Codon initiator. Medical search

A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).

A codon that directs initiation of protein translation (TRANSLATION, GENETIC) by stimulating the binding of initiator tRNA (RNA, TRANSFER, MET). In prokaryotes, the codons AUG or GUG can act as initiators while in eukaryotes, AUG is the only initiator codon.

Any codon that signals the termination of genetic translation (TRANSLATION, GENETIC). PEPTIDE TERMINATION FACTORS bind to the stop codon and trigger the hydrolysis of the aminoacyl bond connecting the completed polypeptide to the tRNA. Terminator codons do not specify amino acids.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A transfer RNA which is specific for carrying methionine to sites on the ribosomes. During initiation of protein synthesis, tRNA(f)Met in prokaryotic cells and tRNA(i)Met in eukaryotic cells binds to the start codon (CODON, INITIATOR).

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.

An amino acid-specifying codon that has been converted to a stop codon (CODON, TERMINATOR) by mutation. Its occurance is abnormal causing premature termination of protein translation and results in production of truncated and non-functional proteins. A nonsense mutation is one that converts an amino acid-specific codon to a stop codon.

A process of GENETIC TRANSLATION whereby the formation of a peptide chain is started. It includes assembly of the RIBOSOME components, the MESSENGER RNA coding for the polypeptide to be made, INITIATOR TRNA, and PEPTIDE INITIATION FACTORS; and placement of the first amino acid in the peptide chain. The details and components of this process are unique for prokaryotic protein biosynthesis and eukaryotic protein biosynthesis.

The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.

The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.

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.

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 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.

The sequential set of three nucleotides in TRANSFER RNA that interacts with its complement in MESSENGER RNA, the CODON, during translation in the ribosome.

A subtype of caspases that contain long pro-domain regions that regulate the activation of the enzyme. The pro-domain regions contain protein-protein interaction motifs that can interact with specific signaling adaptor proteins such as DEATH DOMAIN RECEPTORS; DED SIGNALING ADAPTOR PROTEINS; and CARD SIGNALING ADAPTOR PROTEINS. Once activated, the initiator caspases can activate other caspases such as the EFFECTOR CASPASES.

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.

The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.

A unique DNA sequence of a replicon at which DNA REPLICATION is initiated and proceeds bidirectionally or unidirectionally. It contains the sites where the first separation of the complementary strands occurs, a primer RNA is synthesized, and the switch from primer RNA to DNA synthesis takes place. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.

The meaning ascribed to the BASE SEQUENCE with respect to how it is translated into AMINO ACID SEQUENCE. The start, stop, and order of amino acids of a protein is specified by consecutive triplets of nucleotides called codons (CODON).

The process by which a DNA molecule is duplicated.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.

A conserved A-T rich sequence which is contained in promoters for RNA polymerase II. The segment is seven base pairs long and the nucleotides most commonly found are TATAAAA.

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.

Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.

Intermediates in protein biosynthesis. The compounds are formed from amino acids, ATP and transfer RNA, a reaction catalyzed by aminoacyl tRNA synthetase. They are key compounds in the genetic translation process.

DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.

Enzymes that catalyze the transfer of hydroxymethyl or formyl groups. EC 2.1.2.

Proteins found in any species of bacterium.

The largest of the three prokaryotic initiation factors with a molecular size of approximately 80 kD. It functions in the transcription initiation process by promoting the binding of formylmethionine-tRNA to the P-site of the 30S ribosome and by preventing the incorrect binding of elongator tRNA to the translation initiation site.

Protein factors uniquely required during the initiation phase of protein synthesis in GENETIC TRANSLATION.

Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.

A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.

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.

Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.

The functional hereditary units of BACTERIA.

A prokaryotic initiation factor that plays a role in recycling of ribosomal subunits for a new round of translational initiation. It binds to 16S RIBOSOMAL RNA and stimulates the dissociation of vacant 70S ribosomes. It may also be involved in the preferential binding of initiator tRNA to the 30S initiation complex.

The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.

An enzyme that activates methionine with its specific transfer RNA. EC 6.1.1.10.

A eukaryotic initiation factor that binds to 40S ribosomal subunits. Although initially considered a "non-essential" factor for eukaryotic transcription initiation, eukaryotic initiation factor-1 is now thought to play an important role in localizing RIBOSOMES at the initiation codon of MRNA.

A process of GENETIC TRANSLATION whereby the terminal amino acid is added to a lengthening polypeptide. This termination process is signaled from the MESSENGER RNA, by one of three termination codons (CODON, TERMINATOR) that immediately follows the last amino acid-specifying CODON.

Proteins found in any species of virus.

A sulfur-containing essential L-amino acid that is important in many body functions.

A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

Biochemical identification of mutational changes in a nucleotide sequence.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.

A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Activation of this enzyme can occur via the interaction of its caspase recruitment domain with CARD SIGNALING ADAPTOR PROTEINS. Caspase 2 plays a role in APOPTOSIS by cleaving and activating effector pro-caspases. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.

Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.

A group of transfer RNAs which are specific for carrying each one of the 20 amino acids to the ribosome in preparation for protein synthesis.

A group of ribonucleotides (up to 12) in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.

The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.

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.

A peroxide derivative that has been used topically for BURNS and as a dermatologic agent in the treatment of ACNE and POISON IVY DERMATITIS. It is used also as a bleach in the food industry.

Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.

A process of GENETIC TRANSLATION, when an amino acid is transferred from its cognate TRANSFER RNA to the lengthening chain of PEPTIDES.

Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.

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 process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.

A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Caspase 9 is activated during cell stress by mitochondria-derived proapoptotic factors and by CARD SIGNALING ADAPTOR PROTEINS such as APOPTOTIC PROTEASE-ACTIVATING FACTOR 1. It activates APOPTOSIS by cleaving and activating EFFECTOR CASPASES.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

Constituent composed of protein and phospholipid that is widely distributed in many tissues. It serves as a cofactor with factor VIIa to activate factor X in the extrinsic pathway of blood coagulation.

Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

Established cell cultures that have the potential to propagate indefinitely.

Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.

A long pro-domain caspase that contains a death effector domain in its pro-domain region. Caspase 8 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS.

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.

Eukaryotic initiation factor of protein synthesis. In higher eukaryotes the factor consists of three subunits: alpha, beta, and gamma. As initiation proceeds, eIF-2 forms a ternary complex with Met-tRNAi and GTP.

Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.

Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).

Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.

A long pro-domain caspase that contains a death effector domain in its pro-domain region. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS. Caspase 10 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

The functional hereditary units of VIRUSES.

Proteins that are involved in the peptide chain termination reaction (PEPTIDE CHAIN TERMINATION, TRANSLATIONAL) on RIBOSOMES. They include codon-specific class-I release factors, which recognize stop signals (TERMINATOR CODON) in the MESSENGER RNA; and codon-nonspecific class-II release factors.

A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.

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.

Deletion of sequences of nucleic acids from the genetic material of an individual.

The combination of two or more different factors in the production of cancer.

The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.

The major sequence-specific DNA-binding component involved in the activation of transcription of RNA POLYMERASE II. It was originally described as a complex of TATA-BOX BINDING PROTEIN and TATA-BINDING PROTEIN ASSOCIATED FACTORS. It is now know that TATA BOX BINDING PROTEIN-LIKE PROTEINS may take the place of TATA-box binding protein in the complex.

The rate dynamics in chemical or physical systems.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.

Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)

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.

The origin recognition complex is a multi-subunit DNA-binding protein that initiates DNA REPLICATION in eukaryotes.

A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.

Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.

Proteins obtained from ESCHERICHIA COLI.

A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.

An enzyme that activates alanine with its specific transfer RNA. EC 6.1.1.7.

One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.

Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.

Nucleic acid sequences involved in regulating the expression of genes.

Any DNA sequence capable of independent replication or a molecule that possesses a REPLICATION ORIGIN and which is therefore potentially capable of being replicated in a suitable cell. (Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

The three possible sequences of CODONS by which GENETIC TRANSLATION may occur from one nucleotide sequence. A segment of mRNA 5'AUCCGA3' could be translated as 5'AUC.. or 5'UCC.. or 5'CCG.., depending on the location of the START CODON.

Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.

The relationships of groups of organisms as reflected by their genetic makeup.

Proteins prepared by recombinant DNA technology.

Endogenous and exogenous compounds and that either inhibit CASPASES or prevent their activation.

A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)

In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

The first nucleotide of a transcribed DNA sequence where RNA polymerase (DNA-DIRECTED RNA POLYMERASE) begins synthesizing the RNA transcript.

The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.

Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

Immature ERYTHROCYTES. In humans, these are ERYTHROID CELLS that have just undergone extrusion of their CELL NUCLEUS. They still contain some organelles that gradually decrease in number as the cells mature. RIBOSOMES are last to disappear. Certain staining techniques cause components of the ribosomes to precipitate into characteristic "reticulum" (not the same as the ENDOPLASMIC RETICULUM), hence the name reticulocytes.

Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.

A method for determining the sequence specificity of DNA-binding proteins. DNA footprinting utilizes a DNA damaging agent (either a chemical reagent or a nuclease) which cleaves DNA at every base pair. DNA cleavage is inhibited where the ligand binds to DNA. (from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

A theoretical representative nucleotide or amino acid sequence in which each nucleotide or amino acid is the one which occurs most frequently at that site in the different sequences which occur in nature. The phrase also refers to an actual sequence which approximates the theoretical consensus. A known CONSERVED SEQUENCE set is represented by a consensus sequence. Commonly observed supersecondary protein structures (AMINO ACID MOTIFS) are often formed by conserved sequences.

Enzymes that catalyze the endonucleolytic cleavage of single-stranded regions of DNA or RNA molecules while leaving the double-stranded regions intact. They are particularly useful in the laboratory for producing "blunt-ended" DNA molecules from DNA with single-stranded ends and for sensitive GENETIC TECHNIQUES such as NUCLEASE PROTECTION ASSAYS that involve the detection of single-stranded DNA and RNA.

Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.

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.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest.

Any method used for determining the location of and relative distances between genes on a chromosome.

Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.

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.

A death domain receptor signaling adaptor protein that plays a role in signaling the activation of INITIATOR CASPASES such as CASPASE 2. It contains a death domain that is specific for RIP SERINE-THEONINE KINASES and a caspase-binding domain that binds to and activates CASPASES such as CASPASE 2.

Basic peptide antibiotic from Bacillus brevis. It exhibits broad-spectrum antibacterial activity and inhibits bacterial DNA synthesis.

Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.

A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)

The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.

Multimeric protein complexes formed in the CYTOSOL that play a role in the activation of APOPTOSIS. They can occur when MITOCHONDRIA become damaged due to cell stress and release CYTOCHROME C. Cytosolic cytochrome C associates with APOPTOTIC PROTEASE-ACTIVATING FACTOR 1 to form the apoptosomal protein complex. The apoptosome signals apoptosis by binding to and activating specific INITIATOR CASPASES such as CASPASE 9.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

An enzyme catalyzing the endonucleolytic cleavage of RNA at the 3'-position of a guanylate residue. EC 3.1.27.3.

A multisubunit eukaryotic initiation factor that contains at least 8 distinct polypeptides. It plays a role in recycling of ribosomal subunits to the site of transcription initiation by promoting the dissociation of non-translating ribosomal subunits. It also is involved in promoting the binding of a ternary complex of EUKARYOTIC INITIATION FACTOR-2; GTP; and INITIATOR TRNA to the 40S ribosomal subunit.

Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.

Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.

Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.

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.

Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

Chemical compound used to initiate polymerization of dental resins by the use of DENTAL CURING LIGHTS. It absorbs UV light and undergoes decomposition into free radicals that initiate polymerization process of the resins in the mix. Each photoinitiator has optimum emission spectrum and intensity for proper curing of dental materials.

The methyl ester of methacrylic acid. It polymerizes easily to form POLYMETHYL METHACRYLATE. It is used as a bone cement.

The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.

Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.

A species of DELTAPAPILLOMAVIRUS infecting cattle.

The functional hereditary units of FUNGI.

Enzymes that catalyze the S-adenosyl-L-methionine-dependent methylation of ribonucleotide bases within a transfer RNA molecule. EC 2.1.1.

7,12-Dimethylbenzanthracene. Polycyclic aromatic hydrocarbon found in tobacco smoke that is a potent carcinogen.

The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)

Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)

Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.

The conversion of uncharged TRANSFER RNA to AMINO ACYL TRNA.

Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.

A directed change in translational READING FRAMES that allows the production of a single protein from two or more OVERLAPPING GENES. The process is programmed by the nucleotide sequence of the MRNA and is sometimes also affected by the secondary or tertiary mRNA structure. It has been described mainly in VIRUSES (especially RETROVIRUSES); RETROTRANSPOSONS; and bacterial insertion elements but also in some cellular genes.

Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.

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.

Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.

The process by which two molecules of the same chemical composition form a condensation product or polymer.

A transfer RNA which is specific for carrying glutamine to sites on the ribosomes in preparation for protein synthesis.

A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

Deoxyribonucleic acid that makes up the genetic material of viruses.

Pairing of purine and pyrimidine bases by HYDROGEN BONDING in double-stranded DNA or RNA.

The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.

Permanganic acid (HMnO4), potassium salt. A highly oxidative, water-soluble compound with purple crystals, and a sweet taste. (From McGraw-Hill Dictionary of Scientific and Technical Information, 4th ed)

Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.

Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.

Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.

Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.

Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.

A genus in the family NANOVIRIDAE containing multiple circular single-stranded DNA molecules. The type species is Subterranean clover stunt virus.

A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.

Promoter-specific RNA polymerase II transcription factor that binds to the GC box, one of the upstream promoter elements, in mammalian cells. The binding of Sp1 is necessary for the initiation of transcription in the promoters of a variety of cellular and viral GENES.

Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).

The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.

Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.

Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)

Genotypic differences observed among individuals in a population.

A transfer RNA which is specific for carrying serine to sites on the ribosomes in preparation for protein synthesis.

A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.

Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.

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.

A transfer RNA which is specific for carrying arginine to sites on the ribosomes in preparation for protein synthesis.

Tumors or cancer of the SKIN.

Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.

Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.

Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)

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).

A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 7; CASPASE 8; and CASPASE 10. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.

A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP.

An enzyme that catalyzes the acetylation of chloramphenicol to yield chloramphenicol 3-acetate. Since chloramphenicol 3-acetate does not bind to bacterial ribosomes and is not an inhibitor of peptidyltransferase, the enzyme is responsible for the naturally occurring chloramphenicol resistance in bacteria. The enzyme, for which variants are known, is found in both gram-negative and gram-positive bacteria. EC 2.3.1.28.

Aminopeptidases that remove METHIONINE from the amino-terminus of a peptide chain, such as the initiator METHIONINE found on nascent peptide chains.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.

A family of DNA helicases that participate in DNA REPLICATION. They assemble into hexameric rings with a central channel and unwind DNA processively in the 5' to 3' direction. DnaB helicases are considered the primary replicative helicases for most prokaryotic organisms.

Machine learning approaches for the prediction of signal peptides and other protein sorting signals. (1/852)

Prediction of protein sorting signals from the sequence of amino acids has great importance in the field of proteomics today. Recently, the growth of protein databases, combined with machine learning approaches, such as neural networks and hidden Markov models, have made it possible to achieve a level of reliability where practical use in, for example automatic database annotation is feasible. In this review, we concentrate on the present status and future perspectives of SignalP, our neural network-based method for prediction of the most well-known sorting signal: the secretory signal peptide. We discuss the problems associated with the use of SignalP on genomic sequences, showing that signal peptide prediction will improve further if integrated with predictions of start codons and transmembrane helices. As a step towards this goal, a hidden Markov model version of SignalP has been developed, making it possible to discriminate between cleaved signal peptides and uncleaved signal anchors. Furthermore, we show how SignalP can be used to characterize putative signal peptides from an archaeon, Methanococcus jannaschii. Finally, we briefly review a few methods for predicting other protein sorting signals and discuss the future of protein sorting prediction in general. (+info)

Exon shuffling by L1 retrotransposition. (2/852)

Long interspersed nuclear elements (LINE-1s or L1s) are the most abundant retrotransposons in the human genome, and they serve as major sources of reverse transcriptase activity. Engineered L1s retrotranspose at high frequency in cultured human cells. Here it is shown that L1s insert into transcribed genes and retrotranspose sequences derived from their 3' flanks to new genomic locations. Thus, retrotransposition-competent L1s provide a vehicle to mobilize non-L1 sequences, such as exons or promoters, into existing genes and may represent a general mechanism for the evolution of new genes. (+info)

The chloroplast infA gene with a functional UUG initiation codon. (3/852)

All chloroplast genes reported so far possess ATG start codons and sometimes GTGs as an exception. Sequence alignments suggested that the chloroplast infA gene encoding initiation factor 1 in the green alga Chlorella vulgaris has TTG as a putative initiation codon. This gene was shown to be transcribed by RT-PCR analysis. The infA mRNA was translated accurately from the UUG codon in a tobacco chloroplast in vitro translation system. Mutation of the UUG codon to AUG increased translation efficiency approximately 300-fold. These results indicate that the UUG is functional for accurate translation initiation of Chlorella infA mRNA but it is an inefficient initiation codon. (+info)

Involvement of the aphthovirus RNA region located between the two functional AUGs in start codon selection. (4/852)

Initiation of translation in picornavirus RNAs occurs internally, mediated by an element termed internal ribosome entry site (IRES). In the aphthovirus RNA, the IRES element directs translation initiation at two in-frame AUGs separated by 84 nucleotides. We have found that bicistronic constructs that contained the IRES element followed by the fragment including the aphthovirus start codons in front of the second gene mimicked the translation initiation pattern of viral RNA observed in infected cells. In those constructs, the frequency of initiation at the first AUG was increased by a sequence context that resembled the favorable consensus for cap-dependent translation, although initiation at the second site was always preferred. In addition, we have found that initiation at the second start codon was not diminished under conditions in which the first initiation codon was blocked by antisense oligonucleotide interference. Interestingly, mutations that positioned the second AUG out-of-frame with the first AUG did not interfere with the frequency of initiation at the second one. On the contrary, IRES-dependent translation initiation in bicistronic constructs lacking the sequences present between functional AUGs in the viral RNA was sensitive to the presence of out-of-frame initiator codons and hairpins in the spacer region. This remarkable difference in start codon recognition was due to the nucleotide composition of the RNA that separated the IRES from the initiator codon. Thus our results indicate that the region located in the aphthovirus RNA between functional AUGs is involved in start codon recognition, strongly favoring selection of the second start AUG as the main initiator codon. (+info)

Analysis of elements involved in pseudoknot-dependent expression and regulation of the repA gene of an IncL/M plasmid. (5/852)

Replication of the IncL/M plasmid pMU604 is controlled by a small antisense RNA molecule (RNAI), which, by inhibiting the formation of an RNA pseudoknot, regulates translation of the replication initiator protein, RepA. Efficient translation of the repA mRNA was shown to require the translation and correct termination of the leader peptide, RepB, and the formation of the pseudoknot. Although the pseudoknot was essential for the expression of repA, its presence was shown to interfere with the translation of repB. The requirement for pseudoknot formation could in large part be obviated by improving the ribosome binding region of repA, either by replacing the GUG start codon by AUG or by increasing the spacing between the start codon and the Shine-Dalgarno sequence (SD). The spacing between the distal pseudoknot sequence and the repA SD was shown to be suboptimal for maximal expression of repA. (+info)

Multiple murine double minute gene 2 (MDM2) proteins are induced by ultraviolet light. (6/852)

The mdm2 (murine double minute 2) oncogene encodes several proteins, the largest of which (p90) binds to and inactivates the p53 tumor suppressor protein. Multiple MDM2 proteins have been detected in tumors and in cell lines expressing high levels of mdm2 mRNAs. Here we show that one of these proteins (p76) is expressed, along with p90, in wild-type and p53-null mouse embryo fibroblasts, indicating that it may have an important physiological role in normal cells. Expression of this protein is induced, as is that of p90, by UV light in a p53-dependent manner. The p76 protein is synthesized via translational initiation at AUG codon 50 and thus lacks the N terminus of p90 and does not bind p53. In cells, p90 and p76 can be synthesized from mdm2 mRNAs transcribed from both the P1 (constitutive) and P2 (p53-responsive) promoters. Site-directed mutagenesis reveals that these RNAs give rise to p76 via internal initiation of translation. In addition, mdm2 mRNAs lacking exon 3 give rise to p76 exclusively, and such mRNAs are induced by p53 in response to UV light. These data indicate that p76 may be an important product of the mdm2 gene and a downstream effector of p53. (+info)

Postsynaptic alpha-neurotoxin gene of the spitting cobra, Naja naja sputatrix: structure, organization, and phylogenetic analysis. (7/852)

The venom of the spitting cobra, Naja naja sputatrix contains highly potent alpha-neurotoxins (NTXs) in addition to phospholipase A2 (PLA2) and cardiotoxin (CTX). In this study, we report the complete characterization of three genes that are responsible for the synthesis of three isoforms of alpha-NTX in the venom of a single spitting cobra. DNA amplification by long-distance polymerase chain reaction (LD-PCR) and genome walking have provided information on the gene structure including their promoter and 5' and 3' UTRs. Each NTX isoform is approximately 4 kb in size and contains three exons and two introns. The sequence homology among these isoforms was found to be 99%. Two possible transcription sites were identified by primer extension analysis and they corresponded to the adenine (A) nucleotide at positions +1 and -45. The promoter also contains two TATA boxes and a CCAAT box. Putative binding sites for transcriptional factors AP-2 and GATA are also present. The high percentage of similarity observed among the NTX gene isoforms of N. n. sputatrix as well as with the alpha-NTX and kappa-NTX genes from other land snakes suggests that the NTX gene has probably evolved from a common ancestral gene. (+info)

The cis acting sequences responsible for the differential decay of the unstable MFA2 and stable PGK1 transcripts in yeast include the context of the translational start codon. (8/852)

A general pathway of mRNA turnover has been described for yeast in which the 3' poly(A) tail is first deadenylated to an oligo(A) length, leading to decapping and subsequent 5'-3' exonucleolytic decay. The unstable MFA2 mRNA and the stable PGK1 mRNAs both decay through this pathway, albeit at different rates of deadenylation and decapping. To determine the regions of the mRNAs that are responsible for these differences, we examined the decay of chimeric mRNAs derived from the 5' untranslated, coding, and 3' untranslated regions of these two mRNAs. These experiments have led to the identification of the features of these mRNAs that lead to their different stabilities. The MFA2 mRNA is unstable solely because its 3' UTR promotes the rates of deadenylation and decapping; all other features of this mRNA are neutral with respect to mRNA decay rates. The PGK1 mRNA is stable because the sequence context of the PGK1 translation start codon and the coding region function together to stabilize the transcript, whereas the PGK13' UTR is neutral with respect to decay. Importantly, changes in the PGK1 start codon context that destabilized the transcript also reduced its translational efficiency. This observation suggests that the nature of the translation initiation complex modulates the rates of mRNA decapping and decay. (+info)

Cocarcinogenesis can occur through various mechanisms, such as:

1. Synergistic effects: The combined effect of two or more substances is greater than the sum of their individual effects. For example, smoking and exposure to asbestos can increase the risk of lung cancer more than either factor alone.
2. Antagonism: One substance may counteract the protective effects of another substance, leading to an increased risk of cancer. For example, alcohol consumption may antagonize the protective effects of a healthy diet against liver cancer.
3. Potentiation: One substance may enhance the carcinogenic effects of another substance. For example, smoking can potentiate the carcinogenic effects of exposure to certain chemicals in tobacco smoke.
4. Multistage carcinogenesis: Cocarcinogens can contribute to the development of cancer through multiple stages of carcinogenesis, including initiation, promotion, and progression.

Understanding cocarcinogenesis is important for developing effective cancer prevention strategies and for identifying potential co-carcinogens in our environment and diet. By identifying and avoiding co-carcinogens, we can reduce our risk of cancer and improve our overall health.

Papillomas can occur anywhere on the body, but they are most commonly found on the face, neck, and scalp. They may appear as small bumps or growths that look like a wart. In some cases, papillomas may be associated with human papillomavirus (HPV) infection.

Papillomas are typically diagnosed through a physical examination of the affected area. In some cases, a biopsy may be performed to confirm the diagnosis and rule out other potential causes. Treatment for papillomas usually involves removal of the growth through a minor surgical procedure or cryotherapy (freezing).

Papillomas are not cancerous and do not typically pose any long-term health risks. However, they may be unsightly and can cause psychological distress for some people. In these cases, treatment may be sought for cosmetic reasons. It is important to note that papillomas should not be confused with squamous cell carcinoma, a type of skin cancer that can resemble a papilloma in appearance but has the potential to be more aggressive and harmful.

There are several types of skin neoplasms, including:

1. Basal cell carcinoma (BCC): This is the most common type of skin cancer, and it usually appears as a small, fleshy bump or a flat, scaly patch. BCC is highly treatable, but if left untreated, it can grow and invade surrounding tissue.
2. Squamous cell carcinoma (SCC): This type of skin cancer is less common than BCC but more aggressive. It typically appears as a firm, flat, or raised bump on sun-exposed areas. SCC can spread to other parts of the body if left untreated.
3. Melanoma: This is the most serious type of skin cancer, accounting for only 1% of all skin neoplasms but responsible for the majority of skin cancer deaths. Melanoma can appear as a new or changing mole, and it's essential to recognize the ABCDE signs (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving size, shape, or color) to detect it early.
4. Sebaceous gland carcinoma: This rare type of skin cancer originates in the oil-producing glands of the skin and can appear as a firm, painless nodule on the forehead, nose, or other oily areas.
5. Merkel cell carcinoma: This is a rare and aggressive skin cancer that typically appears as a firm, shiny bump on the skin. It's more common in older adults and those with a history of sun exposure.
6. Cutaneous lymphoma: This type of cancer affects the immune system and can appear as a rash, nodules, or tumors on the skin.
7. Kaposi sarcoma: This is a rare type of skin cancer that affects people with weakened immune systems, such as those with HIV/AIDS. It typically appears as a flat, red or purple lesion on the skin.

While skin cancers are generally curable when detected early, it's important to be aware of your skin and notice any changes or unusual spots, especially if you have a history of sun exposure or other risk factors. If you suspect anything suspicious, see a dermatologist for an evaluation and potential biopsy. Remember, prevention is key to avoiding the harmful effects of UV radiation and reducing your risk of developing skin cancer.

Engineered initiator tRNAs (tRNAfMet2 with CUA anticodon) have been used to initiate translation at the amber stop codon UAG. ... The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes ... start codons in the sense that they upstream of the regular start codons and thus could be used as alternative start codons. ... Alternate start codons are still translated as Met when they are at the start of a protein (even if the codon encodes a ...

https://en.wikipedia.org/wiki/Start_codon

Kozak, M (31 January 1986). "Point mutations define a sequence flanking the AUG initiator codon that modulates translation by ... Kozak, M (January 1986). "Point mutations define a sequence flanking the AUG initiator codon that modulates translation by ... Kozak, M (1981). "Possible role of flanking nucleotides in recognition of the AUG initiator codon by eukaryotic ribosomes". ... Kozak, Marilyn (1981-10-24). "Possible role of flanking nucleotides in recognition of the AUG initiator codon by eukaryotic ...

https://en.wikipedia.org/wiki/Marilyn_Kozak

... a new initiator codon in vertebrate mitochondrial genome". Nucleic Acids Research. 16 (13): 6233. doi:10.1093/nar/16.13.6233. ... GUG may possibly function as an initiator in Drosophila. AUU is not used as an initiator in Mytilus "An exceptional mechanism ... Sengupta S, Yang X, Higgs PG (June 2007). "The mechanisms of codon reassignments in mitochondrial genetic codes". Journal of ... The codon AGG is absent in Drosophila. AUA, AUU AUC: Apis GUG: Polyplacophora UUG: Ascaris, Caenorhabditis. Nematoda: Ascaris, ...

https://en.wikipedia.org/wiki/Invertebrate_mitochondrial_code

Kozak M (1984). "Point mutations close to the AUG initiator codon affect the efficiency of translation of rat preproinsulin in ... At the AUG codon a Methionine tRNA anticodon is recognized by mRNA codon. Upon base pairing to the start codon the eIF5 in the ... Kozak, Marilyn (March 1984). "Point mutations close to the AUG initiator codon affect the efficiency of translation of rat ... Kozak M (1986). "Point mutations define a sequence flanking the AUG initiator codon that modulates translation by eukaryotic ...

https://en.wikipedia.org/wiki/Kozak_consensus_sequence

Kozak, M. (November 1990). "Downstream secondary structure facilitates recognition of initiator codons by eukaryotic ribosomes ... scanning where the start codon is skipped, whereas a strong Kozak context leads to start codon recognition by the 48S PIC and ... inspecting each successive triplet for a functional start codon. Translation initiation is most successful at an AUG codon ... Cigan, A M; Pabich, E K; Donahue, T F (July 1988). "Mutational analysis of the HIS4 translational initiator region in ...

https://en.wikipedia.org/wiki/Translation_regulation_by_5′_transcript_leader_cis-elements

It also allows for rapid codon-anticodon pairing for the initiator tRNA to bind quickly. IF3 is required by the small subunit ... The chloroplast homolog enhances the poly(A,U,G)-dependent binding of the initiator tRNA to its ribosomal 30s subunits. IF1-IF3 ... the initiator tRNA and the messenger RNA. IF-3 is a basic protein that binds to the 30S ribosomal subunit. ...

https://en.wikipedia.org/wiki/Translation_initiation_factor_IF-3

It also allows for rapid codon-anticodon pairing for the initiator tRNA to bind quickly to. IF3 is required by the small ... Bacterial initiation factor 2 binds to an initiator tRNA and controls the entry of that tRNA into the ribosome. IF2, bound to ...

https://en.wikipedia.org/wiki/Bacterial_initiation_factor

Wuitschick JD, Karrer KM (1999). "Analysis of genomic G + C content, codon usage, initiator codon context and translation ... Codon usage bias, a measure related to codon frequencies, was one of the first detection methods used in methodical assessments ... This approach requires a host genome which contains a bias towards certain synonymous codons (different codons which code for ... for example the third nucleotide in a codon and the first nucleotide in the following codon represent the dinucleotide least ...

https://en.wikipedia.org/wiki/Inferring_horizontal_gene_transfer

Wuitschick JD, Karrer KM (1999). "Analysis of genomic G + C content, codon usage, initiator codon context and translation ... This has been pointed to the fact that the stop codon has a bias towards A and T nucleotides, and, thus, the shorter the ... Codon usage bias Definition of GC - content on CancerWeb of Newcastle University,UK Yakovchuk P, Protozanova E, Frank- ... Comparison of more than 1,000 orthologous genes in mammals showed marked within-genome variations of the third-codon position ...

https://en.wikipedia.org/wiki/GC-content

... exons either provide or deny an initiator methionine codon to the same alpha-tubulin coding region". Nucleic Acids Research. 15 ...

https://en.wikipedia.org/wiki/TUBA4A

Start codons can also be suppressed with suppressor initiator tRNAs, such as the amber stop codon suppressor tRNAfMet2(CUA). ... In addition, many genes do not have only one termination codon, and cells commonly use ochre codons as the termination signal, ... Nonsense suppressors can be generally divided into two classes: a) a mutated tRNA which can bind with a termination codon on ... Genes with different or multiple stop codons will be unaffected. SUP35, a nonsense suppressor identified by Wickner in 1994, is ...

https://en.wikipedia.org/wiki/Nonsense_suppressor

The amber initiator tRNA inserts methionine and glutamine at UAG codons preceded by a strong Shine-Dalgarno sequence. An ... and several different 3-nucleotide codons can express the same amino acid. This codon bias is what necessitates codon ... Highly expressed genes seem to be enriched in codons that are exclusively using codons that will be decoded by these modified ... Once the A/A and P/P tRNAs have moved to the P/P and E/E sites, the mRNA has also moved over by one codon and the A/T site is ...

https://en.wikipedia.org/wiki/Transfer_RNA

... helped by eIF2 and the initiator Met-tRNAiMet. SUI1 ensures that translation initiation commences from the correct start codon ... SUI1 promotes a high initiation fidelity for the AUG codon, discriminating against non-AUG codons. In E. coli however, it seems ... and 2β discriminate against poor AUG context and non-AUG start codons". Molecular and Cellular Biology. 31 (23): 4814-31. doi: ... recognition of the start codon". Molecular and Cellular Biology. 12 (1): 248-60. doi:10.1128/mcb.12.1.248. PMC 364089. PMID ...

https://en.wikipedia.org/wiki/SUI1

These genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription ...

https://en.wikipedia.org/wiki/TPSB2

HCV-like IRESs directly bind the 40S ribosomal subunit to position their initiator codons are located in ribosomal P-site ...

https://en.wikipedia.org/wiki/Internal_ribosome_entry_site

These genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription ...

https://en.wikipedia.org/wiki/TPSAB1

The degree of base pairing also plays a role in determining the rate of initiation at different AUG initiator codons. In 1973 ... Steitz J A, Jakes K (1975). "How ribosomes select initiator regions in mRNA: base pair formation between the 3'-terminus of 16S ... Once recruited, tRNA may add amino acids in sequence as dictated by the codons, moving downstream from the translational start ... Since this conserved sequence contained the complement of each of the three eukaryotic termination codons (UAA, UAG and UGA) it ...

https://en.wikipedia.org/wiki/Shine–Dalgarno_sequence

2005). "A single nucleotide substitution that abolishes the initiator methionine codon of the GLDC gene is prevalent among ...

https://en.wikipedia.org/wiki/Glycine_dehydrogenase_(decarboxylating)

Moreover, it binds 40S in such a manner that AUG initiator codon is positioned in the ribosomal P-site, thus no ribosomal ... Initiator tRNA is delivered either by eIF2 or, in stress conditions when eIF2 is inactivated, by eIF2A, eIF2D, or possibly ... UTR to reach to start codon. In contrast, translation of hepatitis C virus (HCV) mRNA is initiated by a different mechanism ...

https://en.wikipedia.org/wiki/Hepatitis_C_virus_internal_ribosome_entry_site

The ribosome reads the mRNA triplet codons, usually beginning with an AUG (adenine−uracil−guanine), or initiator methionine ... The encoding of proteins is done in groups of three, known as codons. The standard codon table applies for humans and mammals, ... matching the codon in the mRNA to the anti-codon on the tRNA. Each tRNA bears the appropriate amino acid residue to add to the ... Translation ends with a stop codon which may be a UAA, UGA, or UAG triplet. The mRNA does not contain all the information for ...

https://en.wikipedia.org/wiki/Central_dogma_of_molecular_biology

... the amino acid encoded by the start codon is methionine. The Met-charged initiator tRNA (Met-tRNAiMet) is brought to the P-site ... The initiator tRNA occupies the P site in the ribosome, and the A site is ready to receive an aminoacyl-tRNA. During chain ... At the end of the initiation step, the mRNA is positioned so that the next codon can be translated during the elongation stage ... Leaky termination in these genes leads to translational readthrough of up to 10% of the stop codons of these genes. Some of ...

https://en.wikipedia.org/wiki/Eukaryotic_translation

For instance, the rare alternative start codon CTG codes for Methionine when used as a start codon, and for Leucine in all ... Once the mRNA and 30S subunit are properly bound, an initiation factor brings the initiator tRNA-amino acid complex, f-Met-tRNA ... tRNA usually cannot recognize or bind to stop codons. Instead, the stop codon induces the binding of a release factor protein ( ... The A-site binds the incoming tRNA with the complementary codon on the mRNA. The P/E-site holds the tRNA with the growing ...

https://en.wikipedia.org/wiki/Translation_(biology)

... codon MeSH G14.340.024.340.137.190.225 - codon, initiator MeSH G14.340.024.340.137.190.250 - codon, terminator MeSH G14.340. ... codon, initiator MeSH G14.335.355.250 - codon, terminator MeSH G14.335.355.250.235 - codon, nonsense MeSH G14.335.760.640 - ...

https://en.wikipedia.org/wiki/List_of_MeSH_codes_(G14)

... most of the tryptase genes have an intron immediately upstream of the initiator Met codon, which separates the site of ...

https://en.wikipedia.org/wiki/TPSD1

It is essentially the same as the standard code, however there are some variations in alternative start codons. A The codon AUG ... CUG is known to function as an initiator for one plasmid-encoded protein (RepA) in E. coli. In addition to the NUG initiations ... The other start codons listed by GenBank are rare in eukaryotes and generally codes for Met/fMet. B ^ ^ ^ The historical basis ... Golderer, G; Dlaska, M; Gröbner, P; Piendl, W (October 1995). "TTG serves as an initiation codon for the ribosomal protein ...

https://en.wikipedia.org/wiki/Bacterial,_archaeal_and_plant_plastid_code

Initiation involves recognition of the start codon (AUG) by initiator tRNA in the P-site, elongation involves passage of many ... The A-site binds to incoming aminoacyl-tRNA which has the anti-codon for the corresponding codon in the mRNA presented in the A ... When a stop codon is reached, the peptidyl-tRNA bond of the tRNA located in the P-site is cleaved releasing the newly ... Translation moves the tRNA from the A-site through the P- and E-sites, with the exception of the initiator tRNA, which binds ...

https://en.wikipedia.org/wiki/P-site

ATG initiator codon of the RELN gene in an Italian population. Longer triplet repeats in the 5' region were associated with an ...

https://en.wikipedia.org/wiki/Reelin

Industrial melanism Infectious transfer Informed consent Inherit Inherited Initiation codon Initiation Initiation Initiator ... bank Cloned DNA Cloning Cloning vector Coccus Code Code dictionary Coding strand Codominance Codon Codon usage bias aka Codon ... Ochre codon Okazaki fragment Oligo Oligogenic Oligonucleotide Oncogene Oncogenes Oncovirus Oocyte Oogenesis Oogonia Opal codon ... Non-disjunction Non-histone protein Non-linear tetrad Non-Mendelian ratio Non-parental Non-recombinant Nonsense codon Nonsense ...

https://en.wikipedia.org/wiki/Index_of_genetics_articles

... in-frame and downstream of the initiator AUG codon, to give rise to nuclear forms of this hormone. The protein was first ...

https://en.wikipedia.org/wiki/Parathyroid_hormone-related_protein

... codon MeSH D13.444.735.544.355.225 - codon, initiator MeSH D13.444.735.544.355.250 - codon, terminator MeSH D13.444.735.544. ... 355.250.235 - codon, nonsense MeSH D13.444.735.544.500 - rna caps MeSH D13.444.735.544.500.710 - rna cap analogs MeSH D13.444. ...

https://en.wikipedia.org/wiki/List_of_MeSH_codes_(D13)

This suggests that these prion domains are, in fact, portable and are the sole initiator of prionogenesis. This supports the ... leading to more frequent stop codon read-through and the development of novel phenotypes. With over 20 prion-like domains ...

https://en.wikipedia.org/wiki/Fungal_prion

"Thermodynamic characterization of ppGpp binding to EF-G or IF2 and of initiator tRNA binding to free IF2 in the presence of GDP ... and pentaphosphate requires the presence of a codon-specific, uncharged transfer ribonucleic acid in the acceptor site of ...

https://en.wikipedia.org/wiki/Stringent_response

With Kjeld Marcker he found that the initiator methionine tRNA binds directly to the peptide (P) site on the ribosome and that ... Protein Synthesis In his first paper, on the genetic code, the word "codon" first appeared in print (inserted by Francis Crick ... the correct initiator AUG is not found by starting at one end of the mRNA and then selecting the first AUG. He proposed that, ...

https://en.wikipedia.org/wiki/Mark_Bretscher

Alteration of the ATG start codon of the A protein of bacteriophage phi X174 into an ATT codon yields a viable phage indicating ... an initiator of DNA replication. Nature 288(5791) 561-566 van Mansfeld AD, van Teeffelen HA, Baas PD, Jansz HS (1987) Two ...

https://en.wikipedia.org/wiki/Microviridae

The principal functions these proteins perform include ribosome RNA/mRNA recognition, delivery of the initiator Met-tRNAiMet, ... these TIFs help correct the identification of the initiation codon, while its function is unknown in bacteria. Just between ...

https://en.wikipedia.org/wiki/Archaeal_initiation_factors

Since the start codon of the genetic code codes for the amino acid methionine, most protein sequences start with a methionine ( ... Modifications include the removal of initiator methionine (iMet) by aminopeptidases, attachment of small chemical groups such ...

https://en.wikipedia.org/wiki/N-terminus

Hofman is the initiator and principal investigator of two population-based, prospective cohort studies in the city of Rotterdam ... Presenile-dementia and cerebral- hemorrhage linked to a mutation at codon-692 of the beta-amyloid precursor protein gene. Nat ...

https://en.wikipedia.org/wiki/Albert_Hofman

Once bound to the 5' cap of mRNA, this 48S complex then searches for the (usually) AUG start codon and translation begins. In ... Eukaryotic initiation factor complex 2 (eIF2) forms a ternary complex with GTP and the initiator Met-tRNA - this process is ...

https://en.wikipedia.org/wiki/EIF4A

... it acts more like a near-cognate codon interaction instead of the cognate codon interaction. This can be seen in the delay in ... such as separating the initiator tRNAMet from elongator tRNAMet.. Moreover, they increase overall tRNA stability. Some studies ... All eukaryotic stop codons contain one uridine (UAA, UGA and UGA); conversion of this uridine to pseudouridine results in ... Secondly, this mark is enriched in specific regions of the transcriptome; it is mostly found close to stop codons, in 3'-UTRs ...

https://en.wikipedia.org/wiki/Epitranscriptome

... along with its corresponding codons move to the E and P sites, respectively, and a new codon moves into the A site. This ... In the canonical mode, the 30S ribosomal subunit, initiation factors, and initiator fMet-tRNA bind to the mRNA to form the pre- ... Termination occurs when one of the three termination codons moves into the A site. These codons are not recognized by any tRNAs ... Well-known coding regions that do not have AUG initiation codons are those of lacI (GUG) and lacA (UUG) in the E. coli lac ...

https://en.wikipedia.org/wiki/Bacterial_translation

... and an initiator. Exons are the part of the transcript that will eventually be transported to the cytoplasm for translation. ... region downstream from the stop codon is separated into two parts: 3' UTR is never translated, but serves to add mRNA stability ...

https://en.wikipedia.org/wiki/Eukaryotic_chromosome_fine_structure

Bases downstream the stop codon affect the activity of these release factors. In fact, some bases proximal to the stop codon ... Hartz D, McPheeters DS, Gold L. Selection of the initiator tRNA by Escherichia coli initiation factors. Genes Dev. 1989;3:1899- ... Once a termination codon is read, release factors RF-1, RF-2, and RF-3 contribute to the hydrolysis of the growing polypeptide ... This is possible due to the matching of 2 out 3 bases within the stop codon by tRNAs that may occasionally outcompete release ...

https://en.wikipedia.org/wiki/Translational_regulation

Instead, kasugamycin mimics the codon nucleotides at the P and E sites by binding within the path of the mRNA, thus perturbing ... Kasugamycin inhibition is thought to occur by direct competition with initiator transfer RNA. Recent experiments suggest that ... the mRNA-tRNA codon-anticodon interaction. Low level resistance to kasugamycin is acquired by mutations in the 16S rRNA ...

https://en.wikipedia.org/wiki/Kasugamycin

... in which the anticodon of the tRNA binds to the codon of the mRNA. If the correct anticodon binds to the mRNA codon, the ... in both EF-1alpha/EF-Tu and also in EF-2/EF-G and thus seems typical for GTP-dependent proteins which bind non-initiator tRNAs ... Messenger RNA (mRNA) carries the genetic information that encodes the primary structure of a protein, and contains codons that ... In translation, a fundamental problem is that near-cognate anticodons have similar binding affinity to a codon as cognate ...

https://en.wikipedia.org/wiki/EF-Tu

initiator_codon_variant. A codon variant that changes at least one base of the first codon of a transcript. ... initiator_codon_variant, incomplete_terminal_codon_variant, stop_lost, stop_retained_variant, stop_gained, NMD_transcript_ ... incomplete_terminal_codon_variant. A sequence variant where at least one base of the final codon of an incompletely annotated ... A sequence variant whereby at least one base of a codon is changed, resulting in a premature stop codon, leading to a shortened ...

http://genome.ucsc.edu/cgi-bin/hgVai?hgsid=1598039869_nQbdcMkP7WAtk7G38zZAkabvy2GS

http://www.genome.ucsc.edu/cgi-bin/hgVai?hgsid=1596486439_HYMOwqvfT1Wi5AB6ovnSKjOARuoe

https://genome.cse.ucsc.edu/cgi-bin/hgVai?hgsid=1594472105_J86BXPaxha1OAI8ecad1KPnrab9i

To study the function of initiator tRNAs in translation initiation in Haloferax volcanii, the initiator AUG codon of the bgaH ... The serine codon at position 184 of the bgaH gene was mutated to the termination codons UAA and UAG. H. volcanii serine tRNA ... in particular the question of whether suppressors of the UAA codon can also suppress the UAG codon in archaea. H. volcanii WFD ... When plasmids carrying the bgaH reporter and mutant initiator tRNAs were coexpressed in H. volcanii, the UGA and GUC decoding ...

https://dspace.mit.edu/handle/1721.1/43232

Mitchell GA, Brody LC, Looney J, Steel G, Suchanek M, Dowling C, Der Kaloustian V, Kaiser-Kupfer M, Valle D. An initiator codon ...

https://medlineplus.gov/genetics/gene/oat/

Codons, Initiator Codons, Start Initiation Codon Initiation Codons Initiator Codon Initiator Codons Start Codon Start Codons ... Codons, Initiator. Codons, Start. Initiation Codon. Initiation Codons. Initiator Codon. Initiator Codons. Start Codon. Start ... Codon, Initiator Entry term(s). Codon, Initiation Codon, Start Codons, Initiation ... Codon dinitiation Entry term(s):. Codon, Initiation. Codon, Start. Codons, Initiation. ...

https://decs.bvsalud.org/en/ths/resource/?id=32305&filter=ths_exact_term&q=CODON+DE+INICIO

... interplay between different initiation factors able to deliver the initiator tRNA to different but physically close AUG codons ... uAUG codons that are immediately followed by a stop codon (designated as start-stop uORFs) are also found in the 5-UTRs of ... Interestingly, the AUG codon of the CrPV ORF1 is immediately preceded by a start-stop uORF (Gross et al., 2017). ... Non-canonical base pairing in the 5-UTR-IRES DIII places the uAUG codon near the P-site. Threading through the 40S channel ...

https://elifesciences.org/articles/54575

One variant was an initiator codon change (c.1A > T) that disrupted protein translation, consistent with the observation that ...

https://pesquisa.bvsalud.org/portal/?lang=pt&q=au:Patel,+Anup+D

http://mgc.ucsc.edu/cgi-bin/hgVai?hgsid=1598472855_ANhDLg7a8HEafUAdKqTmgY6oc69v

https://genome-asia.ucsc.edu/cgi-bin/hgVai?hgsid=790462452_48fACzX6YRTrYPUP0gApNZB2LOZT

https://genome-euro.ucsc.edu/cgi-bin/hgVai?hgsid=295891674_5jXZABaEVO5TK7cYTHc6oBjvL4Px

... initiator codon variant. *Modifiers:5-utr variant, 3-utr variant, intron variant, non-coding transcript exon variant, non- ... Low:splice region variant, start retained variant, stop retained variant, synonymous variant, 5-utr premature start codon gain ...

https://pophumanvar.uab.cat/

Initiator Codon 10% * Nonsense Codon 10% * In Vitro Techniques 3% * Proteins 3% ...

https://okayama.elsevierpure.com/en/publications/translation-of-partially-overlapping-psbd-psbc-mrnas-in-chloropla-2/fingerprints/

Initiator Codon Medicine & Life Sciences 60% * Proteins Medicine & Life Sciences 30% * Genome Medicine & Life Sciences 22% ... initiation codon (INIT) and splice site mutations (n=930, OR=1.3, P=1.5×E-5). There was no enrichment across all rare protein ... initiation codon (INIT) and splice site mutations (n=930, OR=1.3, P=1.5×E-5). There was no enrichment across all rare protein ... initiation codon (INIT) and splice site mutations (n=930, OR=1.3, P=1.5×E-5). There was no enrichment across all rare protein ...

https://cris.haifa.ac.il/en/publications/differential-burden-of-rare-protein-truncating-variants-in-alzhei

Initiator Codon Medicine & Life Sciences 33% * Chromatin Immunoprecipitation Medicine & Life Sciences 30% ... 29 nucleotides upstream of the ATG translation start codon. Electrophoretic Mobility Shift Assay (EMSA) and Chromatin ... 29 nucleotides upstream of the ATG translation start codon. Electrophoretic Mobility Shift Assay (EMSA) and Chromatin ... 29 nucleotides upstream of the ATG translation start codon. Electrophoretic Mobility Shift Assay (EMSA) and Chromatin ...

https://experts.unthsc.edu/en/publications/blimp-1prdm1-regulates-the-transcription-of-human-cs1-slamf7-gene

Initiator Codon Medicine & Life Sciences 66% * Consensus Sequence Medicine & Life Sciences 62% ... 22 bp upstream from the first ATG codon. A number of minor transcriptional start points were also identified in this region, ... 22 bp upstream from the first ATG codon. A number of minor transcriptional start points were also identified in this region, ... 22 bp upstream from the first ATG codon. A number of minor transcriptional start points were also identified in this region, ...

https://utsouthwestern.elsevierpure.com/en/publications/the-rad2-gene-of-saccharomyces-cerevisiae-nucleotide-sequence-and

Codon. *Codon, Initiator. *Crystallography, X-Ray. *Cytidine. *Cytidine Deaminase. *DNA Methylation. *DNA Transposable Elements ...

https://connects.catalyst.harvard.edu/Profiles/display/Person/137864/Network/ResearchAreas

... the initiator methionine tRNA responsible for recognising the start codon and initiating translation), is upregulated in cancer ... The initiator methionine tRNA drives cell migration and invasion leading to increased metastatic potential in melanoma Joanna ... The initiator methionine tRNA drives secretion of type II collagen from stromal fibroblasts to promote tumor growth and ... Overexpression of initiator methionine tRNA leads to global reprogramming of tRNA expression and increased proliferation in ...

https://journals.biologists.com/bio/article/5/10/1371/1479/The-initiator-methionine-tRNA-drives-cell

Point mutations define a sequence flanking the AUG initiator codon that modulates translation by eukaryotic ribosomes ...

https://m.wikidata.org/wiki/Q37620889

Suppression of amber codons in vivo as evidence that mutants derived from Escherichia coli initiator tRNA can act at the step ...

https://yonsei.elsevierpure.com/en/publications/?showAdvanced=false&allConcepts=true&inferConcepts=true&publicationYear=2018&publicationYear=2019&publicationYear=2020&publicationYear=2021&author=54cfa439-aac6-457d-b4b2-9e2aeda2b467&format=&nofollow=true&page=6&ordering=publicationYearThenTitle&descending=false

No recognizable promoter sequences (e.g., TATA boxes or initiator elements) have been identified in dinoflagellate genes. ... genes present in tandem arrays lack stop codons and are therefore not only co-transcribed, but also co-translated into ... through the trans-splicing of the leader sequence at a splice acceptor site approximately 100 nt upstream of each start codon [ ...

https://bmcgenomics.biomedcentral.com/articles/10.1186/1471-2164-12-346

Position from initiation codon. Strand. Start. End. Start. End. initiator. Not Available. Not Available. Not Available. ...

https://ppdb.agr.gifu-u.ac.jp/ppdb/cgi-bin/display.cgi?organism=At&gene=AT5G15960&pos=5215742&rev=&all=

eIF2α interactions with mRNA control accurate start codon selection by the translation preinitiation complex. Nucleic Acids Res ... and of initiator tRNAi, 18S rRNA, and ribosomal proteins uS7/Rps5, uS3/Rps3, and uS5/Rps2 involved in accurate and efficient ... and a signaling pathway that attenuates the function of eIF2 in recruiting initiator methionyl tRNA (tRNAi) to the small (40S) ... is illuminating in vivo mechanisms involved in recruitment of tRNAi and mRNA to ribosomes and recognition of start codons ...

https://irp.nih.gov/pi/alan-hinnebusch

... initiator tRNA to the small ribosomal subunit and releases it upon GTP hydrolysis after the recognition of the initiation codon ... They are required for formation of the ternary complex with GTP and initiator tRNA [1]. ...

http://eurbpdb.gzsys.org.cn/rbp_genelist.php?domain=eIF2_C&species=Mus_musculus

Well known promoter elements used by many viruses are the TATA box and the initiator sequence, which is located at or near the ... The TS gene includes a transcription start at −22 nt relative to the ATG translational start codon, a putative TATA box at −28 ... Besides, the structure of the WSSV dnapol promoter (having an initiator sequence with a CAGT motif located −25 nt downstream of ... The encoding gene, named wdut, consisting of 1383 nt, includes a putative translation codon (GCCATGG) and a putative TATA box ...

https://www.vetres.org/articles/vetres/full_html/2010/06/v09431/v09431.html

The stop codon should be UAA. If UAG or UGA is used as a stop codon, they should be followed by nucleotide U. Start codon, SD, ... or stop codon should not be embedded in a secondary structure that may obscure the signals and interfere with their decoding. ... For optimizing phage genes against M. abscessus, the start codon should be AUG. The DtoStart distance from base-pairing between ... Steitz, J.A.; Jakes, K. How ribosomes select initiator regions in mRNA: Base pair formation between the 3 terminus of 16S rRNA ...

https://www.mdpi.com/2813-2998/2/1/12

GCG is the codon for alanine. If you think a codon can specify more than one amino acid (except in the special cases of ... A real-life complication is that a polypeptide chain has to be initiated by an initiator methionine-tRNA that is distinct from ... I am unclear why you are concerned with this problem, but if there were two alanine codons in the mRNA, in theory after a ... An amino acid is attached to the appropriate tRNA (the one with the anticodon that recognizes a codon for that amino acid) by ...

https://biology.stackexchange.com/questions/57822/translation-of-rna-into-proteins

... initiator codon, Mammalian wide Interspersed repeat, Mitochondrial DNA polymerase, POLGARF, synonymous codon , Comments (0) ... Different codons for the same amino acid can produce wildly different effects leaving the amino acid sequence of a given ... The previous links show how the redundant codons for some amino acids arent redundant at all but used to code for the speed of ... There really is no way around the redundancy producing synonymous codons. If you want to code for 20 different amino acids with ...

https://luysii.wordpress.com/tag/polg/

... the rate of biological chemical reaction are called asAllosteric enzymes consist of multipleIn eukaryotes the initiator codon ...

https://mcqslearn.com/mcat/biology/absolute-configuration.php

We also showed that there is an affinity switch upon start codon recognition. mRNAs with AUG codon in the P site are stabilized ... initiator tRNA (fMet-tRNAfMet), mRNA, and three initiation factors IF1, IF2, IF3. There are two main steps in initiation. ... In the second part of the present work influence of mRNA regulatory elements (Shine-Dalgarno (SD) sequence, initiation codon) ...

https://ediss.uni-goettingen.de/handle/11858/00-1735-0000-0022-5DEA-9?show=full

Nucleotides Termination codons Upstream TRNA Ribosomes Mutation Eukaryotes Vertebrate MRNA Start EIF2 Suppress Protein Amino acid Mutations Gene MRNAs Methionine Found Initiation Methionine Triggers Sequences Shown

We identified a novel mutation in the 5' region of the LMNA gene -3del15, resulting in the loss of 15 nucleotides from -3 to +12, including the translation ATG initiator codon. (nih.gov)
6. Modulation of translational efficiency by contextual nucleotides flanking a baculovirus initiator AUG codon. (nih.gov)
Proximal region of CS1 promoter contains a CAAT box and atypical TATA-box that might result in common transcription initiation at -29 nucleotides upstream of the ATG translation start codon. (unthsc.edu)

I also describe modifications of the bgaH reporter for studying suppression of termination codons in H. volcanii. (mit.edu)
The serine codon at position 184 of the bgaH gene was mutated to the termination codons UAA and UAG. (mit.edu)
However, at least in humans it has now been shown that AGA and AGG sequences are not recognized as termination codons. (nih.gov)

13. Posttranscriptional regulation of human ADH5/FDH and Myf6 gene expression by upstream AUG codons. (nih.gov)
Canonical start codon selection is thought to occur by the base-pairing of the 16S rRNA with a Shine-Dalgarno (SD) sequence in the mRNA located 5nt upstream of the start codon ( 4 - 6 ). (biorxiv.org)
These genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription initiation from protein coding sequence. (abnova.com)
Although this gene may be an exception, most of the tryptase genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription initiation from protein coding sequence. (nih.gov)

A codon that directs initiation of protein translation ( TRANSLATION, GENETIC ) by stimulating the binding of initiator tRNA ( RNA, TRANSFER, MET ). (nih.gov)
Four different H. volcanii initiator tRNA derived mutants with complementary anticodons were also made. (mit.edu)
When plasmids carrying the bgaH reporter and mutant initiator tRNAs were coexpressed in H. volcanii, the UGA and GUC decoding tRNAs were aminoacylated, but functional 0-galactosidase was produced only in the presence of the latter tRNA. (mit.edu)
This result confirms that translation can initiate with some alternative codons, but suggests that the amino acid attached to the tRNA also plays a role. (mit.edu)
Since little is known about translation in archaea, future work will involve modifying identity elements in the initiator tRNA to study their requirements in both initiation and elongation in archaea. (mit.edu)
This conformational change is accompanied by the release of eIF1, eIF2 and GDP, leaving the Met-tRNA i Met at the P-site of the 40S base paired with the AUG codon ( Aitken and Lorsch, 2012 ). (elifesciences.org)
promotes recruitmnet of aminoacetyled initiator tRNA to P site of 40S ribosomes. (nih.gov)
During the second phase, the nucleotide sequences of RNA codons were deciphered by deter- mining the species of aminoacyl-tRNA that bound to ribosomes in response to trinucleotides of known sequence. (nih.gov)
in which initiator Met-tRNA Met i is base-paired with the AUG codon of an mRNA. (nih.gov)

Indeed, "orthogonal" ribosomes with altered 16S rRNA aSD sequences were found to initiate at the normal start codons throughout the transcriptome ( 11 ). (biorxiv.org)
To account for the lack of essentiality of the SD site, a "Unique accessibility model" was proposed which posited that start codon selection occurs due to the TIR being accessible to initiating ribosomes, while elongator AUGs are physically inaccessible due to RNA secondary structures ( 18 ). (biorxiv.org)
In starvation conditions, the reinitiating ribosomes bypass uORFs 2-4 and reinitiate at GCN4 instead, owing to lowered availability of the ternary complex (TC)-comprised of initiation factor 2 (eIF2), GTP, and initiator Met-tRNAi-which binds to the small (40S) ribosomal subunit to assemble a 43S preinitiation complex (PIC). (nih.gov)

5. The 185delAG mutation (c.68_69delAG) in the BRCA1 gene triggers translation reinitiation at a downstream AUG codon. (nih.gov)
Mitchell GA, Brody LC, Looney J, Steel G, Suchanek M, Dowling C, Der Kaloustian V, Kaiser-Kupfer M, Valle D. An initiator codon mutation in ornithine-delta-aminotransferase causing gyrate atrophy of the choroid and retina. (medlineplus.gov)
During the course of a screening program for βthalassemia mutations among p-thalassemia heterozygotes in Yugoslavia we observed a mutation (ATG-ACG) in the initiation codon of the B-globin gene which has not been described before. (elsevierpure.com)

In prokaryotes, the codons AUG or GUG can act as initiators while in eukaryotes, AUG is the only initiator codon. (nih.gov)

AGA and AGG were thought to have become mitochondrial stop codons early in vertebrate evolution ( Osawa, Ohama, Jukes & Watanabe 1989 ). (nih.gov)

7. Translation initiation of a bicistronic mRNA of Borna disease virus: a 16-kDa phosphoprotein is initiated at an internal start codon. (nih.gov)
To investigate the mechanism of leaderless mRNA translation initiation, synthetic in vivo translation reporters were designed that systematically tested the effects of start codon accessibility, leader length, and start codon identity on leaderless mRNA translation initiation. (biorxiv.org)
Thus, start codon accessibility, leader length, and start codon identity combine to define leaderless mRNA translation initiation in bacteria. (biorxiv.org)
Translation initiation is a critical step for fidelity of gene expression in which the ribosome initiation complex is formed on the start codon of the mRNA. (biorxiv.org)
We have also investigated the roles of various eIFs, tRNAi and the 40S subunit in scanning the mRNA 5′ untranslated region and in accurately identifying the AUG initiation codon. (nih.gov)

Since the canonical start codon, AUG, compliments both initiator and elongator methionyl-tRNAs, the ribosome must distinguish the start AUG codon from elongator AUG codons. (biorxiv.org)
While the SD-aSD pairing clearly impacts translation initiation efficiency (TIE) in E. coli , other studies have found that the SD:aSD interaction is not essential for correct selection of the start codon ( 9 , 10 ). (biorxiv.org)
Indeed, RNA-seq based transcription mapping experiments have found that many bacterial mRNAs are "leaderless" and begin directly at the AUG start codon ( 14 - 16 ), and that these mRNAs are abundant in pathogens such as M. tuberculosis and in the mammalian mitochondria ( 17 ). (biorxiv.org)
ii) identifying a higher-order assembly of initiation factors 1, 2, 3, and 5-the multifactor complex (MFC)-and elucidating its roles in PIC assembly and accurate start codon selection. (nih.gov)
These studies exploit a genetic selection for mutations that elevate initiation at near-cognate UUG start codons (Sui− phenotype) or suppress this aberrant initiation event (Ssu− phenotype) (Figure 1B). (nih.gov)

These proteins share a common core structure, codon triggers GTP hydrolysis by eIF2 and release of the guanine-nucleotide binding domain (G domain). (nih.gov)

These suppressor tRNAs should allow a study of the requirements for suppression of UAG and UAA codons in H. volcanii, in particular the question of whether suppressors of the UAA codon can also suppress the UAG codon in archaea. (mit.edu)

1. Initiation of translation from a downstream in-frame AUG codon on BRCA1 can generate the novel isoform protein DeltaBRCA1(17aa). (nih.gov)
During the first stage, the base compo- sitions of codons were deciphered by the directing cell- free protein synthesis with randomly ordered RNA preparations. (nih.gov)

Q. A codon always codes for a single amino acid and never otherwise. (byjus.com)

We observed an increased burden among AD subjects for predicted loss-of-function (LoFs) variants defined as stop-gain, frame shift, initiation codon (INIT) and splice site mutations (n=930, OR=1.3, P=1.5×E-5). (haifa.ac.il)

To study the function of initiator tRNAs in translation initiation in Haloferax volcanii, the initiator AUG codon of the bgaH gene was mutated to UAG, UAA, UGA, and GUC. (mit.edu)

May be involved in the translation of target mRNAs by scanning and recognition of the initiation codon. (nih.gov)

Thus, for the convenience of people reading GenBank records, the genetic code tables shown here use T instead of U. The initiator codon - whether it is AUG, CTG, TTG or something else, - is by default translated as methionine (Met, M). The possible intiator codons are marked as 'M' in the second ('Starts') row of the translation tables. (nih.gov)

Detailed information on codon usage can be found at the Codon Usage Database . (nih.gov)

Initiation of translation at the closest in-frame methionine codon would truncate OAT by 138 amino acids, eliminating the entire mitochondrial leader sequence and 113 amino acids of the mature peptide. (nih.gov)
1. Initiation of translation from a downstream in-frame AUG codon on BRCA1 can generate the novel isoform protein DeltaBRCA1(17aa). (nih.gov)
7. Translation initiation of a bicistronic mRNA of Borna disease virus: a 16-kDa phosphoprotein is initiated at an internal start codon. (nih.gov)
18. Unconventional translation initiation of human trypsinogen 4 at a CUG codon with an N-terminal leucine. (nih.gov)
20. Translational enhancement of FGF-2 by eIF-4 factors, and alternate utilization of CUG and AUG codons for translation initiation. (nih.gov)
A codon that directs initiation of protein translation (TRANSLATION, GENETIC) by stimulating the binding of initiator tRNA (RNA, TRANSFER, MET). (bvsalud.org)
May be involved in the translation of target mRNAs by scanning and recognition of the initiation codon. (nih.gov)

Sequence analysis showed a G----A transition, changing the initiator ATG (methionine) codon to ATA. (nih.gov)
Thus, for the convenience of people reading GenBank records, the genetic code tables shown here use T instead of U. The initiator codon - whether it is AUG, CTG, TTG or something else, - is by default translated as methionine (Met, M). The possible intiator codons are marked as 'M' in the second ('Starts') row of the translation tables. (nih.gov)

5. The 185delAG mutation (c.68_69delAG) in the BRCA1 gene triggers translation reinitiation at a downstream AUG codon. (nih.gov)
These proteins share a common core structure, codon triggers GTP hydrolysis by eIF2 and release of the guanine-nucleotide binding domain (G domain). (nih.gov)

However, at least in humans it has now been shown that AGA and AGG sequences are not recognized as termination codons. (nih.gov)

A (initiator codon), in IER3IP1 that were subsequently shown to be inherited in trans. (bvsalud.org)

Anatomy12

Organisms10

Diseases3

Chemicals and Drugs111

Analytical, Diagnostic and Therapeutic Techniques and Equipment22

Phenomena and Processes96

Technology, Industry, Agriculture5

Information Science4

Health Care1

Machine learning approaches for the prediction of signal peptides and other protein sorting signals. (1/852)

Exon shuffling by L1 retrotransposition. (2/852)

The chloroplast infA gene with a functional UUG initiation codon. (3/852)

Involvement of the aphthovirus RNA region located between the two functional AUGs in start codon selection. (4/852)

Analysis of elements involved in pseudoknot-dependent expression and regulation of the repA gene of an IncL/M plasmid. (5/852)

Multiple murine double minute gene 2 (MDM2) proteins are induced by ultraviolet light. (6/852)

Postsynaptic alpha-neurotoxin gene of the spitting cobra, Naja naja sputatrix: structure, organization, and phylogenetic analysis. (7/852)

The cis acting sequences responsible for the differential decay of the unstable MFA2 and stable PGK1 transcripts in yeast include the context of the translational start codon. (8/852)

Codon

Codon, Initiator

Codon, Terminator

Base Sequence

RNA, Transfer, Met

Molecular Sequence Data

Codon, Nonsense

Peptide Chain Initiation, Translational

Protein Biosynthesis

RNA, Transfer

Amino Acid Sequence

Mutation

Escherichia coli

Anticodon

Caspases, Initiator

Plasmids

Nucleic Acid Conformation

Replication Origin

Ribosomes

Genetic Code

DNA Replication

RNA, Messenger

Transcription, Genetic

TATA Box

Cloning, Molecular

DNA-Binding Proteins

RNA, Transfer, Amino Acyl

Promoter Regions, Genetic

Hydroxymethyl and Formyl Transferases

Bacterial Proteins

Prokaryotic Initiation Factor-2

Peptide Initiation Factors

DNA Helicases

Binding Sites

DNA

Base Composition

Genes

Sequence Homology, Nucleic Acid

Restriction Mapping

Genes, Bacterial

Prokaryotic Initiation Factor-3

Exons

Polymerase Chain Reaction

Point Mutation

Methionine-tRNA Ligase

Eukaryotic Initiation Factor-1

Peptide Chain Termination, Translational

Viral Proteins

Methionine

Caspases

DNA, Bacterial

DNA Mutational Analysis

Sequence Analysis, DNA

Saccharomyces cerevisiae

Caspase 2

N-Formylmethionine

Models, Genetic

RNA, Transfer, Amino Acid-Specific

Oligoribonucleotides

Protein Binding

DNA Primers

Benzoyl Peroxide

RNA, Bacterial

Peptide Chain Elongation, Translational

Mutagenesis, Site-Directed

Sequence Alignment

Evolution, Molecular

Trans-Activators

Caspase 9

Sequence Homology, Amino Acid

Thromboplastin

Transcription Factors

Cell Line

Genes, ras

Caspase 8

HeLa Cells

Eukaryotic Initiation Factor-2

Gene Expression Regulation, Bacterial

Suppression, Genetic

Introns