An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)
An enzyme that catalyzes the replication of the RNA of coliphage Q beta. EC 2.7.7.-.
Enzymes that catalyze the template-directed incorporation of ribonucleotides into an RNA chain. EC 2.7.7.-.
Ribonucleic acid that makes up the genetic material of viruses.
Viruses whose genetic material is RNA.
Viruses whose host is Escherichia coli.
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.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
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.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
A bacteriophage genus of the family LEVIVIRIDAE, whose viruses contain the longer version of the genome and have no separate cell lysis gene.
A genus of plant viruses that infects ANGIOSPERMS. Transmission occurs mechanically and through soil, with one species transmitted via a fungal vector. The type species is Tomato bushy stunt virus.
A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE).
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).
The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
The type species of the genus ARTERIVIRUS and the etiologic agent of an important equine respiratory disease causing abortion, pneumonia, or other infections.
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.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A family of proteins that promote unwinding of RNA during splicing and translation.
A family of RNA plant viruses infecting dicotyledons. Transmission is mainly by mechanical inoculation and through propagative plant material. All species elicit formation of multivesicular inclusion bodies. There are at least eight genera: Aureusvirus, Avenavirus, CARMOVIRUS, Dianthovirus, Machlomovirus, Necrovirus, Panicovirus, and TOMBUSVIRUS.
Bacteriophages whose genetic material is RNA, which is single-stranded in all except the Pseudomonas phage phi 6 (BACTERIOPHAGE PHI 6). All RNA phages infect their host bacteria via the host's surface pili. Some frequently encountered RNA phages are: BF23, F2, R17, fr, PhiCb5, PhiCb12r, PhiCb8r, PhiCb23r, 7s, PP7, Q beta phage, MS2 phage, and BACTERIOPHAGE PHI 6.
Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.
A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.
RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.
The processes of RNA tertiary structure formation.
A genus of tripartite plant viruses in the family BROMOVIRIDAE. Transmission is by beetles. Brome mosaic virus is the type species.
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.
The type species of TOBAMOVIRUS which causes mosaic disease of tobacco. Transmission occurs by mechanical inoculation.
The complete genetic complement contained in a DNA or RNA molecule in a virus.
Proteins found in any species of virus.
Viruses parasitic on plants higher than bacteria.
Proteins which are synthesized as a single polymer and then cleaved into several distinct proteins.
The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.
Nucleic acid structures found on the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear RNAs. These structures, which are positively charged, protect the above specified RNAs at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA CAP ANALOGS), which lack the positive charge, inhibit the initiation of protein synthesis.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The extent to which an RNA molecule retains its structural integrity and resists degradation by RNASE, and base-catalyzed HYDROLYSIS, under changing in vivo or in vitro conditions.
RNA molecules which hybridize to complementary sequences in either RNA or DNA altering the function of the latter. Endogenous antisense RNAs function as regulators of gene expression by a variety of mechanisms. Synthetic antisense RNAs are used to effect the functioning of specific genes for investigative or therapeutic purposes.
A genus of the family ARTERIVIRIDAE, in the order NIDOVIRALES. The type species is ARTERITIS VIRUS, EQUINE.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Small, linear single-stranded RNA molecules functionally acting as molecular parasites of certain RNA plant viruses. Satellite RNAs exhibit four characteristic traits: (1) they require helper viruses to replicate; (2) they are unnecessary for the replication of helper viruses; (3) they are encapsidated in the coat protein of the helper virus; (4) they have no extensive sequence homology to the helper virus. Thus they differ from SATELLITE VIRUSES which encode their own coat protein, and from the genomic RNA; (=RNA, VIRAL); of satellite viruses. (From Maramorosch, Viroids and Satellites, 1991, p143)
Plants or plant parts which are harmful to man or other animals.
Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.
A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A creeping annual plant species of the CUCURBITACEAE family. It has a rough succulent, trailing stem and hairy leaves with three to five pointed lobes.
RNA which does not code for protein but has some enzymatic, structural or regulatory function. Although ribosomal RNA (RNA, RIBOSOMAL) and transfer RNA (RNA, TRANSFER) are also untranslated RNAs they are not included in this scope.
A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.
Viruses which produce a mottled appearance of the leaves of plants.
A species of the CORONAVIRUS genus causing hepatitis in mice. Four strains have been identified as MHV 1, MHV 2, MHV 3, and MHV 4 (also known as MHV-JHM, which is neurotropic and causes disseminated encephalomyelitis with demyelination as well as focal liver necrosis).
The protoplasm and plasma membrane of plant, fungal, bacterial or archaeon cells without the CELL WALL.
A genus of plant viruses of the family BROMOVIRIDAE, which infect cucurbits and solanaceous plants. Transmission occurs via aphids in a non-persistent manner, and also via seeds. The type species Cucumber mosaic virus, a CUCUMOVIRUS, should not be confused with Cucumber green mottle mosaic virus, a TOBAMOVIRUS.
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.
A multistage process that includes cloning, physical mapping, subcloning, sequencing, and information analysis of an RNA SEQUENCE.
The type species of the genus ALFAMOVIRUS that is non-persistently transmitted by aphids.
Established cell cultures that have the potential to propagate indefinitely.
A genus of plant viruses in the family FLEXIVIRIDAE, that cause mosaic and ringspot symptoms. Transmission occurs mechanically. Potato virus X is the type species.
Nucleic acid sequences that are involved in the negative regulation of GENETIC TRANSCRIPTION by chromatin silencing.

Mutations in the retinoblastoma protein-binding LXCXE motif of rubella virus putative replicase affect virus replication. (1/1725)

The rubella virus (RV)-encoded protein NSP90, which contains the retinoblastoma protein (Rb)-binding motif LXCXE, interacts with Rb and RV replication is reduced in cells lacking Rb. Whether the LXCXE motif of RV NSP90 itself is essential for Rb binding and virus replication is not known. Therefore, in the present study, the functional role of this motif was investigated by site-directed mutagenesis in a plasmid from which infectious RV RNA can be produced. Three critical mutations in the motif, two substitutions at the conserved cysteine residue (C --> G and C --> R) and a deletion of the entire motif, were created. A cell-free translated NSP90 C terminus polypeptide containing the deletion did not bind to Rb and a polypeptide carrying the C --> R substitution had barely detectable binding affinity for Rb. Rb binding by the C --> G mutant was reduced significantly compared to that of wild-type protein. Correlating with the binding results, mutant viruses containing the LXRXE and LXGXE motifs had a reduction in replication to < 0.5% and 47% of the wild-type, respectively, while deletion of the motif was found to be lethal. By the first serial passage, replication of the LXRXE-carrying virus had increased from < 0.5% to 2% of the wild-type. Sequencing of the genome of this virus revealed a nucleotide change that altered the motif from LXRXE to LXSXE, which is a known Rb-binding motif in two protein phosphatase subunits. Thus, our results clearly demonstrate that the LXCXE motif is required for efficient RV replication.  (+info)

Characterization of the L gene and 5' trailer region of Ebola virus. (2/1725)

The nucleotide sequences of the L gene and 5' trailer region of Ebola virus strain Mayinga (subtype Zaire) have been determined, thus completing the sequence of the Ebola virus genome. The putative transcription start signal of the L gene was identical to the determined 5' terminus of the L mRNA (5' GAGGAAGAUUAA) and showed a high degree of similarity to the corresponding regions of other Ebola virus genes. The 3' end of the L mRNA terminated with 5' AUUAUAAAAAA, a sequence which is distinct from the proposed transcription termination signals of other genes. The 5' trailer sequence of the Ebola virus genomic RNA consisted of 676 nt and revealed a self-complementary sequence at the extreme end which may play an important role in virus replication. The L gene contained a single ORF encoding a polypeptide of 2212 aa. The deduced amino acid sequence showed identities of about 73 and 44% to the L proteins of Ebola virus strain Maleo (subtype Sudan) and Marburg virus, respectively. Sequence comparison studies of the Ebola virus L proteins with several corresponding proteins of other non-segmented, negative-strand RNA viruses, including Marburg viruses, confirmed a close relationship between filoviruses and members of the Paramyxovirinae. The presence of several conserved linear domains commonly found within L proteins of other members of the order Mononegavirales identified this protein as the RNA-dependent RNA polymerase of Ebola virus.  (+info)

A brome mosaic virus intergenic RNA3 replication signal functions with viral replication protein 1a to dramatically stabilize RNA in vivo. (3/1725)

Brome mosaic virus (BMV), a positive-strand RNA virus in the alphavirus-like superfamily, encodes two RNA replication proteins. The 1a protein has putative helicase and RNA-capping domains, whereas 2a contains a polymerase-like domain. Saccharomyces cerevisiae expressing 1a and 2a is capable of replicating a BMV RNA3 template produced by in vivo transcription of a DNA copy of RNA3. Although insufficient for RNA3 replication, the expression of 1a protein alone results in a dramatic and specific stabilization of the RNA3 template in yeast. As one step toward understanding 1a-induced stabilization of RNA3, the interactions involved, and its possible relation to RNA replication, we have identified the cis-acting sequences required for this effect. We find that 1a-induced stabilization is mediated by a 150- to 190-base segment of the RNA3 intergenic region corresponding to a previously identified enhancer of RNA3 replication. Moreover, this segment is sufficient to confer 1a-induced stability on a heterologous beta-globin RNA. Within this intergenic segment, partial deletions that inhibited 1a-induced stabilization in yeast expressing 1a alone resulted in parallel decreases in the levels of negative- and positive-strand RNA3 replication products in yeast expressing 1a and 2a. In particular, a small deletion encompassing a motif corresponding to the box B element of RNA polymerase III promoters dramatically reduced the ability of RNAs to respond to 1a or 1a and 2a. These and other findings suggest that 1a-induced stabilization likely reflects an early template selection step in BMV RNA replication.  (+info)

Molecular mapping of influenza virus RNA polymerase by site-specific antibodies. (4/1725)

Influenza virus RNA polymerase with the subunit structure PB1-PB2-PA is involved in both transcription and replication of the RNA genome, including the unique cap-I-dependent RNase activity. To map the important domains for RNA polymerization, cap-I-dependent RNase, and cap-I-binding activity, we generated site-specific antibodies against overlapping 150-amino-acid peptides that cover each entire subunit. Monospecific antibodies against each subunit inhibited RNA synthesis in vitro. Those against PB1 and PB2 inhibited the cap-I-dependent RNase activity, but those against PB2 alone slightly inhibited the cap-I-binding activity. Antibodies against the N-terminal amino acids 1-159 of PB2 that overlap the PB1-binding site on PB2 and the C-terminal amino acids 501-617 of PA that overlap the putative nucleotide-binding site and PB1-binding site on PA inhibited RNA polymerizing activity as well as monospecific antibodies. Those against the N-terminal (amino acids 1-159); the central region (amino acids 305-559) of PB2, where a part of the cap-binding domain predicted previously is localized; the N-terminal (amino acids 1-222) of PB1; and amino acids 301-517 and 601-716 of PA inhibited the cap-I-dependent RNase activity. The cap-binding domain on PB2 could be mapped in amino acids 402-559, where one of the cap-binding domains mapped previously overlapped.  (+info)

Genetic diversity of equine arteritis virus. (5/1725)

Equine arteritis viruses (EAV) from Europe and America were compared by phylogenetic analysis of 43 isolates obtained over four decades. An additional 22 virus sequences were retrieved from GenBank. Fragments of the glycoprotein G(L) and the replicase genes were amplified by RT-PCR, prior to sequencing and construction of phylogenetic trees. The trees revealed many distinctive lineages, consistent with prolonged diversification within geographically separated host populations. Two large groups and five subgroups were distinguished. Group I consisted mainly of viruses from North America, whilst group II consisted mainly of European isolates. In most instances, where the geographic origin of the viruses appeared to be at variance with the phylogenetically predicted relationships, the horses from which the viruses were recovered had been transported between Europe and America or vice versa. Analysis of the replicase gene revealed similar phylogenetic relationships although not all of the groups were as clearly defined. Virus strains CH1 (Switzerland, 1964) and S1 (Sweden, 1989) represented separate 'outgroups' based on analysis of both genomic regions. The results of this study confirm the value of the G(L) gene of EAV for estimating virus genetic diversity and as a useful tool for tracing routes by which EAV is spread. In addition, computer-assisted predictions of antigenic sites on the G(L) protein revealed considerable variability among the isolates, especially with respect to regions associated with neutralization domains.  (+info)

Proteolytic processing of tomato ringspot nepovirus 3C-like protease precursors: definition of the domains for the VPg, protease and putative RNA-dependent RNA polymerase. (6/1725)

Tomato ringspot nepovirus (TomRSV) RNA-1 encodes a putative NTP-binding protein (NTB), a putative viral genome-linked protein (VPg), a putative RNA-dependent RNA polymerase (Pol) and a serine-like protease (Pro), which have been suggested to be involved in viral RNA replication. Proteolytic processing of protease precursors containing these proteins was studied in Escherichia coli and in vitro. The TomRSV protease could cleave the precursor proteins and release the predicted mature proteins or intermediate precursors. Although processing was detected at all three predicted cleavage sites (NTB-VPg, VPg-Pro and Pro-Pol), processing at the VPg-Pro cleavage site was inefficient, resulting in accumulation of the VPg-Pro intermediate precursor in E. coli and in vitro. In addition, the presence of the VPg sequence in the precursor resulted in increased cleavage at the Pro-Pol cleavage site in E. coli and in vitro. Direct N-terminal sequencing of the genomic RNA-linked VPg, of the mature protease purified from E. coli extracts and of radiolabelled mature polymerase purified from in vitro translation products revealed the sequences of the NTB-VPg, VPg-Pro and Pro-Pol dipeptide cleavage sites to be Q/S, Q/G and Q/S, respectively. In vitro processing at the NTB-VPg and Pro-Pol cleavage sites was not detected upon mutation or deletion of the conserved glutamine at the -1 position of the cleavage site. These results are discussed in light of the cleavage site specificity of the TomRSV protease.  (+info)

New defective RNAs from citrus tristeza virus: evidence for a replicase-driven template switching mechanism in their generation. (7/1725)

Defective RNAs (D-RNAs) ranging in size from 1968 to 2759 nt were detected in four citrus tristeza virus (CTV) isolates by hybridization of electroblotted dsRNAs with two probes specific for the 5'- and 3'-terminal genomic regions. The RNAs that hybridized with both probes were eluted, cloned and sequenced. Comparison with the sequences of the corresponding genomic regions of the helper virus showed, in all cases, over 99% nucleotide identity and direct repeats of 4-5 nt flanking or in the vicinity of the junction sites. The presence of the repeats from two separate genome locations suggests a replicase-driven template switching mechanism for the generation of these CTV D-RNAs. Two of the CTV isolates that differed greatly in their pathogenicity contained an identical D-RNA, suggesting that it is unlikely that this D-RNA is involved in symptom modulation, which may be caused by another factor.  (+info)

Packaging and replication regulation revealed by chimeric genome segments of double-stranded RNA bacteriophage phi6. (8/1725)

Bacteriophage phi6 has a double-stranded RNA genome composed of three linear segments, L, M, and S. The innermost particle in the virion of phi6, like in the other dsRNA viruses, is an RNA-dependent RNA polymerase complex, which carries out all the functions needed for the replication of the viral genome. Empty polymerase complexes can package the single-stranded copies of the viral genome segments, replicate the packaged segments into double-stranded form (minus strand synthesis), and then produce new plus strands (transcripts) from the double-stranded RNA templates. The three viral genomic segments contain unique packaging signals at their 5' ends, and minus strand synthesis initiation is dependent on the sequence at the 3' end. Here we have constructed chimeric segments that have the packaging signal from one segment and the minus strand synthesis initiation signal from another segment. Using purified recombinant polymerase complexes and single-stranded/chimeric and original RNA segments, we have analyzed the packaging and replication regulation operating in in vitro conditions. We show that the 5' end of the L genome segment in single-stranded form is needed to switch from the packaging to the minus strand synthesis and the same sequence is required in double-stranded form to switch on plus strand synthesis. In addition we have constructed deletions to the M segment to analyze the possible regulatory role of the internal noncoding area of this segment.  (+info)

RNA-dependent RNA polymerase, also known as RNA replicase, is an enzyme that catalyzes the production of RNA from an RNA template. It plays a crucial role in the replication of certain viruses, such as positive-strand RNA viruses and retroviruses, which use RNA as their genetic material. The enzyme uses the existing RNA strand as a template to create a new complementary RNA strand, effectively replicating the viral genome. This process is essential for the propagation of these viruses within host cells and is a target for antiviral therapies.

Qβ replicase, also known as MS2 replicase or R17 replicase, is not a medical term per se, but rather a scientific term used in the field of molecular biology. It refers to an enzyme that is derived from the Qβ bacteriophage (a type of virus that infects bacteria) and is capable of synthesizing RNA complementary to an RNA template. Specifically, Qβ replicase is involved in the replication of the single-stranded RNA genome of the Qβ phage. It has been used in various laboratory settings as a tool for studying RNA replication and as a component in the production of RNA molecules for research purposes.

RNA nucleotidyltransferases are a class of enzymes that catalyze the template-independent addition of nucleotides to the 3' end of RNA molecules, using nucleoside triphosphates as substrates. These enzymes play crucial roles in various biological processes, including RNA maturation, quality control, and regulation.

The reaction catalyzed by RNA nucleotidyltransferases involves the formation of a phosphodiester bond between the 3'-hydroxyl group of the RNA substrate and the alpha-phosphate group of the incoming nucleoside triphosphate. This results in the elongation of the RNA molecule by one or more nucleotides, depending on the specific enzyme and context.

Examples of RNA nucleotidyltransferases include poly(A) polymerases, which add poly(A) tails to mRNAs during processing, and terminal transferases, which are involved in DNA repair and V(D)J recombination in the immune system. These enzymes have been implicated in various diseases, including cancer and neurological disorders, making them potential targets for therapeutic intervention.

A viral RNA (ribonucleic acid) is the genetic material found in certain types of viruses, as opposed to viruses that contain DNA (deoxyribonucleic acid). These viruses are known as RNA viruses. The RNA can be single-stranded or double-stranded and can exist as several different forms, such as positive-sense, negative-sense, or ambisense RNA. Upon infecting a host cell, the viral RNA uses the host's cellular machinery to translate the genetic information into proteins, leading to the production of new virus particles and the continuation of the viral life cycle. Examples of human diseases caused by RNA viruses include influenza, COVID-19 (SARS-CoV-2), hepatitis C, and polio.

RNA viruses are a type of virus that contain ribonucleic acid (RNA) as their genetic material, as opposed to deoxyribonucleic acid (DNA). RNA viruses replicate by using an enzyme called RNA-dependent RNA polymerase to transcribe and replicate their RNA genome.

There are several different groups of RNA viruses, including:

1. Negative-sense single-stranded RNA viruses: These viruses have a genome that is complementary to the mRNA and must undergo transcription to produce mRNA before translation can occur. Examples include influenza virus, measles virus, and rabies virus.
2. Positive-sense single-stranded RNA viruses: These viruses have a genome that can serve as mRNA and can be directly translated into protein after entry into the host cell. Examples include poliovirus, rhinoviruses, and coronaviruses.
3. Double-stranded RNA viruses: These viruses have a genome consisting of double-stranded RNA and use a complex replication strategy involving both transcription and reverse transcription. Examples include rotaviruses and reoviruses.

RNA viruses are known to cause a wide range of human diseases, ranging from the common cold to more severe illnesses such as hepatitis C, polio, and COVID-19. Due to their high mutation rates and ability to adapt quickly to new environments, RNA viruses can be difficult to control and treat with antiviral drugs or vaccines.

Coliphages are viruses that infect and replicate within certain species of bacteria that belong to the coliform group, particularly Escherichia coli (E. coli). These viruses are commonly found in water and soil environments and are frequently used as indicators of fecal contamination in water quality testing. Coliphages are not harmful to humans or animals, but their presence in water can suggest the potential presence of pathogenic bacteria or other microorganisms that may pose a health risk. There are two main types of coliphages: F-specific RNA coliphages and somatic (or non-F specific) DNA coliphages.

Virus replication is the process by which a virus produces copies or reproduces itself inside a host cell. This involves several steps:

1. Attachment: The virus attaches to a specific receptor on the surface of the host cell.
2. Penetration: The viral genetic material enters the host cell, either by invagination of the cell membrane or endocytosis.
3. Uncoating: The viral genetic material is released from its protective coat (capsid) inside the host cell.
4. Replication: The viral genetic material uses the host cell's machinery to produce new viral components, such as proteins and nucleic acids.
5. Assembly: The newly synthesized viral components are assembled into new virus particles.
6. Release: The newly formed viruses are released from the host cell, often through lysis (breaking) of the cell membrane or by budding off the cell membrane.

The specific mechanisms and details of virus replication can vary depending on the type of virus. Some viruses, such as DNA viruses, use the host cell's DNA polymerase to replicate their genetic material, while others, such as RNA viruses, use their own RNA-dependent RNA polymerase or reverse transcriptase enzymes. Understanding the process of virus replication is important for developing antiviral therapies and vaccines.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.

Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Å and a pitch of 34 Å, while the A-form has a smaller diameter (about 18 Å) and a shorter pitch (about 25 Å). RNA typically adopts an A-form conformation.

The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Small interfering RNA (siRNA) is a type of short, double-stranded RNA molecule that plays a role in the RNA interference (RNAi) pathway. The RNAi pathway is a natural cellular process that regulates gene expression by targeting and destroying specific messenger RNA (mRNA) molecules, thereby preventing the translation of those mRNAs into proteins.

SiRNAs are typically 20-25 base pairs in length and are generated from longer double-stranded RNA precursors called hairpin RNAs or dsRNAs by an enzyme called Dicer. Once generated, siRNAs associate with a protein complex called the RNA-induced silencing complex (RISC), which uses one strand of the siRNA (the guide strand) to recognize and bind to complementary sequences in the target mRNA. The RISC then cleaves the target mRNA, leading to its degradation and the inhibition of protein synthesis.

SiRNAs have emerged as a powerful tool for studying gene function and have shown promise as therapeutic agents for a variety of diseases, including viral infections, cancer, and genetic disorders. However, their use as therapeutics is still in the early stages of development, and there are challenges associated with delivering siRNAs to specific cells and tissues in the body.

I apologize, but "Allolevivirus" is not a recognized term in medical or virological nomenclature. It is possible that you may have misspelled or are thinking of a different virus name. If you meant "Levivirus," this is a type of small, naked RNA virus that infects bacteria and does not infect humans or animals. If you have any other questions or need clarification on a different topic, please let me know!

Tombusvirus is a genus of viruses in the family Tombusviridae, order Tymovirales. These are positive-strand RNA viruses that infect a wide range of plants, causing various symptoms such as mosaic patterns, necrotic lesions, and stunting. The name "tombusvirus" is derived from the type species, Tomato bushy stunt virus (TBSV). TBSV has a 4.8 kb RNA genome that encodes for five proteins involved in replication, encapsidation, and movement within the host plant. Other notable tombusviruses include Cucumber necrosis virus (CNV) and Pelargonium leaf curl virus (PelLCV).

RNA editing is a process that alters the sequence of a transcribed RNA molecule after it has been synthesized from DNA, but before it is translated into protein. This can result in changes to the amino acid sequence of the resulting protein or to the regulation of gene expression. The most common type of RNA editing in mammals is the hydrolytic deamination of adenosine (A) to inosine (I), catalyzed by a family of enzymes called adenosine deaminases acting on RNA (ADARs). Inosine is recognized as guanosine (G) by the translation machinery, leading to A-to-G changes in the RNA sequence. Other types of RNA editing include cytidine (C) to uridine (U) deamination and insertion/deletion of nucleotides. RNA editing is a crucial mechanism for generating diversity in gene expression and has been implicated in various biological processes, including development, differentiation, and disease.

RNA splicing is a post-transcriptional modification process in which the non-coding sequences (introns) are removed and the coding sequences (exons) are joined together in a messenger RNA (mRNA) molecule. This results in a continuous mRNA sequence that can be translated into a single protein. Alternative splicing, where different combinations of exons are included or excluded, allows for the creation of multiple proteins from a single gene.

DNA-directed RNA polymerases are enzymes that synthesize RNA molecules using a DNA template in a process called transcription. These enzymes read the sequence of nucleotides in a DNA molecule and use it as a blueprint to construct a complementary RNA strand.

The RNA polymerase moves along the DNA template, adding ribonucleotides one by one to the growing RNA chain. The synthesis is directional, starting at the promoter region of the DNA and moving towards the terminator region.

In bacteria, there is a single type of RNA polymerase that is responsible for transcribing all types of RNA (mRNA, tRNA, and rRNA). In eukaryotic cells, however, there are three different types of RNA polymerases: RNA polymerase I, II, and III. Each type is responsible for transcribing specific types of RNA.

RNA polymerases play a crucial role in gene expression, as they link the genetic information encoded in DNA to the production of functional proteins. Inhibition or mutation of these enzymes can have significant consequences for cellular function and survival.

Ribosomal RNA (rRNA) is a type of RNA molecule that is a key component of ribosomes, which are the cellular structures where protein synthesis occurs in cells. In ribosomes, rRNA plays a crucial role in the process of translation, where genetic information from messenger RNA (mRNA) is translated into proteins.

Ribosomal RNA is synthesized in the nucleus and then transported to the cytoplasm, where it assembles with ribosomal proteins to form ribosomes. Within the ribosome, rRNA provides a structural framework for the assembly of the ribosome and also plays an active role in catalyzing the formation of peptide bonds between amino acids during protein synthesis.

There are several different types of rRNA molecules, including 5S, 5.8S, 18S, and 28S rRNA, which vary in size and function. These rRNA molecules are highly conserved across different species, indicating their essential role in protein synthesis and cellular function.

Bacterial RNA refers to the genetic material present in bacteria that is composed of ribonucleic acid (RNA). Unlike higher organisms, bacteria contain a single circular chromosome made up of DNA, along with smaller circular pieces of DNA called plasmids. These bacterial genetic materials contain the information necessary for the growth and reproduction of the organism.

Bacterial RNA can be divided into three main categories: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). mRNA carries genetic information copied from DNA, which is then translated into proteins by the rRNA and tRNA molecules. rRNA is a structural component of the ribosome, where protein synthesis occurs, while tRNA acts as an adapter that brings amino acids to the ribosome during protein synthesis.

Bacterial RNA plays a crucial role in various cellular processes, including gene expression, protein synthesis, and regulation of metabolic pathways. Understanding the structure and function of bacterial RNA is essential for developing new antibiotics and other therapeutic strategies to combat bacterial infections.

I'm sorry for any confusion, but there seems to be a mistake in your question. "Arteritis Virus, Equine" is not a recognized medical term or virus in humans or animals. There is a condition called "Equine Viral Arteritis (EVA)," which is a viral disease that affects horses and other equine species. However, it does not affect humans.

Equine Viral Arteritis (EVA) is caused by the Equine Arteritis Virus (EAV). This virus primarily affects the respiratory system and can cause symptoms such as fever, lethargy, loss of appetite, and a runny nose in infected horses. In some cases, it may also lead to inflammation of the lining of blood vessels (vasculitis), which can result in abortion in pregnant mares or infertility in stallions.

It's essential to maintain proper biosecurity measures when dealing with horses, especially those that have been exposed to EVA, to prevent its spread and protect the health of other equine populations.

I'm happy to help! However, it seems there might be a slight misunderstanding in your question. RNA, or ribonucleic acid, is typically single-stranded. Unlike DNA, which is double-stranded and forms a double helix, RNA usually exists as a single strand of nucleotides.

There are exceptions to this rule, such as certain types of RNA molecules that can form double-stranded structures in specific contexts. For example:

1. Double-Stranded RNA (dsRNA) viruses: These viruses have genomes made entirely of RNA, which is double-stranded throughout or partially double-stranded. The dsRNA viruses include important pathogens such as rotaviruses and reoviruses.
2. Hairpin loops in RNA structures: Some single-stranded RNA molecules can fold back on themselves to form short double-stranded regions, called hairpin loops, within their overall structure. These are often found in ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA) molecules.

So, while 'double-stranded RNA' is not a standard medical definition for RNA itself, there are specific instances where RNA can form double-stranded structures as described above.

RNA interference (RNAi) is a biological process in which RNA molecules inhibit the expression of specific genes. This process is mediated by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), that bind to complementary sequences on messenger RNA (mRNA) molecules, leading to their degradation or translation inhibition.

RNAi plays a crucial role in regulating gene expression and defending against foreign genetic elements, such as viruses and transposons. It has also emerged as an important tool for studying gene function and developing therapeutic strategies for various diseases, including cancer and viral infections.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

RNA helicases are a class of enzymes that are capable of unwinding RNA secondary structures using the energy derived from ATP hydrolysis. They play crucial roles in various cellular processes involving RNA, such as transcription, splicing, translation, ribosome biogenesis, and RNA degradation. RNA helicases can be divided into several superfamilies based on their sequence and structural similarities, with the two largest being superfamily 1 (SF1) and superfamily 2 (SF2). These enzymes typically contain conserved motifs that are involved in ATP binding and hydrolysis, as well as RNA binding. By unwinding RNA structures, RNA helicases facilitate the access of other proteins to their target RNAs, thereby enabling the coordinated regulation of RNA metabolism.

Tombusviridae is a family of viruses in the order Picornavirales, characterized by having single-stranded, positive-sense RNA genomes. Members of this family typically infect plants and are transmitted by mechanical means or through contact with contaminated soil. The virions are non-enveloped and have icosahedral symmetry, with a diameter of about 30-34 nanometers. Tombusviruses are known to cause various symptoms in their host plants, including mottling, necrosis, and stunting. Some notable examples of tombusviruses include Tomato bushy stunt virus (TBSV) and Cucumber necrosis virus (CNV).

RNA phages are a type of bacteriophage, which is a virus that infects bacteria. Unlike most other bacteriophages, RNA phages have an RNA genome instead of a DNA genome. These viruses infect and replicate within bacteria that have an RNA genome or those that can incorporate RNA into their replication cycle.

RNA phages are relatively simple in structure, consisting of an icosahedral capsid (protein shell) containing the single-stranded RNA genome. The genome may be either positive-sense (+) or negative-sense (-), depending on whether it can serve directly as messenger RNA (mRNA) for translation or if it must first be transcribed into a complementary RNA strand before translation.

Examples of well-known RNA phages include the MS2, Qβ, and φ6 phages. These viruses have been extensively studied as model systems to understand fundamental principles of RNA biology, virus replication strategies, and host-pathogen interactions. They also have potential applications in biotechnology, such as in the development of RNA-based vaccines and gene therapy vectors.

Viral nonstructural proteins (NS) are viral proteins that are not part of the virion structure. They play various roles in the viral life cycle, such as replication of the viral genome, transcription, translation regulation, and modulation of the host cell environment to favor virus replication. These proteins are often produced in large quantities during infection and can manipulate or disrupt various cellular pathways to benefit the virus. They may also be involved in evasion of the host's immune response. The specific functions of viral nonstructural proteins vary depending on the type of virus.

Tobacco is not a medical term, but it refers to the leaves of the plant Nicotiana tabacum that are dried and fermented before being used in a variety of ways. Medically speaking, tobacco is often referred to in the context of its health effects. According to the World Health Organization (WHO), "tobacco" can also refer to any product prepared from the leaf of the tobacco plant for smoking, sucking, chewing or snuffing.

Tobacco use is a major risk factor for a number of diseases, including cancer, heart disease, stroke, lung disease, and various other medical conditions. The smoke produced by burning tobacco contains thousands of chemicals, many of which are toxic and can cause serious health problems. Nicotine, one of the primary active constituents in tobacco, is highly addictive and can lead to dependence.

A catalytic RNA, often referred to as a ribozyme, is a type of RNA molecule that has the ability to act as an enzyme and catalyze chemical reactions. These RNA molecules contain specific sequences and structures that allow them to bind to other molecules and accelerate chemical reactions without being consumed in the process.

Ribozymes play important roles in various biological processes, such as RNA splicing, translation regulation, and gene expression. One of the most well-known ribozymes is the self-splicing intron found in certain RNA molecules, which can excise itself from the host RNA and then ligase the flanking exons together.

The discovery of catalytic RNAs challenged the central dogma of molecular biology, which held that proteins were solely responsible for carrying out biological catalysis. The finding that RNA could also function as an enzyme opened up new avenues of research and expanded our understanding of the complexity and versatility of biological systems.

A genetic template refers to the sequence of DNA or RNA that contains the instructions for the development and function of an organism or any of its components. These templates provide the code for the synthesis of proteins and other functional molecules, and determine many of the inherited traits and characteristics of an individual. In this sense, genetic templates serve as the blueprint for life and are passed down from one generation to the next through the process of reproduction.

In molecular biology, the term "template" is used to describe the strand of DNA or RNA that serves as a guide or pattern for the synthesis of a complementary strand during processes such as transcription and replication. During transcription, the template strand of DNA is transcribed into a complementary RNA molecule, while during replication, each parental DNA strand serves as a template for the synthesis of a new complementary strand.

In genetic engineering and synthetic biology, genetic templates can be manipulated and modified to introduce new functions or alter existing ones in organisms. This is achieved through techniques such as gene editing, where specific sequences in the genetic template are targeted and altered using tools like CRISPR-Cas9. Overall, genetic templates play a crucial role in shaping the structure, function, and evolution of all living organisms.

RNA folding, also known as RNA structure formation or RNA tertiary structure prediction, refers to the process by which an RNA molecule folds into a specific three-dimensional shape based on its primary sequence. This shape is determined by intramolecular interactions between nucleotides within the RNA chain, including base pairing (through hydrogen bonding) and stacking interactions. The folded structure of RNA plays a crucial role in its function, as it can create specific binding sites for proteins or other molecules, facilitate or inhibit enzymatic activity, or influence the stability and localization of the RNA within the cell.

RNA folding is a complex process that can be influenced by various factors such as temperature, ionic conditions, and molecular crowding. The folded structure of an RNA molecule can be predicted using computational methods, such as thermodynamic modeling and machine learning algorithms, which take into account the primary sequence and known patterns of base pairing and stacking interactions to generate a model of the three-dimensional structure. However, experimental techniques, such as chemical probing and crystallography, are often necessary to validate and refine these predictions.

Bromovirus is a genus of viruses in the family Bromoviridae, order Picornavirales. These viruses have single-stranded, positive-sense RNA genomes and are transmitted by insects, primarily aphids. They infect a wide range of plants, causing various symptoms such as mosaic patterns on leaves, stunting, and reduced yield. The genus Bromovirus includes several important plant pathogens, including Alfalfa mosaic virus (AMV), Broad bean mottle virus (BBMV), and Cucumber mosaic virus (CMV).

RNA Polymerase II is a type of enzyme responsible for transcribing DNA into RNA in eukaryotic cells. It plays a crucial role in the process of gene expression, where the information stored in DNA is used to create proteins. Specifically, RNA Polymerase II transcribes protein-coding genes to produce precursor messenger RNA (pre-mRNA), which is then processed into mature mRNA. This mature mRNA serves as a template for protein synthesis during translation.

RNA Polymerase II has a complex structure, consisting of multiple subunits, and it requires the assistance of various transcription factors and coactivators to initiate and regulate transcription. The enzyme recognizes specific promoter sequences in DNA, unwinds the double-stranded DNA, and synthesizes a complementary RNA strand using one of the unwound DNA strands as a template. This process results in the formation of a nascent RNA molecule that is further processed into mature mRNA for protein synthesis or other functional RNAs involved in gene regulation.

Tobacco mosaic virus (TMV) is not typically considered in the context of medical definitions, as it's primarily known for its impact on plants rather than humans or animals. However, I will provide the botanical definition for your interest.

Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus that infects a wide range of plants, including tobacco, tomatoes, cucumbers, and many ornamental plants. The virus is named after its initial discovery in tobacco plants, which exhibit symptoms such as mosaic patterns of light and dark green on the leaves, leaf curling, and stunted growth. TMV is highly contagious and can be spread through mechanical means, such as touching infected plants or using contaminated tools. It's also one of the most well-studied viruses due to its impact on agriculture and its historical significance in early virology research.

A viral genome is the genetic material (DNA or RNA) that is present in a virus. It contains all the genetic information that a virus needs to replicate itself and infect its host. The size and complexity of viral genomes can vary greatly, ranging from a few thousand bases to hundreds of thousands of bases. Some viruses have linear genomes, while others have circular genomes. The genome of a virus also contains the information necessary for the virus to hijack the host cell's machinery and use it to produce new copies of the virus. Understanding the genetic makeup of viruses is important for developing vaccines and antiviral treatments.

Viral proteins are the proteins that are encoded by the viral genome and are essential for the viral life cycle. These proteins can be structural or non-structural and play various roles in the virus's replication, infection, and assembly process. Structural proteins make up the physical structure of the virus, including the capsid (the protein shell that surrounds the viral genome) and any envelope proteins (that may be present on enveloped viruses). Non-structural proteins are involved in the replication of the viral genome and modulation of the host cell environment to favor viral replication. Overall, a thorough understanding of viral proteins is crucial for developing antiviral therapies and vaccines.

A plant virus is not defined in medical terms, as viruses are typically considered within the context of living organisms and plants are not classified as such. However, I can provide a general virology definition for you:

Plant viruses are small infectious agents that consist of nucleic acid (DNA or RNA) enclosed in a protein coat. They infect various plant species, causing a wide range of symptoms and diseases, which can result in significant economic losses in agriculture and horticulture. Plant viruses lack the ability to replicate outside a host cell, and they rely on the host's metabolic machinery for their reproduction. They can be transmitted through various means, such as insect vectors, seeds, or mechanical contact.

A polyprotein is a long, continuous chain of amino acids that are produced through the translation of a single mRNA (messenger RNA) molecule. This occurs in some viruses, including retroviruses like HIV, where the viral genome contains instructions for the production of one or more polyproteins.

After the polyprotein is synthesized, it is cleaved into smaller, functional proteins by virus-encoded proteases. These individual proteins then assemble to form new virus particles. The concept of polyproteins is important in understanding viral replication and may provide targets for antiviral therapy.

Transfer RNA (tRNA) is a type of RNA molecule that plays a crucial role in protein synthesis, the process by which cells create proteins. In protein synthesis, tRNAs serve as adaptors, translating the genetic code present in messenger RNA (mRNA) into the corresponding amino acids required to build a protein.

Each tRNA molecule has a distinct structure, consisting of approximately 70-90 nucleotides arranged in a cloverleaf shape with several loops and stems. The most important feature of a tRNA is its anticodon, a sequence of three nucleotides located in one of the loops. This anticodon base-pairs with a complementary codon on the mRNA during translation, ensuring that the correct amino acid is added to the growing polypeptide chain.

Before tRNAs can participate in protein synthesis, they must be charged with their specific amino acids through an enzymatic process involving aminoacyl-tRNA synthetases. These enzymes recognize and bind to both the tRNA and its corresponding amino acid, forming a covalent bond between them. Once charged, the aminoacyl-tRNA complex is ready to engage in translation and contribute to protein formation.

In summary, transfer RNA (tRNA) is a small RNA molecule that facilitates protein synthesis by translating genetic information from messenger RNA into specific amino acids, ultimately leading to the creation of functional proteins within cells.

Ribonucleic acid (RNA) is a type of nucleic acid that plays a crucial role in the process of gene expression. There are several types of RNA molecules, including messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). These RNA molecules help to transcribe DNA into mRNA, which is then translated into proteins by the ribosomes.

Fungi are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. Like other eukaryotes, fungi contain DNA and RNA as part of their genetic material. The RNA in fungi is similar to the RNA found in other organisms, including humans, and plays a role in gene expression and protein synthesis.

A specific medical definition of "RNA, fungal" does not exist, as RNA is a fundamental component of all living organisms, including fungi. However, RNA can be used as a target for antifungal drugs, as certain enzymes involved in RNA synthesis and processing are unique to fungi and can be inhibited by these drugs. For example, the antifungal drug flucytosine is converted into a toxic metabolite that inhibits fungal RNA and DNA synthesis.

RNA caps are structures found at the 5' end of RNA molecules, including messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). These caps consist of a modified guanine nucleotide (called 7-methylguanosine) that is linked to the first nucleotide of the RNA chain through a triphosphate bridge. The RNA cap plays several important roles in regulating RNA metabolism, including protecting the RNA from degradation by exonucleases, promoting the recognition and binding of the RNA by ribosomes during translation, and modulating the stability and transport of the RNA within the cell.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

RNA stability refers to the duration that a ribonucleic acid (RNA) molecule remains intact and functional within a cell before it is degraded or broken down into its component nucleotides. Various factors can influence RNA stability, including:

1. Primary sequence: Certain sequences in the RNA molecule may be more susceptible to degradation by ribonucleases (RNases), enzymes that break down RNA.
2. Secondary structure: The formation of stable secondary structures, such as hairpins or stem-loop structures, can protect RNA from degradation.
3. Presence of RNA-binding proteins: Proteins that bind to RNA can either stabilize or destabilize the RNA molecule, depending on the type and location of the protein-RNA interaction.
4. Chemical modifications: Modifications to the RNA nucleotides, such as methylation, can increase RNA stability by preventing degradation.
5. Subcellular localization: The subcellular location of an RNA molecule can affect its stability, with some locations providing more protection from ribonucleases than others.
6. Cellular conditions: Changes in cellular conditions, such as pH or temperature, can also impact RNA stability.

Understanding RNA stability is important for understanding gene regulation and the function of non-coding RNAs, as well as for developing RNA-based therapeutic strategies.

Antisense RNA is a type of RNA molecule that is complementary to another RNA called sense RNA. In the context of gene expression, sense RNA is the RNA transcribed from a protein-coding gene, which serves as a template for translation into a protein. Antisense RNA, on the other hand, is transcribed from the opposite strand of the DNA and is complementary to the sense RNA.

Antisense RNA can bind to its complementary sense RNA through base-pairing, forming a double-stranded RNA structure. This interaction can prevent the sense RNA from being translated into protein or can target it for degradation by cellular machinery, thereby reducing the amount of protein produced from the gene. Antisense RNA can be used as a tool in molecular biology to study gene function or as a therapeutic strategy to silence disease-causing genes.

Arterivirus is a type of enveloped, single-stranded, positive-sense RNA virus that belongs to the family Arteriviridae. These viruses are named after their initial discovery in arteries and have since been found to infect a wide range of mammals, including pigs, horses, cats, and primates.

Arteriviruses can cause various diseases, such as porcine reproductive and respiratory syndrome (PRRS) in pigs, equine arteritis virus (EAV) in horses, and simian hemorrhagic fever virus (SHFV) in non-human primates. In humans, Arterivirus infection is rare, but some cases of human infection with porcine reproductive and respiratory syndrome virus have been reported.

Arteriviruses are characterized by their unique viral structure, including a distinctive "coronavirus-like" appearance due to the presence of club-shaped projections on their surface called peplomers. However, they differ from coronaviruses in several ways, such as genome organization and replication strategy.

Overall, Arterivirus is an important group of viruses that can cause significant economic losses in the livestock industry and pose a potential threat to human health.

Post-transcriptional RNA processing refers to the modifications and regulations that occur on RNA molecules after the transcription of DNA into RNA. This process includes several steps:

1. 5' capping: The addition of a cap structure, usually a methylated guanosine triphosphate (GTP), to the 5' end of the RNA molecule. This helps protect the RNA from degradation and plays a role in its transport, stability, and translation.
2. 3' polyadenylation: The addition of a string of adenosine residues (poly(A) tail) to the 3' end of the RNA molecule. This process is important for mRNA stability, export from the nucleus, and translation initiation.
3. Intron removal and exon ligation: Eukaryotic pre-messenger RNAs (pre-mRNAs) contain intronic sequences that do not code for proteins. These introns are removed by a process called splicing, where the flanking exons are joined together to form a continuous mRNA sequence. Alternative splicing can lead to different mature mRNAs from a single pre-mRNA, increasing transcriptomic and proteomic diversity.
4. RNA editing: Specific nucleotide changes in RNA molecules that alter the coding potential or regulatory functions of RNA. This process is catalyzed by enzymes like ADAR (Adenosine Deaminases Acting on RNA) and APOBEC (Apolipoprotein B mRNA Editing Catalytic Polypeptide-like).
5. Chemical modifications: Various chemical modifications can occur on RNA nucleotides, such as methylation, pseudouridination, and isomerization. These modifications can influence RNA stability, localization, and interaction with proteins or other RNAs.
6. Transport and localization: Mature mRNAs are transported from the nucleus to the cytoplasm for translation. In some cases, specific mRNAs are localized to particular cellular compartments to ensure local protein synthesis.
7. Degradation: RNA molecules have finite lifetimes and undergo degradation by various ribonucleases (RNases). The rate of degradation can be influenced by factors such as RNA structure, modifications, or interactions with proteins.

A satellite RNA is a type of non-coding RNA that does not encode proteins but instead plays a role in the regulation of gene expression. It is so named because it can exist as a separate, smaller molecule that "satellites" around a larger RNA molecule called the helper RNA. Satellite RNAs are often associated with viruses and can affect their replication and packaging. They can also be found in some eukaryotic cells, where they may play a role in regulating the expression of certain genes or in the development of diseases such as cancer.

'Toxic plants' refer to those species of plants that contain toxic substances capable of causing harmful effects or adverse health reactions in humans and animals when ingested, touched, or inhaled. These toxins can cause a range of symptoms from mild irritation to serious conditions such as organ failure, paralysis, or even death depending on the plant, the amount consumed, and the individual's sensitivity to the toxin.

Toxic plants may contain various types of toxins, including alkaloids, glycosides, proteins, resinous substances, and essential oils. Some common examples of toxic plants include poison ivy, poison oak, nightshade, hemlock, oleander, castor bean, and foxglove. It is important to note that some parts of a plant may be toxic while others are not, and the toxicity can also vary depending on the stage of growth or environmental conditions.

If you suspect exposure to a toxic plant, it is essential to seek medical attention immediately and, if possible, bring a sample of the plant for identification.

Small nuclear RNA (snRNA) are a type of RNA molecules that are typically around 100-300 nucleotides in length. They are found within the nucleus of eukaryotic cells and are components of small nuclear ribonucleoproteins (snRNPs), which play important roles in various aspects of RNA processing, including splicing of pre-messenger RNA (pre-mRNA) and regulation of transcription.

There are several classes of snRNAs, each with a distinct function. The most well-studied class is the spliceosomal snRNAs, which include U1, U2, U4, U5, and U6 snRNAs. These snRNAs form complexes with proteins to form small nuclear ribonucleoprotein particles (snRNPs) that recognize specific sequences in pre-mRNA and catalyze the removal of introns during splicing.

Other classes of snRNAs include signal recognition particle (SRP) RNA, which is involved in targeting proteins to the endoplasmic reticulum, and Ro60 RNA, which is associated with autoimmune diseases such as systemic lupus erythematosus.

Overall, small nuclear RNAs are essential components of the cellular machinery that regulates gene expression and protein synthesis in eukaryotic cells.

An open reading frame (ORF) is a continuous stretch of DNA or RNA sequence that has the potential to be translated into a protein. It begins with a start codon (usually "ATG" in DNA, which corresponds to "AUG" in RNA) and ends with a stop codon ("TAA", "TAG", or "TGA" in DNA; "UAA", "UAG", or "UGA" in RNA). The sequence between these two points is called a coding sequence (CDS), which, when transcribed into mRNA and translated into amino acids, forms a polypeptide chain.

In eukaryotic cells, ORFs can be located in either protein-coding genes or non-coding regions of the genome. In prokaryotic cells, multiple ORFs may be present on a single strand of DNA, often organized into operons that are transcribed together as a single mRNA molecule.

It's important to note that not all ORFs necessarily represent functional proteins; some may be pseudogenes or result from errors in genome annotation. Therefore, additional experimental evidence is typically required to confirm the expression and functionality of a given ORF.

RNA precursors, also known as primary transcripts or pre-messenger RNAs (pre-mRNAs), refer to the initial RNA molecules that are synthesized during the transcription process in which DNA is copied into RNA. These precursor molecules still contain non-coding sequences and introns, which need to be removed through a process called splicing, before they can become mature and functional RNAs such as messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), or transfer RNAs (tRNAs).

Pre-mRNAs undergo several processing steps, including 5' capping, 3' polyadenylation, and splicing, to generate mature mRNA molecules that can be translated into proteins. The accurate and efficient production of RNA precursors and their subsequent processing are crucial for gene expression and regulation in cells.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

'Cucumis sativus' is the scientific name for the vegetable we commonly know as a cucumber. It belongs to the family Cucurbitaceae and is believed to have originated in South Asia. Cucumbers are widely consumed raw in salads, pickled, or used in various culinary applications. They have a high water content and contain various nutrients such as vitamin K, vitamin C, and potassium.

Untranslated regions (UTRs) of RNA are the non-coding sequences that are present in mRNA (messenger RNA) molecules, which are located at both the 5' end (5' UTR) and the 3' end (3' UTR) of the mRNA, outside of the coding sequence (CDS). These regions do not get translated into proteins. They contain regulatory elements that play a role in the regulation of gene expression by affecting the stability, localization, and translation efficiency of the mRNA molecule. The 5' UTR typically contains the Shine-Dalgarno sequence in prokaryotes or the Kozak consensus sequence in eukaryotes, which are important for the initiation of translation. The 3' UTR often contains regulatory elements such as AU-rich elements (AREs) and microRNA (miRNA) binding sites that can affect mRNA stability and translation.

Semliki Forest Virus (SFV) is an alphavirus in the Togaviridae family, which is primarily transmitted to vertebrates through mosquito vectors. The virus was initially isolated from mosquitoes in the Semliki Forest of Uganda and has since been found in various parts of Africa and Asia. SFV infection in humans can cause a mild febrile illness characterized by fever, headache, muscle pain, and rash. However, it is more commonly known for causing severe disease in animals, particularly non-human primates and cattle, where it can lead to encephalitis or hemorrhagic fever. SFV has also been used as a model organism in laboratory studies of virus replication and pathogenesis.

Mosaic viruses are a group of plant viruses that can cause mottled or mosaic patterns of discoloration on leaves, which is why they're named as such. These viruses infect a wide range of plants, including important crops like tobacco, tomatoes, and cucumbers. The infection can lead to various symptoms such as stunted growth, leaf deformation, reduced yield, or even plant death.

Mosaic viruses are typically spread by insects, such as aphids, that feed on the sap of infected plants and then transmit the virus to healthy plants. They can also be spread through contaminated seeds, tools, or contact with infected plant material. Once inside a plant, these viruses hijack the plant's cellular machinery to replicate themselves, causing damage to the host plant in the process.

It is important to note that mosaic viruses are not related to human or animal health; they only affect plants.

Murine hepatitis virus (MHV) is a type of coronavirus that primarily infects laboratory mice. It is not related to the human hepatitis viruses A, B, C, D, or E. MHV causes a range of diseases in mice, including hepatitis (liver inflammation), encephalomyelitis (inflammation of the brain and spinal cord), and enteritis (inflammation of the intestine). The virus is transmitted through fecal-oral route and respiratory droplets. It's widely used in research to understand the pathogenesis, immunity, and molecular biology of coronaviruses.

A protoplast is not a term that is typically used in medical definitions, but rather it is a term commonly used in cell biology and botany. A protoplast refers to a plant or bacterial cell that has had its cell wall removed, leaving only the plasma membrane and the cytoplasmic contents, including organelles such as mitochondria, chloroplasts, ribosomes, and other cellular structures.

Protoplasts can be created through enzymatic or mechanical means to isolate the intracellular components for various research purposes, such as studying membrane transport, gene transfer, or cell fusion. In some cases, protoplasts may be used in medical research, particularly in areas related to plant pathology and genetic engineering of plants for medical applications.

A cucumovirus is a type of plant virus that belongs to the family Bromoviridae and the genus Cucumovirus. These viruses have a single-stranded, positive-sense RNA genome and are transmitted by various means, including mechanical inoculation, seed transmission, and insect vectors such as aphids.

Cucumoviruses infect a wide range of plants, causing symptoms such as mosaic patterns on leaves, stunted growth, and reduced yield. The type species of the genus Cucumovirus is cucumber mosaic virus (CMV), which is one of the most widespread and economically important plant viruses worldwide. Other important cucumoviruses include tomato aspermy virus (TAV) and peanut stunt virus (PSV).

Cucumoviruses have a tripartite genome, meaning that the RNA genome is divided into three segments, each of which encodes one or more viral proteins. The coat protein of cucumoviruses plays an important role in virus transmission by insect vectors and in the induction of symptoms in infected plants.

Preventing the spread of cucumoviruses involves using good hygiene practices, such as cleaning tools and equipment, removing infected plants, and using resistant plant varieties when available. There are no known treatments for plants infected with cucumoviruses, so prevention is key to managing these viruses in agricultural settings.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

RNA Sequence Analysis is a branch of bioinformatics that involves the determination and analysis of the nucleotide sequence of Ribonucleic Acid (RNA) molecules. This process includes identifying and characterizing the individual RNA molecules, determining their functions, and studying their evolutionary relationships.

RNA Sequence Analysis typically involves the use of high-throughput sequencing technologies to generate large datasets of RNA sequences, which are then analyzed using computational methods. The analysis may include comparing the sequences to reference databases to identify known RNA molecules or discovering new ones, identifying patterns and features in the sequences, such as motifs or domains, and predicting the secondary and tertiary structures of the RNA molecules.

RNA Sequence Analysis has many applications in basic research, including understanding gene regulation, identifying novel non-coding RNAs, and studying evolutionary relationships between organisms. It also has practical applications in clinical settings, such as diagnosing and monitoring diseases, developing new therapies, and personalized medicine.

Alfalfa mosaic virus (AMV) is a plant-infecting virus that belongs to the family Bromoviridae and the genus Alfamovirus. It has a tripartite, single-stranded, positive-sense RNA genome. The virus is transmitted by various mechanical means, including sap transfer, as well as through seed and vegetative propagation. Insects such as aphids can also transmit the virus in a nonpersistent manner.

AMV infects a wide range of plant species, including many important agricultural crops like alfalfa, tobacco, tomatoes, beans, beets, and various ornamental plants. The virus causes a mosaic pattern of light and dark green areas on the leaves, along with other symptoms such as leaf curl, stunting, and reduced yield. There are no known treatments to cure infected plants, and control measures typically focus on preventing the spread of the virus through the use of disease-free seed and planting material, as well as controlling insect vectors.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Potexvirus is a genus of viruses in the family Alphaflexiviridae. These are positive-sense single-stranded RNA viruses that infect a wide range of plants, causing various diseases such as mosaic, necrosis, and stunting. The name "Potexvirus" is derived from the type species potato virus X (PVX). The virions are flexuous rods, non-enveloped, and about 12-13 nm in diameter and 470-580 nm in length. The genome is approximately 6.4 kb in size and encodes five open reading frames (ORFs). The first ORF encodes the replicase protein, while the other four ORFs encode the triple gene block proteins involved in viral movement, a coat protein, and a small cysteine-rich protein of unknown function. Potexviruses are transmitted by mechanical contact or contaminated tools and seeds.

Transcriptional silencer elements are DNA sequences that bind to specific proteins, known as transcriptional repressors or silencers, to inhibit the transcription of nearby genes. These elements typically recruit chromatin-modifying complexes that alter the structure of the chromatin, making it inaccessible to the transcription machinery. This results in the downregulation or silencing of gene expression. Transcriptional silencer elements can be found in both the promoter and enhancer regions of genes and play crucial roles in regulating various cellular processes, including development, differentiation, and disease pathogenesis.

This process is catalyzed by a viral RNA replicase.[clarification needed] A DNA transcription unit encoding for a protein may ... RNA sugar-phosphate backbone forms with assistance from RNA polymerase to form an RNA strand. Hydrogen bonds of the RNA-DNA ... small nuclear RNA (snRNA), or enzymatic RNA molecules called ribozymes as well as larger non-coding RNAs such as ribosomal RNA ... RNA synthesis by RNA polymerase was established in vitro by several laboratories by 1965; however, the RNA synthesized by these ...
"RNA helicase activity of Semliki Forest virus replicase protein NSP2". FEBS Letters. 448 (1): 19-22. doi:10.1016/S0014-5793(99) ... Replication occurs via a negative strand intermediate giving rise to a full length genomic RNA for export in new virions and a ... The Semliki Forest virus is a positive-strand RNA virus with a genome of approximately 13,000 base pairs which encodes nine ... The 5' two thirds of the genome encode four non-structural proteins concerned with RNA synthesis; the structural proteins are ...
Doudna, Jennifer Anne (1989). Towards the Design of an RNA Replicase (Ph.D. thesis). Harvard University. OCLC 23230360. ... Her Ph.D. dissertation was on a system that increased the efficiency of a self-replicating catalytic RNA and was supervised by ... This initial work to solve large RNA structures led to further structural studies on an internal ribosome entry site(IRES) and ... Early in her scientific career, Doudna worked to uncover the structure and biological function of RNA enzymes or ribozymes. ...
RNA1 is required in replication as it encodes for RNA replicase components. This RNA contains structural elements within the 3 ... RCNMV contains a genome that encodes for two positive sense RNA strands known as RNA1 and RNA2 and both these RNA strands lack ... UTR was shown to also play a role in RNA stability. Removal of the secondary structure correlated with a decrease in RNA ... RNA. 7 (12): 1743-1752. PMC 1370214. PMID 11780631. Pfingsten JS, Kieft JS (July 2008). "RNA structure-based ribosome ...
For RNA-based phages, RNA replicase is synthesized early in the process. Proteins modify the bacterial RNA polymerase so it ... April 1976). "Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". ... RNA phages such as MS2 have the smallest genomes, with only a few kilobases. However, some DNA phages such as T4 may have large ... Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or ...
Bacteriophage RNA replicase keeps the template and daughter strand separated during RNA synthesis; duplex RNA is not an ... Borst P, Weissmann C. Replication of viral RNA, 8. Studies on the enzymatic mechanism of replication of MS2 RNA. Proc Natl Acad ... RNA splicing is required to make the messenger RNA for a variant surface antigen in trypanosomes. NAR. 1982;10:3591-604. Kooter ... 1977;80:360-4. Heyting C, Meijlink FC, Verbeet MP, Sanders JP, Bos JL, Borst P. Fine structure of the 21S ribosomal RNA region ...
OrfB (Q04350) cleaves into a p48 C8 protease and the RNA replicase-helicase. Viral replication is cytoplasmic. Replication ... Double-stranded RNA virus transcription is the method of transcription. The virus exits the host cell by cell to cell movement ... follows the double-stranded RNA virus replication model. ...
... and the β-subunit of an RNA-dependent RNA-polymerase (RdRp) termed the replicase. The genome is highly structured, regulating ... The RNA-dependent RNA polymerase that replicates both the positive and negative RNA strands is a complex of four proteins: the ... He ended up with Spiegelman's Monster, a minimal RNA chain of only 218 nucleotides that can be replicated by Qβ replicase. ... All positive-strand RNA phages encode a maturation protein, whose function is to bind the host pilus and the viral RNA. The ...
One of these includes RNA-dependent RNA polymerase (RNA replicase), which copies the viral RNA to form a double-stranded ... Negative-sense viral RNA is complementary to mRNA and thus must be converted to positive-sense RNA by an RNA-dependent RNA ... This means that the virus must bring along with it the enzyme RNA replicase. The positive-sense RNA molecule then acts as viral ... Negative-sense ssRNA viruses (Group V) must have their genome copied by an RNA replicase to form positive-sense RNA. ...
1976). "Complete nucleotide-sequence of bacteriophage MS2-RNA - primary and secondary structure of replicase gene". Nature. 260 ... The intervening sequences in the RNA strand are first spliced out so that only the RNA segment left behind after splicing would ... 1964: Howard Temin showed using RNA viruses that the direction of DNA to RNA transcription can be reversed. 1964: Lysenkoism ... 1933: Jean Brachet, while studying virgin sea urchin eggs, suggested that DNA is found in cell nucleus and that RNA is present ...
RNA-dependent RNA polymerase (RdRp), also called RNA replicase, produces RNA (ribonucleic acid) from RNA. RNA-dependent DNA ... RNA-dependent RNA polymerase (RdRp), also called RNA replicase, which synthesizes RNA from RNA, and RNA-dependent DNA ... It includes RNA viruses that encode an RNA-dependent RNA polymerase, as well as reverse-transcribing viruses (with either RNA ... All members of Riboviria contain a gene that encodes for an RNA-dependent polymerase, also called RNA-directed polymerase. ...
"Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". Nature. 260 ( ...
"Complete nucleotide sequence of bacteriophage MS2 RNA: Primary and secondary structure of the replicase gene". Nature. 260 ( ... DNA and RNA-based approaches. A further important step was the introduction of phylogenetic markers such as the 16S rRNA gene ... RNA (metatranscriptomics), protein (metaproteomics), and metabolites (metabolomics). In that order, the focus of the studies ...
"Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". Nature. 260 ( ... Viroids are circular molecules RNA which do not have any protein-coding genes at all, although the RNA molecule itself acts as ... For instance, bacteriophage MS2 consists of only 3569 nucleotides (single-stranded RNA) and encodes just four proteins which ... such as an RNA world genome which does not have the need for DNA replication machinery, which is otherwise part of the minimal ...
April 1976). "Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". ... On the general nature of the RNA code". Proceedings of the National Academy of Sciences of the United States of America. 53 (5 ... Some new and exciting examples of progress in this field are the identification of genes for regulatory RNAs, insights into the ... Nirenberg M, Leder P, Bernfield M, Brimacombe R, Trupin J, Rottman F, O'Neal C (May 1965). "RNA codewords and protein synthesis ...
Synergism of mutations in bacteriophage Q_ RNA affecting host factor dependence of Q_ replicase. J. Mol. Biol. 295:149-154. The ... Evolvability of an RNA virus is determined by its mutational neighbourhood. Nature 406:625-628. Wichman, H. A., L. A. Scott, C ... Altered 3'-terminal RNA structure in phage Q_ adapted to host factor-less Escherichia coli. Proc. Natl. Acad. Sci. USA 94:10239 ... Fitness of RNA virus decreased by Muller's ratchet. Nature 348:454-455. Turner, P. E., and L. Chao. 2003. Escape from ...
"Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". Nature. 260 ( ... RNA sequencing was one of the earliest forms of nucleotide sequencing. The major landmark of RNA sequencing is the sequence of ... A successful RNA extraction will yield a RNA sample that should be converted to complementary DNA (cDNA) using reverse ... Viral genomes can be based in DNA or RNA. RNA viruses are more time-sensitive for genome sequencing, as they degrade faster in ...
The translation start of the replicase gene is normally hidden within RNA secondary structure, but can be transiently opened as ... Once the viral RNA has entered the cell, it begins to function as a messenger RNA for the production of phage proteins. The ... The positive-stranded RNA genome serves as a messenger RNA, and is translated upon viral uncoating within the host cell. ... The start of the maturation protein gene is accessible in RNA being replicated but hidden within RNA secondary structure in the ...
"Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". Nature. 260 ( ... The genomes of RNA viruses can be either single-stranded RNA or double-stranded RNA, and may contain one or more separate RNA ... It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non- ... Retrotransposons are composed of DNA, but are transcribed into RNA for transposition, then the RNA transcript is copied back to ...
April 1976). "Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene". ... These were the fundamental molecules that combined in series to form the original RNA genome. Molecules as complex as RNA must ... RNA. 17 (5): 792-8. doi:10.1261/rna.2658311. PMC 3078729. PMID 21398401. Sharon D, Glusman G, Pilpel Y, Horn-Saban S, Lancet D ... RNA is composed of purine and pyrimidine nucleotides, both of which are necessary for reliable information transfer, and thus ...
"Evidence for de novo production of self-replicating and environmentally adapted RNA structures by bacteriophage Qbeta replicase ... Both selection and screening can be performed in living cells (in vivo evolution) or performed directly on the protein or RNA ... Directed evolution has its origins in the 1960s with the evolution of RNA molecules in the "Spiegelman's Monster" experiment. ... When performed without cells, DE involves using in vitro transcription translation to produce proteins or RNA free in solution ...
"Evidence for de novo production of self-replicating and environmentally adapted RNA structures by bacteriophage Qbeta replicase ... biogenesis and increasing the expression of ribosomal protein clusters and non-coding RNAs such as nucleolar small RNAs. ...
Chai Y, Winans SC (June 2005). "A small antisense RNA downregulates expression of an essential replicase protein of an ... Furthermore, there is a small RNA known as RepE encoded between repB and repC that lowers the expression of repC. RepE is ... repE encodes for a small antisense RNA and is located between repB and repC. Additionally, there is a partitioning site (parS) ...
B1 is used as the end terminal for RNA replicase, but the function is to totally clear. B2 is a separate unique protein which ... Because the virus only has 2 initial RNAs, this is the simplest class of virus. There is an RNA 3 that does appear only in ... RNA1 sequence encodes for the virus' RNA-dependand RNA polymerase which is protein A. Thee virion also contains code for RNA2 ... Once in the cytoplasm, RNA is transcribed within envagininations of the host cell using its own RNA dependent polymerase. To ...
"Comparisons among the larger genome segments of six nodaviruses and their encoded RNA replicases". Journal of General Virology ... After comparing the RNA genome of this virus with that of other members of the Nodaviridae, it was found to be different and ... Boolarra virus typically measures around 30 nano-meters and is approximately 21 percent RNA. Boolarra virus is characterized by ...
RNA 1 is responsible for encoding the viral replicase protein P1. This family is required for negative strand RNA synthesis in ... The Alfalfa mosaic virus RNA 1 5′ UTR stem-loop represents a putative stem-loop structure found in the 5′ UTR in RNA 1 of ... Page for Alfalfa mosaic virus RNA 1 5′ UTR stem-loop at Rfam v t e (Cis-regulatory RNA elements, Bromoviridae, All stub ... untranslated region of alfalfa mosaic virus RNA 1 is involved in negative-strand RNA synthesis". Journal of Virology. 77 (20): ...
... (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. ... This RNA-directed RNA polymerase possesses a number of short regions and motifs homologous to other RNA-directed RNA ... By inhibiting RNA-dependent RNA polymerase function, new RNAs cannot be replicated from an RNA template strand, however, DNA- ... The use of RNA-dependent RNA polymerase plays a major role in RNA interference in eukaryotes, a process used to silence gene ...
... including the first description of an RNA replicase. After his PhD, Baltimore returned to MIT for postdoctoral research with ... VSV entered a host cell as a single negative strand of RNA, but brought with it RNA polymerase to stimulate the processes of ... History of RNA biology List of Jewish Nobel laureates List of RNA biologists Baltimore classification 73079 Davidbaltimore " ... At MIT, Huang, Baltimore, and graduate student Martha Stampfer discovered that VSV replication involved an RNA-dependent RNA ...
For example, humans can make neither RNA replicases nor reverse transcriptase, and the presence of these enzymes are ... An interesting fact that gas chromatography-mass spectrometry, 16S ribosomal RNA analysis, omics, and other advanced ...
Visser CM (1984). "Evolution of biocatalysis 1. Possible pre-genetic-code RNA catalysts which are their own replicase". Origins ... In brief, a circularly permutated (CP) ribozyme RNA was generated by in vitro transcription using T7 RNA polymerase. The 5' and ... Beckert, Bertrand; Masquida, Benoît (2011), Nielsen, Henrik (ed.), "Synthesis of RNA by In Vitro Transcription", RNA: Methods ... as well as intron RNA circularization. The other catalytic RNA domain is the group I-like ribozyme (GIR1) directly involved in ...
SEARCH RESULTS for: RNA Replicase Inhibitors [Drug Class] (9 results) *Share : JavaScript needed for Sharing tools. Bookmark & ...
In vitro replicase assays performed with purified CNV replicase preparations from yeast revealed critical roles for three RNA ... In vitro replicase assays performed with purified CNV replicase preparations from yeast revealed critical roles for three RNA ... In vitro replicase assays performed with purified CNV replicase preparations from yeast revealed critical roles for three RNA ... In vitro replicase assays performed with purified CNV replicase preparations from yeast revealed critical roles for three RNA ...
The template RNA of EEEV was shown to be replicated by replicases of diverse alphaviruses. The EEEV replicase, on the other ... The ability of EEEV P123 to form functional RNA replicases with heterologous nsP4s was more efficient using EEEV template RNA ... representing subunits of the RNA replicase. Here, we report the construction and properties of a trans-replicase for EEEV. ... RNA Viral/metabolismo; RNA Polimerase Dependente de RNA/metabolismo; Proteínas não Estruturais Virais/metabolismo; Replicação ...
This process is catalyzed by a viral RNA replicase.[clarification needed] A DNA transcription unit encoding for a protein may ... RNA sugar-phosphate backbone forms with assistance from RNA polymerase to form an RNA strand. Hydrogen bonds of the RNA-DNA ... small nuclear RNA (snRNA), or enzymatic RNA molecules called ribozymes as well as larger non-coding RNAs such as ribosomal RNA ... RNA synthesis by RNA polymerase was established in vitro by several laboratories by 1965; however, the RNA synthesized by these ...
Replication of viral RNA genomes requires the specific interaction between the replicase and the RNA template. Members of the ... Dive into the research topics of Recognition of the core RNA promoter for minus-strand RNA synthesis by the replicases of ... T1 - Recognition of the core RNA promoter for minus-strand RNA synthesis by the replicases of Brome mosaic virus and Cucumber ... Recognition of the core RNA promoter for minus-strand RNA synthesis by the replicases of Brome mosaic virus and Cucumber mosaic ...
Compartmentalization in a water-in-oil emulsion repressed the spontaneous amplification of RNA by Qβ replicase. Biochemistry 49 ...
Viral RNA-dependent RNA polymerases and replicases. email. Ralph Baric, PhD Professor. Department of Epidemiology. email ...
These genetic/holographic DNA/RNA replicas have been in the perfecting for well over four decades. All that is required is a ... From page 93, Shrouds Of The Seventh Seal, Phoenix Journal #24:] These genetic/holographic DNA/RNA replicas have been in the ... I request that herein you not ask me for details of the replicas for they are not the point of my story and they will be ... 4 & 5, p. 9 ( The world s leaders are Replicas, Ronald Reagan was slain ):]. You say, ...but there was to be one slain only to ...
Sequence analysis of RNA species synthesized by Q beta replicase without template. Biochemistry. 1993;32:4848-54.DOIPubMed ...
Protease; RNA Replicase inhibitor. Using COVID-19 Docking Server. Chloroquine (37). Accessory proteins prevents binding of ... Protease; RNA Replicase inhibitor. Using COVID-19 Docking Server. Phycocyanobilin, Riboflavin, Cyanidin, Daidzein, Genistein ( ... Protease (Mpro); RNA Replicase inhibitors. COVID-19 Docking Server to inhibit Mpro and RdRp. ... SARS-CoV2 consists of two types of molecules: RNA and proteins; RNA encodes for 27 viral proteins, of which 16 are non- ...
... for RNA viruses like TCV, SIE manifests a viral function that denies progeny viruses the chance of re-replicating their genomes ... for RNA viruses like TCV, SIE manifests a viral function that denies progeny viruses the chance of re-replicating their genomes ... 2017). Partially uncleaved alphavirus replicase forms spherule structures in the presence and absence of RNA template. J. Virol ... The RNA-dependent RNA polymerase (RdRP) encoded by many RNA viruses are known to be error prone, estimated to introduce ...
... ribozymes can catalyse the copying of structured RNA sequences, allowing self-synthesis by part of a newly evolved symbiotic ... RNA replicase ribozyme. RNA strands are made of four different letters attached to each other in a specific order. When RNA is ... Yet, although ribozymes can be made to copy straight RNA templates this way, folded RNA templates - including the replicase ... However, RNA catalysis is dependent upon RNA folding, and this yields structures that can block replication of such RNAs. To ...
An early RNA replicase probably would not have a built-in way of differentiating between a replicase or non-replicase sequence ... Without some means of separating the replicases from the non-replicases, the population of replicases is unlikely to grow and ... Without compartmentalization, RNA replicases would be unlikely to prosper. Fatty acids may have formed near hydrothermal vents ... If the nucleotides are incorporated into a strand of RNA, they become trapped inside the vesicle, since long polymers of RNA ...
Total RNA and TENT lysates were also extracted from replica plates for RT-PCR and western blot analyses. For retroviral HUVEC ... qRT-PCR. RNA was isolated 24 hours after adenoviral infections (65). qRT-PCR was performed as described in ref. 16. PCR primers ... Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal. Biochem. 162:156-159. ... After 7 days, total RNA was isolated and qRT-PCR performed to determine the expression of the VEGFRs, VEGFR-2 and VEGFR-3 ( ...
S is a previously described platform28 based on the alphavirus genome encoding the genes for the viral RNA replicase but ... DNA-launched RNA replicon vaccines induce potent anti-SARS-CoV-2 immune responses in mice. Scientific Reports 11, 3125 (2021). ... Molecular Genetics of RNA Viruses, Department of Virology, Institut Pasteur, CNRS UMR 3569, Université de Paris, Paris, France ... All naive animals became infected, as shown by the detection of viral genomic (gRNA) and sub-genomic (sgRNA) RNA in tracheal ( ...
RNA, protein and other information. These virtual replicas are known as molecular twins. They will be used to help identify ... Researchers are using AI and data to create virtual replicas of cancer patients DNA, ... Researchers at Cedars-Sinai Cancer are using artificial intelligence and data to create virtual replicas of patients DNA, RNA ... These virtual replicas are known as "molecular twins." They will be used to help identify the most effective approach to ...
... are RNA viruses of the genus Enterovirus and the family Picornaviridae. EVs were first isolated from the feces of asymptomatic ... This RNA is approximately 7.5 kilobase (kb) long and contains an RNA replicase, viral-coded proteases, a single polyprotein ... Echoviruses (EVs) are RNA viruses of the genus Enterovirus and the family Picornaviridae. EVs were first isolated from the ... and they play a crucial role in delivering the RNA genome into the cytoplasm of new host cells. ...
Double-labelled immunofluorescence showed that both p33 and p92 replicase proteins localized to peroxisomes, independently of ... whereas in situ hybridization indicated that DI RNA progeny were diffused throughout the cytoplasm. DI RNA replication also ... DI RNA replication occurred in yeast cells, as demonstrated by the presence of monomers and dimers of positive and negative ... RNA in Saccharomyces cerevisiae cells. Two yeast strains were used, differing in the biogenesis of peroxisomes, the organelles ...
RNA replicases) capable of catalyzing replication and parasites that do not possess replicase activity but can be replicated by ... In this paper, we try to answer this question based on the parasite-replicase model (RP model), which divides RNA molecules ... RNA replicases. We describe the aforementioned system using partial differential equations and, based on the analysis of the ... RNA World Modeling: A Comparison of Two Complementary Approaches by Jaroslaw Synak ...
... the process of producing two identical replicas of RNA, ribonucleic acid or DNA, deoxyribonucleic acid) and take over the ... Researchers found that the RNA sequences they analyzed contained a signature gene called RdRp that codes for RNA-dependent RNA ... Evolutionary connection between the catalytic subunits of DNA-dependent RNA polmerases and eukaryotic RNA-dependent RNA ... RNA viruses are clearly important in our world, but we usually only study a tiny slice of them- the few hundred that harm ...
... that immediately is translated to form the viral replicase complex that includes the RNA-dependent RNA polymerase, which then ... And we look for TCR beta RNA as well as CD3 RNA to determine if there are any CD4 cells present once we differentiate. So we ... We can measure this using primer specific for early RNA products or late RNA products, such as from the gag region of the ... cluster in genomic RNA, and the subcluster and subgenomic RNAs that are responsible for production of viral proteins and for ...
LLC to screen their library of nucleotide analogues to identify those with efficacy against the SARS CoV-2 replicase, the RNA- ... One project using gene expression data (i.e., RNA) is assembling expression signatures that appear similar to expression ...
Recognition of bacteriophage Qbeta plus strand RNA as a template by Qbeta replicase: Role of RNA interactions mediated by ... Synergism of mutations in bacteriophage Qbeta RNA affecting host factor dependence of Qbeta replicase. Journal of Molecular ... segmented RNA (reoviruses and rotaviruses); bisegmented and double-stranded RNA (picobirnaviruses); single-stranded DNA ( ... There also appear to be genetic differences in the host ranges of at least some coliphages, such as the RNA and DNA containing ...
pharmaceutical agents that target viral enzymes such as protease and RNA-replicase (potential "designer drugs"). , Angiotensin ...
... by the results of aminopropylcadaverine stimulation of the in vitro synthesis of polyphenylalanine and MS2 RNA replicase and of ...
This single-stranded RNA encodes four genes: two replicase-associated proteins that are directly translated from the TMV RNA, ... RNA. The - sense RNA is the template to produce both full-length genomic + sense RNA as well as the + sense subgenomic RNAs ( ... As soon as these proteins have been synthesized, the replicase associates with the 3 end of the + sense TMV RNA for the ... The virus RNA is positive-sense, or + sense, and serves directly as a messenger RNA (mRNA) that is translated using host ...
Evidence for de novo production of self-replicating and environmentally adapted RNA structures by bacteriophage Qbeta replicase ... approach to general RNA-dependent RNA synthesis. Proc. of the National Academy of Sciences of the USA: PNAS 72 (7), pp. 2640- ... Wolf, Hans J. (1975) A procedure for simultaneous preparation of large amounts of DNA and RNA by the use of potassium iodide ... Küppers, B. and Sumper, Manfred (1975) Minimal requirements for template recognition by bacteriophage Qbeta replicase: ...
  • EEEV has a positive-sense RNA genome that, in infected cells , serves as an mRNA for the P1234 polyprotein . (bvsalud.org)
  • For instance, the genome of a negative-sense single-stranded RNA (ssRNA -) virus may be a template for a positive-sense single-stranded RNA (ssRNA +)[clarification needed]. (wikipedia.org)
  • These structural proteins are important to determine host range and tropism, and they play a crucial role in delivering the RNA genome into the cytoplasm of new host cells. (medscape.com)
  • The viral genome (total genetic information) can be RNA or DNA. (icr.org)
  • Negative-stranded RNA linear genome,about 13.2 kb in size. (expasy.org)
  • The viral RNA dependent RNA polymerase binds the encapsidated genome at the leader region, then sequentially transcribes each genes by recognizing start and stop signals flanking viral genes. (expasy.org)
  • Segmented Negative-stranded RNA linear genome, L segment is between 6.8 and 12 kb, M segment between 3.2 and 4.9 kb and S segment between 1 and 3 kb. (expasy.org)
  • Coronaviruses: Molecular and Cellular Biology is divided into two sections: Part I focuses on the molecular biology of the virus itself and includes topics such as coronavirus binding and entry, replicase gene function, cis-acting RNA elements, coronavirus discontinuous transcription, reverse genetics, genome packaging and molecular evolution. (nhbs.com)
  • Several RNA binding sites, resulting from the quaternary organization of NSP2 monomers, may be required for the helix destabilizing activity of NSP2 and its function during genome replication and packaging. (nih.gov)
  • The Streptococcus pyogenes Cas9 (SpCas9) nuclease can be efficiently targeted to genomic loci by means of singleguide RNAs (sgRNAs) to enable genome editing 1 - 10 . (cdc.gov)
  • The replicase of Cucumber necrosis virus (CNV), a tombusvirus, contains the viral p33 and p92 replication proteins and possible host factors. (uky.edu)
  • To define cis-acting viral RNA sequences that stimulate replicase assembly, we performed a systematic deletion approach with a model tombusvirus replicon RNA in Saccharomyces cerevisiae, which also coexpressed p33 and p92 replication proteins. (uky.edu)
  • P1234 undergoes a series of precise cleavage events producing four nonstructural proteins (nsP1-4) representing subunits of the RNA replicase . (bvsalud.org)
  • The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). (wikipedia.org)
  • However, some scientists think that before life adopted DNA and proteins, it relied primarily on RNA. (elifesciences.org)
  • Yet, some RNA strands can also fold to form ribozymes, 3D structures that could have guided life's chemical processes the way proteins do now. (elifesciences.org)
  • All life on Earth today uses a triplet RNA code to make proteins from DNA, and these experiments showed how RNA triplets might have helped RNA sustain early life forms. (elifesciences.org)
  • This RNA is approximately 7.5 kilobase (kb) long and contains an RNA replicase, viral-coded proteases, a single polyprotein that is responsible for forming structural polypeptides, and other proteins necessary for cellular replication. (medscape.com)
  • The replicase proteins p33 and p92 of Cymbidium ringspot virus (CymRSV) were found to support the replication of defective interfering (DI) RNA in Saccharomyces cerevisiae cells. (microbiologyresearch.org)
  • Double-labelled immunofluorescence showed that both p33 and p92 replicase proteins localized to peroxisomes, independently of one another and of the presence of the replication template. (microbiologyresearch.org)
  • Translation of the replicase-associated proteins (RP) 126- and 183-kDa) begins within a few minutes of infection. (apsnet.org)
  • As soon as these proteins have been synthesized, the replicase associates with the 3' end of the + sense TMV RNA for the production of a negative sense, or '- sense', RNA. (apsnet.org)
  • The movement protein (probably with the assistance of as yet unidentified host proteins) enlarges the plasmodesmatal openings so that TMV RNA can move to the adjacent cells, release the movement protein and host proteins, and initiate a new round of infection. (apsnet.org)
  • In plants, RNase III Dicer-like proteins (DCLs) act as sensors of dsRNAs and process them into short 21- to 24-nucleotide (nt) (s)RNAs. (biomedcentral.com)
  • Plant Dicer-like proteins (DCLs) are RNase III, double-stranded RNA (dsRNA)-specific endonucleases with specialized functions in producing short (s)RNAs of 21- to 24-nucleotides (nt), including micro (mi)RNAs and short interfering (si)RNAs of endogenous or viral origin. (biomedcentral.com)
  • Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified. (lookformedical.com)
  • Altogether, the two host factors enhance TBSV replication synergistically by interacting with the viral (−)RNA and the replication proteins. (prolekarniky.cz)
  • After translation of their mRNA-sense genomic RNA(s), the viral RNA and the viral replication proteins are recruited to the site of viral replication in membranous compartments. (prolekarniky.cz)
  • For efficient replication, (+)RNA viruses recruit numerous host proteins [1] - [5] . (prolekarniky.cz)
  • Among the identified host proteins are RNA-binding proteins, such as translation factors, ribosomal proteins and RNA-modifying enzymes [1] . (prolekarniky.cz)
  • The co-opted host proteins likely affect several steps in viral RNA replication, including the assembly of the replicase complex and/or viral RNA synthesis. (prolekarniky.cz)
  • The single genomic RNA codes for two replication proteins, p33 and p92 pol , which are sufficient to support TBSV replicon (rep)RNA replication in yeast ( Saccharomyces cerevisiae ) model host [13] , [14] . (prolekarniky.cz)
  • During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. (wikipedia.org)
  • Transcription proceeds in the following general steps: RNA polymerase, together with one or more general transcription factors, binds to promoter DNA. (wikipedia.org)
  • RNA polymerase generates a transcription bubble, which separates the two strands of the DNA helix. (wikipedia.org)
  • RNA polymerase adds RNA nucleotides (which are complementary to the nucleotides of one DNA strand). (wikipedia.org)
  • RNA sugar-phosphate backbone forms with assistance from RNA polymerase to form an RNA strand. (wikipedia.org)
  • This directionality is because RNA polymerase can only add nucleotides to the 3' end of the growing mRNA chain. (wikipedia.org)
  • We report RNA-catalysed RNA synthesis on structured templates when using trinucleotide triphosphates (triplets) as substrates, catalysed by a general and accurate triplet polymerase ribozyme that emerged from in vitro evolution as a mutualistic RNA heterodimer. (elifesciences.org)
  • Researchers found that the RNA sequences they analyzed contained a signature gene called RdRp that codes for RNA-dependent RNA polymerase-a complex enzyme designed to catalyze replication. (icr.org)
  • Craig Cameron, Jeffrey Houpt Distinguished Professor and Chair of the Department of Microbiology and Immunology, and Jamie Arnold, research associate professor in the UNC Department of Cell Biology and Physiology , has partnered with Riboscience, LLC to screen their library of nucleotide analogues to identify those with efficacy against the SARS CoV-2 replicase, the RNA-dependent RNA-polymerase needed for multiplication of all RNA viruses. (unc.edu)
  • In this study we expressed plant DCL4 in Saccharomyces cerevisiae , an RNAi-depleted organism, in which we could highlight the role of dicing as neither Argonautes nor RNA-dependent RNA polymerase is present. (biomedcentral.com)
  • The viral RNA dependent RNA polymerase (L) binds to a promoter on each encapsidated segment, and transcribes the mRNA. (expasy.org)
  • In virology, the term transcription may also be used when referring to mRNA synthesis from an RNA molecule (i.e., equivalent to RNA replication). (wikipedia.org)
  • This also removes the need for an RNA primer to initiate RNA synthesis, as is the case in DNA replication. (wikipedia.org)
  • Members of the Bromovirus and Cucumovirus genera have a tRNA-like structure at the 3' end of their genomic RNAs that interacts with the replicase and is required for minus-strand synthesis. (psu.edu)
  • In Brome mosaic virus (BMV), a stem-loop structure named C (SLC) is present within the tRNA-like region and is required for replicase binding and initiation of RNA synthesis in vitro. (psu.edu)
  • We have prepared an enriched replicase fraction from tobacco plants infected with the Fny isolate of Cucumber mosaic virus (Fny-CMV) that will direct synthesis from exogenously added templates. (psu.edu)
  • While the majority of CMV isolates have SLC-like elements similar to that of Fny-CMV, a second group displays sequence or structural features that are distinct but nonetheless recognized by Fny-CMV replicase for RNA synthesis. (psu.edu)
  • However, neither motif can direct synthesis by the BMV replicase in the absence of other tRNA-like elements, indicating that other features of the CMV tRNA can induce promoter recognition by a heterologous replicase. (psu.edu)
  • The triplets cooperatively invaded and unraveled even highly stable RNA secondary structures, and support non-canonical primer-free and bidirectional modes of RNA synthesis and replication. (elifesciences.org)
  • Labelling with BrUTP showed that peroxisomes were the sites of nascent viral synthesis, whereas in situ hybridization indicated that DI RNA progeny were diffused throughout the cytoplasm. (microbiologyresearch.org)
  • The in vitro data show that Ded1p plays a role in enhancing plus-strand synthesis by the viral replicase. (prolekarniky.cz)
  • The data obtained with wt and ATPase deficient Ded1p mutants support the model that Ded1p unwinds local structures at the 3′-end of the TBSV (−)RNA, rendering the RNA compatible for initiation of (+)-strand synthesis. (prolekarniky.cz)
  • They are composed of a naked protein capsid, constituting about 75% of the particle and enclosing a dense central core of single-stranded RNA. (medscape.com)
  • The non-structural protein NSP2 of rotavirus, which exhibits nucleoside triphosphatase, single-stranded RNA binding, and nucleic-acid helix-destabilizing activities, is a major component of viral replicase complexes. (nih.gov)
  • Our new mechanistic model postulates that, for RNA viruses like TCV, SIE manifests a viral function that denies progeny viruses the chance of re-replicating their genomes in the cells of their "parents," and it collaterally targets highly homologous superinfecting viruses that are indistinguishable from progeny viruses. (frontiersin.org)
  • While this model could have broader implications on many viruses, our discussions will center primarily on a few plant-infecting, positive sense (+) RNA viruses that were subjects of extensive SIE investigations. (frontiersin.org)
  • Echoviruses (EVs) are RNA viruses of the genus Enterovirus and the family Picornaviridae. (medscape.com)
  • 2 Viruses enter into a host cell for replication (the process of producing two identical replicas of RNA, ribonucleic acid or DNA, deoxyribonucleic acid) and take over the cell's biological machinery. (icr.org)
  • RNA viruses are clearly important in our world, but we usually only study a tiny slice of them- the few hundred that harm humans, plants and animals. (icr.org)
  • state a new phylum called Taraviricota is supposedly a missing link in early RNA virus evolution, 4 but Taraviricota is still composed of 100% viruses, and their RNA has always been RNA. (icr.org)
  • 2022. Cryptic and abundant marine viruses at the evolutionary origins of Earth's RNA virome. (icr.org)
  • Infections caused by several positive-stranded RNA viruses allow the characterization of DCLs involved in the RNA-silencing-based antiviral immune responses of plants. (biomedcentral.com)
  • Coronaviruses are positive-strand, enveloped RNA viruses that are important pathogens of mammals and birds. (nhbs.com)
  • Replication of plus-strand RNA viruses depends on recruited host factors that aid several critical steps during replication. (prolekarniky.cz)
  • Thus, two small RNA viruses, which do not code for their own helicases, seems to recruit a host RNA helicase to aid their replication in infected cells. (prolekarniky.cz)
  • All eukaryotic plus-stranded (+)RNA viruses have similar replication cycles in infected cells. (prolekarniky.cz)
  • Viruses are classified as DNA viruses or RNA viruses, depending on whether they use DNA or RNA to replicate. (msdmanuals.com)
  • RNA viruses, particularly retroviruses, are prone to mutate, meaning the set of genetic instructions that contain all the information that the virus needs to function can change as the virus spreads. (msdmanuals.com)
  • In vitro replicase assays performed with purified CNV replicase preparations from yeast revealed critical roles for three RNA elements in CNV replicase assembly: the internal p33 recognition element (p33RE), the replication silencer element (RSE), and the 3′-terminal minus-strand initiation promoter (gPR). (uky.edu)
  • In addition, we have developed an in vitro assay for Flock house virus (FHV), a small RNA virus of insects, that also demonstrated positive effect on FHV replicase activity by the added Ded1p helicase. (prolekarniky.cz)
  • 2003. Evolutionary connection between the catalytic subunits of DNA-dependent RNA polmerases and eukaryotic RNA-dependent RNA polymerases. (icr.org)
  • mRNA comprises only 1-3% of total RNA samples. (wikipedia.org)
  • Messenger RNA (mRNA) vaccines represent a relatively new vaccine class showing great promise for the future. (researchgate.net)
  • The virus RNA is positive-sense, or '+ sense', and serves directly as a messenger RNA (mRNA) that is translated using host ribosomes. (apsnet.org)
  • Plus-strand RNA virus replication requires the assembly of the viral replicase complexes on intracellular membranes in the host cells. (uky.edu)
  • In turn, miRNAs and siRNAs guide the effector Argonautes (AGOs)-containing complexes to silence RNA target transcripts. (biomedcentral.com)
  • After the assembly of the membrane-bound viral replicase complexes (VRC), the viral replicase uses the viral RNA as a template to produce complementary (−)RNA. (prolekarniky.cz)
  • We have therefore tested the DCL4 functionality in processing exogenous dsRNA-like substrates, such as a replicase-assisted viral replicon defective-interfering RNA and RNA hairpin substrates, or endogenous antisense transcripts. (biomedcentral.com)
  • Conversely, DCL4 did not efficiently process a replicase-assisted viral replicon in vivo, providing evidence that viral RNAs are not accessible to DCL4 in membranes associated in active replication. (biomedcentral.com)
  • Thus it is likely that hantavirus RdRp has multiple activities, including endonuclease, replicase, transcriptase and RNA helix unwinding activities. (interprefa.com)
  • For early life to be built on RNA, though, this molecule must have had the ability to make copies of itself. (elifesciences.org)
  • The simplest form of RNA silencing, widely known as RNA interference (RNAi), is conserved in diverse eukaryotic species, including the fungal kingdom, but has been lost in the model budding yeast, Saccharomyces cerevisiae [ 15 ]. (biomedcentral.com)
  • In addition to the primary sequences of gPR, RSE, and p33RE, formation of two alternative structures among these elements may also play a role in replicase assembly. (uky.edu)
  • We performed northern blot analyses for the guide RNA truncations and found increased levels of expression for the longer tracrRNA sequences, suggesting that improved target cleavage was at least partially due to higher sgRNA expression or stability ( Fig. 1c ). (cdc.gov)
  • This idea anticipated the influential 'messenger' concept developed by French investigators François Jacob and Jacques Monod ten years later, which led to the discovery of messenger RNA as the transmitter of the genetic information in DNA. (nih.gov)
  • Altogether, the role of multiple RNA elements in tombusvirus replicase assembly could be an important factor to ensure fidelity of template selection during replication. (uky.edu)
  • The replication of cymbidium ringspot tombusvirus defective interfering-satellite RNA hybrid molecules. (microbiologyresearch.org)
  • We also find that Ded1p is a component of the tombusvirus replicase complex and Ded1p binds to the 3′-end of the viral minus-stranded RNA. (prolekarniky.cz)
  • Other stretches of DNA may be transcribed into small non-coding RNAs such as microRNA, transfer RNA (tRNA), small nucleolar RNA (snoRNA), small nuclear RNA (snRNA), or enzymatic RNA molecules called ribozymes as well as larger non-coding RNAs such as ribosomal RNA (rRNA), and long non-coding RNA (lncRNA). (wikipedia.org)
  • Researchers at Cedars-Sinai Cancer are using artificial intelligence and data to create virtual replicas of patients' DNA, RNA, protein and other information. (lex18.com)
  • The coat protein then interacts with the newly synthesized + sense TMV RNA for assembly of progeny virions. (apsnet.org)
  • Alternatively, the + sense TMV RNA is wrapped in movement protein, and this complex can infect adjacent cells. (apsnet.org)
  • Ribonucleic acid (RNA) has multiple roles in cellular functions, from coding genes to non-coding regulatory activities. (biomedcentral.com)
  • The RNA may remain in the nucleus or exit the cytoplasm through the nuclear pore complex. (wikipedia.org)
  • The ability of EEEV P123 to form functional RNA replicases with heterologous nsP4s was more efficient using EEEV template RNA than heterologous alphavirus template RNA . (bvsalud.org)
  • In addition, the assembly of CNV replicase is stimulated in the presence of plus-stranded viral RNA (Z. Panaviene et al. (uky.edu)
  • The complementary RNA is created in the opposite direction, in the 5' → 3' direction, matching the sequence of the sense strand except switching uracil for thymine. (wikipedia.org)
  • The non-template (sense) strand of DNA is called the coding strand, because its sequence is the same as the newly created RNA transcript (except for the substitution of uracil for thymine). (wikipedia.org)
  • Biebricher CK , Luce R . Sequence analysis of RNA species synthesized by Q beta replicase without template. (cdc.gov)
  • Using three-letter 'triplet' building blocks, this new ribozyme can copy various folded RNA strands, including the active part of its own sequence. (elifesciences.org)
  • An early RNA replicase probably would not have a built-in way of differentiating between a replicase or non-replicase sequence, and as a result, will make a copy of any RNA that happens to be close by. (exploringorigins.org)
  • We find that SpCas9 tolerates mismatches between guide RNA and target DNA at different positions in a sequence-dependent manner, sensitive to the number, position and distribution of mismatches. (cdc.gov)
  • Two yeast strains were used, differing in the biogenesis of peroxisomes, the organelles supplying the membranous vesicular environment in which CymRSV RNA replication takes place in infected plant cells. (microbiologyresearch.org)
  • DI RNA replication occurred in yeast cells, as demonstrated by the presence of monomers and dimers of positive and negative polarities. (microbiologyresearch.org)
  • DI RNA replication also took place in yeast cells devoid of peroxisomes. (microbiologyresearch.org)
  • In this paper, we show that an essential translation factor, Ded1p DEAD-box RNA helicase of yeast, directly affects replication of Tomato bushy stunt virus (TBSV). (prolekarniky.cz)
  • In the context of the entire tRNA-like element, both CMV SLC-like motifs are recognized by the BMV replicase. (psu.edu)
  • Plant DCL4 is involved in the biogenesis of either functional endogenous or exogenous (i.e. viral) short interfering (si)RNAs, thus playing crucial antiviral roles. (biomedcentral.com)
  • These led to the conclusion that DCL4 and DCL2 act redundantly and one of the two alone is sufficient to perceive dsRNA of viral origin, process it into siRNA of viral origin (vsiRNAs) and initiate the plant RNA silencing-based antiviral defense [ 14 ]. (biomedcentral.com)
  • Triplet substrates thus resolve a central incongruity of RNA replication, and here allow the ribozyme to synthesise its own catalytic subunit '+' and '-' strands in segments and assemble them into a new active ribozyme. (elifesciences.org)
  • this has led scientists to try to artificially create RNA replicase ribozymes that could copy themselves. (elifesciences.org)
  • Yet, although ribozymes can be made to copy straight RNA templates this way, folded RNA templates - including the replicase ribozyme itself - impede copying. (elifesciences.org)
  • However, RNA catalysis is dependent upon RNA folding, and this yields structures that can block replication of such RNAs. (elifesciences.org)
  • Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. (wikipedia.org)
  • The research is part of the Tara Oceans Consortium and has identified 5,500 new RNA virus species that represent all five known RNA virus phyla (a taxonomic category). (icr.org)
  • This finding indicates that unlike with previously studied Semliki Forest complex alphaviruses , P123 and/or its processing products have a leading role in EEEV template RNA recognition. (bvsalud.org)
  • Hydrogen bonds of the RNA-DNA helix break, freeing the newly synthesized RNA strand. (wikipedia.org)
  • Like DNA, strands of RNA contain genetic data. (elifesciences.org)
  • The virus's DNA or RNA is the genetic material containing the information needed to replicate the virus. (msdmanuals.com)
  • Activity, Template Preference, and Compatibility of Components of RNA Replicase of Eastern Equine Encephalitis Virus. (bvsalud.org)
  • The EEEV replicase, on the other hand , demonstrated limited ability in replicating template RNAs originating from alphaviruses of the Semliki Forest virus complex. (bvsalud.org)
  • At the same time , EEEV infection resulted only in a limited activation of the template RNA of chikungunya virus . (bvsalud.org)
  • The EEEV trans-replicase developed here contributes significantly to research on EEEV, providing a safe and versatile tool for studying the virus RNA replication. (bvsalud.org)
  • Ocean water samples yield treasure trove of RNA virus data. (icr.org)
  • Once TMV enters the cell, the virus particles disassemble in an organized manner to expose the TMV RNA. (apsnet.org)
  • However, the functions of host factors in (+)RNA virus replication are known only for a small number of host factors [1] - [9] . (prolekarniky.cz)
  • Peu de renseignements sont disponibles sur les mutations des virus saisonniers de la grippe A(H1N1)pdm09 et H3N2 en Jordanie. (who.int)
  • Afin de remédier à ce problème et d'étudier les variations génétiques et antigéniques des virus A(H1N1)pdm09 et H3N2, nous avons procédé à des analyses génétiques et phylogénétiques des gènes de l'hémagglutinine (HA) et de la neuraminidase (NA) de ces virus, sur la période 2011-2013 en Jordanie. (who.int)
  • L'analyse a porté sur les séquences complètes des gènes de l'HA et de la NA de 16 échantillons positifs au virus H1N1 prélevés dans le cadre de cette étude, ainsi que sur 21 séquences publiées de l'HA et 20 séquences publiées de la NA, issues de virus jordaniens disponibles sur les bases de données de gènes en ligne. (who.int)
  • Pueden producir enfermedades en humanos y animales, también incluyen virus específicos de insectos que solo infectan y se replican en los insectos, no así en vertebrados. (bvsalud.org)
  • En Paraguay los virus dengue, fiebre amarilla y Zika fueron detectados en infecciones humanas, pero los estudios de flavivirus en mosquitos son aún escasos. (bvsalud.org)
  • The latter function is associated with the ability of RNA to form double-stranded (ds) or ds-like secondary structures. (biomedcentral.com)
  • The template RNA of EEEV was shown to be replicated by replicases of diverse alphaviruses . (bvsalud.org)
  • Replication of viral RNA genomes requires the specific interaction between the replicase and the RNA template. (psu.edu)
  • When RNA is copied, one strand acts as a template, and a replicase ribozyme would accurately guide which letters are added to the strand under construction. (elifesciences.org)
  • Transcription is the process of copying a segment of DNA into RNA. (wikipedia.org)
  • As opposed to DNA replication, transcription results in an RNA complement that includes the nucleotide uracil (U) in all instances where thymine (T) would have occurred in a DNA complement. (wikipedia.org)
  • RNA-catalyzed RNA replication is widely believed to have supported a primordial biology. (elifesciences.org)
  • The results all together confirm the role of sense/antisense RNA-based regulation of gene expression, expanding the sense/antisense atlas of S. cerevisiae . (biomedcentral.com)
  • These virtual replicas are known as "molecular twins. (lex18.com)
  • Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). (wikipedia.org)
  • Until now, the best approaches have assumed that a replicase would add building blocks formed of a single letter one by one to grow a new strand. (elifesciences.org)
  • Biochemical techniques were used to engineer a ribozyme that copies RNA strands by adding letters not one-by-one, but three-by-three. (elifesciences.org)
  • Using this replicase, we demonstrate that the SLC-like structure in Fny-CMV plays a role similar to that of BMV SLC in interacting with the CMV replicase. (psu.edu)