DNA (deoxyribonucleic acid)
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  DNA (deoxyribonucleic acid)



DNA (deoxyribonucleic acid)

   Any of various acids that are found in cell nuclei and are the principal components of chromosomes; the molecular basis of heredity.

RELATED TERMS
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Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.

Nuclei
See nucleus.

Chromosomes
Filaments of genetic material in every cell nucleus that are made up of genes and that transmit genetic information from one generation of cells to the next.

Molecular
Refers to the basic building blocks of the genetic material, such as DNA, genes and the other chemicals involved with the functioning of genes.

Heredity
Transmission of genetic traits from parents to children.



SIMILAR TERMS
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DNA (Cytosine 5) Methyltransferase
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to the 5-position of cytosine or to the 6-position in adenine in mammalian DNA. EC 2.1.1.37.

DNA (Cytosine-5-)-Methyltransferase
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to the 5-position of cytosine or to the 6-position in adenine in mammalian DNA. EC 2.1.1.37.

DNA Adducts
Covalent adducts between chemical mutagens and DNA. Such couplings activate DNA repair processes and, unless repaired prior to DNA replication, may lead to nucleotide substitutions, deletions, and chromosome rearrangements. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

DNA Adenine Methylases
An enzyme responsible for producing a species-characteristic methylation pattern on adenine residues in a specific short base sequence in the host cell DNA. The enzyme catalyzes the methylation of DNA adenine in the presence of S-adenosyl-L-methionine to form DNA containing 6-methylaminopurine and S-adenosyl-L-homocysteine. EC 2.1.1.72.

DNA amplification
The production of multiple copies of a sequence of DNA. Repeated copying of a piece of DNA. DNA amplification plays a role in cancer cells. A tumor cell amplifies, or copies, DNA segments as a result of cell signals and sometimes environmental events. Amplification can occur in vivo (in the living individual) or in vitro (literally "in glass", or in a plastic vessel in the laboratory).

DNA Amplification Technic
Laboratory techniques that involve the in-vitro synthesis of many copies of DNA or RNA from one orginal template.

DNA Amplification Technics
Laboratory techniques that involve the in-vitro synthesis of many copies of DNA or RNA from one orginal template.

DNA Amplification Technique
Laboratory techniques that involve the in-vitro synthesis of many copies of DNA or RNA from one orginal template.

DNA Amplification Techniques
Laboratory techniques that involve the in-vitro synthesis of many copies of DNA or RNA from one orginal template.

DNA assembly
The process of putting fragments of DNA that have been sequenced into their correct chromosomal positions. The pieces of DNA are assembled to reconstitute the sequence of the chromosome from which they came.

DNA Binding Protein
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.

DNA Binding Protein, Cyclic AMP Responsive
A protein that has been shown to function as a calcium regulated transcription factor as well as a substrate for depolarization-activated calcium calmodulin-dependent protein kinases I and II. This protein functions to integrate both calcium and cAMP signals.

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.

DNA Chip
Hybridization of a nucleic acid sample to a very large set of oligonucleotide probes, which are attached to a solid support, to determine sequence or to detect variations in a gene sequence or expression or for gene mapping.

DNA Chips
Hybridization of a nucleic acid sample to a very large set of oligonucleotide probes, which are attached to a solid support, to determine sequence or to detect variations in a gene sequence or expression or for gene mapping.

DNA cloning
The use of DNA manipulation procedures to produce multiple copies of a single gene or segment of DNA.

DNA Cytosine 5 Methylase
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to the 5-position of cytosine or to the 6-position in adenine in mammalian DNA. EC 2.1.1.37.

DNA Cytosine-5-Methylase
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to the 5-position of cytosine or to the 6-position in adenine in mammalian DNA. EC 2.1.1.37.

DNA Damage
Drug- or radiation-induced injuries in DNA that introduce deviations from its normal double-helical conformation. These changes include structural distortions which interfere with replication and transcription, as well as point mutations which disrupt base pairs and exert damaging effects on future generations through changes in DNA sequence. If the damage is minor, it can often be repaired (DNA REPAIR). If the damage is extensive, it can induce apoptosis.

DNA Damages
Drug- or radiation-induced injuries in DNA that introduce deviations from its normal double-helical conformation. These changes include structural distortions which interfere with replication and transcription, as well as point mutations which disrupt base pairs and exert damaging effects on future generations through changes in DNA sequence. If the damage is minor, it can often be repaired (DNA REPAIR). If the damage is extensive, it can induce apoptosis.

DNA Data Bank
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Data Bank of Japan
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Data Banks
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Databank
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Databanks
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Database
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Databases
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Dependent DNA Polymerases
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. EC 2.7.7.7.

DNA Dependent RNA Polymerase I
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin. EC 2.7.7.6.

DNA Dependent RNA Polymerase II
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.

DNA Dependent RNA Polymerase III
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure where it transcribes DNA into RNA. It has specific requirements for cations and salt and has shown an intermediate sensitivity to alpha-amanitin in comparison to RNA polymerase I and II. EC 2.7.7.6.

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. EC 2.7.7.7.

DNA Fingerprint
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Fingerprinting
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Fingerprintings
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Fingerprints
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Footprint
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)

DNA Footprinting
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)

DNA Footprintings
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)

DNA Footprints
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)

DNA forensics
The application of DNA technology and the knowledge of DNA genetics to the practice of forensic medicine and to the power of legal medicine. Crime scene investigation has been markedly changed -- some would say revolutionized -- by the advent of DNA forensics. This has led to the invention of devices for DNA forensics. One is a plate of glass about the size of a hand is etched with very thin channels and reservoirs. A minute sample of DNA is moved between reservoir and channel through timed electric pulses. These thin channels then act like capillary tubes and can resolve the constituents of this minute sample of DNA. At the crime scene, the forensic technician can perform the PCR reactions for DNA fingerprinting and immediately resolve the samples on the glass plate. What normally would take more than a day, once the sample is taken to the laboratory, now takes only a few hours at the crime scene.

DNA Fragmentation
Endonucleolytic cleavage of genomic DNA into oligonucleosomal fragments at internucleosomal sites. DNA fragmentation along with chromatin condensation are considered the hallmarks of APOPTOSIS.

DNA Fragmentation, Internucleosomal
Endonucleolytic cleavage of genomic DNA into oligonucleosomal fragments at internucleosomal sites. DNA fragmentation along with chromatin condensation are considered the hallmarks of APOPTOSIS.

DNA Gene Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA 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 DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.

DNA Gyrase
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting two A and two B subunits. In the presence of ATP, gyrase is able to convert relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.

DNA Gyrase A Subunit
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting two A and two B subunits. In the presence of ATP, gyrase is able to convert relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.

DNA Gyrase B Subunit
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting two A and two B subunits. In the presence of ATP, gyrase is able to convert relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.

DNA Helicases
Proteins that promote 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. EC 5.99.-.

DNA Helix Destabilizing 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.

DNA Hybridization Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA 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 DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.

DNA Injuries
Drug- or radiation-induced injuries in DNA that introduce deviations from its normal double-helical conformation. These changes include structural distortions which interfere with replication and transcription, as well as point mutations which disrupt base pairs and exert damaging effects on future generations through changes in DNA sequence. If the damage is minor, it can often be repaired (DNA REPAIR). If the damage is extensive, it can induce apoptosis.

DNA Injury
Drug- or radiation-induced injuries in DNA that introduce deviations from its normal double-helical conformation. These changes include structural distortions which interfere with replication and transcription, as well as point mutations which disrupt base pairs and exert damaging effects on future generations through changes in DNA sequence. If the damage is minor, it can often be repaired (DNA REPAIR). If the damage is extensive, it can induce apoptosis.

DNA Insertion Element
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.

DNA Insertion 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.

DNA Joinases
Poly(deoxyribonucleotide):poly(deoxyribonucleotide)ligases. Enzymes that catalyze the joining of preformed deoxyribonucleotides in phosphodiester linkage during genetic processes during repair of a single-stranded break in duplex DNA. The class includes both EC 6.5.1.1 (ATP) and EC 6.5.1.2 (NAD).

DNA Libraries
A large collection of cloned DNA fragments 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.

DNA Library
A large collection of cloned DNA fragments 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.

DNA Ligase, T4
Poly(deoxyribonucleotide):poly(deoxyribonucleotide)ligases. Enzymes that catalyze the joining of preformed deoxyribonucleotides in phosphodiester linkage during genetic processes during repair of a single-stranded break in duplex DNA. The class includes both EC 6.5.1.1 (ATP) and EC 6.5.1.2 (NAD).

DNA Ligases
Poly(deoxyribonucleotide):poly(deoxyribonucleotide)ligases. Enzymes that catalyze the joining of preformed deoxyribonucleotides in phosphodiester linkage during genetic processes during repair of a single-stranded break in duplex DNA. The class includes both EC 6.5.1.1 (ATP) and EC 6.5.1.2 (NAD).

DNA Marker
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.

DNA Markers
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.

DNA Maxicircles, Kinetoplast
DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.

DNA methylation
A biochemical process involving the addition of chemical tags called methyl groups (-CH3) to DNA. Methylation can be a signal for a gene or a section of a chromosome to turn off gene expression and become inactive or "silent".

DNA Methylation
Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.

DNA Methylations
Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.

DNA Microarrays
Hybridization of a nucleic acid sample to a very large set of oligonucleotide probes, which are attached to a solid support, to determine sequence or to detect variations in a gene sequence or expression or for gene mapping.

DNA Microchip
Hybridization of a nucleic acid sample to a very large set of oligonucleotide probes, which are attached to a solid support, to determine sequence or to detect variations in a gene sequence or expression or for gene mapping.

DNA Microchips
Hybridization of a nucleic acid sample to a very large set of oligonucleotide probes, which are attached to a solid support, to determine sequence or to detect variations in a gene sequence or expression or for gene mapping.

DNA Mimicries
The process in which structural properties of an introduced molecule imitate or simulate molecules of the host. Direct mimicry of a molecule enables a viral protein to bind directly to a normal substrate as a substitute for the homologous normal ligand. Immunologic molecular mimicry generally refers to what can be described as antigenic mimicry and is defined by the properties of antibodies raised against various facets of epitopes on the viral protein. (From Immunology Letters 1991 May;28(2):91-9)

DNA Mimicry
The process in which structural properties of an introduced molecule imitate or simulate molecules of the host. Direct mimicry of a molecule enables a viral protein to bind directly to a normal substrate as a substitute for the homologous normal ligand. Immunologic molecular mimicry generally refers to what can be described as antigenic mimicry and is defined by the properties of antibodies raised against various facets of epitopes on the viral protein. (From Immunology Letters 1991 May;28(2):91-9)

DNA Minicircles, Kinetoplast
DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.

DNA Modification Methylases (Adenine-Specific)
An enzyme responsible for producing a species-characteristic methylation pattern on adenine residues in a specific short base sequence in the host cell DNA. The enzyme catalyzes the methylation of DNA adenine in the presence of S-adenosyl-L-methionine to form DNA containing 6-methylaminopurine and S-adenosyl-L-homocysteine. EC 2.1.1.72.

DNA Modification Methylases Adenine Specific
An enzyme responsible for producing a species-characteristic methylation pattern on adenine residues in a specific short base sequence in the host cell DNA. The enzyme catalyzes the methylation of DNA adenine in the presence of S-adenosyl-L-methionine to form DNA containing 6-methylaminopurine and S-adenosyl-L-homocysteine. EC 2.1.1.72.

DNA molecules, recombinant
A combination of DNA molecules of different origin that are joined using recombinant DNA technology.

DNA Mutational Analyses
Biochemical identification of mutational changes in a nucleotide sequence.

DNA Mutational Analysis
Biochemical identification of mutational changes in a nucleotide sequence.

DNA Nicking-Closing Protein
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Nicking-Closing Proteins
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Nucleases
Enzymes which catalyze the hydrolases of ester bonds within DNA. EC 3.1.-.

DNA Nucleotidylexotransferase
A non-template-directed DNA polymerase normally found in vertebrate thymus and bone marrow. It catalyzes the elongation of oligo- or polydeoxynucleotide chains and is widely used as a tool in the differential diagnosis of acute leukemias in man. EC 2.7.7.31.

DNA Nucleotidyltransferases
Enzymes that catalyze the incorporation of deoxyribonucleotides into a chain of DNA. EC 2.7.7.-.

DNA Photolyase
An enzyme that catalyzes the reactivation by light of UV-irradiated DNA. It breaks two carbon-carbon bonds in pyrimidine dimers in DNA. EC 4.1.99.3.

DNA Photoreactivating Enzyme
An enzyme that catalyzes the reactivation by light of UV-irradiated DNA. It breaks two carbon-carbon bonds in pyrimidine dimers in DNA. EC 4.1.99.3.

DNA polymerase
Enzyme that catalyzes (speeds) the polymerization of DNA. DNA polymerase uses preexisting nucleic acid templates and assembles the DNA from deoxyribonucleotides.

DNA Polymerase beta
A DNA repair enzyme that catalyzes DNA synthesis during base excision DNA repair. EC 2.7.7.7.

DNA Polymerase IV
A DNA repair enzyme that catalyzes DNA synthesis during base excision DNA repair. EC 2.7.7.7.

DNA Polymerase N3
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. EC 2.7.7.7.

DNA Polymerase, DNA-Directed
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. EC 2.7.7.7.

DNA Polymerase, RNA Directed
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.

DNA Polymerase, RNA-Dependent
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.

DNA Polymerase, RNA-Directed
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.

DNA Polymerase, Taq
A heat stable DNA-DIRECTED DNA POLYMERASE from the bacteria Thermus aquaticus. It is widely used for the amplification of genes through the process of POLYMERASE CHAIN REACTION. EC 2.7.7.-.

DNA Polymerases
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. EC 2.7.7.7.

DNA Polymerases, DNA-Dependent
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. EC 2.7.7.7.

DNA Primase
A single-stranded DNA-dependent RNA polymerase that functions to initiate, or prime, DNA synthesis by synthesizing oligoribonucleotide primers. EC 2.7.7.-.

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.

DNA Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA 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 DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.

DNA Probes, Histocompatibility Antigen
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-A
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-B
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-C
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-D
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-DR
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HLA-Dw
DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as A, B, C, and D. Specific antigens are identified by a locus notation and number, e.g., HLA-A11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus).

DNA Probes, HPV
DNA probes specific for the identification of human papilloma virus.

DNA Profiling
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Profilings
A procedure in which multilocus band patterns of a DNA sample are generated by digestion of the DNA with restriction enzymes followed by electrophoresis and visualization by hybridization with probes specific for repetitive sequences. In forensic medicine the probes used are ""core"" sequences specific for simple tandem-repetitive sequences (MINISATELLITE REPEATS or VNTRs). The multilocus band patterns, known as DNA fingerprints, are evaluated for similarities with DNA from an individual.

DNA Proteins, Recombinant
Proteins prepared by recombinant DNA technology.

DNA Rearrangement
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.

DNA Rearrangements
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.

DNA Recombinant Proteins
Proteins prepared by recombinant DNA technology.

DNA Relaxing Enzyme
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Relaxing Enzymes
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Relaxing Protein
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA repair
The body has a series of special enzymes to repair mutations (changes) in the DNA and restore the DNA to its original state. The DNA in genes is constantly mutating and being repaired. This repair process is controlled by special genes. A mutation in a DNA repair gene can cripple the repair process and cause a cascade of unrepaired mutations in the genome that lead to cancer.

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 Repair Enzymes
Poly(deoxyribonucleotide):poly(deoxyribonucleotide)ligases. Enzymes that catalyze the joining of preformed deoxyribonucleotides in phosphodiester linkage during genetic processes during repair of a single-stranded break in duplex DNA. The class includes both EC 6.5.1.1 (ATP) and EC 6.5.1.2 (NAD).

DNA repair gene
A gene engaged in DNA repair. When a DNA repair gene is impaired, mutations pile up throughout the DNA. The DNA in genes is constantly mutating and being repaired. This repair process is controlled by special genes. A mutation in a DNA repair gene can cripple the repair process and cause a cascade of unrepaired mutations in the genome that lead to cancer.

DNA repair gene, Med1
A gene that codes for one of the key enzymes involved in repairing DNA. The DNA in genes is constantly mutating and being repaired. This repair process is controlled by special genes. A mutation in a DNA repair gene such as Med1 can cripple the repair process and cause a cascade of unrepaired mutations in the genome that lead to cancer.

DNA Repair Methyltransferase I
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moities of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.

DNA Repair Methyltransferase II
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moities of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.

DNA repair pathway
The sequence of steps in the repair of DNA. Each step is governed by an enzyme.

DNA Repairs
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 Repetitious Region
Nucleotide sequences present in multiple copies in the genome. There are several types of repeated sequences. Interspersed (or dispersed) DNA repeats (INTERSPERSED REPETITIVE SEQUENCES) are copies of transposable elements interspersed throughout the genome. Flanking (or terminal) repeats (TERMINAL REPEAT SEQUENCES) are sequences that are repeated on both ends of a sequence, for example, the long terminal repeats (LTRs) on retroviruses. Direct terminal repeats are in the same direction and inverted terminal repeats are opposite to each other in direction. Tandem repeats (TANDEM REPEAT SEQUENCES) are repeated copies which lie adjacent to each other. These can also be direct or inverted. The ribosomal RNA and transfer RNA genes belong to the class of middle repetitive DNA.

DNA Repetitious Regions
Nucleotide sequences present in multiple copies in the genome. There are several types of repeated sequences. Interspersed (or dispersed) DNA repeats (INTERSPERSED REPETITIVE SEQUENCES) are copies of transposable elements interspersed throughout the genome. Flanking (or terminal) repeats (TERMINAL REPEAT SEQUENCES) are sequences that are repeated on both ends of a sequence, for example, the long terminal repeats (LTRs) on retroviruses. Direct terminal repeats are in the same direction and inverted terminal repeats are opposite to each other in direction. Tandem repeats (TANDEM REPEAT SEQUENCES) are repeated copies which lie adjacent to each other. These can also be direct or inverted. The ribosomal RNA and transfer RNA genes belong to the class of middle repetitive DNA.

DNA replication
A wondrous complex process whereby the ("parent") strands of DNA in the double helix are separated and each one is copied to produce a new ("daughter") strand. This process is said to be "semi-conservative" since one of each parent strand is conserved and remains intact after replication has taken place.

DNA Replication
The process by which a DNA molecule is duplicated.

DNA Replications
The process by which a DNA molecule is duplicated.

DNA Research, 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.

DNA Restriction Enzyme BamHI
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence G/GATCC at the slash. BamHI is from Bacillus amyloliquefaciens N. Numerous isoschizomers have been identified. EC 3.1.21.-.

DNA Restriction Enzyme EcoRI
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence G/AATTC at the slash. EcoRI is from E coliRY13. Several isoschizomers have been identified. EC 3.1.21.-.

DNA Restriction Enzyme HindIII
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence A/AGCTT at the slash. HindIII is from Haemophilus influenzae R(d). Numerous isoschizomers have been identified. EC 3.1.21.-.

DNA Restriction Enzyme HpaII
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequences C/CGG and GGC/C at the slash. HpaII is from Haemophilus parainfluenzae. Several isoschizomers have been identified. EC 3.1.21.-.

DNA Restriction Modification Enzymes
Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. They are closely related in their specificity and protect the DNA of a given bacterial species. The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. The methylation renders the target site resistant to restriction, thereby protecting DNA against cleavage.

DNA Restriction-Modification Enzymes
Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. They are closely related in their specificity and protect the DNA of a given bacterial species. The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. The methylation renders the target site resistant to restriction, thereby protecting DNA against cleavage.

DNA sequence
The precise ordering of the bases (A,T,G,C) from which the DNA is composed. DNA sequencing involves determining the exact order of the base pairs in a segment of DNA.

DNA Sequence
The sequence of purines and pyrimidines in nucleic acids and polynucleotides. It is also called nucleotide or nucleoside sequence.

DNA Sequence Analyses
A multistage process that includes DNA cloning, physical mapping, subcloning, sequencing, and information analysis.

DNA Sequence Analysis
A multistage process that includes DNA cloning, physical mapping, subcloning, sequencing, and information analysis.

DNA Sequence Database
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Sequence Databases
DATABASES containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS (POLYMORPHISM, SINGLE NUCLEOTIDE); NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.

DNA Sequence Determination
A multistage process that includes DNA cloning, physical mapping, subcloning, sequencing, and information analysis.

DNA Sequence Determinations
A multistage process that includes DNA cloning, physical mapping, subcloning, sequencing, and information analysis.

DNA sequence, draft
Sequence of a DNA with less accuracy than a finished sequence. In a draft sequence, some segments are missing or are in the wrong order or are oriented incorrectly. A draft sequence is as opposed to a finished DNA sequence.

DNA sequence, finished
A DNA sequence in which the bases are identified to an accuracy of no more than 1 error in 10,000 and are placed in the right order and orientation along a chromosome with almost no gaps. A finished sequence is as opposed to a draft DNA sequence.

DNA Sequence, Unstable
DNA region comprised of a variable number of repetitive, contiguous trinucleotide sequences. The presence of these regions is associated with diseases such as Fragile X Syndrome and MYOTONIC DYSTROPHY. Many chromosome fragile sites (CHROMOSOME FRAGILITY) contain expanded trinucleotide repeats.

DNA Sequences
The sequence of purines and pyrimidines in nucleic acids and polynucleotides. It is also called nucleotide or nucleoside sequence.

DNA Sequences, Unstable
DNA region comprised of a variable number of repetitive, contiguous trinucleotide sequences. The presence of these regions is associated with diseases such as Fragile X Syndrome and MYOTONIC DYSTROPHY. Many chromosome fragile sites (CHROMOSOME FRAGILITY) contain expanded trinucleotide repeats.

DNA Single Stranded Binding Protein
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.

DNA Single-Stranded Binding Protein
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.

DNA Synthesis Factor
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.

DNA Synthesis Inhibitors
Compounds that inhibit cell production of DNA or RNA.

DNA technology, recombinant
A series of procedures used to join together (recombine) DNA segments. A recombinant DNA molecule is constructed (recombined) from segments from 2 or more different DNA molecules. Under certain conditions, a recombinant DNA molecule can enter a cell and replicate there, autonomously (on its own) or after it has become integrated into a chromosome.

DNA Therapy
The introduction of new genes into cells for the purpose of treating disease by restoring or adding gene expression. Techniques include insertion of retroviral vectors, transfection, homologous recombination, and injection of new genes into the nuclei of single cell embryos. The entire gene therapy process may consist of multiple steps. The new genes may be introduced into proliferating cells in vivo (e.g., bone marrow) or in vitro (e.g., fibroblast cultures) and the modified cells transferred to the site where the gene expression is required. Gene therapy may be particularly useful for treating enzyme deficiency diseases, hemoglobinopathies, and leukemias and may also prove useful in restoring drug sensitivity, particularly for leukemia.

DNA Topoisomerase
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Topoisomerase (ATP-Hydrolysing)
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerase 1, Archaeal
Archaeal enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These archaeal enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerase I
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Topoisomerase I, Bacterial
Bacterial enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These bacterial enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerase I, Eukaryotic
Eukaryotic enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These eukaryotic enzymes reduce the topological stress in the DNA structure by relaxing both negatively and positively supercoiled DNA.

DNA Topoisomerase II
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerase II, Bacterial
Bacterial enzymes of the DNA TOPOISOMERASES TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA duplex. Bacterial DNA topoisomerases in the Type II class exist as heterotetramers of 2 subunits, such as 2 gyrA and 2 gyrB in DNA GYRASE.

DNA Topoisomerase IV
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Topoisomerase IV binds to DNA as a heterotetramer consisting 2 parC and 2 parE subunits. Topoisomerase IV is a decatenating enzyme that resolves interlinked daughter chromosomes following DNA replication.

DNA Topoisomerases
Enzymes that regulate the topology of DNA by actions such as breaking, relaxing, passing, and rejoining strands of DNA in cells. These enzymes are important components of the DNA replication system. They are classified by their substrate specificities. DNA TOPOISOMERASE, TYPE I enzymes act on a single strand of DNA. DNA TOPOISOMERASE, TYPE II enzymes act on double strands of DNA.

DNA Topoisomerases II, Eukaryotic
Eukaryotic enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex. Isozymes of the eukaryotic DNA topoisomerase II consist of homodimers of alpha or beta subunits.

DNA Topoisomerases, Type I
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Topoisomerases, Type I, Archaeal
Archaeal enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These archaeal enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerases, Type I, Bacterial
Bacterial enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These bacterial enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerases, Type I, Eukaryotic
Eukaryotic enzymes of the DNA TOPOISOMERASES TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These eukaryotic enzymes reduce the topological stress in the DNA structure by relaxing both negatively and positively supercoiled DNA.

DNA Topoisomerases, Type II
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerases, Type II, Archaeal
Archaeal enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerases, Type II, Bacterial
Bacterial enzymes of the DNA TOPOISOMERASES TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA duplex. Bacterial DNA topoisomerases in the Type II class exist as heterotetramers of 2 subunits, such as 2 gyrA and 2 gyrB in DNA GYRASE.

DNA Topoisomerases, Type II, Eukaryotic
Eukaryotic enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex. Isozymes of the eukaryotic DNA topoisomerase II consist of homodimers of alpha or beta subunits.

DNA Transposable Element
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.

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.

DNA Transposon
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.

DNA Transposons
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.

DNA Tumor Virus
DNA viruses producing malignant tumors. Of the six major groupings of DNA viruses four contain members which are actually or potentially oncogenic: the Adenoviridae, the Herpesviridae, the Papovaviridae, and the Poxviridae.

DNA Tumor Viruses
DNA viruses producing malignant tumors. Of the six major groupings of DNA viruses four contain members which are actually or potentially oncogenic: the Adenoviridae, the Herpesviridae, the Papovaviridae, and the Poxviridae.

DNA Type 1 Topoisomerase
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Type 2 Topoisomerase
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Untwisting Enzyme
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Untwisting Enzymes
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Untwisting Protein
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Untwisting Proteins
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Unwinding Proteins
Proteins that promote 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. EC 5.99.-.

DNA Vaccines
Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.

DNA Vaccines, Naked
Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.

DNA Vaccines, Recombinant
Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.

DNA virus
A virus in which the genetic material is DNA rather than RNA. The DNA may be either double- or single-stranded. Major groups of double-stranded DNA viruses (class I viruses) include the adenoviruses, the herpes viruses, and the poxviruses. Major groups of single-stranded DNA viruses (class II viruses) include the parvoviruses and coliphages.

DNA Virus
Viruses whose nucleic acid is DNA.

DNA Viruses
Viruses whose nucleic acid is DNA.



PREVIOUS AND NEXT TERMS
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D.C.
Doctor of Chiropractic.

D.D.
Doctor of Divinity.

D.H.M.
Doctor of Homeopathic Medicine.

Divination (divining)
Alleged supernatural (a) foreseeing of events or (b) attainment of occult knowledge.

D.N.
1. Doctor of Naprapathy (see below). 2. Doctor of Nutripathy. 3. Doctor of Naturology.

DNA (deoxyribonucleic acid)

D.O.
Doctor of Osteopathy.

Doctor
1. One whose occupation is to treat diseases, particularly a physician, dentist, or veterinarian with an appropriate license. 2. A teacher (particularly at a college or university), a scholar, or one who holds a postgraduate degree (especially a Ph.D. degree). 3. A shaman.

D.Pharm.
Doctor of Pharmacy.

Dawn Phenomenon
A sudden rise in blood glucose levels in the early morning hours. This condition sometimes occurs in people with insulin-dependent diabetes and (rarely) in people with noninsulin-dependent diabetes. Unlike the Somogyi effect, it is not a result of an insulin reaction. People who have high levels of blood glucose in the mornings before eating may need to monitor their blood glucose during the night. If blood glucose levels are rising, adjustments in evening snacks or insulin dosages may be recommended.

Delta Cell
A type of cell in the pancreas in areas called the islets of Langerhans. Delta cells make somatostatin, a hormone that is believed to control how the beta cells make and release insulin and how the alpha cells make and release glucagon.

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   dna(deoxyribonucleicacid) / na (deoxyribonucleic acid) / da (deoxyribonucleic acid) / dn (deoxyribonucleic acid) / dna(deoxyribonucleic acid) / dna deoxyribonucleic acid) / dna (eoxyribonucleic acid) / dna (doxyribonucleic acid) / dna (dexyribonucleic acid) / dna (deoyribonucleic acid) / dna (deoxribonucleic acid) / dna (deoxyibonucleic acid) / dna (deoxyrbonucleic acid) / dna (deoxyrionucleic acid) / dna (deoxyribnucleic acid) / dna (deoxyriboucleic acid) / dna (deoxyriboncleic acid) / dna (deoxyribonuleic acid) / dna (deoxyribonuceic acid) / dna (deoxyribonuclic acid) / dna (deoxyribonuclec acid) / dna (deoxyribonuclei acid) / dna (deoxyribonucleicacid) / dna (deoxyribonucleic cid) / dna (deoxyribonucleic aid) / dna (deoxyribonucleic acd) / dna (deoxyribonucleic aci) / dna (deoxyribonucleic acid / ddna (deoxyribonucleic acid) / dnna (deoxyribonucleic acid) / dnaa (deoxyribonucleic acid) / dna (deoxyribonucleic acid) / dna ((deoxyribonucleic acid) / dna (ddeoxyribonucleic acid) / dna (deeoxyribonucleic acid) / dna (deooxyribonucleic acid) / dna (deoxxyribonucleic acid) / dna (deoxyyribonucleic acid) / dna (deoxyrribonucleic acid) / dna (deoxyriibonucleic acid) / dna (deoxyribbonucleic acid) / dna (deoxyriboonucleic acid) / dna (deoxyribonnucleic acid) / dna (deoxyribonuucleic acid) / dna (deoxyribonuccleic acid) / dna (deoxyribonuclleic acid) / dna (deoxyribonucleeic acid) / dna (deoxyribonucleiic acid) / dna (deoxyribonucleicc acid) / dna (deoxyribonucleic acid) / dna (deoxyribonucleic aacid) / dna (deoxyribonucleic accid) / dna (deoxyribonucleic aciid) / dna (deoxyribonucleic acidd) / dna (deoxyribonucleic acid)) / ena (deoxyribonucleic acid) / rna (deoxyribonucleic acid) / fna (deoxyribonucleic acid) / vna (deoxyribonucleic acid) / cna (deoxyribonucleic acid) / xna (deoxyribonucleic acid) / sna (deoxyribonucleic acid) / wna (deoxyribonucleic acid) / dba (deoxyribonucleic acid) / dha (deoxyribonucleic acid) / dja (deoxyribonucleic acid) / dma (deoxyribonucleic acid) / d a (deoxyribonucleic acid) / dnq (deoxyribonucleic acid) / dnw (deoxyribonucleic acid) / dns (deoxyribonucleic acid) / dnx (deoxyribonucleic acid) / dnz (deoxyribonucleic acid) / dna (eeoxyribonucleic acid) / dna (reoxyribonucleic acid) / dna (feoxyribonucleic acid) / dna (veoxyribonucleic acid) / dna (ceoxyribonucleic acid) / dna (xeoxyribonucleic acid) / dna (seoxyribonucleic acid) / dna (weoxyribonucleic acid) / dna (d3oxyribonucleic acid) / dna (d4oxyribonucleic acid) / dna (droxyribonucleic acid) / dna (dfoxyribonucleic acid) / dna (ddoxyribonucleic acid) / dna (dsoxyribonucleic acid) / dna (dwoxyribonucleic acid) / dna (de9xyribonucleic acid) / dna (de0xyribonucleic acid) / dna (depxyribonucleic acid) / dna (delxyribonucleic acid) / dna (dekxyribonucleic acid) / dna (deixyribonucleic acid) / dna (de8xyribonucleic acid) / dna (deozyribonucleic acid) / dna (deoayribonucleic acid) / dna (deosyribonucleic acid) / dna (deodyribonucleic acid) / dna (deocyribonucleic acid) / dna (deo yribonucleic acid) / dna (deox6ribonucleic acid) / dna (deox7ribonucleic acid) / dna (deoxuribonucleic acid) / dna (deoxjribonucleic acid) / dna (deoxhribonucleic acid) / dna (deoxgribonucleic acid) / dna (deoxtribonucleic acid) / dna (deox5ribonucleic acid) / dna (deoxy4ibonucleic acid) / dna (deoxy5ibonucleic acid) / dna (deoxytibonucleic acid) / dna (deoxygibonucleic acid) / dna (deoxyfibonucleic acid) / dna (deoxydibonucleic acid) / dna (deoxyeibonucleic acid) / dna (deoxy3ibonucleic acid) / dna (deoxyrbonucleic acid) / dna (deoxyrivonucleic acid) / dna (deoxyrifonucleic acid) / dna (deoxyrigonucleic acid) / dna (deoxyrihonucleic acid) / dna (deoxyrinonucleic acid) / dna (deoxyri onucleic acid) / dna (deoxyrib9nucleic acid) / dna (deoxyrib0nucleic acid) / dna (deoxyribpnucleic acid) / dna (deoxyriblnucleic acid) / dna (deoxyribknucleic acid) / dna (deoxyribinucleic acid) / dna (deoxyrib8nucleic acid) / dna (deoxyribobucleic acid) / dna (deoxyribohucleic acid) / dna (deoxyribojucleic acid) / dna (deoxyribomucleic acid) / dna (deoxyribo ucleic acid) / dna (deoxyribon7cleic acid) / dna (deoxyribon8cleic acid) / dna (deoxyribonicleic acid) / dna (deoxyribonkcleic acid) / dna (deoxyribonjcleic acid) / dna (deoxyribonhcleic acid) / dna (deoxyribonycleic acid) / dna (deoxyribon6cleic acid) / dna (deoxyribonuxleic acid) / dna (deoxyribonusleic acid) / dna (deoxyribonudleic acid) / dna (deoxyribonufleic acid) / dna (deoxyribonuvleic acid) / dna (deoxyribonu leic acid) / dna (deoxyribonucoeic acid) / dna (deoxyribonucpeic acid) / dna (deoxyribonuc;eic acid) / dna (deoxyribonuc.eic acid) / dna (deoxyribonuc,eic acid) / dna (deoxyribonuckeic acid) / dna (deoxyribonucieic acid) / dna (deoxyribonucl3ic acid) / dna (deoxyribonucl4ic acid) / dna (deoxyribonuclric acid) / dna (deoxyribonuclfic acid) / dna (deoxyribonucldic acid) / dna (deoxyribonuclsic acid) / dna (deoxyribonuclwic acid) / dna (deoxyribonuclec acid) / dna (deoxyribonucleix acid) / dna (deoxyribonucleis acid) / dna (deoxyribonucleid acid) / dna (deoxyribonucleif acid) / dna (deoxyribonucleiv acid) / dna (deoxyribonuclei acid) / dna (deoxyribonucleic qcid) / dna (deoxyribonucleic wcid) / dna (deoxyribonucleic scid) / dna (deoxyribonucleic xcid) / dna (deoxyribonucleic zcid) / dna (deoxyribonucleic axid) / dna (deoxyribonucleic asid) / dna (deoxyribonucleic adid) / dna (deoxyribonucleic afid) / dna (deoxyribonucleic avid) / dna (deoxyribonucleic a id) / dna (deoxyribonucleic acd) / dna (deoxyribonucleic acie) / dna (deoxyribonucleic acir) / dna (deoxyribonucleic acif) / dna (deoxyribonucleic aciv) / dna (deoxyribonucleic acic) / dna (deoxyribonucleic acix) / dna (deoxyribonucleic acis) / dna (deoxyribonucleic aciw) /