partially overlapping open reading frames (ORFs). The first ORF in segment A encodes viral protein 5 (VP5).
Avibirnavirus | Genome
Rotavirus is the most common cause of acute gastroenteritis in infants and young children worldwide. This virus contains a dsRNA genome and is a member of the "Reoviridae" family. The genome of rotavirus consists of eleven segments of dsRNA. Each genome segment codes for one protein with the exception of segment 11, which codes for two proteins. Among the twelve proteins, six are structural and six are non-structural proteins. It is a double-stranded RNA non-enveloped virus
Double-stranded RNA viruses | Rotavirus
Double stranded RNA viruses are recognized by either the transmembrane toll-like receptor 3 (TLR3) or by one of two cytosolic proteins, retinoic acid-inducible gene I (RIG-I)-like receptors and melanoma differentiation-associated gene 5 (MDA5). RIG-I and MDA5 differ in the viral RNA that they recognize, but they share many structural features, including the N-terminal CARD that allows them to bind to MAVS. MAVS activation leads to the increased levels of pro-inflammatory cytokines via activation of transcription factors, nuclear factor kB (NF-kB), interferon regulatory factor 1 (IRF1), and interferon regulatory factor 3 (IRF3). NFkB, IRF1, and IRF3 are transcription factors and play critical roles in the production of cytokines.
Mitochondrial antiviral-signaling protein | Function
The genetic structure of Schmallenberg virus is typical for Bunyavirales viruses, which are a family of enveloped negative-sense single stranded RNA viruses with a genome split into three parts—Small (S), Medium (M) and Large (L). The L RNA segment encodes an RNA-dependent RNA polymerase (L protein), the M RNA segment encodes two surface glycoproteins (Gc and Gn) and a nonstructural protein (NSm), while the S RNA segment encodes a nucleocapsid protein (N) and, in an alternative overlapping reading frame, a second nonstructural protein (NSs). The genomic RNA segments are encapsidated by copies of the N protein in the form of ribonucleoprotein (RNP) complexes.
Schmallenberg orthobunyavirus | Molecular biology
The "Pithoviridae" have only two known representatives. These viruses infects amoebas and can survive in low temperatures. For years this virus was believed to be frozen, but due to climate change it has begun to show up again. This is a double stranded DNA virus with its size being 610 kilobases long. The genome is estimated to code for 476 open reading frames. The viron is rod shaped with a length of 1,100 nm long and 500 nm in diameter.
Nucleocytoviricota | "Pithoviridae"
Dube et al., from Cruchaga lab (https://neurogenomics.wustl.edu/) performed for the first time a genome-wide calling of circRNA in several brain areas from Alzheimer disease cases and controls demonstrating the role of this RNA species in health and disease.
Circular RNA | Dube et al. 2019
Alsuviricetes is a class of RNA viruses which infect eukaryotes. Member viruses have a positive-sense single-stranded RNA genome. The name of the group is a portmanteau of ""al"pha "su"pergroup" and -"viricetes" which is the suffix for a virus class.
Alsuviricetes | Introduction
The Nobel Prize-winning biologist David Baltimore devised the Baltimore classification system. The ICTV classification system is used in conjunction with the Baltimore classification system in modern virus classification. The Baltimore classification of viruses is based on the mechanism of mRNA production. Viruses must generate mRNAs from their genomes to produce proteins and replicate themselves, but different mechanisms are used to achieve this in each virus family. Viral genomes may be single-stranded (ss) or double-stranded (ds), RNA or DNA, and may or may not use reverse transcriptase (RT). In addition, ssRNA viruses may be either sense (+) or antisense (−). This classification places viruses into seven groups:
Virus | Baltimore classification
The sixth Baltimore group contains viruses that have a (positive-sense) single-stranded RNA genome that has a DNA intermediate ((+)ssRNA-RT) in its replication cycle. ssRNA-RT viruses are transcribed in the same manner as DNA viruses, but their linear genomes are first converted to a dsDNA form through a process called reverse transcription. The viral reverse transcriptase enzyme synthesizes a DNA strand from the ssRNA strand, and the RNA strand is degraded and replaced with a DNA strand to create a dsDNA genome. The genome is then integrated into the DNA of the host cell, where it is now called a provirus.
Baltimore classification | Group VI: single-stranded RNA viruses with a DNA intermediate
Chrysoviridae is a family of double-stranded RNA viruses. Members of the family are called chrysoviruses.
Chrysoviridae | Introduction
Two double-stranded RNA viruses, designated L and M, are responsible for this phenotype. The L virus codes for the capsid proteins of both viruses, as well as an RNA polymerase. Thus the M virus can only infect cells already harbouring L virus particles. The M viral RNA encodes a toxin that is secreted from the host cell. It kills susceptible cells growing in close proximity to the host. The M viral RNA also renders the host cell immune to the lethal effects of the toxin. For a cell to be susceptible it must therefore be either uninfected or harbour only the L virus.
Non-Mendelian inheritance | Infectious heredity
Mymonaviridae is a family in the order "Mononegavirales". This family was established in 2016 to taxonomically accommodate "Sclerotinia sclerotiorum negative-stranded RNA virus 1" (SsNSRV-1), a novel virus discovered in a hypovirulent strain of "Sclerotinia sclerotiorum".
Mymonaviridae | Introduction
In the nucleus the single-stranded virus genome is converted to dsDNA by a cell DNA polymerase. The ends of the genome are double stranded as a result of base pairing, and at the 3' end the terminal nucleotides act as a primer to which the polymerase binds.
Parvoviridae | Single-stranded DNA to double-stranded DNA
This is the single largest group of RNA viruses with 30 families. Attempts have been made to group these families in higher orders. These proposals were based on an analysis of the RNA polymerases and are still under consideration. To date, the suggestions proposed have not been broadly accepted because of doubts over the suitability of a single gene to determine the taxonomy of the clade. The proposed classification of positive-strand RNA viruses is based on the RNA-dependent RNA polymerase. Three groups have been recognised: A division of the alpha-like (Sindbis-like) supergroup on the basis of a novel domain located near the N termini of the proteins involved in viral replication has been proposed.
RNA virus | Positive strand RNA viruses
Viral genomes may be either linear with ends or circular in a loop. Whether a virus has a linear or circular genome varies from group to group. A significant percentage of dsDNA viruses are both, ssDNA viruses are primarily circular, RNA viruses and ssRNA-RT viruses are typically linear, and dsDNA-RT viruses are typically circular. In the dsDNA family "Sphaerolipoviridae", and in the family "Pleolipoviridae", viruses contain both linear and circular genomes, varying from genus to genus.
Baltimore classification | Linear vs circular genomes
Ligamenvirales is an order of linear viruses that infect archaea of the kingdom Crenarchaeota and have double-stranded DNA genomes. The order was proposed by David Prangishvili and Mart Krupovic in 2012 and subsequently created by the International Committee on Taxonomy of Viruses (ICTV). The name is derived from the Latin , meaning "string" or "thread".
Ligamenvirales | Introduction
Infectious bursal disease virus (IBDV) is the best-characterized member of the family "Birnaviridae". These viruses have bipartite dsRNA genomes enclosed in single layered icosahedral capsids with "T" = 13l geometry. IBDV shares functional strategies and structural features with many other icosahedral dsRNA viruses, except that it lacks the "T" = 1 (or pseudo "T" = 2) core common to the "Reoviridae", "Cystoviridae", and "Totiviridae". The IBDV capsid protein exhibits structural domains that show homology to those of the capsid proteins of some positive-sense single-stranded RNA viruses, such as the nodaviruses and tetraviruses, as well as the "T" = 13 capsid shell protein of the "Reoviridae".
Double-stranded RNA viruses | Infectious bursal disease virus
Duplornaviricota is a phylum of RNA viruses, which contains all double-stranded RNA viruses, except for those in phylum "Pisuviricota." Characteristic of the group is a viral capsid composed of 60 homo- or heterodimers of capsid protein on a pseudo-T=2 lattice. Duplornaviruses infect both prokaryotes and eukaryotes. The name of the group derives from Italian "duplo" which means double (a reference to double-stranded), "rna" for the type of virus, and -"viricota" which is the suffix for a virus phylum.
Duplornaviricota | Introduction
Baltimore classification (first defined in 1971) is a classification system that places viruses into one of seven groups depending on a combination of their nucleic acid (DNA or RNA), strandedness (single-stranded or double-stranded), sense, and method of replication. Named after David Baltimore, a Nobel Prize-winning biologist, these groups are designated by Roman numerals. Other classifications are determined by the disease caused by the virus or its morphology, neither of which are satisfactory due to different viruses either causing the same disease or looking very similar. In addition, viral structures are often difficult to determine under the microscope. Classifying viruses according to their genome means that those in a given category will all behave in a similar fashion, offering some indication of how to proceed with further research.
Virus classification | Baltimore classification
Viruses that replicate via RdRp belong to three groups in the Baltimore classification system, all of which are in the kingdom "Orthornavirae": single-stranded RNA (ssRNA) viruses, which are either positive (+) or negative (-) sense, and double-stranded RNA viruses (dsRNA). +ssRNA viruses have genomes that can functionally act as mRNA, and a negative sense strand can also be created to form dsRNA from which mRNA is transcribed from the negative strand. The genomes of -ssRNA viruses and dsRNA viruses act as templates from which RdRp creates mRNA. Viruses that replicate via reverse transcription belong to two Baltimore groups, both of which are in the kingdom "Pararnavirae": single-stranded RNA (ssRNA-RT) viruses, all of which belong to the order "Ortervirales", and double-stranded DNA (dsDNA-RT) viruses, which belong to the family "Caulimoviridae", also in "Ortervirales", and the family "Hepadnaviridae" of the order "Blubervirales".
Riboviria | Characteristics
For dsRNA viruses, RdRp transcribes mRNA by using the negative strand as a template. Positive strands may also be used as templates to synthesize negative strands for the construction of genomic dsRNA. dsRNA is not a molecule produced by cells, so cellular life has evolved mechanisms to detect and inactive viral dsRNA. To counter this, dsRNA viruses typically retain their genomes inside of viral capsid in order to evade the host's immune system.
Orthornavirae | Double-stranded RNA viruses
The first Baltimore group contains viruses that have a double-stranded DNA (dsDNA) genome. All dsDNA viruses have their mRNA synthesized in a three-step process. First, a transcription preinitiation complex binds to the DNA upstream of the site where transcription begins, allowing for the recruitment of a host RNA polymerase. Second, once the RNA polymerase is recruited, it uses the negative strand as a template for synthesizing mRNA strands. Third, the RNA polymerase terminates transcription upon reaching a specific signal, such as a polyadenylation site. dsDNA viruses make use of several mechanisms to replicate their genome. Bidirectional replication, which is the typical form of DNA replication in eukaryotes, is widely used.
Baltimore classification | Group I: double-stranded DNA viruses
Ortervirales is an order that contains all accepted species of single-stranded RNA viruses that replicate through a DNA intermediate (Group VI) and all accepted species of double-stranded DNA viruses (except "Hepadnaviridae") that replicate through an RNA intermediate (Group VII). All reverse-transcribing viruses possess significant similarities to each other. Their reverse transcriptase proteins share a common origin. Moreover, belpaoviruses, metaviruses, pseudoviruses, and retroviruses have other features in common. Their polymerase proteins are similar in structure and include aspartic protease (retroviral aspartyl protease) and an integrase belonging to the DDE recombinase superfamily (see Recombination-activating gene [structure]). They also share similar capsid and nucleocapsid proteins/domains.
Ortervirales | Introduction
The second Baltimore group of DNA viruses are those that have a single-stranded DNA genome. ssDNA viruses have the same manner of transcription as dsDNA viruses. However, because the genome is single-stranded, it is first made into a double-stranded form by a DNA polymerase upon entering a host cell. mRNA is then synthesized from the double-stranded form. The double-stranded form of ssDNA viruses may be produced either directly after entry into a cell or as a consequence of replication of the viral genome. Eukaryotic ssDNA viruses are replicated in the nucleus. Most ssDNA viruses contain circular genomes that are replicated via rolling circle replication (RCR).
DNA virus | Single-stranded DNA viruses
"Orthoreovirus" is part of the family "Reoviridae". Its genome is composed of segmented double-stranded RNA (dsRNA), thus it is classified as a group III virus according to the Baltimore classification system of viruses. This family of viruses is taxonomically classified into 15 distinct genera. These genera are sorted out taking into account the number of dsRNA genomes. The "Orthoreovirus" genus has 10 segments that have been isolated from a large range of hosts including mammals, birds, and reptiles. These genera are further divided into two phenotypic groups: fusogenic and non-fusogenic. The way that they are determined to belong to a specific group is if the virus is able to cause multinucleated cells known as syncytial cells.
Orthoreovirus | Classification
These are plant viruses which have single-stranded circular DNA genomes encoding genes that diverge in both directions from a virion strand origin of replication (i.e. geminivirus genomes are ambisense). According to the Baltimore classification, they are considered to be class II viruses. The genome can either be a single component between 2500 and 3100 nucleotides, or, in the case of some begomoviruses, two similar-sized components each between 2600 and 2800 nucleotides. They have elongated, geminate capsids with two incomplete T=1 icosahedra joined at the missing vertex. The capsids range in size from 18–20 nm in diameter with a length of about 30 nm.
Mungbean yellow mosaic virus | Viral structure
The stacking of turret protein functional domains and the presence of constrictions and A spikes along the mRNA release pathway indicate a mechanism that uses pores and channels to regulate the highly coordinated steps of RNA transcription, processing, and release.
Double-stranded RNA viruses | Cypovirus
Dube et al., demonstrated for the first time that brain circular RNAs (circRNA) are part of the pathogenic events that lead to Alzheimer’s disease (Dube et al., Nature Neuroscience 2019). Dube et al., hypothesized that specific circRNA would be differentially expressed in AD cases compared to controls and that those effects could be detected early in the disease. They optimized and validated a novel analyses pipeline for circular RNAs (circRNA). They performed a three-stage study design, using the Knight ADRC brain RNA-seq data as discovery (stage 1), using the data from Mount Sinai as replication (stage 2) and a meta-analysis (stage 3) to identify the most significant circRNA differentially expressed in Alzheimer disease.
Circular RNA | Circular RNAs play a role in Alzheimer disease pathogenesis
The relaxed, partially double-stranded circular DNA genome is able to diffuse into an empty capsid through large pores in the capsid. The capsid is then enveloped and exported from the cell through a process that is not yet well understood.
Woolly monkey hepatitis B virus | Assembly and release
The antisense RNA, BACE1-AS is transcribed from the opposite strand to BACE1 and is upregulated in patients with Alzheimer's disease. BACE1-AS regulates the expression of BACE1 by increasing BACE1 mRNA stability and generating additional BACE1 through a post-transcriptional feed-forward mechanism. By the same mechanism it also raises concentrations of beta amyloid, the main constituent of senile plaques. BACE1-AS concentrations are elevated in subjects with Alzheimer's disease and in amyloid precursor protein transgenic mice.
Non-coding RNA | Alzheimer's disease
Viruses in the ssDNA plant virus family "Geminiviridae" likewise vary between being monopartite and bipartite.
Baltimore classification | Genome segmentation
The third phylum that contains +ssRNA viruses is "Pisuviricota", which has been informally called the "picornavirus supergroup". The phylum contains a large assemblage of eukaryotic viruses known to infect animals, plants, fungi, and protists. The phylum contains three classes, two of which contain only +ssRNA viruses: "Pisoniviricetes", which contains nidoviruses, picornaviruses, and sobeliviruses, and "Stelpaviricetes", which contains potyviruses and astroviruses. The third class is "Duplopiviricetes", whose members are double-stranded RNA viruses that are descended from +ssRNA viruses.
Positive-strand RNA virus | "Pisuviricota"
RNA viruses typically do not encode that many proteins, but most positive-sense, single-stranded (+ssRNA) viruses and some double-stranded RNA (dsRNA) viruses encode a major capsid protein that has a single jelly roll fold, so named because the folded structure of the protein contains a structure that resembles a jelly roll. Many RNA viruses also encode an envelope, a type of lipid membrane that typically surrounds the capsid. In particular, the viral envelope is near-universal among negative-sense, single-stranded (-ssRNA) viruses.
Orthornavirae | Structure
The double-stranded RNA panhandle structure is critical for efficient viral RNA synthesis, but potential interterminal double-stranded RNA interactions must be transiently relieved in order to recruit the viral polymerase. The S-segment RNA is approximately 3.5 kb, and encodes the viral nucleocapsid protein (NP) and glycoprotein (GPC). The L-segment RNA is approximately 7.2 kb, and encodes the viral RNA-dependent RNA-polymerase (L) and a small RING-domain containing protein (Z).
Arenavirus | Genome
The virus genome consists of three segments of negative-stranded RNA; the large (L) segment encodes the viral RNA-dependent RNA polymerase, the medium (M) segment encodes the envelope glycoproteins Gn and Gc (cotranslationally cleaved from a glycoprotein precursor), and the small (S) segment encodes the nucleocapsid (N) protein.
Sangassou orthohantavirus | Genome