Proteins which are synthesized as a single polymer and then cleaved into several distinct proteins.
Proteins coded by the retroviral gag gene. The products are usually synthesized as protein precursors or POLYPROTEINS, which are then cleaved by viral proteases to yield the final products. Many of the final products are associated with the nucleoprotein core of the virion. gag is short for group-specific antigen.
A species in the genus CORONAVIRUS causing the common cold and possibly nervous system infections in humans. It lacks hemagglutinin-esterase.
Proteins found in any species of virus.
A species of BETARETROVIRUS isolated from mammary carcinoma in rhesus monkeys. It appears to have evolved from a recombination between a murine B oncovirus and a primate C oncovirus related to the baboon endogenous virus. Several serologically distinct strains exist. MPMV induces SIMIAN AIDS.
Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification, such as cleavage, to produce the active functional protein or peptide hormone.
Polyprotein products of a fused portion of retroviral mRNA containing the gag and pol genes. The polyprotein is synthesized only five percent of the time since pol is out of frame with gag, and is generated by ribosomal frameshifting.
Species of GAMMARETROVIRUS isolated from fibrosarcoma in cats. The viruses are actually recombinant feline leukemia viruses (FeLV) where part of the genome has been replaced by cellular oncogenes. It is unique to individuals and not transmitted naturally to other cats. FeSVs are replication defective and require FeLV to reproduce.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
A strain of MURINE LEUKEMIA VIRUS associated with mouse tumors similar to those caused by the FRIEND MURINE LEUKEMIA VIRUS. It is a replication-competent murine leukemia virus. It can act as a helper virus when complexing with a defective transforming component, RAUSCHER SPLEEN FOCUS-FORMING VIRUS.
Enzyme of the human immunodeficiency virus that is required for post-translational cleavage of gag and gag-pol precursor polyproteins into functional products needed for viral assembly. HIV protease is an aspartic protease encoded by the amino terminus of the pol gene.
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.
Retroviral proteins coded by the pol gene. They are usually synthesized as a protein precursor (POLYPROTEINS) and later cleaved into final products that include reverse transcriptase, endonuclease/integrase, and viral protease. Sometimes they are synthesized as a gag-pol fusion protein (FUSION PROTEINS, GAG-POL). pol is short for polymerase, the enzyme class of reverse transcriptase.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
Proteins from the family Retroviridae. The most frequently encountered member of this family is the Rous sarcoma virus protein.
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.
A genus of the family CORONAVIRIDAE which causes respiratory or gastrointestinal disease in a variety of vertebrates.
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.
The type species of the genus ARTERIVIRUS and the etiologic agent of an important equine respiratory disease causing abortion, pneumonia, or other infections.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
DNA sequences that form the coding region for proteins associated with the viral core in retroviruses. gag is short for group-specific antigen.
ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
A species of CORONAVIRUS causing infections in chickens and possibly pheasants. Chicks up to four weeks old are the most severely affected.
Genes of IAP elements (a family of retrovirus-like genetic elements) which code for virus-like particles (IAPs) found regularly in rodent early embryos. ("Intracisternal" refers to the cisternae of the endoplasmic reticulum.) Under certain circumstances, such as DNA hypomethylation they are transcribed. Their transcripts are found in a variety of neoplasms, including plasmacytomas, neuroblastoma, rhabdomyosarcomas, teratocarcinomas, and colon carcinomas.
Ribonucleic acid that makes up the genetic material of viruses.
Proteins encoded by the GAG GENE of the HUMAN IMMUNODEFICIENCY VIRUS.
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)
The type species of ALPHAVIRUS normally transmitted to birds by CULEX mosquitoes in Egypt, South Africa, India, Malaya, the Philippines, and Australia. It may be associated with fever in humans. Serotypes (differing by less than 17% in nucleotide sequence) include Babanki, Kyzylagach, and Ockelbo viruses.
A family of small RNA viruses comprising some important pathogens of humans and animals. Transmission usually occurs mechanically. There are nine genera: APHTHOVIRUS; CARDIOVIRUS; ENTEROVIRUS; ERBOVIRUS; HEPATOVIRUS; KOBUVIRUS; PARECHOVIRUS; RHINOVIRUS; and TESCHOVIRUS.
The outer protein protective shell of a virus, which protects the viral nucleic acid.
Viruses which produce a mottled appearance of the leaves of plants.
The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.
The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.
The functional hereditary units of VIRUSES.
A genus of the family ARTERIVIRIDAE, in the order NIDOVIRALES. The type species is ARTERITIS VIRUS, EQUINE.
A genus of polyhedral plant viruses of the family COMOVIRIDAE causing ringspots and spotting on leaves or sometimes symptomless infection. Transmission occurs by seeds, soil nematodes, or experimentally by mechanical inoculation. Tobacco ringspot virus is the type species.
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC 3.4.22.2.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) arising during the propagation of S37 mouse sarcoma, and causing lymphoid leukemia in mice. It also infects rats and newborn hamsters. It is apparently transmitted to embryos in utero and to newborns through mother's milk.
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 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).
Viruses parasitic on plants higher than bacteria.
The complete genetic complement contained in a DNA or RNA molecule in a virus.
Established cell cultures that have the potential to propagate indefinitely.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
A genus of the family RETROVIRIDAE with type C morphology, that causes malignant and other diseases in wild birds and domestic fowl.
A protein-nucleic acid complex which forms part or all of a virion. It consists of a CAPSID plus enclosed nucleic acid. Depending on the virus, the nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.
Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.
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 characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
The type species of BETARETROVIRUS commonly latent in mice. It causes mammary adenocarcinoma in a genetically susceptible strain of mice when the appropriate hormonal influences operate.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Inhibitors of HIV PROTEASE, an enzyme required for production of proteins needed for viral assembly.
The sum of the weight of all the atoms in a molecule.
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.
A family of proteins that promote unwinding of RNA during splicing and translation.
Species of GAMMARETROVIRUS, containing many well-defined strains, producing leukemia in mice. Disease is commonly induced by injecting filtrates of propagable tumors into newborn mice.
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).
An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.
Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.
A species of ENTEROVIRUS which is the causal agent of POLIOMYELITIS in humans. Three serotypes (strains) exist. Transmission is by the fecal-oral route, pharyngeal secretions, or mechanical vector (flies). Vaccines with both inactivated and live attenuated virus have proven effective in immunizing against the infection.
Viral proteins that are components of the mature assembled VIRUS PARTICLES. They may include nucleocapsid core proteins (gag proteins), enzymes packaged within the virus particle (pol proteins), and membrane components (env proteins). These do not include the proteins encoded in the VIRAL GENOME that are produced in infected cells but which are not packaged in the mature virus particle,i.e. the so called non-structural proteins (VIRAL NONSTRUCTURAL PROTEINS).
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
Proteins prepared by recombinant DNA technology.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Deoxyribonucleic acid that makes up the genetic material of viruses.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
The process by which two molecules of the same chemical composition form a condensation product or polymer.
Sites on an antigen that interact with specific antibodies.
Deletion of sequences of nucleic acids from the genetic material of an individual.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The rate dynamics in chemical or physical systems.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The relationships of groups of organisms as reflected by their genetic makeup.
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.

Improving proteolytic cleavage at the 3A/3B site of the hepatitis A virus polyprotein impairs processing and particle formation, and the impairment can be complemented in trans by 3AB and 3ABC. (1/193)

The orchestrated liberation of viral proteins by 3C(pro)-mediated proteolysis is pivotal for gene expression by picornaviruses. Proteolytic processing is regulated either by the amino acid sequence at the cleavage site of the substrate or by cofactors covalently or noncovalently linked to the viral proteinase. To determine the role of the amino acid sequence at cleavage sites 3A/3B and 3B/3C that are essential for the liberation of 3C(pro) from its precursors and to assess the function of the stable processing intermediates 3AB and 3ABC, we studied the effect of cleavage site mutations on hepatitis A virus (HAV) polyprotein processing, particle formation, and replication. Using the recombinant vaccinia virus system, we showed that the normally retarded cleavage at the 3A/3B junction can be improved by altering the amino acid sequence at the scissile bond such that it matches the preferred HAV 3C cleavage sites. In contrast to the processing products of the wild-type polyprotein, 3ABC was no longer detectable in the mutant. VP0 and VP3 were generated less efficiently, implying that processing of the structural protein precursor P1-2A depends on the presence of stable 3ABC and/or 3AB. In addition, cleavage of 2BC was impaired in 3AB/3ABC-deficient mutants. Formation of HAV particles was not affected in mutants with blocked 3A/3B and/or 3B/3C cleavage sites. However, 3ABC-deficient mutants produced small numbers of HAV particles, which could be augmented by coexpressing 3AB or 3ABC. The hydrophobic domain of 3A that has been proposed to mediate membrane anchorage of the replication complex was crucial for restoration of defective particle formation. In vitro transcripts of the various cleavage site mutants were unable to initiate an infectious cycle, and no progeny viruses were obtained even after blind passages. Taken together, the data suggest that accumulation of uncleaved HAV 3AB and/or 3ABC is pivotal for both viral replication and efficient particle formation.  (+info)

Hyperphosphorylation of the hepatitis C virus NS5A protein requires an active NS3 protease, NS4A, NS4B, and NS5A encoded on the same polyprotein. (2/193)

The nonstructural protein NS5A of hepatitis c virus (HCV) has been demonstrated to be a phosphoprotein with an apparent molecular mass of 56 kDa. In the presence of other viral proteins, p56 is converted into a slower-migrating form of NS5A (p58) by additional phosphorylation events. In this report, we show that the presence of NS3, NS4A, and NS4B together with NS5A is necessary and sufficient for the generation of the hyperphosphorylated form of NS5A (p58) and that all proteins must be encoded on the same polyprotein (in cis). Kinetic studies of NS5A synthesis and pulse-chase experiments demonstrate that fully processed NS5A is the substrate for the formation of p58 and that p56 is converted to p58. To investigate the role of NS3 in NS5A hyperphosphorylation, point and deletion mutations were introduced into NS3 in the context of a polyprotein containing the proteins from NS3 to NS5A. Mutation of the catalytic serine residue into alanine abolished protease activity of NS3 and resulted in total inhibition of NS5A hyperphosphorylation, even if polyprotein processing was allowed by addition of NS3 and NS4A in trans. The same result was obtained by deletion of the first 10 or 28 N-terminal amino acids of NS3, which are known to be important for the formation of a stable complex between NS3 and its cofactor NS4A. These data suggest that the formation of p58 is closely connected to HCV polyprotein processing events. Additional data obtained with NS3 containing the 34 C-terminal residues of NS2 provide evidence that in addition to NS3 protease activity the authentic N-terminal sequence is required for NS5A hyperphosphorylation.  (+info)

Bovine leukemia virus Gag particle assembly in insect cells: formation of chimeric particles by domain-switched leukemia/lentivirus Gag polyprotein. (3/193)

A key stage in the life cycle of C-type retroviruses is the assembly of Gag precursor protein at the plasma membrane of infected cells. Here we report the assembly of bovine leukemia virus (BLV) gag gene product into virus-like particles (VLPs) using the baculovirus expression system. Expression of BLV Pr44(Gag) resulted in the assembly and release of VLPs, thereby confirming the ability of retroviral Gag polyprotein to assemble and bud from insect cells. Efficient particle formation required a myristoylation signal at the N-terminus of BLV Pr44(Gag). Recombinant baculoviruses expressing matrix (MA) or capsid-nucleocapsid (CA-NC) proteins of BLV were generated but neither of these domains was capable of assembling into particulate structures. To assess the compatibility of Gag domains between leukemia and lentivirus groups three different recombinant chimeras each expressing MA of one virus (e.g., simian immunodeficiency or BLV) and CA-NC of another (e.g., BLV or human T-cell leukemia virus type-I) were constructed. Each of the chimeric proteins assembled efficiently and budded as VLPs, suggesting that the MA and CA domains of these two evolutionary divergent retrovirus groups can be functionally exchanged without perturbation of Gag VLP formation. The lenti-leukemia chimeric Gag approach has potential for studying protein-protein interactions in other retroviruses.  (+info)

Crystal structure of an inhibitor complex of the 3C proteinase from hepatitis A virus (HAV) and implications for the polyprotein processing in HAV. (4/193)

The proteolytic processing of the viral polyprotein is an essential step during the life cycle of hepatitis A virus (HAV), as it is in all positive-sense, single-stranded RNA viruses of animals. In HAV the 3C proteinase is the only proteolytic activity involved in the polyprotein processing. The specific recognition of the cleavage sites by the 3C proteinase depends on the amino acid sequence of the cleavage site. The structure of the complex of the HAV 3C proteinase and a dipeptide inhibitor has been determined by X-ray crystallography. The double-mutant of HAV 3C (C24S, F82A) was inhibited with the specific inhibitor iodoacetyl-valyl-phenylalanyl-amide. The resulting complex had an acetyl-Val-Phe-amide group covalently attached to the S(gamma) atom of the nucleophilic Cys 172 of the enzyme. Crystals of the complex of HAV 3C (C24S, F82A) acetyl-Val-Phe-amide were found to be monoclinic, space group P2(1), having 4 molecules in the asymmetric unit and diffracting to 1.9-A resolution. The final refined structure consists of 4 molecules of HAV 3C (C24S,F82A) acetyl-Val-Phe-amide, 1 molecule of DMSO, 1 molecule of glycerol, and 514 water molecules. There are considerable conformational differences among the four molecules in the asymmetric unit. The final R-factor is 20.4% for all observed reflections between 15.0- and 1.9-A resolution and the corresponding R(free) is 29.8%. The dipeptide inhibitor is bound to the S(1)(') and S(2)(') specificity subsites of the proteinase. The crystal structure reveals that the HAV 3C proteinase possesses a well-defined S(2)(') specificity pocket and suggests that the P(2)(') residue could be an important determinant for the selection of the primary cleavage site during the polyprotein processing in HAV.  (+info)

Mutational analysis of the GB virus B internal ribosome entry site. (5/193)

GB virus B (GBV-B) is a recently discovered hepatotropic flavivirus that is distantly related to hepatitis C virus (HCV). We show here that translation of its polyprotein is initiated by internal entry of ribosomes on GBV-B RNA. We analyzed the translational activity of dicistronic RNA transcripts containing wild-type or mutated 5' nontranslated GBV-B RNA (5'NTR) segments, placed between the coding sequences of two reporter proteins, in vitro in rabbit reticulocyte lysate and in vivo in transfected BT7-H cells. We related these results to a previously proposed model of the secondary structure of the GBV-B 5'NTR (M. Honda, et al. RNA 2:955-968, 1996). We identified an internal ribosome entry site (IRES) bounded at its 5' end by structural domain II, a location analogous to the 5' limit of the IRES in both the HCV and pestivirus 5'NTRs. Mutational analysis confirmed the structure proposed for domain II of GBV-B RNA, and demonstrated that optimal IRES-mediated translation is dependent on each of the putative RNA hairpins in this domain, including two stem-loops not present in the HCV or pestivirus structures. IRES activity was also absolutely dependent on (i) phylogenetically conserved, adenosine-containing bulge loops in domain III and (ii) the primary nucleotide sequence of stem-loop IIIe. IRES-directed translation was inhibited by a series of point mutations predicted to stabilize stem-loop IV, which contains the initiator AUG codon in its loop segment. A reporter gene was translated most efficiently when fused directly to the initiator AUG codon, with no intervening downstream GBV-B sequence. This finding indicates that the 3' limit of the GBV-B IRES is at the initiator AUG and that it does not require downstream polyprotein-coding sequence as suggested for the HCV IRES. These results show that the GBV-B IRES, while sharing a common general structure, differs both structurally and functionally from other flavivirus IRES elements.  (+info)

Identification of a novel cleavage activity of the first papain-like proteinase domain encoded by open reading frame 1a of the coronavirus Avian infectious bronchitis virus and characterization of the cleavage products. (6/193)

The coronavirus Avian infectious bronchitis virus (IBV) employs polyprotein processing as a strategy to express its gene products. Previously we identified the first cleavage event as proteolysis at the Gly(673)-Gly(674) dipeptide bond mediated by the first papain-like proteinase domain (PLPD-1) to release an 87-kDa mature protein. In this report, we demonstrate a novel cleavage activity of PLPD-1. Expression, deletion, and mutagenesis studies showed that the product encoded between nucleotides 2548 and 8865 was further cleaved by PLPD-1 at the Gly(2265)-Gly(2266) dipeptide bond to release an N-terminal 195-kDa and a C-terminal 41-kDa cleavage product. Characterization of the cleavage activity revealed that the proteinase is active on this scissile bond when expressed in vitro in rabbit reticulocyte lysates and can act on the same substrate in trans when expressed in intact cells. Both the N- and C-terminal cleavage products were detected in virus-infected cells and were found to be physically associated. Glycosidase digestion and site-directed mutagenesis studies of the 41-kDa protein demonstrated that it is modified by N-linked glycosylation at the Asn(2313) residue encoded by nucleotides 7465 to 7467. By using a region-specific antiserum raised against the IBV sequence encoded by nucleotides 8865 to 9786, we also demonstrated that a 33-kDa protein, representing the 3C-like proteinase (3CLP), was specifically immunoprecipitated from the virus-infected cells. Site-directed mutagenesis and expression studies showed that a previously predicted cleavage site (Q(2583)-G(2584)) located within the 41-kDa protein-encoding region was not utilized by 3CLP, supporting the conclusion that the 41-kDa protein is a mature viral product.  (+info)

Multiple interactions among proteins encoded by the mite-transmitted wheat streak mosaic tritimovirus. (7/193)

The genome organization of the mite-transmitted wheat streak mosaic virus (WSMV) appears to parallel that of members of the Potyviridae with monopartite genomes, but there are substantial amino acid dissimilarities with other potyviral polyproteins. To initiate studies on the functions of WSMV-encoded proteins, a protein interaction map was generated using a yeast two-hybrid system. Because the pathway of proteolytic maturation of the WSMV polyprotein has not been experimentally determined, random libraries of WSMV cDNA were made both in DNA-binding domain and activation domain plasmid vectors and introduced into yeast. Sequence analysis of multiple interacting pairs revealed that interactions largely occurred between domains within two groups of proteins. The first involved interactions among nuclear inclusion protein a, nuclear inclusion protein b, and coat protein (CP), and the second involved helper component-proteinase (HC-Pro) and cylindrical inclusion protein (CI). Further immunoblot and deletion mapping analyses of the interactions suggest that subdomains of CI, HC-Pro, and P1 interact with one another. The two-hybrid assay was then performed using full-length genes of CI, HC-Pro, P1, P3, and CP, but no heterologous interactions were detected. In vitro binding assay using glutathione-S-transferase fusion proteins and in vitro translation products, however, revealed mutual interactions among CI, HC-Pro, P1, and P3. The failure to detect interactions between full-length proteins by the two-hybrid assay might be due to adverse effects of expression of viral proteins in yeast cells. The capacity to participate in multiple homomeric and heteromeric molecular interactions is consistent with the pleiotropic nature of many potyviral gene mutants and suggests mechanisms for regulation of various viral processes via a network of viral protein complexes.  (+info)

Virus-specific cofactor requirement and chimeric hepatitis C virus/GB virus B nonstructural protein 3. (8/193)

GB virus B (GBV-B) is closely related to hepatitis C virus (HCV) and causes acute hepatitis in tamarins (Saguinus species), making it an attractive surrogate virus for in vivo testing of anti-HCV inhibitors in a small monkey model. It has been reported that the nonstructural protein 3 (NS3) serine protease of GBV-B shares similar substrate specificity with its counterpart in HCV. Authentic proteolytic processing of the HCV polyprotein junctions (NS4A/4B, NS4B/5A, and NS5A/5B) can be accomplished by the GBV-B NS3 protease in an HCV NS4A cofactor-independent fashion. We further characterized the protease activity of a full-length GBV-B NS3 protein and its cofactor requirement using in vitro-translated GBV-B substrates. Cleavages at the NS4A/4B and NS5A/5B junctions were readily detectable only in the presence of a cofactor peptide derived from the central region of GBV-B NS4A. Interestingly, the GBV-B substrates could also be cleaved by the HCV NS3 protease in an HCV NS4A cofactor-dependent manner, supporting the notion that HCV and GBV-B share similar NS3 protease specificity while retaining a virus-specific cofactor requirement. This finding of a strict virus-specific cofactor requirement is consistent with the lack of sequence homology in the NS4A cofactor regions of HCV and GBV-B. The minimum cofactor region that supported GBV-B protease activity was mapped to a central region of GBV-B NS4A (between amino acids Phe22 and Val36) which overlapped with the cofactor region of HCV. Alanine substitution analysis demonstrated that two amino acids, Val27 and Trp31, were essential for the cofactor activity, a finding reminiscent of the two critical residues in the HCV NS4A cofactor, Ile25 and Ile29. A model for the GBV-B NS3 protease domain and NS4A cofactor complex revealed that GBV-B might have developed a similar structural strategy in the activation and regulation of its NS3 protease activity. Finally, a chimeric HCV/GBV-B bifunctional NS3, consisting of an N-terminal HCV protease domain and a C-terminal GBV-B RNA helicase domain, was engineered. Both enzymatic activities were retained by the chimeric protein, which could lead to the development of a chimeric GBV-B virus that depends on HCV protease function.  (+info)

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.

"Gene products, GAG" refer to the proteins that are produced by the GAG (Group-specific Antigen) gene found in retroviruses, such as HIV (Human Immunodeficiency Virus). These proteins play a crucial role in the structure and function of the viral particle or virion.

The GAG gene encodes for a polyprotein that is cleaved by a protease into several individual proteins, including matrix (MA), capsid (CA), and nucleocapsid (NC) proteins. These proteins are involved in the formation of the viral core, which encloses the viral RNA genome and associated enzymes required for replication.

The MA protein is responsible for binding to the host cell membrane during viral entry, while the CA protein forms the capsid shell that surrounds the viral RNA and NC protein. The NC protein binds to the viral RNA and helps to package it into the virion during assembly. Overall, GAG gene products are essential for the life cycle of retroviruses and are important targets for antiretroviral therapy in HIV-infected individuals.

Human coronavirus 229E (HCoV-229E) is a species of coronavirus that causes respiratory infections in humans. It is one of the several coronaviruses known to cause the common cold. HCoV-229E was first identified in the 1960s and is named after the number assigned to it in the laboratory where it was discovered.

HCoV-229E infects the human body through the respiratory tract, and it primarily affects the upper respiratory system, causing symptoms such as runny nose, sore throat, cough, and fever. In some cases, HCoV-229E can also cause lower respiratory infections, such as pneumonia, especially in individuals with weakened immune systems or underlying medical conditions.

HCoV-229E is an enveloped, positive-sense, single-stranded RNA virus that belongs to the family Coronaviridae and the genus Alphacoronavirus. It is transmitted through respiratory droplets produced when an infected person coughs, sneezes, or talks. The virus can also survive on surfaces for several hours, making it possible to contract the infection by touching contaminated objects.

There is no specific treatment for HCoV-229E infections, and most people recover within a week or two with rest and symptomatic relief. However, severe cases may require hospitalization and supportive care, such as oxygen therapy and mechanical ventilation. Preventive measures, such as hand hygiene, wearing masks, and avoiding close contact with infected individuals, can help reduce the transmission of HCoV-229E and other respiratory viruses.

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.

The Mason-Pfizer monkey virus (MPMV) is a type of retrovirus, specifically a betaretrovirus, that naturally infects certain species of primates. It was first discovered in 1966 and has been studied extensively due to its ability to cause immunodeficiency in its host, similar to the human immunodeficiency virus (HIV).

MPMV is not a significant threat to humans as it does not infect human cells efficiently. However, it has been used as a model system for studying retroviral replication and pathogenesis, which has contributed significantly to our understanding of HIV and other related viruses.

It's worth noting that MPMV should not be confused with SIV (Simian Immunodeficiency Virus), another primate virus that is more closely related to HIV and can infect humans under certain circumstances, causing a disease known as AIDS.

Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification to become active. These modifications typically include cleavage of the precursor protein by specific enzymes, resulting in the release of the active protein. This process allows for the regulation and control of protein activity within the body. Protein precursors can be found in various biological processes, including the endocrine system where they serve as inactive hormones that can be converted into their active forms when needed.

"Gag-Pol" fusion proteins are a crucial component in the life cycle of retroviruses, such as HIV (Human Immunodeficiency Virus). These proteins are created through the joining of two viral gene products: the "gag" gene and the "pol" gene.

The "gag" gene encodes for structural proteins that make up the viral matrix and capsid, while the "pol" gene encodes for enzymes necessary for viral replication, including reverse transcriptase, integrase, and protease.

Through a process called ribosomal frameshifting or translational readthrough, the viral RNA genome is translated into a single large polyprotein that contains both Gag and Pol domains. This Gag-Pol fusion protein is then cleaved by the viral protease into its individual functional components, allowing for the assembly of new virus particles and the replication of the viral genome in the host cell.

The formation of Gag-Pol fusion proteins is essential for retroviral replication and represents a key target for antiretroviral therapy in the treatment of HIV infection.

Sarcoma viruses in cats, also known as feline sarcoma viruses (FeSVs), are a group of retroviruses that can cause tumors and other diseases in felines. There are two main types of FeSVs: the feline leukemia virus (FeLV)-related sarcoma viruses and the independent feline sarcoma viruses.

The FeLV-related sarcoma viruses are formed when a cat is infected with FeLV, and the FeLV genome integrates into the host's DNA in such a way that it becomes rearranged and acquires new oncogenic properties. These rearranged FeLV proviruses can then cause various types of tumors, including fibrosarcomas, lymphosarcomas, and leukemias.

The independent feline sarcoma viruses, on the other hand, are not associated with FeLV infection. They contain their own unique oncogenes that can induce the formation of fibrosarcomas, a type of soft tissue cancer. These viruses are typically transmitted through direct contact with an infected cat or its saliva and can cause rapidly growing tumors at the site of inoculation.

It is important to note that not all cats infected with FeSVs will develop tumors, and other factors such as the cat's age, immune status, and genetic background may also play a role in the development of disease.

Post-translational protein processing refers to the modifications and changes that proteins undergo after their synthesis on ribosomes, which are complex molecular machines responsible for protein synthesis. These modifications occur through various biochemical processes and play a crucial role in determining the final structure, function, and stability of the protein.

The process begins with the translation of messenger RNA (mRNA) into a linear polypeptide chain, which is then subjected to several post-translational modifications. These modifications can include:

1. Proteolytic cleavage: The removal of specific segments or domains from the polypeptide chain by proteases, resulting in the formation of mature, functional protein subunits.
2. Chemical modifications: Addition or modification of chemical groups to the side chains of amino acids, such as phosphorylation (addition of a phosphate group), glycosylation (addition of sugar moieties), methylation (addition of a methyl group), acetylation (addition of an acetyl group), and ubiquitination (addition of a ubiquitin protein).
3. Disulfide bond formation: The oxidation of specific cysteine residues within the polypeptide chain, leading to the formation of disulfide bonds between them. This process helps stabilize the three-dimensional structure of proteins, particularly in extracellular environments.
4. Folding and assembly: The acquisition of a specific three-dimensional conformation by the polypeptide chain, which is essential for its function. Chaperone proteins assist in this process to ensure proper folding and prevent aggregation.
5. Protein targeting: The directed transport of proteins to their appropriate cellular locations, such as the nucleus, mitochondria, endoplasmic reticulum, or plasma membrane. This is often facilitated by specific signal sequences within the protein that are recognized and bound by transport machinery.

Collectively, these post-translational modifications contribute to the functional diversity of proteins in living organisms, allowing them to perform a wide range of cellular processes, including signaling, catalysis, regulation, and structural support.

I'm sorry for any confusion, but there seems to be no established medical definition or recognition of a "Rauscher Virus" in human or veterinary medicine. It is possible that you may have misspelled or misremembered the name of a specific virus or medical term. If you have more information or context about where this term was used, I'd be happy to help you further research the topic.

HIV Protease is a crucial enzyme that plays a significant role in the replication cycle of the Human Immunodeficiency Virus (HIV). It is responsible for cleaving or cutting specific long protein chains, produced during the translation of viral RNA, into smaller functional proteins. These proteins are essential for the formation of new virus particles.

The HIV Protease enzyme functions like a pair of molecular scissors, recognizing and cutting particular amino acid sequences in these polyprotein chains. By inhibiting this enzyme's activity with antiretroviral drugs known as protease inhibitors, the production of mature, infectious viral particles can be effectively prevented, which is a crucial component of highly active antiretroviral therapy (HAART) for managing HIV infection and reducing the risk of transmitting the virus to others.

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.

A gene product is the biochemical material, such as a protein or RNA, that is produced by the expression of a gene. "pol" in gene products usually refers to "polymerase," which is an enzyme that synthesizes DNA or RNA molecules by adding nucleotides one by one to a growing chain. Therefore, "gene products, pol" typically refer to the proteins that make up various types of RNA and DNA polymerases, which are involved in the transcription and replication of genetic material. These enzymes play crucial roles in many cellular processes, including gene expression, DNA repair, and cell division.

Endopeptidases are a type of enzyme that breaks down proteins by cleaving peptide bonds inside the polypeptide chain. They are also known as proteinases or endoproteinases. These enzymes work within the interior of the protein molecule, cutting it at specific points along its length, as opposed to exopeptidases, which remove individual amino acids from the ends of the protein chain.

Endopeptidases play a crucial role in various biological processes, such as digestion, blood coagulation, and programmed cell death (apoptosis). They are classified based on their catalytic mechanism and the structure of their active site. Some examples of endopeptidase families include serine proteases, cysteine proteases, aspartic proteases, and metalloproteases.

It is important to note that while endopeptidases are essential for normal physiological functions, they can also contribute to disease processes when their activity is unregulated or misdirected. For instance, excessive endopeptidase activity has been implicated in the pathogenesis of neurodegenerative disorders, cancer, and inflammatory conditions.

Retroviridae is a family of viruses that includes HIV (Human Immunodeficiency Virus). Retroviridae proteins refer to the various structural and functional proteins that are encoded by the retroviral genome. These proteins can be categorized into three main groups:

1. Group-specific antigen (Gag) proteins: These proteins make up the viral matrix, capsid, and nucleocapsid. They are involved in the assembly of new virus particles.

2. Polymerase (Pol) proteins: These proteins include the reverse transcriptase, integrase, and protease enzymes. Reverse transcriptase is responsible for converting the viral RNA genome into DNA, which can then be integrated into the host cell's genome by the integrase enzyme. The protease enzyme is involved in processing the polyprotein precursors of Gag and Pol into their mature forms.

3. Envelope (Env) proteins: These proteins are responsible for the attachment and fusion of the virus to the host cell membrane. They are synthesized as a precursor protein, which is then cleaved by a host cell protease to form two distinct proteins - the surface unit (SU) and the transmembrane unit (TM). The SU protein contains the receptor-binding domain, while the TM protein forms the transmembrane anchor.

Retroviral proteins play crucial roles in various stages of the viral life cycle, including entry, reverse transcription, integration, transcription, translation, assembly, and release. Understanding the functions of these proteins is essential for developing effective antiretroviral therapies and vaccines against retroviral infections.

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.

A coronavirus is a type of virus that causes respiratory illnesses, such as the common cold, and more severe diseases including Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). These viruses are typically spread through close contact with an infected person when they cough or sneeze. They can also spread by touching a surface or object that has the virus on it and then touching your own mouth, nose, or eyes.

Coronaviruses are named for the crown-like spikes on their surface. They are zoonotic, meaning they can be transmitted between animals and people. Common signs of infection include fever, cough, and shortness of breath. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure, and even death.

One of the most recently discovered coronaviruses is SARS-CoV-2, which causes the disease COVID-19. This virus was first identified in Wuhan, China in late 2019 and has since spread to become a global pandemic.

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.

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.

Retroviridae is a family of viruses that includes human immunodeficiency virus (HIV) and other viruses that primarily use RNA as their genetic material. The name "retrovirus" comes from the fact that these viruses reverse transcribe their RNA genome into DNA, which then becomes integrated into the host cell's genome. This is a unique characteristic of retroviruses, as most other viruses use DNA as their genetic material.

Retroviruses can cause a variety of diseases in animals and humans, including cancer, neurological disorders, and immunodeficiency syndromes like AIDS. They have a lipid membrane envelope that contains glycoprotein spikes, which allow them to attach to and enter host cells. Once inside the host cell, the viral RNA is reverse transcribed into DNA by the enzyme reverse transcriptase, which is then integrated into the host genome by the enzyme integrase.

Retroviruses can remain dormant in the host genome for extended periods of time, and may be reactivated under certain conditions to produce new viral particles. This ability to integrate into the host genome has also made retroviruses useful tools in molecular biology, where they are used as vectors for gene therapy and other genetic manipulations.

"Gag" is a term that refers to a group of genes found in retroviruses, a type of virus that includes HIV (human immunodeficiency virus). These genes encode proteins that play a crucial role in the replication and packaging of the viral genome into new virus particles.

The "gag" gene encodes a polyprotein, which is cleaved by viral proteases into several individual proteins during the maturation of the virus. The resulting proteins include matrix (MA), capsid (CA), and nucleocapsid (NC) proteins, as well as smaller peptides that help to facilitate the assembly and release of new virus particles.

The gag gene is an essential component of retroviruses, and its function has been extensively studied in order to better understand the replication cycle of these viruses and to develop potential therapies for retroviral infections.

Cysteine endopeptidases are a type of enzymes that cleave peptide bonds within proteins. They are also known as cysteine proteases or cysteine proteinases. These enzymes contain a catalytic triad consisting of three amino acids: cysteine, histidine, and aspartate. The thiol group (-SH) of the cysteine residue acts as a nucleophile and attacks the carbonyl carbon of the peptide bond, leading to its cleavage.

Cysteine endopeptidases play important roles in various biological processes, including protein degradation, cell signaling, and inflammation. They are involved in many physiological and pathological conditions, such as apoptosis, immune response, and cancer. Some examples of cysteine endopeptidases include cathepsins, caspases, and calpains.

It is important to note that these enzymes require a reducing environment to maintain the reduced state of their active site cysteine residue. Therefore, they are sensitive to oxidizing agents and inhibitors that target the thiol group. Understanding the structure and function of cysteine endopeptidases is crucial for developing therapeutic strategies that target these enzymes in various diseases.

Peptide hydrolases, also known as proteases or peptidases, are a group of enzymes that catalyze the hydrolysis of peptide bonds in proteins and peptides. They play a crucial role in various biological processes such as protein degradation, digestion, cell signaling, and regulation of various physiological functions. Based on their catalytic mechanism and the specificity for the peptide bond, they are classified into several types, including serine proteases, cysteine proteases, aspartic proteases, and metalloproteases. These enzymes have important clinical applications in the diagnosis and treatment of various diseases, such as cancer, viral infections, and inflammatory disorders.

Infectious Bronchitis Virus (IBV) is a single-stranded, enveloped RNA virus belonging to the genus Gammacoronavirus and family Coronaviridae. It is the causative agent of infectious bronchitis (IB), a highly contagious respiratory disease in birds, particularly in chickens. The virus primarily affects the upper respiratory tract, causing tracheitis, bronchitis, and sinusitis. In addition to respiratory issues, IBV can also lead to decreased egg production, poor growth rates, and impaired immune response in infected birds. Several serotypes and variants of IBV exist worldwide, making vaccine development and disease control challenging.

An Intracisternal A-Particle (IAP) is a type of transposable element in the genome of mice and other rodents. Transposable elements are mobile pieces of DNA that can move or "jump" from one location in the genome to another. IAPs were first discovered in the 1970s and are named for their location within the cisterna of the endoplasmic reticulum in the cell.

IAPs are typically several hundred to a few thousand base pairs in length and contain two main regions: a long terminal repeat (LTR) region at each end, which contains regulatory elements that control the transposition of the IAP, and an internal region that contains genes encoding proteins involved in the transposition process.

IAPs are thought to play a role in genome evolution and have been implicated in various genetic disorders in mice. They can also affect the expression of nearby genes by providing promoter or enhancer elements, or by interfering with normal gene function through insertion into or near a gene.

It's important to note that while IAPs are present in the genomes of many organisms, including humans, they are not typically referred to as "genes" in the traditional sense, as they do not encode functional proteins or RNA molecules that have a direct role in the organism's phenotype.

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.

A "gag gene product" in the context of Human Immunodeficiency Virus (HIV) refers to the proteins produced by the viral gag gene. The gag gene is one of the nine genes found in the HIV genome and it plays a crucial role in the viral replication cycle.

The gag gene encodes for the group-specific antigen (GAG) proteins, which are structural components of the virus. These proteins include matrix (MA), capsid (CA), and nucleocapsid (NC) proteins, as well as several smaller peptides. Together, these GAG proteins form the viral core, which encapsulates the viral RNA genome and enzymes necessary for replication.

The matrix protein is responsible for forming a layer underneath the viral envelope, while the capsid protein forms the inner shell of the viral core. The nucleocapsid protein binds to the viral RNA genome and protects it from degradation by host cell enzymes. Overall, the gag gene products are essential for the assembly and infectivity of HIV particles.

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.

Sindbis virus is an alphavirus that belongs to the Togaviridae family. It's named after the location where it was first isolated, in Sindbis, Egypt, in 1952. This virus is primarily transmitted by mosquitoes and can infect a wide range of animals, including birds and humans. In humans, Sindbis virus infection often causes a mild flu-like illness characterized by fever, rash, and joint pain. However, some people may develop more severe symptoms, such as neurological disorders, although this is relatively rare. There is no specific treatment for Sindbis virus infection, and management typically involves supportive care to alleviate symptoms.

Picornaviridae is a family of small, single-stranded RNA viruses that are non-enveloped and have an icosahedral symmetry. The name "picornavirus" is derived from "pico," meaning small, and "RNA." These viruses are responsible for a variety of human and animal diseases, including the common cold, poliomyelitis, hepatitis A, hand-foot-and-mouth disease, and myocarditis. The genome of picornaviruses is around 7.5 to 8.5 kilobases in length and encodes a single polyprotein that is processed into structural and nonstructural proteins by viral proteases. Picornaviridae includes several important genera, such as Enterovirus, Rhinovirus, Hepatovirus, Cardiovirus, Aphthovirus, and Erbovirus.

A capsid is the protein shell that encloses and protects the genetic material of a virus. It is composed of multiple copies of one or more proteins that are arranged in a specific structure, which can vary in shape and symmetry depending on the type of virus. The capsid plays a crucial role in the viral life cycle, including protecting the viral genome from host cell defenses, mediating attachment to and entry into host cells, and assisting with the assembly of new virus particles during replication.

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.

A virion is the complete, infectious form of a virus outside its host cell. It consists of the viral genome (DNA or RNA) enclosed within a protein coat called the capsid, which is often surrounded by a lipid membrane called the envelope. The envelope may contain viral proteins and glycoproteins that aid in attachment to and entry into host cells during infection. The term "virion" emphasizes the infectious nature of the virus particle, as opposed to non-infectious components like individual capsid proteins or naked viral genome.

Virus assembly, also known as virion assembly, is the final stage in the virus life cycle where individual viral components come together to form a complete viral particle or virion. This process typically involves the self-assembly of viral capsid proteins around the viral genome (DNA or RNA) and, in enveloped viruses, the acquisition of a lipid bilayer membrane containing viral glycoproteins. The specific mechanisms and regulation of virus assembly vary among different viral families, but it is often directed by interactions between viral structural proteins and genomic nucleic acid.

Viral genes refer to the genetic material present in viruses that contains the information necessary for their replication and the production of viral proteins. In DNA viruses, the genetic material is composed of double-stranded or single-stranded DNA, while in RNA viruses, it is composed of single-stranded or double-stranded RNA.

Viral genes can be classified into three categories: early, late, and structural. Early genes encode proteins involved in the replication of the viral genome, modulation of host cell processes, and regulation of viral gene expression. Late genes encode structural proteins that make up the viral capsid or envelope. Some viruses also have structural genes that are expressed throughout their replication cycle.

Understanding the genetic makeup of viruses is crucial for developing antiviral therapies and vaccines. By targeting specific viral genes, researchers can develop drugs that inhibit viral replication and reduce the severity of viral infections. Additionally, knowledge of viral gene sequences can inform the development of vaccines that stimulate an immune response to specific viral proteins.

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.

Nepovirus is a genus of viruses in the family Secoviridae, order Picornavirales. They are non-enveloped, icosahedral viruses with a positive-sense single-stranded RNA genome. Nepoviruses infect a wide range of plants and are transmitted by nematodes or through seed transmission. The name "Nepovirus" is derived from "ne"matode "po"ssessing virus.

These viruses cause various symptoms in plants, including stunting, mosaic patterns on leaves, ringspots, and necrotic spots. Some Nepoviruses can also reduce crop yields significantly. Important species of Nepovirus include Tobacco ringspot virus (TRSV), Grapevine fanleaf virus (GFLV), Arabis mosaic virus (ArMV), and Tomato black ring virus (TBRV).

HIV-1 (Human Immunodeficiency Virus type 1) is a species of the retrovirus genus that causes acquired immunodeficiency syndrome (AIDS). It is primarily transmitted through sexual contact, exposure to infected blood or blood products, and from mother to child during pregnancy, childbirth, or breastfeeding. HIV-1 infects vital cells in the human immune system, such as CD4+ T cells, macrophages, and dendritic cells, leading to a decline in their numbers and weakening of the immune response over time. This results in the individual becoming susceptible to various opportunistic infections and cancers that ultimately cause death if left untreated. HIV-1 is the most prevalent form of HIV worldwide and has been identified as the causative agent of the global AIDS pandemic.

Papain is defined as a proteolytic enzyme that is derived from the latex of the papaya tree (Carica papaya). It has the ability to break down other proteins into smaller peptides or individual amino acids. Papain is widely used in various industries, including the food industry for tenderizing meat and brewing beer, as well as in the medical field for its digestive and anti-inflammatory properties.

In medicine, papain is sometimes used topically to help heal burns, wounds, and skin ulcers. It can also be taken orally to treat indigestion, parasitic infections, and other gastrointestinal disorders. However, its use as a medical treatment is not widely accepted and more research is needed to establish its safety and efficacy.

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.

The Moloney murine leukemia virus (Mo-MLV) is a type of retrovirus, specifically a gammaretrovirus, that is commonly found in mice. It was first discovered and isolated by John Moloney in 1960. Mo-MLV is known to cause various types of cancerous conditions, particularly leukemia, in susceptible mouse strains.

Mo-MLV has a single-stranded RNA genome that is reverse transcribed into double-stranded DNA upon infection of the host cell. This viral DNA then integrates into the host's genome and utilizes the host's cellular machinery to produce new virus particles. The Mo-MLV genome encodes for several viral proteins, including gag (group-specific antigen), pol (polymerase), and env (envelope) proteins, which are essential for the replication cycle of the virus.

Mo-MLV is widely used in laboratory research as a model retrovirus to study various aspects of viral replication, gene therapy, and oncogenesis. It has also been engineered as a vector for gene delivery applications due to its ability to efficiently integrate into the host genome and deliver large DNA sequences. However, it is important to note that Mo-MLV and other retroviruses have the potential to cause insertional mutagenesis, which can lead to unintended genetic alterations and adverse effects in some cases.

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.

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.

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 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.

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.

Protein biosynthesis is the process by which cells generate new proteins. It involves two major steps: transcription and translation. Transcription is the process of creating a complementary RNA copy of a sequence of DNA. This RNA copy, or messenger RNA (mRNA), carries the genetic information to the site of protein synthesis, the ribosome. During translation, the mRNA is read by transfer RNA (tRNA) molecules, which bring specific amino acids to the ribosome based on the sequence of nucleotides in the mRNA. The ribosome then links these amino acids together in the correct order to form a polypeptide chain, which may then fold into a functional protein. Protein biosynthesis is essential for the growth and maintenance of all living organisms.

An alpharetrovirus is a type of retrovirus, which is a group of viruses that integrate their genetic material into the DNA of the host cell. Alpharetroviruses are characterized by their ability to cause persistent infections and are associated with various diseases in animals. One well-known example of an alpharetrovirus is the Rous sarcoma virus (RSV), which was the first retrovirus to be discovered and is known to cause cancer in chickens.

Alpharetroviruses have a complex structure, consisting of an outer envelope that contains glycoprotein spikes, and an inner core that contains the viral RNA genome and associated enzymes. The viral RNA genome contains three main genes: gag, pol, and env, which encode for the structural proteins, enzymes, and envelope proteins of the virus, respectively.

Alpharetroviruses are transmitted through various routes, including horizontal transmission (from host to host) and vertical transmission (from parent to offspring). They can cause a range of diseases, depending on the specific virus and the host species. In addition to RSV, other examples of alpharetroviruses include the avian leukosis virus, which causes tumors and immunosuppression in birds, and the Jaagsiekte sheep retrovirus, which causes a wasting disease in sheep.

It's worth noting that while alpharetroviruses are associated with diseases in animals, there are no known alpharetroviruses that infect humans. However, understanding the biology and behavior of these viruses in animal hosts can provide valuable insights into retroviral replication and pathogenesis, which may have implications for human health.

A nucleocapsid is a protein structure that encloses the genetic material (nucleic acid) of certain viruses. It is composed of proteins encoded by the virus itself, which are synthesized inside the host cell and then assemble around the viral genome to form a stable complex.

The nucleocapsid plays an important role in the viral life cycle. It protects the viral genome from degradation by host enzymes and helps to facilitate the packaging of the genome into new virus particles during assembly. Additionally, the nucleocapsid can also play a role in the regulation of viral gene expression and replication.

In some viruses, such as coronaviruses, the nucleocapsid is encased within an envelope derived from the host cell membrane, while in others, it exists as a naked capsid. The structure and composition of the nucleocapsid can vary significantly between different virus families.

'Cercopithecus aethiops' is the scientific name for the monkey species more commonly known as the green monkey. It belongs to the family Cercopithecidae and is native to western Africa. The green monkey is omnivorous, with a diet that includes fruits, nuts, seeds, insects, and small vertebrates. They are known for their distinctive greenish-brown fur and long tail. Green monkeys are also important animal models in biomedical research due to their susceptibility to certain diseases, such as SIV (simian immunodeficiency virus), which is closely related to HIV.

Severe Acute Respiratory Syndrome (SARS) is a viral respiratory illness caused by the SARS coronavirus (SARS-CoV). This virus is a member of the Coronaviridae family and is thought to be transmitted most readily through close person-to-person contact via respiratory droplets produced when an infected person coughs or sneezes.

The SARS outbreak began in southern China in 2002 and spread to several other countries before it was contained. The illness causes symptoms such as fever, chills, and body aches, which progress to a dry cough and sometimes pneumonia. Some people also report diarrhea. In severe cases, the illness can cause respiratory failure or death.

It's important to note that SARS is not currently a global health concern, as there have been no known cases since 2004. However, it remains a significant example of how quickly and widely a new infectious disease can spread in today's interconnected world.

Viral core proteins are the structural proteins that make up the viral capsid or protein shell, enclosing and protecting the viral genome. These proteins play a crucial role in the assembly of the virion, assist in the infection process by helping to deliver the viral genome into the host cell, and may also have functions in regulating viral replication. The specific composition and structure of viral core proteins vary among different types of viruses.

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.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

Medical Definition:

Mammary tumor virus, mouse (MMTV) is a type of retrovirus that specifically infects mice and is associated with the development of mammary tumors or breast cancer in these animals. The virus is primarily transmitted through mother's milk, leading to a high incidence of mammary tumors in female offspring.

MMTV contains an oncogene, which can integrate into the host's genome and induce uncontrolled cell growth and division, ultimately resulting in the formation of tumors. While MMTV is not known to infect humans, it has been a valuable model for studying retroviral pathogenesis and cancer biology.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

HIV Protease Inhibitors are a class of antiretroviral medications used in the treatment of HIV infection. They work by blocking the activity of the HIV protease enzyme, which is necessary for the virus to replicate and infect new cells. By inhibiting this enzyme, the medication prevents the virus from maturing and assembling into new infectious particles.

HIV protease inhibitors are often used in combination with other antiretroviral drugs as part of a highly active antiretroviral therapy (HAART) regimen. This approach has been shown to effectively suppress viral replication, reduce the amount of virus in the bloodstream (viral load), and improve the health and longevity of people living with HIV.

Examples of HIV protease inhibitors include saquinavir, ritonavir, indinavir, nelfinavir, amprenavir, fosamprenavir, atazanavir, darunavir, and tipranavir. These medications are usually taken orally in the form of tablets or capsules, and may be prescribed alone or in combination with other antiretroviral drugs.

It is important to note that HIV protease inhibitors can have significant side effects, including gastrointestinal symptoms such as nausea, diarrhea, and abdominal pain, as well as metabolic changes such as increased cholesterol and triglyceride levels. Therefore, regular monitoring of liver function, lipid levels, and other health parameters is necessary to ensure safe and effective use of these medications.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

RNA-directed DNA polymerase is a type of enzyme that can synthesize DNA using an RNA molecule as a template. This process is called reverse transcription, and it is the mechanism by which retroviruses, such as HIV, replicate their genetic material. The enzyme responsible for this reaction in retroviruses is called reverse transcriptase.

Reverse transcriptase is an important target for antiretroviral therapy used to treat HIV infection and AIDS. In addition to its role in viral replication, RNA-directed DNA polymerase also has applications in molecular biology research, such as in the production of complementary DNA (cDNA) copies of RNA molecules for use in downstream applications like cloning and sequencing.

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.

Medical Definition:

Murine leukemia virus (MLV) is a type of retrovirus that primarily infects and causes various types of malignancies such as leukemias and lymphomas in mice. It is a complex genus of viruses, with many strains showing different pathogenic properties.

MLV contains two identical single-stranded RNA genomes and has the ability to reverse transcribe its RNA into DNA upon infection, integrating this proviral DNA into the host cell's genome. This is facilitated by an enzyme called reverse transcriptase, which MLV carries within its viral particle.

The virus can be horizontally transmitted between mice through close contact with infected saliva, urine, or milk. Vertical transmission from mother to offspring can also occur either in-utero or through the ingestion of infected breast milk.

MLV has been extensively studied as a model system for retroviral pathogenesis and tumorigenesis, contributing significantly to our understanding of oncogenes and their role in cancer development. It's important to note that Murine Leukemia Virus does not infect humans.

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.

Cell transformation, viral refers to the process by which a virus causes normal cells to become cancerous or tumorigenic. This occurs when the genetic material of the virus integrates into the DNA of the host cell and alters its regulation, leading to uncontrolled cell growth and division. Some viruses known to cause cell transformation include human papillomavirus (HPV), hepatitis B virus (HBV), and certain types of herpesviruses.

Gene expression regulation, viral, refers to the processes that control the production of viral gene products, such as proteins and nucleic acids, during the viral life cycle. This can involve both viral and host cell factors that regulate transcription, RNA processing, translation, and post-translational modifications of viral genes.

Viral gene expression regulation is critical for the virus to replicate and produce progeny virions. Different types of viruses have evolved diverse mechanisms to regulate their gene expression, including the use of promoters, enhancers, transcription factors, RNA silencing, and epigenetic modifications. Understanding these regulatory processes can provide insights into viral pathogenesis and help in the development of antiviral therapies.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Defective viruses are viruses that have lost the ability to complete a full replication cycle and produce progeny virions independently. These viruses require the assistance of a helper virus, which provides the necessary functions for replication. Defective viruses can arise due to mutations, deletions, or other genetic changes that result in the loss of essential genes. They are often non-infectious and cannot cause disease on their own, but they may interfere with the replication of the helper virus and modulate the course of infection. Defective viruses can be found in various types of viruses, including retroviruses, bacteriophages, and DNA viruses.

Site-directed mutagenesis is a molecular biology technique used to introduce specific and targeted changes to a specific DNA sequence. This process involves creating a new variant of a gene or a specific region of interest within a DNA molecule by introducing a planned, deliberate change, or mutation, at a predetermined site within the DNA sequence.

The methodology typically involves the use of molecular tools such as PCR (polymerase chain reaction), restriction enzymes, and/or ligases to introduce the desired mutation(s) into a plasmid or other vector containing the target DNA sequence. The resulting modified DNA molecule can then be used to transform host cells, allowing for the production of large quantities of the mutated gene or protein for further study.

Site-directed mutagenesis is a valuable tool in basic research, drug discovery, and biotechnology applications where specific changes to a DNA sequence are required to understand gene function, investigate protein structure/function relationships, or engineer novel biological properties into existing genes or proteins.

Glycoproteins are complex proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. These glycans are linked to the protein through asparagine residues (N-linked) or serine/threonine residues (O-linked). Glycoproteins play crucial roles in various biological processes, including cell recognition, cell-cell interactions, cell adhesion, and signal transduction. They are widely distributed in nature and can be found on the outer surface of cell membranes, in extracellular fluids, and as components of the extracellular matrix. The structure and composition of glycoproteins can vary significantly depending on their function and location within an organism.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

Vero cells are a line of cultured kidney epithelial cells that were isolated from an African green monkey (Cercopithecus aethiops) in the 1960s. They are named after the location where they were initially developed, the Vervet Research Institute in Japan.

Vero cells have the ability to divide indefinitely under certain laboratory conditions and are often used in scientific research, including virology, as a host cell for viruses to replicate. This allows researchers to study the characteristics of various viruses, such as their growth patterns and interactions with host cells. Vero cells are also used in the production of some vaccines, including those for rabies, polio, and Japanese encephalitis.

It is important to note that while Vero cells have been widely used in research and vaccine production, they can still have variations between different cell lines due to factors like passage number or culture conditions. Therefore, it's essential to specify the exact source and condition of Vero cells when reporting experimental results.

Poliovirus is a human enterovirus, specifically a type of picornavirus, that is the causative agent of poliomyelitis (polio). It is a small, non-enveloped, single-stranded, positive-sense RNA virus. There are three serotypes of Poliovirus (types 1, 2 and 3) which can cause different degrees of severity in the disease. The virus primarily spreads through the fecal-oral route and infects the gastrointestinal tract, from where it can invade the nervous system and cause paralysis.

The Poliovirus has an icosahedral symmetry, with a diameter of about 30 nanometers. It contains a single stranded RNA genome which is encapsidated in a protein shell called capsid. The capsid is made up of 60 units of four different proteins (VP1, VP2, VP3 and VP4).

Poliovirus has been eradicated from most countries of the world through widespread vaccination with inactivated poliovirus vaccine (IPV) or oral poliovirus vaccine (OPV). However, it still remains endemic in a few countries and is considered a major public health concern.

Viral structural proteins are the protein components that make up the viral particle or capsid, providing structure and stability to the virus. These proteins are encoded by the viral genome and are involved in the assembly of new virus particles during the replication cycle. They can be classified into different types based on their location and function, such as capsid proteins, matrix proteins, and envelope proteins. Capsid proteins form the protein shell that encapsulates the viral genome, while matrix proteins are located between the capsid and the envelope, and envelope proteins are embedded in the lipid bilayer membrane that surrounds some viruses.

COS cells are a type of cell line that are commonly used in molecular biology and genetic research. The name "COS" is an acronym for "CV-1 in Origin," as these cells were originally derived from the African green monkey kidney cell line CV-1. COS cells have been modified through genetic engineering to express high levels of a protein called SV40 large T antigen, which allows them to efficiently take up and replicate exogenous DNA.

There are several different types of COS cells that are commonly used in research, including COS-1, COS-3, and COS-7 cells. These cells are widely used for the production of recombinant proteins, as well as for studies of gene expression, protein localization, and signal transduction.

It is important to note that while COS cells have been a valuable tool in scientific research, they are not without their limitations. For example, because they are derived from monkey kidney cells, there may be differences in the way that human genes are expressed or regulated in these cells compared to human cells. Additionally, because COS cells express SV40 large T antigen, they may have altered cell cycle regulation and other phenotypic changes that could affect experimental results. Therefore, it is important to carefully consider the choice of cell line when designing experiments and interpreting results.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

Viral DNA refers to the genetic material present in viruses that consist of DNA as their core component. Deoxyribonucleic acid (DNA) is one of the two types of nucleic acids that are responsible for storing and transmitting genetic information in living organisms. Viruses are infectious agents much smaller than bacteria that can only replicate inside the cells of other organisms, called hosts.

Viral DNA can be double-stranded (dsDNA) or single-stranded (ssDNA), depending on the type of virus. Double-stranded DNA viruses have a genome made up of two complementary strands of DNA, while single-stranded DNA viruses contain only one strand of DNA.

Examples of dsDNA viruses include Adenoviruses, Herpesviruses, and Poxviruses, while ssDNA viruses include Parvoviruses and Circoviruses. Viral DNA plays a crucial role in the replication cycle of the virus, encoding for various proteins necessary for its multiplication and survival within the host cell.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

Dimerization is a process in which two molecules, usually proteins or similar structures, bind together to form a larger complex. This can occur through various mechanisms, such as the formation of disulfide bonds, hydrogen bonding, or other non-covalent interactions. Dimerization can play important roles in cell signaling, enzyme function, and the regulation of gene expression.

In the context of medical research and therapy, dimerization is often studied in relation to specific proteins that are involved in diseases such as cancer. For example, some drugs have been developed to target and inhibit the dimerization of certain proteins, with the goal of disrupting their function and slowing or stopping the progression of the disease.

An epitope is a specific region on the surface of an antigen (a molecule that can trigger an immune response) that is recognized by an antibody, B-cell receptor, or T-cell receptor. It is also commonly referred to as an antigenic determinant. Epitopes are typically composed of linear amino acid sequences or conformational structures made up of discontinuous amino acids in the antigen. They play a crucial role in the immune system's ability to differentiate between self and non-self molecules, leading to the targeted destruction of foreign substances like viruses and bacteria. Understanding epitopes is essential for developing vaccines, diagnostic tests, and immunotherapies.

A sequence deletion in a genetic context refers to the removal or absence of one or more nucleotides (the building blocks of DNA or RNA) from a specific region in a DNA or RNA molecule. This type of mutation can lead to the loss of genetic information, potentially resulting in changes in the function or expression of a gene. If the deletion involves a critical portion of the gene, it can cause diseases, depending on the role of that gene in the body. The size of the deleted sequence can vary, ranging from a single nucleotide to a large segment of DNA.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Phylogeny is the evolutionary history and relationship among biological entities, such as species or genes, based on their shared characteristics. In other words, it refers to the branching pattern of evolution that shows how various organisms have descended from a common ancestor over time. Phylogenetic analysis involves constructing a tree-like diagram called a phylogenetic tree, which depicts the inferred evolutionary relationships among organisms or genes based on molecular sequence data or other types of characters. This information is crucial for understanding the diversity and distribution of life on Earth, as well as for studying the emergence and spread of diseases.

'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.

Pestivirus+NS3+polyprotein+peptidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology ( ... Pestivirus NS3 polyprotein peptidase (EC 3.4.21.113, border disease virus NS3 endopeptidase, BDV NS3 endopeptidase, bovine ... polyprotein cleavage sites, cofactor requirements, and molecular model of an enzyme essential for pestivirus replication". ... protein p80 of bovine viral diarrhea virus is a proteinase involved in polyprotein processing". Virology. 184 (1): 341-50. doi: ...
The genome encodes two polyproteins. The first polyprotein consists of four non-structural units: in order from the N terminal ... The second is a structural polyprotein composed of five expression units: from the N terminal to the C terminal - Capsid, E3, ... The processing of the polyprotein occurs in a highly regulated manner, with cleavage at the P2/3 junction influencing RNA ... Four nonstructural proteins (nsP1-4) which are produced as a single polyprotein constitute the virus' replication machinery. ...
Ott W, Jobst MA, Schoeler C, Gaub HE, Nash MA (January 2017). "Single-molecule force spectroscopy on polyproteins and receptor- ... Hoffmann T, Dougan L (July 2012). "Single molecule force spectroscopy using polyproteins". Chemical Society Reviews. 41 (14): ...
"Replicase polyprotein 1ab". Uniprot. Archived from the original on 2020-05-16. Sato K, Masuda T, Hu Q, Tobo T, Gillaspie S, ...
Protease degrades peptide bonds of the viral polyproteins, making the separate proteins functional. Reverse transcriptase ... These viral proteins are encoded as polyproteins. In order to carry out their life cycle, the retrovirus relies heavily on the ...
VPg is removed from the viral RNA, which is then translated into a processed ORF1 polyprotein to yield the replication proteins ... ORF2 encodes for minor structural polyproteins, VP2. While there have been predictions of a third ORF (ORF3), there is no proof ...
Such sequences are common in virus polyproteins. The frameshift occurs due to wobble pairing. The Gibbs free energy of ...
An alternative name is the ORF1ab polyprotein. It contains the polyprotein cleavage proteinases. The optimum pH for the ... Replicase polyprotein 1ab protein is in the human Sars coronavirus. Rep is involved in the transcription and replication of ... "P0C6X7- Replicase polyprotein 1ab". UniProt. Sun, Wenjing; Guo, Changlong; Meng, Xiangning; Yu, Yang; Jin, Yan; Tong, Dandan; ... Two viruses that interact are rep and PVR proteins which are replicase polyprotein 1ab and Poliovirus receptor respectively. ...
TEV polyprotein on UniProt TEV protease on MEROPS National Cancer Institute TEV FAQ Portal: Biology (Articles with short ... UniProt: TEV polyprotein: "P04517". Rawlings ND, Barrett AJ, Bateman A (January 2012). "MEROPS: the database of proteolytic ... The tobacco etch virus encodes its entire genome as a single massive polyprotein (350 kDa). This is cleaved into functional ... Dougherty WG, Cary SM, Parks TD (August 1989). "Molecular genetic analysis of a plant virus polyprotein cleavage site: a model ...
These polyproteins are thought to be cleaved into 12 products. The virus contains a nucleocapsid that is spherical with a ... The genome is dominated by two large open reading frames, ORF1a and ORF1ab; these code for two polyproteins, PP1a and PP1ab. ...
Rice, C.M.; Rawlings, N.D.; Woessner, J.F. (1998). "Hepatitis C virus polyprotein peptidase". In Barrett, A.J. (ed.). Handbook ... This enzyme catalyses the following chemical reaction: Hydrolysis of four peptide bonds in the viral precursor polyprotein, ...
The Gag polyprotein directs the assembly and release of virus particles from infected cells. The Gag polyprotein has three ... Another family represents the M domain of the Gag polyprotein found in avian retroviruses. It includes Gag polyproteins from ... Matrix proteins are produced as N-terminal domains of Gag precursor polyproteins. ... the Gag polyprotein is cleaved by the retroviral protease into several corresponding structural proteins, yielding the matrix ( ...
The resulting polyproteins are known as pp1a and pp1ab. ORF1a is the first open reading frame at the 5' end of the genome. ... The polyproteins pp1a and pp1ab contain about 13 to 17 nonstructural proteins. They undergo auto-proteolysis to release the ... Proteins nsp12-16, the C-terminal components of the pp1ab polyprotein, contain the core enzymatic activities necessary for ... The genes express large polyproteins that undergo proteolysis to form several nonstructural proteins with various functions in ...
Biosynthesis as a proteinase-adhesin polyprotein". The Journal of Biological Chemistry. 270 (3): 1007-10. doi:10.1074/jbc.270.3 ...
They are characterised by similarities in their replication-associated polyproteins. These account for the majority of their ...
Martín Alonso JM, Casais R, Boga JA, Parra F (February 1996). "Processing of rabbit hemorrhagic disease virus polyprotein". ... Liu B, Clarke IN, Lambden PR (April 1996). "Polyprotein processing in Southampton virus: identification of 3C-like protease ... identification of cleavage sites in the ORF1 polyprotein and analysis of cleavage specificity". Journal of Virology. 69 (11): ... "Identification of further proteolytic cleavage sites in the Southampton calicivirus polyprotein by expression of the viral ...
ORFs 2a and 2b encode the replicational polyproteins P2a and P2ab. Translation of ORF2a from the genomic RNA is dependent on a ...
The core of the virus contains Gag and Gag-Pol polyproteins. These polyproteins are cleaved in the mature virus to their ...
The polyproteins are cleaved into smaller proteins each with their own function. The nucleotides encoding them are known as ... The proteins encoded by the gag and pol genes are translated from genome-length mRNAs into Gag and Gag-Pol polyproteins. In ... gag and pol encode polyproteins, each managing the capsid and replication. The pol region encodes enzymes necessary for viral ... Depending on the virus, the genes may overlap or fuse into larger polyprotein chains. Some viruses contain additional genes. ...
It is a component of the gag polyprotein. Fourth-generation HIV immunoassays detect viral p24 protein in the blood (as well as ...
It is expressed as part of a large polyprotein from the ORF1a gene and has cysteine protease enzymatic activity responsible for ... This group contains many viral polyprotein-processing proteases. Proteases in this group are found in all domains of life. In ... Nidoviral PLPro domains are expressed as part of the large polyprotein encoded by the ORF1ab gene. They are responsible for ... proteolytic cleavage of some of the N-terminal viral nonstructural proteins within the polyprotein. A second protease also ...
The unspliced viral RNA translation produces env, gag, and gag-pol polyproteins. The Env becomes a polypeptide precursor and ...
Astrovirus genomes have three overlapping reading frames (ORFs) that code for polyproteins. ORF1a and ORF 1b are found at the 5 ...
Through translation of the genome a polyprotein is produced. It is later cleaved in order to give twelve proteins. These ...
The RNA is then translated to produce a polyprotein, which is then processed by viral proteases into RNA dependent RNA ... "Carrot virus Y country Australia polyprotein gene, partial cds". 2002-10-10. Retrieved 13 December 2019. Ekman, Jenny (2015-05- ...
The polyprotein pro-opiomelanocortin (POMC) contains many polypeptide hormones. The cleavage pattern of POMC, however, may vary ... Some proteins and most eukaryotic polypeptide hormones are synthesized as a large precursor polypeptide known as a polyprotein ... Common names for the polyprotein include gag (group-specific antigen) in retroviruses and ORF1ab in Nidovirales. The latter ... between different tissues, yielding different sets of polypeptide hormones from the same polyprotein. Many viruses also produce ...
The protease cleaves the gag and pol polyprotein precursor.[citation needed] The viral tat gene encodes a 94-amino acid protein ... The env gene is translated into a single precursor polyprotein that is cleaved by a host protease into two proteins, the ...
It cleaves the coronavirus polyprotein at eleven conserved sites. It is a cysteine protease and a member of the PA clan of ... It cleaves the coronavirus polyprotein at 11 conserved sites. The 3CL protease has a cysteine-histidine catalytic dyad at its ... protease 3CLpro is used as a drug target for coronavirus infections due to its essential role in processing the polyproteins ... sites of the SARS 3C-like proteinase The protease is important in the processing of the coronavirus replicase polyprotein ( ...
These are initially produced as a polyprotein, but are later cleaved by viral or host proteases, to form separate polyproteins ... Then, the P123 polyprotein is further cleaved to form nsP1, nsP2, and nsP3 proteins, in addition to nsP4. These produce +ssRNA ... The protease function of the C-terminal serves to cleave the capsid protein from the polyprotein in which it was produced, so ... There are five structural proteins - C, E3, E2, 6K, and E1 - as well as the nonstructural polyprotein - nsP1-4. Rio Negro virus ...
... comprehensive annotation of mature peptides from polyproteins in five virus families". Bioinformatics. 36 (5): 1627-1628. doi: ...
Pestivirus+NS3+polyprotein+peptidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology ( ... Pestivirus NS3 polyprotein peptidase (EC 3.4.21.113, border disease virus NS3 endopeptidase, BDV NS3 endopeptidase, bovine ... polyprotein cleavage sites, cofactor requirements, and molecular model of an enzyme essential for pestivirus replication". ... protein p80 of bovine viral diarrhea virus is a proteinase involved in polyprotein processing". Virology. 184 (1): 341-50. doi: ...
Polyprotein processing in caliciviruses. Caliciviruses encode a single capsid protein, which in the Norwalk-like viruses (NLVs ... Bromfield, Annabel (2002) Polyprotein processing in caliciviruses. University of Southampton, Doctoral Thesis. ... These proteins were mapped using polyclonal antisera to defined regions of the polyprotein including the N terminal region. The ... These proteins were mapped using polyclonal antisera to defined regions of the polyprotein including the N terminal region. The ...
Protein target information for Genome polyprotein (Zika virus). Find diseases associated with this biological target and ...
Genome polyprotein Antibody, FITC conjugated from Cusabio. Cat#: CSB-PA362073LC01HQD. US, UK & Europe Distribution. Online ... Genome polyprotein Antibody, FITC conjugated , CSB-PA362073LC01HQD Cusabio Polyclonal Antibodies Genome polyprotein Antibody, ... Genome polyprotein Antibody , CSB-PA18549A0Rb , CusabioGenome polyprotein Antibody is Available at Gentaur Genprice with the ... Genome polyprotein Antibody , CSB-PA362073LA01HQD , CusabioGenome polyprotein Antibody is Available at Gentaur Genprice with ...
The ER membrane protein complex is important for the biogenesis of flavivirus polyproteins. Ashley M Ngo, Matthew J Shurtleff, ... By contrast, polyprotein segments starting with 2K-NS4B were stably expressed in EMC KO cells as was shown using NS4B-5-G2C ... Subsequently, the polyprotein is cleaved by the viral NS2B-NS3 protease and the cellular signal peptidase into the individual ... Figure 4: EMC is required for proper biogenesis of the NS4A-NS4B region of the DENV polyprotein. (A) Overview of dual- ...
... in the largest biology dictionary online. Free learning resources for students covering all major areas of biology. ... Polyprotein. polyprotein (Science: protein) protein that, after synthesis, is cleaved to produce several functionally distinct ... polyprotein. (Science: protein) protein that, after synthesis, is cleaved to produce several functionally distinct polypeptides ... Some viruses produce such proteins and some polypeptide hormones seem to be cleaved from a single precursor polyprotein (pro ...
Retrovirus-related Pol polyprotein from transposon... [more]. A0A4Y1ZU65. 2.683e-11. 34.65. Retrovirus-related Pol polyprotein ... Retrovirus-related Pol polyprotein from transposon... [more]. A0A4Y1ZWJ7. 3.375e-11. 35.77. Retrovirus-related Pol polyprotein ... BLAST of Retrovirus-related Pol polyprotein from transposon 297 vs. TrEMBL. *BLAST of Retrovirus-related Pol polyprotein from ... Match: A0A4Y1ZU65 (Retrovirus-related Pol polyprotein from transposon 297 OS=Araneus ventricosus OX=182803 GN=pol_3552 PE=4 SV= ...
Hepatitis C virus (isolate Con1) Genome polyprotein. Product list Hepatitis C virus is a small (55-65 nm in size), enveloped, ... Recombinant Anti-HCV Con1 polyprotein Antibody (V3S-1022-YC3690) (CAT#: V3S-1022-YC3690) ...
Buy the Anti-CHIKV p130/Structural polyprotein Antibody (DC1.415) at competitive price. Discover a large range of primary ... Be the first to review "Anti-CHIKV p130/Structural polyprotein Antibody (DC1.415)" Cancel reply. Your email address will not be ... p130, Structural polyprotein, Chikungunya Virus (CHIKV). Target species. Anti-Chikungunya virus (strain S27-African prototype ... Home / Products / by Application / FC / Anti-CHIKV p130/Structural polyprotein Antibody (DC1.415) ...
Viral polyproteins. Many viruses encode their proteins in the form of a polyprotein. Cellular ribosomes begin at one promoter ... Gag polyprotein includes the structural components of the virus. When it is newly made and still a polyprotein, it orchestrates ... but each Gag-Pol polyprotein only contains one protease chain. How does the protease clip itself out of the polyprotein to form ... The road to unraveling the structure of the Pol polyprotein from HIV was far from easy. It took years of dedicated work from ...
Antigen Peptide Dengue Polyprotein - HLA-B*07:02 (APTRVVAAEM) - AA 1697 - 1706 (Serine protease NS3) for stimulation of antigen ... Documentation for Antigen Peptide Dengue Polyprotein - HLA-B*07:02 (APTRVVAAEM) * Protocol_PepMix.pdf ... Properties of Antigen Peptide Dengue Polyprotein - HLA-B*07:02 (APTRVVAAEM) Properties. Values. ... Further Information to Antigen Peptide Dengue Polyprotein - HLA-B*07:02 (APTRVVAAEM) Information. Values. ...
... supporting the use of polyprotein inserts to induce multispecific T cells against P. falciparum. The use of polyprotein ... This polyprotein was expressed by a plasmid DNA vaccine vector (DNA) and by two attenuated poxvirus vectors, modified vaccinia ... L3SEPTL induced a strong cellular response directed against an LSA1 peptide located in the C-terminal region of the polyprotein ... subunit malaria vaccines expressing six preerythrocytic antigens linked together to produce a 3240-aa-long polyprotein (L3SEPTL ...
POL POLYPROTEIN: ABC. SMTL:PDB. SMTL Chain Id:. PDB Chain Id:. A. A ...
Application of PolyPRep tools on HIV protease polyproteins using molecular docking Dias, M. F. R.; Oliveira, F. L. L.; Pontes, ... However, when it comes to viral polyprotein interaction studies, there is a gap in the representation of those proteins, given ... Application of PolyPRep tools on HIV protease polyproteins using molecular docking ... We present an alternative to this problem, implementing a fragmentation and modeling protocol to prepare those polyproteins in ...
Genome polyproteinN-(tert-butoxycarbonyl)-3-methyl-L-valyl-(4R)-4-[(7-chloro-4-methoxyisoquinolin-1-yl)oxy]-N-{(1R,2S)-1-[(cyclopropylsulfonyl)carbamoyl]-2-ethenylcyclopropyl}-L-prolinamide
A human Phase I/IIa malaria challenge trial of a polyprotein malaria vaccine. In: Vaccine. 2011 ; Vol. 29, No. 43. pp. 7514- ... A human Phase I/IIa malaria challenge trial of a polyprotein malaria vaccine. Vaccine. 2011 Oct 6;29(43):7514-7522. doi: ... Dive into the research topics of A human Phase I/IIa malaria challenge trial of a polyprotein malaria vaccine. Together they ... A human Phase I/IIa malaria challenge trial of a polyprotein malaria vaccine. / Porter, David; Thompson, Fiona; Berthoud, ...
The replicase polyproteins self-cleave the ORF1a and ORF1ab polyproteins of SARS-CoV-2 to form 16 non-structural proteins (NSP1 ... Cleavage of viral polyproteins. NSP6. 290. Inhibits the lysosomal autophagy system and stimulates the NLRP3 inflammasome- ...
Envelopment polyprotein. C [auth A],. D [auth B]. 248. Bovine Schmallenberg virus BH80/Germany/2011. Mutation(s): 0 Gene Names ...
10-meric peptide from Genome polyprotein: C. SMTL:PDB. SMTL Chain Id:. PDB Chain Id:. A. A ...
11,083 (orf1ab polyprotein). L3606F (TTG→TTT). L3606F (TTG→TTT). L3606F (TTG→TTT). L3606F (TTG→TTT). L3606F (TTG→TTT). Spike_F1 ... 835 (orf1ab polyprotein). F190F (TTC→TTT). F190F (TTC→TTT). F190F (TTC→TTT). F190F (TTC→TTT). F190F (TTC→TTT). NIID_WH-1_R854. ... 884 (orf1ab polyprotein). R207C (CGT→TGT). R207C (CGT→TGT). R207C (CGT→TGT). R207C (CGT→TGT). R207C (CGT→TGT). NIID_WH-1_R913. ... 8653 (orf1ab polyprotein). M2796I (ATG→ATT). M2796I (ATG→ATT). M2796I (ATG→ATT). M2796I (ATG→ATT). M2796I (ATG→ATT). Spike_F1. ...
HCV core recombinant antigen a.a 2 to a.a 192 of HCV polyprotein 22 kDa[HCV core]. ... HCV core recombinant antigen a.a 2 to a.a 192 of HCV polyprotein 22 kDa[HCV core] ... on the production method.The kilo Daltons subunit weight of HCV core recombinant antigen a.a 2 a.a 192 of HCV polyprotein 22 [ ...
Polyprotein Processing and Host Factors * Outlook * Chapter 10. Recombination in Plant RNA Viruses ...
The ORF1ab polyprotein is composed of 16 non-structural proteins (NSPs). The genetic distance of each NSP was also calculated ...
polyproteins. My gut feeling is that functionally important alternative splicing belongs to this list. And I dont think I saw ...
Gag polyprotein File: Download Final_thesis_3.10.10.pdf Committee Members: Leslie Joan Parent, Dissertation Advisor/Co-Advisor ... 7. A Journey to the Center of the Cell: Insights Into Subnuclear Trafficking of the Rous Sarcoma Virus Gag Polyprotein ... A Journey to the Center of the Cell: Insights Into Subnuclear Trafficking of the Rous Sarcoma Virus Gag Polyprotein Graduate ... SUBCELLULAR TRAFFICKING AND EARLY ASSEMBLY OF THE RETROVIRAL GAG POLYPROTEIN Graduate Program: Microbiology and Immunology ...
Compound: Pol polyprotein. Species: Human immunodeficiency virus 1 [TaxId:11676]. Gene: pol. Database cross-references and ... Compound: Pol polyprotein. Species: Human immunodeficiency virus 1 [TaxId:11676]. Gene: pol. Database cross-references and ...
These polyproteins are cleaved into small function fragments or NSPs after translation. (B) Workflow for the comprehensive ... The 16 non-structure proteins (NSPs) are cleaved products of the large polyprotein open reading frame (ORF)1ab or ORF1a. ...
PDB Compounds: (B:) Polyprotein. SCOPe Domain Sequences for d2d41b_:. Sequence, based on SEQRES records: (download). >d2d41b_ e ...
  • Genome polyprotein Antibody, FITC conjugated is Available at Gentaur Genprice with the fastest delivery. (joplink.net)
  • This is an economical way to encode proteins in the small genome (only one promoter is needed), and the polyprotein itself can have different functions than the individual proteins. (hivecenter.net)
  • HIV's genome translates three polyproteins (as well as several accessory proteins). (lifeboat.com)
  • In conclusion, the authors detected and genetically characterized a putative novel Usutu virus strain (Usutu-BONN) by determining its complete genome sequence and comparing it with Usutu virus strains for which complete polyprotein-encoding sequences are available. (cdc.gov)
  • Detection of anti-HCV by SIA methodology is based upon traditional Western and dot blotting techniques, in which specific immunogens (i.e. antigenic polyproteins) encoded by the HCV genome are immobilized onto a membrane support. (cdc.gov)
  • These proteins were mapped using polyclonal antisera to defined regions of the polyprotein including the N terminal region. (soton.ac.uk)
  • Together, our results suggest that the EMC engages with DENV polyproteins to ensure proper biogenesis of the NS4A-NS4B region, and provide further evidence for the cellular function of the EMC in the stable expression of TM proteins. (biorxiv.org)
  • Similar to cellular TM proteins, the viral polyprotein relies on the host cell machinery for targeting to the ER, translocation across the membrane and insertion of transmembrane domains (TMDs) into the lipid bilayer during its translation. (biorxiv.org)
  • Some viruses produce such proteins and some polypeptide hormones seem to be cleaved from a single precursor polyprotein (pro opimelanocortin, for example). (biologyonline.com)
  • Many viruses encode their proteins in the form of a polyprotein. (hivecenter.net)
  • Later in the viral replication cycle, when the time is right, the polyprotein is clipped into its functional proteins, often by a protease that is itself included in the polyprotein. (hivecenter.net)
  • reverse transcriptase and integrase , which play essential roles in viral replication, and protease , which is the enzyme that clips the polyproteins into functional proteins. (hivecenter.net)
  • However, when it comes to viral polyprotein interaction studies, there is a gap in the representation of those proteins , given their size and length. (bvsalud.org)
  • The 16 non-structure proteins (NSPs) are cleaved products of the large polyprotein open reading frame (ORF)1ab or ORF1a. (news-medical.net)
  • The Gag polyprotein contains the HIV structural proteins. (lifeboat.com)
  • In this strain, 1 putative cleavage site of the viral polyprotein responsible for processing of structural proteins was changed. (cdc.gov)
  • These proteins contain within their sequence, papain-like protease (PLpro) and the coronavirus main protease (Mpro, also known as 3CLpro), which cleave the polyproteins into a variety of other functional proteins. (tocris.com)
  • Protease is active as a dimer, but each Gag-Pol polyprotein only contains one protease chain. (hivecenter.net)
  • How does the protease clip itself out of the polyprotein to form the active dimer? (hivecenter.net)
  • Top) Cryo-EM structure of HIV-1 Pol polyprotein, which resolves positions for dimeric reverse transcriptase linked to dimeric protease with atomic-level precision. (hivecenter.net)
  • Antigen Peptide Dengue Polyprotein - HLA-B*07:02 (APTRVVAAEM) - AA 1697 - 1706 (Serine protease NS3) for stimulation of antigen-specific T cells in T cell assays such as ELISPOT, ICS, cytotoxity or proliferation assays. (jpt.com)
  • The Gag-Pol polyprotein contains (within its Pol component) the enzymes viral protease, reverse transcriptase, and integrase. (lifeboat.com)
  • The sequence contains the full polyprotein coding sequence and partial untranslated regions (UTRs). (usda.gov)
  • The possibility of an African origin of this virus strain is strengthened by the fact that phylogenetic analysis of complete polyprotein sequence established a separate basal lineage for the Usutu-BONN strain in a sister relationship with the African Usutu virus strains. (cdc.gov)
  • However, prime boost regimes involving two heterologous viral vectors expressing L3SEPTL induced a strong cellular response directed against an LSA1 peptide located in the C-terminal region of the polyprotein. (ox.ac.uk)
  • We present an alternative to this problem, implementing a fragmentation and modeling protocol to prepare those polyproteins in the form of peptide fragments . (bvsalud.org)
  • Antigens are peptides or recombinant or native dependent on the production method.The kilo Daltons subunit weight of HCV core recombinant antigen a.a 2 a.a 192 of HCV polyprotein 22 [HCV core] compared to your protein ladder can be shifted a little due to electrophoresis effects. (anigenetics.com)
  • ORF1ab polyprotein gene region. (cdc.gov)
  • Genomic analysis revealed several unique amino acid substitutions among the polyprotein gene. (cdc.gov)
  • A Plasmodium falciparum candidate vaccine based on a six-antigen polyprotein encoded by recombinant poxviruses. (ox.ac.uk)
  • The use of polyprotein constructs in nonreplicating poxviruses should broaden the target antigen range of vaccine-induced immunity and increase the number of potential epitopes available for immunogenetically diverse human populations. (ox.ac.uk)
  • The cryo-EM structure determination reveals that the reverse transcriptase portion of the polyprotein forms a dimer that is very similar to the structure of mature reverse transcriptase. (hivecenter.net)
  • To generate broadly protective T cell responses more similar to those acquired after vaccination with radiation-attenuated Plasmodium falciparum sporozoites, we have constructed candidate subunit malaria vaccines expressing six preerythrocytic antigens linked together to produce a 3240-aa-long polyprotein (L3SEPTL). (ox.ac.uk)
  • IFN-gamma-secreting T cells specific for each of the six antigens were induced after vaccination with L3SEPTL, supporting the use of polyprotein inserts to induce multispecific T cells against P. falciparum. (ox.ac.uk)
  • We examined the safety, immunogenicity and efficacy of a prime-boost vaccination regime involving two poxvirus malaria subunit vaccines, FP9-PP and MVA-PP, expressing the same polyprotein consisting of six pre-erythrocytic antigens from Plasmodium falciparum. (northumbria.ac.uk)
  • Adaptive mutations rescued both viral replication and stable expression of the NS4A-NS4B polyprotein segment in EMC KO cells. (biorxiv.org)
  • Pestivirus NS3 polyprotein peptidase (EC 3.4.21.113, border disease virus NS3 endopeptidase, BDV NS3 endopeptidase, bovine viral diarrhea virus NS3 endopeptidase, BVDV NS3 endopeptidase, classical swine fever virus NS3 endopeptidase, CSFV NS3 endopeptidase, p80) is an enzyme. (wikipedia.org)
  • Gag polyprotein includes the structural components of the virus. (hivecenter.net)
  • This polyprotein was expressed by a plasmid DNA vaccine vector (DNA) and by two attenuated poxvirus vectors, modified vaccinia virus Ankara (MVA) and fowlpox virus of the FP9 strain. (ox.ac.uk)
  • We detected a decrease in stability in NS4A-NS4B of the viral polyprotein, a region rich in transmembrane domains. (biorxiv.org)
  • Violin plots show distribution of expression levels for Retrovirus-related Pol polyprotein from transposon 297 (SMED30030244) in cells (dots) of each of the 12 neoblast clusters. (stowers.org)
  • Read 'Organelle-dependent polyprotein designs enable stoichiometric expression of nitrogen fixation components targeted to mitochondria. (jic.ac.uk)
  • First, a new approach to produce and purify the Pol portion of the polyprotein provided enough material to study. (hivecenter.net)
  • 6. Sensitivity of Alphaviruses to G3BP Deletion Correlates with Efficiency of Replicase Polyprotein Processing. (nih.gov)
  • This positive RNA virus encodes a large replicase polyprotein made up of 16 gene products (nsp1-16), amongst which two methyltransferases, nsp14 and nsp16, are involved in viral mRNA cap formation. (iucr.org)
  • Elabscience Category Type: Polyclonal Synonyms: Non-structural protein 3, PL2-PRO, Papain-like proteinase, PL-PRO, Replicase polyprotein. (proteomecommons.org)
  • Whole genome sequencing (WGS)-based SARS-CoV-2 lineages and cycle threshold (Ct) values from qualitative reverse transcription-polymerase chain reaction (RT-PCR) for two SARS-CoV-2 gene targets, including the nucleocapsid (N) protein gene region and the open reading frame 1 ab (ORF1ab) polyprotein gene region,* were reported for a convenience sample of specimens. (cdc.gov)
  • SANS measurements showed that both polyprotein hydrogels have a similar nanoscopic structure, with protein L hydrogels being formed from smaller and more compact clusters. (whiterose.ac.uk)
  • The Gag polyprotein, and in particular its constituent nucleocapsid protein, NCp7, represents a prime target for antiretroviral inhibition. (nih.gov)
  • Genome polyprotein (UniProt: Q32ZE1) from Zika virus strain Mr 766 is a large molecular weight protein. (sigmaaldrich.com)
  • Polyprotein components include Protein C homodimerizes and plays a role in virus budding by binding to membrane and gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. (sigmaaldrich.com)
  • Then the host ribosomes translate the viral RNA into two giant protein chains (polyproteins). (lightsources.org)
  • The replication process begins when the host's ribosomes translate the replication genes into two gigantic protein chains called polyproteins. (lightsources.org)
  • Lipoparticles are produced from mammalian cells by co-expressing the retroviral structural core polyprotein Gag, along with a desired membrane protein. (genengnews.com)
  • Finally, the virus is released from the cell, and the HIV protein called protease cleaves newly synthesized polyproteins to create a mature infectious virus. (nih.gov)
  • In conclusion, the authors detected and genetically characterized a putative novel Usutu virus strain (Usutu-BONN) by determining its complete genome sequence and comparing it with Usutu virus strains for which complete polyprotein-encoding sequences are available. (cdc.gov)
  • Recently, a team of scientists using high-brightness x-rays at the U.S. Department of Energy's Advanced Photon Source (APS) has determined x-ray crystallographic structures of MPro cleaving the polyprotein at ten cleavage sites. (lightsources.org)
  • Description: A polyclonal antibody against Genome polyprotein. (musagenomics.org)
  • A single gene, the ELH gene, specifies a polyprotein that is cut into small biologically active peptides such that individual components of the behavioral array may be mediated by peptides encoded by one gene. (wordnik.com)
  • The number of variations relative to a population consensus is shown for the polyprotein (PP) and for each gene within the polyprotein. (wordnik.com)
  • Genomic analysis revealed several unique amino acid substitutions among the polyprotein gene. (cdc.gov)
  • In summary, the SVR polyprotein sequences were significantly more diverse than the NR sequences by all four analytical methods in both genotypes. (wordnik.com)
  • The envelope polyprotein precursor E3-E2-6K-E1 is translocated to the endoplasmatic reticulum. (prospecbio.com)
  • In fact, the action of the ribozymes may take place mainly, if not exclusively, during the translation of the (+) strand that encodes the polyprotein . (wordnik.com)
  • Herein we describe a single-vector construct SCV vaccine that encodes the structural polyprotein cassettes of both Zika and chikungunya viruses from different loci. (scoop.it)
  • The encoded polyprotein contains the domains of protease, reverse transcriptase, and retroviral integrase, which could have retrotransposase activities. (wordnik.com)
  • For HIV to become infectious, any new virion produced from an infected cell must undergo a maturation process that involves the assembly of viral polyproteins Gag and Gag-Pol at the membrane surface. (nih.gov)
  • In this manuscript, we characterize the unique mechanism by which a mercaptobenzamide thioester small molecule (SAMT-247) interferes with HIV maturation via a series of selective acetylations at highly conserved cysteine and lysine residues in Gag and Gag-Pol polyproteins. (nih.gov)
  • It's holding the protease at arm's length, loosely, and we believe that gives the protease a little bit of movement, which in turn allows it to initiate the cutting of polyproteins that is a prerequisite for viral maturation," says co-first author Dario Passos, a former researcher in Lyumkis' lab at Salk. (salk.edu)
  • Detection of anti-HCV by SIA methodology is based upon traditional Western and dot blotting techniques, in which specific immunogens (i.e. antigenic polyproteins) encoded by the HCV genome are immobilized onto a membrane support. (cdc.gov)
  • The authors say the discovery opens the door for important follow-up research, including studies of the structure of the larger and more complex polyprotein Gag-Pol, also involved in viral assembly, as well as taking a closer look at the role of integrase in assembling the mature form of the HIV virus during replication. (salk.edu)
  • The possibility of an African origin of this virus strain is strengthened by the fact that phylogenetic analysis of complete polyprotein sequence established a separate basal lineage for the Usutu-BONN strain in a sister relationship with the African Usutu virus strains. (cdc.gov)
  • The amino acid mutation V1069I is located in the papain-like protease, which oversees the processing of viral polyproteins. (forbes.com)
  • To investigate the proteolytic cleavage of SaV ORF1 and the function of protease on the cleavage, both full-length and truncated forms of the ORF1 polyprotein either with or without mutation in (1171)Cys to Ala of the GDCG motif were expressed in an in vitro coupled transcription-translation system. (nih.gov)
  • A number of possible explanations are discussed, including the very large insert size of the polyprotein transgene. (ox.ac.uk)
  • To our knowledge this represents the first single-vector construct, multi-pathogen vaccine encoding large polyproteins, and offers both simplified manufacturing and formulation, and reduced "shot burden" for these often co-circulating arboviruses. (scoop.it)
  • We utilized mass spectrometry and NMR spectroscopy to characterize the covalent SAMT reaction sites within the Gag polyprotein. (nih.gov)
  • Here we explore the potential of using folded globular polyproteins as building blocks for hydrogels. (whiterose.ac.uk)
  • The polyprotein hydrogels showed small energy dissipation in a load/unload cycle, which significantly increased when the hydrogels were formed in the unfolded state. (whiterose.ac.uk)
  • Help support Wordnik (and make this page ad-free) by adopting the word polyprotein . (wordnik.com)
  • Polyprotein is processed by host signalases, resulting in E3, E2 & E1 forming viral hetero-trimeric spikes. (prospecbio.com)
  • A human Phase I/IIa malaria challenge trial of a polyprotein malaria vaccine. (ox.ac.uk)
  • Recognizes Genome polyprotein from Human rhinovirus A serotype 89. (musagenomics.org)