BIO - TERMS - DNA Flashcards
A-DNA A right-handed DNA double helix that has 11 base pairs per turn
DNA exists in this form when partially dehydrated.
Acridine dyes
A class of positively charged polycyclic molecules that intercalate into DNA and induce frameshift mutations.
Actinomycin D
An inhibitor of transcription that binds to double-stranded DNA.
Adenine (A)
A purine base found in RNA and DNA.
Agrobacterium tumefaciens-mediated transformation
A naturally occurring process of DNA transfer from the bacterium A. tumefaciens to plants.
AIM2 (absent in melanoma 2)
A member of PYHIN subfamily of NLR (NOD-like receptor) family containing an N-terminal HIN domain. It activates caspase 1 in response to viral double-stranded DNA.
Amplification (recombinant DNA molecules)
The production of many copies of a newly constructed recombinant DNA molecule.
antisense DNA
DNA that is complementary to the DNA encoding a protein; the antisense RNA transcript will hybridize with the mRNA encoding the protein and inhibit synthesis of the protein.
AP endonuclease
An endonuclease that cleaves a phosphodiester bond formed by a baseless (“apurinic”) nucleotide in DNA.
apurinic/apyrimidinic endonuclease 1 (APE1)
A DNA repair endonuclease involved in class switch recombination.
ATM (ataxia telangiectasia mutated protein)
Protein kinase activated by double-strand DNA breaks. If breaks are not repaired, ATM initiates a signal cascade that culminates in cell cycle arrest. Related to ATR.
ATR (ataxia telangiectasia and Rad3 related protein)
Protein kinase activated by DNA damage. If damage remains unrepaired, ATR helps initiate a signal cascade that culminates in cell cycle arrest. Related to ATM.
Autoradiograph
A record or photograph prepared by labeling a substance such as DNA with a radioactive material such as tritiated thymidine and allowing the image produced by radioactive decay to develop on a film over a period of time.
B-DNA
Double-stranded DNA that exists as a right-handed helix with 10.4 base pairs per turn; the conformation of DNA when present in aqueous solutions containing low salt concentrations.
baculovirus
Any of a group of double-stranded DNA viruses that infect invertebrates, particularly insects, and are widely used for purposes of protein expression in biotechnology.
base-excision repair
Type of DNA repair that can lead to mutation and that is involved in somatic hypermutation and class switching in B cells.
branch migration
Movement of the branch point in a branched DNA formed from two DNA molecules with identical sequences. See also Holliday intermediate.
Bromouracil
An analog of thymine that causes mutations after being incorporated into DNA.
Cas9
The CRISPR associated endonuclease from Streptococcus pyogenes that is guided to a specific DNA sequence by an RNA complementary to that sequence.
Cdc6
Protein essential in the preparation of DNA for replication. With Cdt1 it binds to an origin recognition complex on chromosomal DNA and helps load the Mcm proteins onto the complex to form the prereplicative complex.
Cdt1
Protein essential in the preparation of DNA for replication. With Cdc6 it binds to origin recognition complexes on chromosomes and helps load the Mcm proteins on to the complex, forming the prereplicative complex.
cell memory
Retention by cells and their descendants of persistently altered patterns of gene expression, without any change in DNA sequence. See also epigenetic inheritance.
CG island
Region of DNA in vertebrate genomes with a greater than average density of CG sequences; these regions generally remain unmethylated.
Chimeric selectable marker gene
A gene constructed using DNA sequences from two or more sources that allows a cell or organism to survive under conditions where it would otherwise die.
Chromatin fiber
A basic organizational unit of eukaryotic chromosomes that consists of DNA and associated proteins assembled into a strand of average diameter 30 nm.
Chromatin remodeling
The alteration of the structure of DNA and its associated protein molecules, especially histones, by a protein complex; this remodeling often involves the chemical modification of the histones.
Chromosome jumping
A procedure that uses large DNA fragments to move discontinuously along a chromosome from one site to another site. (See also Positional cloning.)
Chromosome painting
The study of the organization and evolution of chromosomes by in situ hybridization using DNA probes labeled with fluorescent dyes that emit light at different wavelengths.
cis-regulatory sequences
DNA sequences to which transcription regulators bind to control the rate of gene transcription. In nearly all cases, these sequences must be on the same chromosome (that is, in cis) to the genes they control.
clamp loader
Protein complex that utilizes ATP hydrolysis to load the sliding clamp on to a primer–template junction in the process of DNA replication.
cloning
The production of large numbers of identical DNA molecules, cells, or organisms from a single ancestral DNA molecule, cell, or organism.
Cloning (gene)
The production of many copies of a gene or specific DNA sequence.
Cloning vector
A small, self-replicating DNA molecule—usually a plasmid or viral chromosome—into which foreign DNAs are inserted in the process of cloning genes or other DNA sequences of interest.
Coactivator
A protein that stimulates transcription by RNA polymerase II without binding to a specific DNA sequence; generally interacts with sequence-specific transcriptional activators. (Chapter 8)
coding joint
DNA join formed by the imprecise joining of a V gene segment to a (D)J gene segment during recombination of the immunoglobulin or T-cell receptor genes. It is the joint retained in the rearranged gene. Cf. signal joint.
colony hybridization
The identification of a colony containing a desired gene by using a DNA probe that is complementary to that gene.
Comparative genomic hybridization
A method for the detection of copy number variations (deletions, duplications) in DNA.
Complementarity
The relationship between the two strands of a double helix of DNA. Thymine in one strand pairs with adenine in the other strand, and cytosine in one strand pairs with guanine in the other strand.
Composite transposon
A transposable element formed when two identical or nearly identical transposons insert on either side of a nontransposable segment of DNA—for example, the bacterial transposon Tn5.
Concatemer
A DNA molecule comprising multiple, tandem copies of a viral genome (or other DNA sequence) joined end to end. (Chapter 9)
conservative site-specifc recombination
A type of DNA recombination that takes place between short, specific sequences of DNA and occurs without the gain or loss of nucleotides. It does not require extensive homology between the recombining DNA molecules.
Continuous replication
The synthesis of a nascent strand of DNA by the sequential addition of nucleotides to the 3′-OH terminus of the strand. Characteristic of the synthesis of the leading strand—the strand being extended in the overall 5′ 3′ direction.
Copy choice
A mechanism of recombination in which an RNA or DNA polymerase first copies the 3’ end of one parental strand and then exchanges one template for another at the corresponding position on a second parental strand. (Chapters 6 and 7)
copy number variations (CNVs)
A difference between two individuals in the same population in the number of copies of a particular block of DNA sequence. This variation arises from occasional duplications and deletions of these sequences.
Core promoter
The minimal set of DNA sequences required for accurate initiation of transcription by RNA polymerase II. (Chapter 8)
Covariance
A measure of the statistical association between variables. cpDNA. The DNA of plant plastids, including chloroplasts.
Cre recombinase
An integrase from a bacteriophage, used for highly selective splicing reactions in recombinant DNA technology.
cruciform
Secondary structure in doublestranded RNA or DNA in which the double helix is denatured at palindromic repeat sequences in each strand, and each separated strand is paired internally to form opposing hairpin structures. See also hairpin.
cryptochrome
Plant flavoprotein sensitive to blue light. Structurally related to blue-light-sensitive enzymes called photolyases (involved in the repair of ultraviolet-induced DNA damage) but do not have a role in DNA repair. Also found in animals, where they have an important role in circadian clocks.
cyclic AMP response element binding protein (CREB)
A protein that binds to specific regions of DNA (cyclic AMP response elements) and functions to regulate gene transcription; a key regulator of protein synthesis–dependent memory consolidation.
Cytosine (C)
A pyrimidine base found in RNA and DNA.
DDX41 (DEAD box polypeptide 41)
A candidate DNA sensor of the RLR family that appears to signal through the STING pathway.
detergent
Small amphiphilic molecule, more soluble in water than lipids, that disrupts hydrophobic associations and destroys the lipid bilayer thereby solubilizing membrane proteins. D gene segment A short DNA sequence that encodes a part of the variable region of an immunoglobulin heavy chain or the β chain of a T cell receptor (TCR).
Dicot
A plant with two cotyledons, or seed leaves. 2′,3′-Dideoxyribonucleoside triphosphates (ddNTPs). Chainterminating DNA precursors (nucleoside triphosphates) with a hydrogen (H) linked to the 3′ carbon in place of the hydroxyl (OH) group in normal DNA precursors (2′-deoxyribonucleotide triphosphates); ddNTPs are used in DNA sequencing reactions.
dideoxy sequencing
The standard enzymatic method of DNA sequencing.
Dideoxyribonucleotides
Nucleotide analogs that are used for chain termination in DNA sequencing.
Discontinuous replication
The synthesis of a nascent strand of DNA by the formation of short segments of DNA (Okazaki fragments) that are subsequently joined by DNA ligase. Characteristic of the synthesis of the lagging strand—the strand being extended in the overall 3′ → 5′ direction.
diversity gene segment (DH)
Short DNA sequences that form a join between the V and J gene segments in rearranged immunoglobulin heavy-chain genes and in T-cell receptor β- and δ-chain genes. See gene segments.
DNA chimera
DNA containing genetic information derived from two different species.
DNA looping
The interaction of proteins bound at distant sites on a DNA molecule so that the intervening DNA forms a loop.
DNA probe
A short, labeled, single strand of DNA or RNA used to locate its complementary strand in a quantity of DNA.
DNA profile (DNA print)
A recorded pattern of DNA polymorphisms.
DNA profiling (DNA fingerprinting)
The use of DNA sequence data—especially highly polymorphic short tandem repeats (STRs) and variable number tandem repeats (VNTRs)—in personal identity cases.
DNA repair
A set of processes for repairing the many accidental lesions that occur continually in DNA.
DNA replication
Process by which a copy of a DNA molecule is made.
DNA transposons
Genetic elements encoding their own transposase that can insert themselves into and excise themselves from the DNA genomes of a host.
DNA tumor virus
General term for a variety of different DNA viruses that can cause tumors.
DNA-dependent protein kinase (DNA-PK)
Protein kinase in the DNA repair pathway involved in the rearrangement of immunoglobulin and T-cell receptor genes.
DNA-only transposon
Transposable element that exists as DNA throughout its life cycle. Many move by cut-and-paste transposition. See also transposon.
Dot blotting
A rapid screening method for mutations and DNA polymorphisms.
double-strand break repair (DSBR)
A nonhomologous end joining pathway of DNA repair used in the completion of isotype switching. double-stranded RNA (dsRNA) A chemical structure that is a replicative intermediate of many viruses that is recognized by TLR-3.
Downstream sequence
A sequence in a unit of transcription that follows (is located 3′ to) the transcription start site. The nucleotide pair in DNA corresponding to the nucleotide at the 5′ end of the transcript (RNA) is designated +1. The following nucleotide pair is designated +2. All of the following (+) nucleotide sequences are downstream sequences (cf. Upstream sequence).
epigenetic inheritance
Inheritance of phenotypic changes in a cell or organism that do not result from changes in the nucleotide sequence of DNA. Can be due to positive feedback loops of transcription regulators or to heritable modifications in chromatin such as DNA methylation or histone modifications.
error-prone ‘translesion’ DNA polymerases
A DNA polymerase operates during DNA repair, such as Polη which can repair a basic lesion by incorporating untemplated nucleotides into the newly formed DNA strand.
Eukaryotic cells
The cells of organisms classified as eukaryotes. These cells are characterized by having a membrane-bound nucleus that contains the chromosomal DNA.
Excinuclease
The endonuclease-containing protein complex that excises a segment of damaged DNA during excision repair.
Excision repair
DNA repair processes that involve the removal of the damaged segment of DNA and its replacement by the synthesis of a new strand using the complementary strand of DNA as template.
Extrachromosomal
Structures that are not part of the chromosomes; DNA units in the cytoplasm that control cytoplasmic inheritance.
extrachromosomal DNA
DNA not contained within chromosomes, such as the circular DNA produced by V(D)J recombination occurring between RSSs in the same chromosomal orientation and is eventually lost from the cell.
Folded genome
The condensed intracellular state of the DNA in the nucleoid of a bacterium. The DNA is segregated into domains, and each domain is independently negatively supercoiled.
footprinting
A technique for identifying the nucleic acid sequence bound by a DNA- or RNA-binding protein.
G-quadruplex
A structure formed from G-rich regions of DNA in which four guanine bases form a planar hydrogen-bonded network, or guanine tetrad, that can further stack on other guanine tetrads. G-quadruplexes processed from intronic switch region RNA may target AID back to the switch regions during isotype switching.
G2/M transition
Point in the eukaryotic cell cycle at which the cell checks for completion of DNA replication before triggering the early mitotic events that lead to chromosome alignment on the spindle.
Gap phases (G 1 and G 2)
Phases in the cell cycle between the mitosis (M) and DNA synthesis (S) phases. (Chapter 6)
gel electrophoresis
The separation of substances (such as serum proteins or DNA) by their rate of movement through an electrical field.
GenBank
The DNA sequence databank maintained by the National Center for Biotechnology Information at the National Institutes of Health in the United States. Similar databanks are maintained in Europe (the European Molecular Biology Laboratory Data Library) and Japan (the DNA DataBank of Japan).
Gene amplification
A phenomenon whereby the DNA of a specific gene or set of genes is replicated independently of the rest of the genome to increase the number of gene copies.
Gene cloning
The incorporation of a gene of interest into a selfreplicating DNA molecule and the amplification of the resulting recombinant DNA molecule in an appropriate host cell.
gene control region
The set of linked DNA sequences regulating expression of a particular gene. Includes promoter and cis-regulatory sequences required to initiate transcription of the gene and control the rate of transcription.
genetic recombination
The process of joining pieces of DNA from different sources.
Genomic DNA library
A collection of clones containing the genomic DNA sequences of an organism.
genotoxin
A chemical that damages DNA or RNA.
Guanine (G)
A purine base found in DNA and RNA.
hairpin
Secondary structure in single-stranded RNA or DNA, in which complementary parts of a palindromic repeat fold back and are paired to form an antiparallel duplex helix that is closed at one end.
haplotype block
Combination of alleles and DNA markers that has been inherited in a large, linked block on one chromosome of a homologous pair—undisturbed by genetic recombination—across many generations.
Helix
Any structure with a spiral shape. The Watson and Crick model of DNA is in the form of a double helix.