Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Mutagenesis, Insertional: 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.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Amino Acid Sequence: 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.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Escherichia coli: 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.Amino Acid Substitution: 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.Structure-Activity Relationship: 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.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Plasmids: 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.Protein Structure, Tertiary: 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.Cloning, Molecular: 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.Bacterial Proteins: Proteins found in any species of bacterium.Kinetics: The rate dynamics in chemical or physical systems.Protein Conformation: 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).Protein Binding: 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.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Sequence Alignment: 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.Genes, Bacterial: The functional hereditary units of BACTERIA.Point Mutation: 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.Mutagens: Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.Ethylnitrosourea: A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Alanine: A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.DNA Primers: 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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.SOS Response (Genetics): An error-prone mechanism or set of functions for repairing damaged microbial DNA. SOS functions (a concept reputedly derived from the SOS of the international distress signal) are involved in DNA repair and mutagenesis, in cell division inhibition, in recovery of normal physiological conditions after DNA repair, and possibly in cell death when DNA damage is extensive.Histidine: An essential amino acid that is required for the production of HISTAMINE.Conserved Sequence: 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.DNA Mutational Analysis: Biochemical identification of mutational changes in a nucleotide sequence.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Transfection: 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.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Ethyl Methanesulfonate: An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Recombinant Fusion Proteins: 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.Protein Engineering: Procedures by which protein structure and function are changed or created in vitro by altering existing or synthesizing new structural genes that direct the synthesis of proteins with sought-after properties. Such procedures may include the design of MOLECULAR MODELS of proteins using COMPUTER GRAPHICS or other molecular modeling techniques; site-specific mutagenesis (MUTAGENESIS, SITE-SPECIFIC) of existing genes; and DIRECTED MOLECULAR EVOLUTION techniques to create new genes.Oligodeoxyribonucleotides: A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.Lysine: An essential amino acid. It is often added to animal feed.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Directed Molecular Evolution: The techniques used to produce molecules exhibiting properties that conform to the demands of the experimenter. These techniques combine methods of generating structural changes with methods of selection. They are also used to examine proposed mechanisms of evolution under in vitro selection conditions.Aspartic Acid: One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.Mutant Proteins: Proteins produced from GENES that have acquired MUTATIONS.Promoter Regions, Genetic: 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.Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Saccharomyces cerevisiae: 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.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Asparagine: A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.DNA-Binding Proteins: 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.Serine: A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.COS Cells: CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)Polymerase Chain Reaction: 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.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.DNA-Directed DNA Polymerase: DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair.Arginine: An essential amino acid that is physiologically active in the L-form.Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.CHO Cells: CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Codon: 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).Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Mutagenicity Tests: Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.Amino Acids: 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.Operon: 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.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.DNA Damage: Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.Transformation, Bacterial: The heritable modification of the properties of a competent bacterium by naked DNA from another source. The uptake of naked DNA is a naturally occuring phenomenon in some bacteria. It is often used as a GENE TRANSFER TECHNIQUE.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Transformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Methylnitronitrosoguanidine: A nitrosoguanidine derivative with potent mutagenic and carcinogenic properties.Genetic Engineering: Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Biocatalysis: The facilitation of biochemical reactions with the aid of naturally occurring catalysts such as ENZYMES.DNA, Complementary: 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.Consensus Sequence: 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.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.DNA Replication: The process by which a DNA molecule is duplicated.Rec A Recombinases: A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.Tyrosine: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.Mutation, Missense: A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Protein Processing, Post-Translational: Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.Oligonucleotides: 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)Sequence Homology, Nucleic Acid: 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.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Protein Structure, Quaternary: The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Transposases: Enzymes that recombine DNA segments by a process which involves the formation of a synapse between two DNA helices, the cleavage of single strands from each DNA helix and the ligation of a DNA strand from one DNA helix to the other. The resulting DNA structure is called a Holliday junction which can be resolved by DNA REPLICATION or by HOLLIDAY JUNCTION RESOLVASES.Saccharomyces cerevisiae Proteins: 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.Oligonucleotide Probes: Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.Frameshift Mutation: A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.Alkylating Agents: Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Genes, Reporter: 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.HeLa Cells: 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.Viral Proteins: Proteins found in any species of virus.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Threonine: An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.Genetic Techniques: Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.Lac Operon: The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Fungal Proteins: Proteins found in any species of fungus.Serine Endopeptidases: Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.Genes: 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.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Hypoxanthine Phosphoribosyltransferase: An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Cricetulus: A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.Gene Expression Regulation: 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.Repressor Proteins: 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.Leucine: An essential branched-chain amino acid important for hemoglobin formation.Glutamine: A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.Bacillus subtilis: A species of gram-positive bacteria that is a common soil and water saprophyte.beta-Galactosidase: 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.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Cells, Cultured: 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.Models, Genetic: 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.Gene Targeting: The integration of exogenous DNA into the genome of an organism at sites where its expression can be suitably controlled. This integration occurs as a result of homologous recombination.Protein Multimerization: The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.Proline: A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.RNA, Messenger: 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.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).HEK293 Cells: A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Genes, Fungal: The functional hereditary units of FUNGI.Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.Structural Homology, Protein: The degree of 3-dimensional shape similarity between proteins. It can be an indication of distant AMINO ACID SEQUENCE HOMOLOGY and used for rational DRUG DESIGN.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA 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.Genes, Suppressor: 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.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Suppression, Genetic: 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).Isoleucine: An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.Protein Interaction Domains and Motifs: Protein modules with conserved ligand-binding surfaces which mediate specific interaction functions in SIGNAL TRANSDUCTION PATHWAYS and the specific BINDING SITES of their cognate protein LIGANDS.Peptide Mapping: Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.Mesylates: Organic salts or esters of methanesulfonic acid.Genes, Lethal: Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.GuanineModels, Structural: A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)DNA, Recombinant: 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.Macromolecular Substances: Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.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.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Enzyme Activation: 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.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Valine: A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Static Electricity: The accumulation of an electric charge on a objectChromosome Deletion: Actual loss of portion of a chromosome.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Transcriptional Activation: Processes that stimulate the GENETIC TRANSCRIPTION of a gene or set of genes.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Oocytes: Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).Streptomyces: A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.

*  Mutagenesis

Click herehere to submit your mutagenesis worksheets. 1. Template Information: My Historical Clones: Please login to see your ...

*  Mutagenesis Problems

... heidi moss hmmoss at MAIL.MED.CORNELL.EDU Fri Oct 18 15:38:34 EST 1996 *Previous message: Transfection of ...

*  site-directed-mutagenesis | NEB

Site-directed mutagenesis (SDM) is a method to create specific, targeted changes in double stranded plasmid DNA. ... site-directed-mutagenesis. Product Listing Application Overview Site-directed mutagenesis (SDM) is a method to create specific ... the mutagenesis reaction is complete in less than two hours.. Figure 2: Q5 Site-Directed Mutagenesis Kit Overview.. This kit is ... Figure 1: Site-specific mutagenesis proceeds in less than 2 hours.. The use of a master mix, a unique multi-enzyme KLD enzyme ...

*  Site-directed mutagenesis definition |

Definition of site-directed mutagenesis. Provided by Stedman's medical dictionary and Includes medical terms and ...

*  Research Chemical Mutagenesis | World of Genetics

This informative article on Chemical Mutagenesis is an excellent resource for your essay or school project. ... Chemical Mutagenesis from Gale. ©2005-2006 Thomson Gale, a part of the Thomson Corporation. All rights reserved. ... These chemical-induced mutations are known as chemical mutagenesis. Most cancers and other degenerative diseases result from ... This encyclopedia article consists of approximately 2 pages of information about Chemical Mutagenesis. ...

*  Mutagenesis

Only N and K are available at this time. We are working on adding other mixed bases such as - R, Y, M, S, W, H, B, V, D. By letting us know what you need for your research on, you can influence how we prioritize our development efforts. In many cases, we can already offer suitable solutions, that are not offered online ...

*  European Commission : CORDIS : Publications : DNA repair and mutagenesis

DNA repair and mutagenesis. Funded under: FP2-RADPROT 7C Additional information. Authors: VAN ZEELAND A A ET AL., Leiden ... Bibliographic Reference: Extract: Molecular mechanisms in radiation mutagenesis and carcinogenesis : Proceedings of an ... University, MGC-Department of Radiation Genetics and Chemical Mutagenesis (NL). ...

*  Mutagenesis PCR - Molecular Cloning

Mutagenesis PCR - (Aug/09/2014 ). Hi, I have two questions about mutagenesis pcr. I want to delete 14 bp from a gene inserted ... Site-directed mutagenesis by overlap extension using the polymerase chain reaction. Gene. 77, 51-9.). The basic method is as ... I have performed similar mutagenesis experiments quite often. The technique I used was first described by Ho, et al (Ho, S.N., ... Thanks for the answer, my initial intent was to understand the plasmid based mutagenesis, not to t on a discussion for which ...

*  'Round-the-horn site-directed mutagenesis -...

Round-the-horn is a PCR-based mutagenesis. The muations are contained in one or both of the primers. The primers are ... Retrieved from "" ...

*  mutagenesis - start to finish - Molecular Biology

6. carry out site directed mutagenesis a la Ho et al 1989 (or the Altered sites mutagenesis kit from promega if i can convince ... mutagenesis - start to finish - (Jul/06/2010 ). Hi, I've recently come from bacteria into mammal work and have been out of the ... i need to perform single aa mutagenesis on a kinase however the lab doesn't have any starting point stock for me. so here's my ... seems good to me.. convince your boss with reg to Quik change mutagenesis kit from stratagene... you wont regret. for step 4, ...

*  Mutagenesis and beyond! Tools for understanding legume biology. - PubMed - NCBI

Mutagenesis and beyond! Tools for understanding legume biology.. Tadege M1, Wang TL, Wen J, Ratet P, Mysore KS. ... Tnt1 mutagenesis starts with a single parental line (Tnk88-7-7) that contains five Tnt1 copies that were initially introduced ...



*  Changes related to 'Richard Lab:Site Directed Mutagenesis' - OpenWetWare

Richard Lab:Site Directed Mutagenesis. No changes on linked pages during the given period. ...

*  Triethylenemelamine mutagenesis in flies: post #1

Yet I have no idea whether the detailed experimental procedures of the TEM mutagenesis are the same with those of EM... ... I am wondering if anybody did mutagenesis in Drosophila by using Triethylenemelamine (or Triethylmelamine, TEM)? If so, would ... Triethylenemelamine mutagenesis in flies - posted in Genetics and Genomics: Hello all, ... Triethylenemelamine mutagenesis in flies. Started by shiuanwang, Sep 01 2009 01:49 PM ...

*  PLOS Pathogens: Targeted mutagenesis in a human-parasitic nematode

We applied CRISPR-Cas9-mediated mutagenesis to parasitic worms in the genus Strongyloides and developed a method that overcomes ... Targeted mutagenesis in a human-parasitic nematode. Fig 3. Nicotine induces twitching in unc F1 iL3s.. (A) A nicotine assay for ... C) CRISPR-Cas9-mediated mutagenesis of Ss-unc-22 requires a highly specific sgRNA. Plasmid vectors for the expression of Cas9 ...

*  Sauer:Site-directed mutagenesis - OpenWetWare

Retrieved from "" ...

*  Historical outline of mutagenesis. | Base documentaire | BDSP

The different periods of the history of mutagenesis are reviewed originating at the beginning of the 20th century. We ... Historical outline of mutagenesis. R f. 121586 Article, Communication - En anglais Belgian Environmental Mutagen Society BEMS. ... However, mutagenesis should not only become an applied science, but should keep strong links with fundamental problems using a ... The different periods of the history of mutagenesis are reviewed originating at the beginning of the 20th century. ...

*  Targeted Mutagenesis in Mice: A Video Guide VHS/PAL | Sigma-Aldrich

Targeted Mutagenesis in Mice: A Video Guide VHS/PAL for your research needs. Find product specific information including CAS, ...®ion=US

*  Richard Lab:Site Directed Mutagenesis - OpenWetWare

Richard Lab:Site Directed Mutagenesis. From OpenWetWare. Revision as of 13:31, 26 June 2011 by Michael A. Speer. (talk , ... An efficient one-step site-directed and site-saturation mutagenesis protocol. Nucleic Acids Res. 2004; 32(14): e115. ... Retrieved from "" ...

*  Site-Directed Mutagenesis with In-Fusion HD Cloning System

In-Fusion HD can be used for site-directed mutagenesis, addition, deletion or substitution of up to 12 bases at a time. ... Site-Directed Mutagenesis: PCR Based Mutagenesis with the In-Fusion HD Cloning System. In-Fusion Cloning Kits enable PCR ... Mutagenesis *PCR cloning *HTP cloning *Gene design *Domain swapping *Domain modification. Choose the Right In-Fusion Cloning ... High efficiency of mutation: Perform in vitro site-directed mutagenesis with ≥ 90% efficiency *Versatility: The same system can ...

*  Query regarding primers for quick change mutagenesis -> Attachments -...

Attachments: Query regarding primers for quick change mutagenesis. Attachment. Size:. Post #. Agilent new primers (1).pdf. ( ...§ion=attach&tid=28887

*  Genes | Free Full-Text | Mechanisms of Base Substitution Mutagenesis in Cancer Genomes | HTML

Although gene expression data on APOBEC3B enzymes provide support for a role in cancer mutagenesis through U:G mismatch ... altered DNA proofreading activities are all now known to contribute to the mechanisms leading to base substitution mutagenesis ... Mutagenesis 2009, 24, 475-480. [Google Scholar] [CrossRef]. *Martinez, V.D.; Thu, K.L.; Vucic, E.A.; Hubaux, R.; Adonis, M.; ... Mutagenesis 2001, 16, 503-515. [Google Scholar] [CrossRef]. *Bacolla, A.; Wang, G.; Jain, A.; Chuzhanova, N.A.; Cer, R.Z.; ...

*  British Library EThOS: Investigation of tetraspanin structure and function by mutagenesis.

Membrane glycoproteins

*  CiNii 論文 - Mitochondrial mutagenesis in the brain in forensic and pathological research ...

Mitochondrial mutagenesis in the brain in forensic and pathological research * * VON WURMB-SCHWARK Nicole ... The rate of mitochondrial mutagenesis is faster in mice than in humans WANG E ...

Signature-tagged mutagenesis: Signature-tagged mutagenesis (STM) is a genetic technique used to study gene function. Recent advances in genome sequencing have allowed us to catalogue a large variety of organisms' genomes, but the function of the genes they contain is still largely unknown.Coles PhillipsProtein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.Silent mutation: Silent mutations are mutations in DNA that do not significantly alter the phenotype of the organism in which they occur. Silent mutations can occur in non-coding regions (outside of genes or within introns), or they may occur within exons.Symmetry element: A symmetry element is a point of reference about which symmetry operations can take place. In particular, symmetry elements can be centers of inversion, axes of rotation and mirror planes.DNA binding site: DNA binding sites are a type of binding site found in DNA where other molecules may bind. DNA binding sites are distinct from other binding sites in that (1) they are part of a DNA sequence (e.Reaction coordinateList of strains of Escherichia coli: Escherichia coli is a well studied bacterium that was first identified by Theodor Escherich, after whom it was later named.Ethyl groupComposite transposon: A composite transposon is similar in function to simple transposons and Insertion Sequence (IS) elements in that it has protein coding DNA segments flanked by inverted, repeated sequences that can be recognized by transposase enzymes. A composite transposon, however, is flanked by two separate IS elements which may or may not be exact replicas.Triparental mating: Triparental mating is a form of Bacterial conjugation where a conjugative plasmid present in one bacterial strain assists the transfer of a mobilizable plasmid present in a second bacterial strain into a third bacterial strain. Plasmids are introduced into bacteria for such purposes as transformation, cloning, or transposon mutagenesis.FERM domain: In molecular biology, the FERM domain (F for 4.1 protein, E for ezrin, R for radixin and M for moesin) is a widespread protein module involved in localising proteins to the plasma membrane.Ligation-independent cloning: Ligation-independent cloning (LIC) is a form of molecular cloning that is able to be performed without the use of restriction endonucleases or DNA ligase. This allows genes that have restriction sites to be cloned without worry of chopping up the insert.Ferric uptake regulator family: In molecular biology, the ferric uptake regulator (FUR) family of proteins includes metal ion uptake regulator proteins. These are responsible for controlling the intracellular concentration of iron in many bacteria.Burst kinetics: Burst kinetics is a form of enzyme kinetics that refers to an initial high velocity of enzymatic turnover when adding enzyme to substrate. This initial period of high velocity product formation is referred to as the "Burst Phase".Database of protein conformational diversity: The Database of protein conformational diversity (PCDB) is a database of diversity of protein tertiary structures within protein domains as determined by X-ray crystallography. Proteins are inherently flexible and this database collects information on this subject for use in molecular research.Proximity ligation assay: Proximity ligation assay (in situ PLA) is a technology that extends the capabilities of traditional immunoassays to include direct detection of proteins, protein interactions and modifications with high specificity and sensitivity. Protein targets can be readily detected and localized with single molecule resolution and objectively quantified in unmodified cells and tissues.Transmembrane domain: Transmembrane segment usually denotes a single transmembrane alpha helix of a transmembrane protein, also known as an integral protein.http://www.CS-BLASTPoint mutationMutagen: In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer, mutagens are therefore also likely to be carcinogens.Forward genetics: Forward genetics is the approach of determining the genetic basis responsible for a phenotype. This was initially done by generating mutants by using radiation, chemicals, or insertional mutagenesis (e.Specificity constant: In the field of biochemistry, the specificity constant (also called kinetic efficiency or k_{cat}/K_{M}), is a measure of how efficiently an enzyme converts substrates into products. A comparison of specificity constants can also be used as a measure of the preference of an enzyme for different substrates (i.Acid catalysis: In acid catalysis and base catalysis a chemical reaction is catalyzed by an acid or a base. The acid is the proton donor and the base is the proton acceptor.Adaptive mutation: Adaptive mutation is a controversial evolutionary theory. It posits that mutations, or genetic changes, are much less random and more purposeful than traditional evolution.HistidineEscherichia coli (molecular biology): Escherichia coli (; commonly abbreviated E. coli) is a gammaproteobacterium commonly found in the lower intestine of warm-blooded organisms (endotherms).Phase problem: In physics the phase problem is the name given to the problem of loss of information concerning the phase that can occur when making a physical measurement. The name itself comes from the field of x-ray crystallography, where the phase problem has to be solved for the determination of a structure from diffraction data.RNA transfection: RNA transfection is the process of deliberately introducing RNA into a living cell. RNA can be purified from cells after lysis or synthesized from free nucleotides either chemically, or enzymatically using an RNA polymerase to transcribe a DNA template.Ethyl methanesulfonateProtein engineering: Protein engineering is the process of developing useful or valuable proteins. It is a young discipline, with much research taking place into the understanding of protein folding and recognition for protein design principles.CpG OligodeoxynucleotideAcetyllysinePhenotype microarray: The phenotype microarray approach is a technology for high-throughput phenotyping of cells.DNA condensation: DNA condensation refers to the process of compacting DNA molecules in vitro or in vivo. Mechanistic details of DNA packing are essential for its functioning in the process of gene regulation in living systems.Short linear motifGC box: In molecular biology, a GC box is a distinct pattern of nucleotides found in the promoter region of some eukaryotic genes upstream of the TATA box and approximately 110 bases upstream from the transcription initiation site. It has a consensus sequence GGGCGG which is position dependent and orientation independent.UVB-induced apoptosis: UVB-induced apoptosis is the programmed cell death of cells that become damaged by ultraviolet rays. This is notable in skin cells, to prevent melanoma.Zuotin: Z-DNA binding protein 1, also known as Zuotin, is a Saccharomyces cerevisiae yeast gene.Eukaryotic transcription: Eukaryotic transcription is the elaborate process that eukaryotic cells use to copy genetic information stored in DNA into units of RNA replica. Gene transcription occurs in both eukaryotic and prokaryotic cells.AsparagineBaby hamster kidney cell: Baby Hamster Kidney fibroblasts (aka BHK cells) are an adherent cell line used in molecular biology.Multiple cloning site: A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (up to ~20) restriction sites - a standard feature of engineered plasmids. Restriction sites within an MCS are typically unique, occurring only once within a given plasmid.DNA-binding proteinRigerimod: Rigerimod (IPP-201101, Lupuzor) is a polypeptide corresponding to the sequence 131-151 of the 70k snRNP protein with a serine phosphorylated in position 140.http://www.Thermal cyclerBase excision repair: frame|right|Basic steps of base excision repair|Basic steps of base excision repairT7 DNA polymerase: T7 DNA polymerase is an enzyme used during the DNA replication of the T7 bacteriophage. During this process, the DNA polymerase “reads” existing DNA strands and creates two new strands that match the existing ones.Protein detoxification: Protein detoxification is the process by which proteins containing methylated arginine are broken down and removed from the body.X-ray magnetic circular dichroismPituitary-specific positive transcription factor 1: POU domain, class 1, transcription factor 1 (Pit1, growth hormone factor 1), also known as POU1F1, is a transcription factor for growth hormone.DNA sequencer: A DNA sequencer is a scientific instrument used to automate the DNA sequencing process. Given a sample of DNA, a DNA sequencer is used to determine the order of the four bases: G (guanine), C (cytosine), A (adenine) and T (thymine).Chemically induced dimerization: Chemically Induced Dimerization (CID) is a biological mechanism in which two proteins bind only in the presence of a certain small molecule, enzyme or other dimerizing agent. Genetically engineered CID systems are used in biological research to control protein localization, to manipulate signalling pathways and to induce protein activation.Ligand (biochemistry): In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. In protein-ligand binding, the ligand is usually a signal-triggering molecule binding to a site on a target protein.Tryptophan operon leaderDeletion (genetics)Codon Adaptation Index: The Codon Adaptation Index (CAI) is the most widespread technique for analyzing Codon usage bias. As opposed to other measures of codon usage bias, such as the 'effective number of codons' (Nc), which measure deviation from a uniform bias (null hypothesis), CAI measures the deviation of a given protein coding gene sequence with respect to a reference set of genes.Margaret Jope: Margaret Jope (1913–2004) was a Scottish biochemist, born as Henrietta Margaret Halliday in Peterhead, Scotland.Proteinogenic amino acid: Proteinogenic amino acids are amino acids that are precursors to proteins, and are incorporated into proteins cotranslationally — that is, during translation. There are 23 proteinogenic amino acids in prokaryotes (including N-Formylmethionine, mainly used to initiate protein synthesis and often removed afterward), but only 21 are encoded by the nuclear genes of eukaryotes.Operon: In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately, i.Alkaliphile: Alkaliphiles are a class of extremophilic microbes capable of survival in alkaline (pH roughly 8.5-11) environments, growing optimally around a pH of 10.Glycosylation: Glycosylation (see also chemical glycosylation) is the reaction in which a carbohydrate, i.e.Library (biology): In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated).Membrane protein: Membrane proteins are proteins that interact with biological membranes. They are one of the common types of protein along with soluble globular proteins, fibrous proteins, and disordered proteins.Recombination (cosmology): In cosmology, recombination refers to the epoch at which charged electrons and protons first became bound to form electrically neutral hydrogen atoms.Note that the term recombination is a misnomer, considering that it represents the first time that electrically neutral hydrogen formed.G2-M DNA damage checkpoint: The G2-M DNA damage checkpoint is an important cell cycle checkpoint in eukaryotic organisms ranging from yeast to mammals. This checkpoint ensures that cells don't initiate mitosis before they have a chance to repair damaged DNA after replication.Avery–MacLeod–McCarty experimentChromosome engineering: Chromosome engineering is "the controlled generation of chromosomal deletions, inversions, or translocations with defined endpoints." For: By combining chromosomal translocation, chromosomal inversion,and chromosomal deletion, chromosome engineering has been shown to identify the underlying genes that cause certain diseases in mice.Ice Ih: [showing details of an ice cube under magnification. Ice Ih is the form of ice commonly seen on Earth.

(1/14345) VEGF is required for growth and survival in neonatal mice.

We employed two independent approaches to inactivate the angiogenic protein VEGF in newborn mice: inducible, Cre-loxP- mediated gene targeting, or administration of mFlt(1-3)-IgG, a soluble VEGF receptor chimeric protein. Partial inhibition of VEGF achieved by inducible gene targeting resulted in increased mortality, stunted body growth and impaired organ development, most notably of the liver. Administration of mFlt(1-3)-IgG, which achieves a higher degree of VEGF inhibition, resulted in nearly complete growth arrest and lethality. Ultrastructural analysis documented alterations in endothelial and other cell types. Histological and biochemical changes consistent with liver and renal failure were observed. Endothelial cells isolated from the liver of mFlt(1-3)-IgG-treated neonates demonstrated an increased apoptotic index, indicating that VEGF is required not only for proliferation but also for survival of endothelial cells. However, such treatment resulted in less significant alterations as the animal matured, and the dependence on VEGF was eventually lost some time after the fourth postnatal week. Administration of mFlt(1-3)-IgG to juvenile mice failed to induce apoptosis in liver endothelial cells. Thus, VEGF is essential for growth and survival in early postnatal life. However, in the fully developed animal, VEGF is likely to be involved primarily in active angiogenesis processes such as corpus luteum development.  (+info)

(2/14345) Membrane-tethered Drosophila Armadillo cannot transduce Wingless signal on its own.

Drosophila Armadillo and its vertebrate homolog beta-catenin are key effectors of Wingless/Wnt signaling. In the current model, Wingless/Wnt signal stabilizes Armadillo/beta-catenin, which then accumulates in nuclei and binds TCF/LEF family proteins, forming bipartite transcription factors which activate transcription of Wingless/Wnt responsive genes. This model was recently challenged. Overexpression in Xenopus of membrane-tethered beta-catenin or its paralog plakoglobin activates Wnt signaling, suggesting that nuclear localization of Armadillo/beta-catenin is not essential for signaling. Tethered plakoglobin or beta-catenin might signal on their own or might act indirectly by elevating levels of endogenous beta-catenin. We tested these hypotheses in Drosophila by removing endogenous Armadillo. We generated a series of mutant Armadillo proteins with altered intracellular localizations, and expressed these in wild-type and armadillo mutant backgrounds. We found that membrane-tethered Armadillo cannot signal on its own; however it can function in adherens junctions. We also created mutant forms of Armadillo carrying heterologous nuclear localization or nuclear export signals. Although these signals alter the subcellular localization of Arm when overexpressed in Xenopus, in Drosophila they have little effect on localization and only subtle effects on signaling. This supports a model in which Armadillo's nuclear localization is key for signaling, but in which Armadillo intracellular localization is controlled by the availability and affinity of its binding partners.  (+info)

(3/14345) Bone resorption induced by parathyroid hormone is strikingly diminished in collagenase-resistant mutant mice.

Parathyroid hormone (PTH) stimulates bone resorption by acting directly on osteoblasts/stromal cells and then indirectly to increase differentiation and function of osteoclasts. PTH acting on osteoblasts/stromal cells increases collagenase gene transcription and synthesis. To assess the role of collagenase in the bone resorptive actions of PTH, we used mice homozygous (r/r) for a targeted mutation (r) in Col1a1 that are resistant to collagenase cleavage of type I collagen. Human PTH(1-34) was injected subcutaneously over the hemicalvariae in wild-type (+/+) or r/r mice four times daily for three days. Osteoclast numbers, the size of the bone marrow spaces and periosteal proliferation were increased in calvariae from PTH-treated +/+ mice, whereas in r/r mice, PTH-induced bone resorption responses were minimal. The r/r mice were not resistant to other skeletal effects of PTH because abundant interstitial collagenase mRNA was detected in the calvarial periosteum of PTH-treated, but not vehicle-treated, r/r and +/+ mice. Calcemic responses, 0.5-10 hours after intraperitoneal injection of PTH, were blunted in r/r mice versus +/+ mice. Thus, collagenase cleavage of type I collagen is necessary for PTH induction of osteoclastic bone resorption.  (+info)

(4/14345) DMPK dosage alterations result in atrioventricular conduction abnormalities in a mouse myotonic dystrophy model.

Myotonic dystrophy (DM) is the most common form of muscular dystrophy and is caused by expansion of a CTG trinucleotide repeat on human chromosome 19. Patients with DM develop atrioventricular conduction disturbances, the principal cardiac manifestation of this disease. The etiology of the pathophysiological changes observed in DM has yet to be resolved. Haploinsufficiency of myotonic dystrophy protein kinase (DMPK), DM locus-associated homeodomain protein (DMAHP) and/or titration of RNA-binding proteins by expanded CUG sequences have been hypothesized to underlie the multi-system defects observed in DM. Using an in vivo murine electrophysiology study, we show that cardiac conduction is exquisitely sensitive to DMPK gene dosage. DMPK-/- mice develop cardiac conduction defects which include first-, second-, and third-degree atrioventricular (A-V) block. Our results demonstrate that the A-V node and the His-Purkinje regions of the conduction system are specifically compromised by DMPK loss. Importantly, DMPK+/- mice develop first-degree heart block, a conduction defect strikingly similar to that observed in DM patients. These results demonstrate that DMPK dosage is a critical element modulating cardiac conduction integrity and conclusively link haploinsufficiency of DMPK with cardiac disease in myotonic dystrophy.  (+info)

(5/14345) Predicting insecticide resistance: mutagenesis, selection and response.

Strategies to manage resistance to a particular insecticide have usually been devised after resistance has evolved. If it were possible to predict likely resistance mechanisms to novel insecticides before they evolved in the field, it might be feasible to have programmes that manage susceptibility. With this approach in mind, single-gene variants of the Australian sheep blowfly, Lucilia cuprina, resistant to dieldrin, diazinon and malathion, were selected in the laboratory after mutagenesis of susceptible strains. The genetic and molecular bases of resistance in these variants were identical to those that had previously evolved in natural populations. Given this predictive capacity for known resistances, the approach was extended to anticipate possible mechanisms of resistance to cyromazine, an insecticide to which L. cuprina populations remain susceptible after almost 20 years of exposure. Analysis of the laboratory-generated resistant variants provides an explanation for this observation. The variants show low levels of resistance and a selective advantage over susceptibles for only a limited concentration range. These results are discussed in the context of the choice of insecticides for control purposes and of delivery strategies to minimize the evolution of resistance.  (+info)

(6/14345) Accelerated accumulation of somatic mutations in mice deficient in the nucleotide excision repair gene XPA.

Inheritable mutations in nucleotide excision repair (NER) genes cause cancer-prone human disorders, such as xeroderma pigmentosum, which are also characterized by symptoms of accelerated ageing. To study the impact of NER deficiency on mutation accumulation in vivo, mutant frequencies have been determined in liver and brain of 2-16 month old NER deficient XPA-/-, lacZ hybrid mice. While mutant frequencies in liver of 2-month old XPA-/-, lacZ mice were comparable to XPA+/-, lacZ and the lacZ parental strain animals, by 4 months of age mutant frequencies in the XPA-deficient mice were significantly increased by a factor of two and increased further until the age of 16 months. In brain, mutant frequencies were not found to increase with age. These results show that a deficiency in the NER gene XPA causes an accelerated accumulation of somatic mutations in liver but not in brain. This is in keeping with a higher incidence of spontaneous liver tumors reported earlier for XPA-/- mice after about 15 months of age.  (+info)

(7/14345) Inward rectification in KATP channels: a pH switch in the pore.

Inward-rectifier potassium channels (Kir channels) stabilize the resting membrane potential and set a threshold for excitation in many types of cell. This function arises from voltage-dependent rectification of these channels due to blockage by intracellular polyamines. In all Kir channels studied to date, the voltage-dependence of rectification is either strong or weak. Here we show that in cardiac as well as in cloned KATP channels (Kir6.2 + sulfonylurea receptor) polyamine-mediated rectification is not fixed but changes with intracellular pH in the physiological range: inward-rectification is prominent at basic pH, while at acidic pH rectification is very weak. The pH-dependence of polyamine block is specific for KATP as shown in experiments with other Kir channels. Systematic mutagenesis revealed a titratable C-terminal histidine residue (H216) in Kir6.2 to be the structural determinant, and electrostatic interaction between this residue and polyamines was shown to be the molecular mechanism underlying pH-dependent rectification. This pH-dependent block of KATP channels may represent a novel and direct link between excitation and intracellular pH.  (+info)

(8/14345) The Gab1 PH domain is required for localization of Gab1 at sites of cell-cell contact and epithelial morphogenesis downstream from the met receptor tyrosine kinase.

Stimulation of the hepatocyte growth factor (HGF) receptor tyrosine kinase, Met, induces mitogenesis, motility, invasion, and branching tubulogenesis of epithelial and endothelial cell lines in culture. We have previously shown that Gab1 is the major phosphorylated protein following stimulation of the Met receptor in epithelial cells that undergo a morphogenic program in response to HGF. Gab1 is a member of the family of IRS-1-like multisubstrate docking proteins and, like IRS-1, contains an amino-terminal pleckstrin homology domain, in addition to multiple tyrosine residues that are potential binding sites for proteins that contain SH2 or PTB domains. Following stimulation of epithelial cells with HGF, Gab1 associates with phosphatidylinositol 3-kinase and the tyrosine phosphatase SHP2. Met receptor mutants that are impaired in their association with Gab1 fail to induce branching tubulogenesis. Overexpression of Gab1 rescues the Met-dependent tubulogenic response in these cell lines. The ability of Gab1 to promote tubulogenesis is dependent on its pleckstrin homology domain. Whereas the wild-type Gab1 protein is localized to areas of cell-cell contact, a Gab1 protein lacking the pleckstrin homology domain is localized predominantly in the cytoplasm. Localization of Gab1 to areas of cell-cell contact is inhibited by LY294002, demonstrating that phosphatidylinositol 3-kinase activity is required. These data show that Gab1 is an important mediator of branching tubulogenesis downstream from the Met receptor and identify phosphatidylinositol 3-kinase and the Gab1 pleckstrin homology domain as crucial for subcellular localization of Gab1 and biological responses.  (+info)

Chemical Mutagenesis

  • This encyclopedia article consists of approximately 2 pages of information about Chemical Mutagenesis. (
  • These chemical-induced mutations are known as chemical mutagenesis. (
  • More summaries and resources for teaching or studying Chemical Mutagenesis . (


  • For these methods, primers can be designed in either an overlapping (QuikChange®, Agilent) or a back-to-back orientation ( Q5® Site-Directed Mutagenesis Kit ) (Figure 1). (
  • Before primers are designed, it is important to determine which mutagenesis workflow is to be used. (
  • As labtastic suggested, for "quickchange" (I call it after the probably most know commercial kit from Agilent, that contains everything needed AND the have online tool to design mutagenesis primers, probably the same thing primerX does) you just design primers that bind the sequence around, missing those 14bp that you want to delete. (
  • 1. Design mutagenesis primers. (


  • The use of a master mix, a unique multi-enzyme KLD enzyme mix, and a fast polymerase ensures that, for most plasmids, the mutagenesis reaction is complete in less than two hours. (
  • Site-directed mutagenesis by overlap extension using the polymerase chain reaction. (


  • Currently, there are a number of commercially available kits that also require specific modification and/or unique E. coli strains (for example, the Phusion Site-Directed Mutagenesis® from Thermo and the GeneArt® system from Life). (



  • Yet I have no idea whether the detailed experimental procedures of the TEM mutagenesis are the same with those of EMS mutagenesis. (


  • i need to perform single aa mutagenesis on a kinase however the lab doesn't have any starting point stock for me. (


  • Site-directed mutagenesis (SDM) is a method to create specific, targeted changes in double stranded plasmid DNA. (
  • Figure 2: Q5 Site-Directed Mutagenesis Kit Overview. (
  • 2004. An efficient one-step site-directed and site-saturation mutagenesis protocol. (
  • In-Fusion Cloning Kits enable PCR mediated site-directed DNA mutagenesis. (


  • After 1965, we emphasize on the origin and development of environmental mutagenesis leading to Genetic Toxicology its aims, and its special methodology. (


  • However, mutagenesis should not only become an applied science, but should keep strong links with fundamental problems using a refined more molecular methodology. (


  • Tnt1 mutagenesis starts with a single parental line (Tnk88-7-7) that contains five Tnt1 copies that were initially introduced into the R108 background by transformation. (


  • Click here here to submit your mutagenesis worksheets. (


  • Figure 1: Site-specific mutagenesis proceeds in less than 2 hours. (


  • C ) CRISPR-Cas9-mediated mutagenesis of Ss-unc-22 requires a highly specific sgRNA. (