Thymine Nucleotides: Phosphate esters of THYMIDINE in N-glycosidic linkage with ribose or deoxyribose, as occurs in nucleic acids. (From Dorland, 28th ed, p1154)Megaloblasts: Red blood cell precursors, corresponding to ERYTHROBLASTS, that are larger than normal, usually resulting from a FOLIC ACID DEFICIENCY or VITAMIN B 12 DEFICIENCY.ThymineAnemia, Megaloblastic: A disorder characterized by the presence of ANEMIA, abnormally large red blood cells (megalocytes or macrocytes), and MEGALOBLASTS.Guanine NucleotidesGuanine Nucleotide Exchange Factors: Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.Nucleotides: The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Leukemia, Lymphoid: Leukemia associated with HYPERPLASIA of the lymphoid tissues and increased numbers of circulating malignant LYMPHOCYTES and lymphoblasts.GuanineBase Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.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.Guanosine Triphosphate: Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.Methotrexate: An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.Base Pairing: Pairing of purine and pyrimidine bases by HYDROGEN BONDING in double-stranded DNA or RNA.Rho Guanine Nucleotide Exchange Factors: Signaling proteins which function as master molecular switches by activating Rho GTPases through conversion of guanine nucleotides. Rho GTPases in turn control many aspects of cell behavior through the regulation of multiple downstream signal transduction pathways.Guanosine Diphosphate: A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.Adenine Nucleotidesras Guanine Nucleotide Exchange Factors: A family of GUANINE NUCLEOTIDE EXCHANGE FACTORS that are specific for RAS PROTEINS.Purine Nucleotides: Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.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.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).GTP-Binding Proteins: Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.Pyrimidine Nucleotides: Pyrimidines with a RIBOSE and phosphate attached that can polymerize to form DNA and RNA.Kinetics: The rate dynamics in chemical or physical systems.Thymine DNA Glycosylase: An enzyme that removes THYMINE and URACIL bases mispaired with GUANINE through hydrolysis of their N-glycosidic bond. These mispaired nucleotides generally occur through the hydrolytic DEAMINATION of 5-METHYLCYTOSINE to thymine.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.Guanylyl Imidodiphosphate: A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES.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.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.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 Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Guanosine 5'-O-(3-Thiotriphosphate): Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Nucleotides, CyclicGuanine Nucleotide Dissociation Inhibitors: Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.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.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)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.GTP Phosphohydrolases: Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.Thionucleotides: Nucleotides in which the base moiety is substituted with one or more sulfur atoms.Purines: A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.Proto-Oncogene Proteins c-vav: Proto-oncogene proteins that are guanine nucleotide exchange factors for RHO GTPASES. They also function as signal transducing adaptor proteins.Uridine Triphosphate: Uridine 5'-(tetrahydrogen triphosphate). A uracil nucleotide containing three phosphate groups esterified to the sugar moiety.Uracilras-GRF1: A guanine nucleotide exchange factor that is expressed primarily in neuronal tissue and may be specific for the Ha-ras homolog of the RAS PROTEINS.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.cdc42 GTP-Binding Protein: A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.ADP-Ribosylation Factors: MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.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.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Adenylate Cyclase: An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.Adenosine Diphosphate: Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.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.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.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.rac1 GTP-Binding Protein: A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.Adenine: A purine base and a fundamental unit of ADENINE NUCLEOTIDES.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Guanosine Monophosphate: A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature.Magnesium: A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.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.rho GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.IMP Dehydrogenase: An enzyme that catalyzes the dehydrogenation of inosine 5'-phosphate to xanthosine 5'-phosphate in the presence of NAD. EC 1.1.1.205.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Nucleosides: Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Receptors, Purinergic P2: A class of cell surface receptors for PURINES that prefer ATP or ADP over ADENOSINE. P2 purinergic receptors are widespread in the periphery and in the central and peripheral nervous system.ral Guanine Nucleotide Exchange Factor: A guanine nucleotide exchange factor that stimulates the dissociation of GDP from RAL GTP-BINDING PROTEINS. It also has GDP exchange activity towards other MONOMERIC GTP-BINDING PROTEINS.Adenosine Monophosphate: Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.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.Ribonucleotides: Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)Pyrimidine Dimers: Dimers found in DNA chains damaged by ULTRAVIOLET RAYS. They consist of two adjacent PYRIMIDINE NUCLEOTIDES, usually THYMINE nucleotides, in which the pyrimidine residues are covalently joined by a cyclobutane ring. These dimers block DNA REPLICATION.rhoA GTP-Binding Protein: A RHO GTP-BINDING PROTEIN involved in regulating signal transduction pathways that control assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.rac GTP-Binding Proteins: A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.GTPase-Activating Proteins: Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.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.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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.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.Cytosine: A pyrimidine base that is a fundamental unit of nucleic acids.Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Guanine Nucleotide-Releasing Factor 2: A 145-kDa guanine nucleotide exchange factor that is specific for rap1 and ras GTP-BINDING PROTEINS. It associates with SH3 domains of the crk family of signaling proteins.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.Virulence Factors, Bordetella: A set of BACTERIAL ADHESINS and TOXINS, BIOLOGICAL produced by BORDETELLA organisms that determine the pathogenesis of BORDETELLA INFECTIONS, such as WHOOPING COUGH. They include filamentous hemagglutinin; FIMBRIAE PROTEINS; pertactin; PERTUSSIS TOXIN; ADENYLATE CYCLASE TOXIN; dermonecrotic toxin; tracheal cytotoxin; Bordetella LIPOPOLYSACCHARIDES; and tracheal colonization factor.Pertussis Toxin: One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.Deoxyribonuclease (Pyrimidine Dimer): An enzyme which catalyzes an endonucleolytic cleavage near PYRIMIDINE DIMERS to produce a 5'-phosphate product. The enzyme acts on the damaged DNA strand, from the 5' side of the damaged site.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Base Pair Mismatch: The presence of an uncomplimentary base in double-stranded DNA caused by spontaneous deamination of cytosine or adenine, mismatching during homologous recombination, or errors in DNA replication. Multiple, sequential base pair mismatches lead to formation of heteroduplex DNA; (NUCLEIC ACID HETERODUPLEXES).Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Deoxyadenine Nucleotides: Adenine nucleotides which contain deoxyribose as the sugar moiety.Cyclic AMP: An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.Guanine Deaminase: An enzyme that catalyzes the deamination of guanine to form xanthine. EC 3.5.4.3.ADP-Ribosylation Factor 1: ADP-RIBOSYLATION FACTOR 1 is involved in regulating intracellular transport by modulating the interaction of coat proteins with organelle membranes in the early secretory pathway. It is a component of COAT PROTEIN COMPLEX I. This enzyme was formerly listed as EC 3.6.1.47.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.rap1 GTP-Binding Proteins: A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Schiff Bases: Condensation products of aromatic amines and aldehydes forming azomethines substituted on the N atom, containing the general formula R-N:CHR. (From Grant & Hackh's Chemical Dictionary, 5th ed)rho-Specific Guanine Nucleotide Dissociation Inhibitors: A subcategory of guanine nucleotide dissociation inhibitors that are specific for RHO GTP-BINDING PROTEINS.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.RNA, Ribosomal: The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)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).Guanosine: A purine nucleoside that has guanine linked by its N9 nitrogen to the C1 carbon of ribose. It is a component of ribonucleic acid and its nucleotides play important roles in metabolism. (From Dorland, 28th ed)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.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Uridine Diphosphate: A uracil nucleotide containing a pyrophosphate group esterified to C5 of the sugar moiety.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Deoxyguanine Nucleotides: Guanine nucleotides which contain deoxyribose as the sugar moiety.SOS1 Protein: A mammalian homolog of the DROSOPHILA SON OF SEVENLESS PROTEIN. It is a guanine nucleotide exchange factor for RAS PROTEINS.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Apyrase: A calcium-activated enzyme that catalyzes the hydrolysis of ATP to yield AMP and orthophosphate. It can also act on ADP and other nucleoside triphosphates and diphosphates. EC 3.6.1.5.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.Bromouracil: 5-Bromo-2,4(1H,3H)-pyrimidinedione. Brominated derivative of uracil that acts as an antimetabolite, substituting for thymine in DNA. It is used mainly as an experimental mutagen, but its deoxyriboside (BROMODEOXYURIDINE) is used to treat neoplasms.DNA Replication: The process by which a DNA molecule is duplicated.Pentoxyl: 5-Hydroxymethyl-6-methyl- 2,4-(1H,3H)-pyrimidinedione. Uracil derivative used in combination with toxic antibiotics to lessen their toxicity; also to stimulate leukopoiesis and immunity. Synonyms: pentoksil; hydroxymethylmethyluracil.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.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.Ribosome Subunits: The two dissimilar sized ribonucleoprotein complexes that comprise a RIBOSOME - the large ribosomal subunit and the small ribosomal subunit. The eukaryotic 80S ribosome is composed of a 60S large subunit and a 40S small subunit. The bacterial 70S ribosome is composed of a 50S large subunit and a 30S small subunit.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.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Nucleotidases: A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.Adenosine Diphosphate Ribose: An ester formed between the aldehydic carbon of RIBOSE and the terminal phosphate of ADENOSINE DIPHOSPHATE. It is produced by the hydrolysis of nicotinamide-adenine dinucleotide (NAD) by a variety of enzymes, some of which transfer an ADP-ribosyl group to target proteins.rap GTP-Binding Proteins: A family of MONOMERIC GTP-BINDING PROTEINS that are related to RAS PROTEINS.This enzyme was formerly listed as EC 3.6.1.47.Molecular Weight: The sum of the weight of all the atoms in a molecule.Genes, Bacterial: The functional hereditary units of BACTERIA.Receptors, Purinergic P2Y2: A subclass of purinergic P2Y receptors that have a preference for ATP and UTP. The activated P2Y2 receptor acts through a G-PROTEIN-coupled PHOSPHATIDYLINOSITOL and intracellular CALCIUM SIGNALING pathway.Cytidine: A pyrimidine nucleoside that is composed of the base CYTOSINE linked to the five-carbon sugar D-RIBOSE.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.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Templates, Genetic: Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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).Bacterial Proteins: Proteins found in any species of bacterium.Oligoribonucleotides: A group of ribonucleotides (up to 12) in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.Proto-Oncogene Proteins p21(ras): Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.Eukaryotic Initiation Factor-2B: A guanine nucleotide exchange factor that acts to restore EUKARYOTIC INITIATION FACTOR-2 to its GTP bound form.Adenylate Cyclase Toxin: One of the virulence factors produced by virulent BORDETELLA organisms. It is a bifunctional protein with both ADENYLYL CYCLASES and hemolysin components.Receptors, Purinergic: Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.Osmium Tetroxide: (T-4)-Osmium oxide (OsO4). A highly toxic and volatile oxide of osmium used in industry as an oxidizing agent. It is also used as a histological fixative and stain and as a synovectomy agent in arthritic joints. Its vapor can cause eye, skin, and lung damage.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.ras Proteins: Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.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.Sodium Fluoride: A source of inorganic fluoride which is used topically to prevent dental caries.RNA, Transfer: The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.Endodeoxyribonucleases: A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.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.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.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.rab GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.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)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.ral GTP-Binding Proteins: A family of ubiquitously expressed MONOMERIC GTP-BINDING PROTEINS that are involved in intracellular signal transduction. This enzyme was formerly listed as EC 3.6.1.47.Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)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.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.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.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.rho Guanine Nucleotide Dissociation Inhibitor alpha: An abundantly-expressed rho GDP-dissociation inhibitor subtype that regulates a broad variety of RHO GTPASES.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.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.Cholera Toxin: An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.Genetic Variation: Genotypic differences observed among individuals in a population.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).NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.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.DNA Glycosylases: A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.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).)Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.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.N-Glycosyl Hydrolases: A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.Adenosine: A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.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).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.Cytosine NucleotidesThymidineSon of Sevenless Proteins: A class of RAS GUANINE NUCLEOTIDE EXCHANGE FACTORS that are genetically related to the Son of Sevenless gene from DROSOPHILA. Sevenless refers to genetic mutations in DROSOPHILA that cause loss of the R7 photoreceptor which is required to see UV light.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.Monomeric GTP-Binding Proteins: A class of monomeric, low molecular weight (20-25 kDa) GTP-binding proteins that regulate a variety of intracellular processes. The GTP bound form of the protein is active and limited by its inherent GTPase activity, which is controlled by an array of GTPase activators, GDP dissociation inhibitors, and guanine nucleotide exchange factors. This enzyme was formerly listed as EC 3.6.1.47Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.DNA Adducts: The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.Phosphoric Diester Hydrolases: A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.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.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.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.Fungal Proteins: Proteins found in any species of fungus.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.5'-Nucleotidase: A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.Genes, Viral: The functional hereditary units of VIRUSES.Transducin: A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.Fluorides: Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.
This process is used to determine the order of nucleotide bases. Each molecule of DNA is made from adenine, guanine, cytosine ... Sequencing methods have evolved from relatively laborious gel-based procedures to modern automated protocols based on dye ... guanine, cytosine, and thymine, in a DNA oligonucleotide. By generating a DNA sequence for a particular organism, you are ... DNA sequencing encompasses biochemical methods for determining the order of the nucleotide bases, adenine, ...
There are four bases in a DNA molecule: adenine (A), cytosine (C), thymine (T), and guanine (G). Nucleotide is a structural ... DNA is composed of base pairs in which adenine pairs with thymine and guanine pairs with cytosine. While DNA serves as template ... RNA uses a similar set of bases except that thymine is replaced with U = uracil. A group of enzymes called RNA polymerases ( ... It's made of a base, a molecule of sugar and a molecule of phosphoric acid. The double helix structure of DNA is composed of ...
... cytosine and thymine or uracil). These nucleotide bases make up DNA and RNA. These nucleotide base codes make the genome of an ... The nucleotide bases are made up of purines (adenine and guanine) and pyrimidines ( ... IUPAC also has a system for giving codes to identify amino acids and nucleotide bases. IUPAC needed a coding system that ... retrieved 15 April 2010 Amino Acid and Nucleotide Base Codes Archived 12 July 2009 at the Wayback Machine. retrieved 15 April ...
... the bases guanine and cytosine were found in equal abundance, and the bases adenine and thymine were found in equal abundance. ... the complementary nucleotides on each strand have equal amounts of a given base and its complement. In other words, in each DNA ... there is an equal frequency of the four DNA bases (Adenine, Guanine, Thymine, and Cytosine) on both single strands of a DNA ... This unique nucleotide composition is thought to be due to selection pressure of adenine over thymine in the coding region. ...
... but that for particular pairs of nucleotides - adenine and thymine, guanine and cytosine - the two nucleotides are always ... Work by Crick and coworkers showed that the genetic code was based on non-overlapping triplets of bases, called codons, and Har ... He called each of these units a nucleotide and suggested the DNA molecule consisted of a string of nucleotide units linked ... Investigations such as this enabled a more precise characterization of the base pairing and base stacking interactions which ...
The genetic code is made up of sequences of four nucleotide bases: Adenine, Guanine, Cytosine and Thymine, commonly referred to ... Genome size is usually measured in base pairs (or bases in single-stranded DNA or RNA). The C-value is another measure of ... Many promoters contain CpG islands, areas of the genome where a cytosine nucleotide occurs next to a guanine nucleotide at a ... Amino acids are made up of three base long codons and both Glycine and Alanine are characterized by codons with Guanine- ...
Because there are only four nucleotides commonly found in DNA (Adenine (A), Cytosine (C), Guanine (G) and Thymine (T)), ... PAM matrices are labelled based on how many nucleotide changes have occurred, per 100 amino acids. While the PAM matrices ... For example, a simple matrix will assign identical bases a score of +1 and non-identical bases a score of −1. A more ... A later refinement was to determine amino acid similarities based on how many base changes were required to change a codon to ...
cytochrome . cytosine One of the four main nucleotide bases found in DNA and RNA, along with adenine, guanine, thymine, and ... Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language. transfer RNA . translation ... deoxyribonucleic acid The four bases found in DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T); these ... anticodon A unit made up of three nucleotides that correspond to the three bases of the codon on the mRNA. arachnology The ...
Each nucleotide has a pentose sugar, a phosphate group, and nitrogenous bases like adenine, guanine, cytosine, and thymine. RNA ... Based on these findings, Baldwin sought a biochemical recapitulation in the development of vertebrates with reference to ... Merriam-Webster defines chemotaxonomy as the method of biological classification based on similarities in the structure of ... DNA always has two chains forming a double helix, and each chain is made up of nucleotides. ...
The hydrogen bond between Asp2 and the N4 of either a cytosine or adenine base paired to the guanine or thymine, respectively ... and bind to an extended target-site of four or even five nucleotides When this occurs in a ZFP in which the three-nucleotide ... and the bases of its associated subsite, influence the binding of residues on the adjacent finger which contains the randomised ... 1 and aspartic acid at position 2 along its alpha-helix will recognise an extended sequence of four nucleotides of the sequence ...
... guanine (G) and thymine (T). These four bases are attached to the sugar-phosphate to form the complete nucleotide, as shown for ... Here, four guanine bases form a flat plate and these flat four-base units then stack on top of each other, to form a stable G- ... Adenine pairs with thymine and guanine pairs with cytosine, forming A-T and G-C base pairs.[18][19] ... guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one ...
They consulted Jerry Donohue who confirmed the most likely structures of the nucleotide bases. The base pairs are held together ... the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England ... The DNA double helix structure proposed by Watson and Crick was based upon "Watson-Crick" bonds between the four bases most ... Crick did tentatively attempt to perform some experiments on nucleotide base pairing, but he was more of a theoretical ...
Nucleotides consist of 3 components: Nitrogenous base Adenine Guanine Cytosine Thymine (present in DNA only) Uracil (present in ... The nitrogen bases adenine and guanine are purine in structure and form a glycosidic bond between their 9 nitrogen and the 1' - ... A purine base always pairs with a pyrimidine base (guanine (G) pairs with cytosine (C) and adenine (A) pairs with thymine (T) ... The nucleotides on one strand base pairs with the nucleotide on the other strand. The secondary structure is responsible for ...
The salvaged bases and nucleosides can then be converted back into nucleotides. The salvage pathway requires distinct ... Thymidine phosphorylase or pyrimidine-nucleoside phosphorylase adds 2-deoxy-alpha-D-ribose 1-phosphate to thymine, forming ... There are two types of phosphoribosyltransferases: adenine phosphoribosyltransferase (APRT) and hypoxanthine-guanine ... substrates: Uridine phosphorylase or pyrimidine-nucleoside phosphorylase adds ribose 1-phosphate to the free base uracil, ...
... representing the four nucleotide bases of a DNA strand - adenine, cytosine, guanine, thymine - covalently linked to a ... Although DNA and RNA nucleotide bases are more similar to each other than are amino acids, the conservation of base pairs can ... thymine). Apart from adenine (A), cytosine (C), guanine (G), thymine (T) and uracil (U), DNA and RNA also contain bases that ... Calculate the percent similarity by taking the number of different DNA bases divided by the total number of nucleotides. In the ...
Nucleotides are distinguished by their bases. There are the purines, large bases which include adenine and guanine, and ... small bases which include thymine and cytosine. Chargaff's rules state that adenine will always pair with thymine and guanine ... Each nucleotide is composed of a five-carbon sugar, a phosphate group, and an organic base. ... DNA polymerase can only connect new DNA nucleotides to a pre-existing chain of nucleotides. Therefore, replication begins as an ...
Nucleotides (bases) are matched between strands through hydrogen bonds to form base pairs. Adenine pairs with thymine (two ... guanine, and thymine, commonly abbreviated as A, C, G and T. Adenine and guanine are purine bases, while cytosine and thymine ... Sequences used by initiator proteins tend to be "AT-rich" (rich in adenine and thymine bases), because A-T base pairs have two ... Free bases with their attached phosphate groups are called nucleotides; in particular, bases with three attached phosphate ...
... which can read up to 1000 nucleotides or bases at a time. (The four bases are adenine, guanine, cytosine, and thymine, ... Even when every base pair of a genome sequence has been determined, there are still likely to be errors present because DNA ... These repeats can be thousands of nucleotides long, and some occur in thousands of different locations, especially in the large ... in terms of cost per base pair) and newer technology has also meant that genomes can be sequenced far more quickly. When ...
The purine bases (adenine and guanine) and pyrimidine bases (thymine and cytosine) are bound to deoxyribose and phosphate and ... This is based on the theory that uric acid is a powerful reducing agent and likely an important human antioxidant, in high ... Normally, the nucleotides are synthetized de novo from amino acids and other precursors. A small part, however, is 'recycled' ... This is termed the "salvage pathway". HGPRT is the "salvage enzyme" for the purines: it channels hypoxanthine and guanine back ...
Rare enol tautomers of the bases guanine and thymine can lead to mutation because of their altered base-pairing properties. In ... the nucleotide bases are in keto form. However, James Watson and Francis Crick first believed them to be in the enol tautomeric ... The keto product is kinetically stable and reverts to the enol in presence of a base. The keto form can be obtained in a pure ...
Each nucleotide is composed of a nitrogen-containing nucleobase-either cytosine (C), guanine (G), adenine (A), or thymine (T)- ... According to base pairing rules (A with T, and C with G), hydrogen bonds bind the nitrogenous bases of the two separate ... NASA findings in 2011, based on studies with meteorites found on Earth, suggest DNA and RNA components (adenine, guanine and ... The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of ...
These nitrogenous bases are adenine (A), uracil (U), guanine (G), thymine (T), and cytosine (C). These nitrogenous bases ... A set of five nitrogenous bases is used in the construction of nucleotides, which in turn build up the nucleic acids like DNA ... Adenine is always paired with thymine, and guanine is always paired with cytosine. These are known as base pairs. Uracil is ... A nitrogenous base owes its basic properties to the lone pair of electrons of a nitrogen atom. Nitrogenous bases are typically ...
Two DNA strands are held together by base pairing that allows the nucleotide bases adenosine (A) to bind with thymine (T), and ... guanine (G) to bind with cytosine (C). It has been proposed that thermophilic archaea would be expected to have higher GC ... The majority of the DNA is composed of G and C nucleotides, but the DNA still contains many A and T nucleotides. These results ...
... guanine (G), and thymine (T). Genetic information exists in the sequence of these nucleotides, and genes exist as stretches of ... The molecular basis for genes is deoxyribonucleic acid (DNA). DNA is composed of a chain of nucleotides, of which there are ... In 1911, Thomas Hunt Morgan argued that genes are on chromosomes, based on observations of a sex-linked white eye mutation in ... Each nucleotide in DNA preferentially pairs with its partner nucleotide on the opposite strand: A pairs with T, and C pairs ...
... a phosphate-sugar-base unit, in which he later called a nucleotide. Although the order of nucleotide components were well ... Both RNA and DNA contain two major purine bases, adenine (A) and guanine (G), and two major pyrimidines. In both DNA and RNA, ... DNA contains thymine (T) while RNA contains uracil (U). There are some rare cases where thymine does occur in RNA and uracil in ... In living organisms, the most common bases for ribonucleotides are adenine (A), guanine (G), cytosine (C), or uracil (U). The ...
Po svojoj kompoziciji, dezoksitimidin je nukleozid koji se sastoji od dezoksiriboze (pentoznog šećera) sjedinjenog sa pirimidinskom bazom timinom. Dezoksitimidin može biti fosforilizovan sa jednim, dve ili tri fosforne grupe, čime nastaju respektivno dTMP, dTDP ili dTTP ((dezoksi) timidin mono- di- ili trifosfat). On se javlja u čvrstom stanju kao mali beli kristali ili beli kristalni prah, sa molekulskom masom od 242.229 Da, i tačkom topljenja od 185 °C. Stabilnost dezoksitimidina pod standardnom temperaturom i pritiskom (STP) je veoma visoka. ...
A deficiency of folate can occur when the body's need for folate is increased, when dietary intake or absorption of folate is inadequate, or when the body excretes (or loses) more folate than usual. Medications that interfere with the body's ability to use folate may also increase the need for this vitamin.[5][6][7][8][9][10] Some research indicates that exposure to ultraviolet light, including the use of tanning beds, can lead to a folate deficiency.[11][12] The deficiency is more common in pregnant women, infants, children, and adolescents. It may also be due to poor diet or a consequence of alcoholism.[13] Additionally, a defect in homocysteine methyltransferase or a deficiency of Vitamin B12 may lead to a so-called "methyl-trap" of tetrahydrofolate (THF), in which THF is converted to a reservoir of methyl-THF which thereafter has no way of being metabolized, and serves as a sink of THF that causes a subsequent deficiency in folate.[14] Thus, a deficiency in B-12 can generate a large pool of ...
PA may be suspected when a patient's blood smear shows large, fragile, immature erythrocytes, known as megaloblasts. A diagnosis of PA first requires demonstration of megaloblastic anemia by conducting a full blood count and blood smear, which evaluates the mean corpuscular volume (MCV), as well the mean corpuscular hemoglobin concentration (MCHC). PA is identified with a high MCV (macrocytic anemia) and a normal MCHC (normochromic anemia).[38] Ovalocytes are also typically seen on the blood smear, and a pathognomonic feature of megaloblastic anemias (which include PA and others) is hypersegmented neutrophils.[18]. Serum vitamin B12 levels are used to detect its deficiency, but they do not distinguish its causes. Vitamin B12 levels can be falsely high or low and data for sensitivity and specificity vary widely. Normal serum levels may be found in cases of deficiency where myeloproliferative disorders, liver disease, transcobalamin II deficiency, or intestinal bacterial overgrowth are present. ...
The ribosome of E. coli has about 22 proteins in the small subunit (labelled S1 to S22) and 33 proteins in the large subunit (somewhat counter-intuitively called L1 to L36). All of them are different with three exceptions: one protein is found in both subunits (S20 and L26), L7 and L12 are acetylated and methylated forms of the same protein, and L8 is a complex of L7/L12 and L10. In addition, L31 is known to exist in two forms, the full length at 7.9 kilodaltons (kDa) and fragmented at 7.0 kDa. This is why the number of proteins in a ribosome is of 56. Except for S1 (with a molecular weight of 61.2 kDa), the other proteins range in weight between 4.4 and 29.7 kDa.[9]. Recent 'de novo' proteomics experiments where the authors characterized in vivo ribosome-assembly intermediates and associated assembly factors from wild-type Escherichia coli cells using a general quantitative mass spectrometry (qMS) approach have confirmed the presence of all the known small and large subunit components and have ...
Esrarın yasallığı, tıbbi ve rekreasyon amaçlı, ülkeye, sahip olma, dağıtma ve yetiştirme ve (tıbbi bakımdan) nasıl tüketilebileceği ve hangi tıbbi koşullar için kullanılabileceği açısından farklılık göstermektedir. Çoğu ülkede bu politikalar, 1961'de kabul edilen Birleşmiş Milletler Narkotik İlaçları Tek Sözleşmesi, 1971 tarihli Psikotrop Maddeler Sözleşmesi ve 1988'de Uyuşturucu Maddeler ve Psikotrop Maddelerdeki Yasadışı Trafik ile Mücadele sözleşmesi ile düzenlenmiştir. [1][2] Birçok ülkede eğlence amaçlı esrar kullanımı yasaktır; bununla birlikte, birçoğu, basit bulundurma işlemini cezai olmayan bir suç (genellikle küçük bir trafik ihlaline benzer şekilde) yapmak için bir suç unsuru haline getirme politikasını benimsemiştir. Bazılarıysa, küçük miktarlarda bile bulundurmanın birkaç yıl hapis cezası ile cezalandırıldığı bazı Asya ve Orta Doğu ülkeleri gibi çok daha ciddi cezalara da sahiptir. .[2] Uruguay ve ...
1761年,有「現代解剖病理學(英語:anatomic pathology)之父」之稱的義大利科學家喬瓦尼·莫爾加尼,在其論文〈五具遺體的病理解剖報告〉('De Sedibus Et Causis Morborum Per Anatomen Indagatis Libri Quinque.')中首次提及胰臟癌[112]。但由於缺乏顯微鏡的證據,無從判斷這份報告的結論是否正確。且由於胰臟癌在巨觀下與胰臟炎相當類似,當時許多醫師質疑原發於胰臟的癌症是否存在[113]。直到1858年,美國的雅各布·曼德斯·達·哥斯達(英語:Jacob Mendes Da ...
Şarkı, Furtado'nun Yeni Zelanda'daki ilk bir numarasıdır ve şarkı, listede yirmi yedi hafta kalmıştır.[2] Şarkı, ülkede 2001 yılının en başarılı 28. şarkısı olurken, Furtado'nun en başarılı şarkısı olmuştur.[3] "Turn Off the Light", ABD Billboard Hot 100'de 5 numaraya çıkmıştır. Parçanın Ms. Jade ve Timbaland vokalleri bulunan bir remixi yayımlandı, ayrıca parçanın dans remixi Billboard Hot Dance Music/Club Play listesinde zirveye yerleşmiştir. Parça, Avustralya'da 7 numaraya ulaşmış ve Furtado'nun bu ülkede ilk ona giren ikinci parçası haline gelmiştir. Listede yirmi bir hafta yer almıştır.[4] Ayrıca Birleşik Krallık'ta 4 numara olan parça, sanatçının ilk beşe girmeyi başaran ikinci parçası olmuştur. Birleşmiş Milletler listesinde 3 numaraya ulaşan şarkı, Furtado'nun kariyeri boyunca en çok satan ikinci teklisi olmuştur. Dünya çapında 3.666.000 adetlik satış rakamına ulaşan tekli, 2001 yıl sonu listelerinde 19 ...
A Rush of Blood to the Head, İngiliz alternatif rock grubu Coldplay'in ikinci stüdyo albümüdür. 26 Ağustos 2002'de İngiltere'de ve daha sonraki günlerde de tüm dünyada yayınlanmıştır. Prodüktörlüğünü Ken Nelson yapmıştır. Albüm, İngiltere listesine 1 numaradan giriş yapmış ve 21. yüzyılda İngiltere'de en çok satan 20 albüm listesinin 7 numarasında yer almıştır. İngiltere'de 2,6 milyon kopya satarak BPI tarafından sekiz kat platin plak ile ödüllendirilmiştir. 2002 Grammy Ödülleri'nde "En İyi Alternatif Albüm" ve "Clocks" parçasıyla "Yılın Kaydı" ödüllerini kazanmıştır. Bu albümde, "In My Place" ve "God Put a Smile upon Your Face" gibi gitar-pop şarkıları, "The Scientist" ve "Warning Sign" gibi balladlar, "Green Eyes" gibi akustik şarkılar bulunmaktadır. Albümün açılış parçası "Politik" ile birlikte, "Clocks" ve "A Whisper" gibi şarkılarda da piyano ön plana çıkarılmıştır. Bazı yönleriyle bu albüm epic-rock tarzına ...
Chargaff kuralları, Avusturyalı biyokimyacı Edwin Chargaff tarafından 1949-1951'de yayımlanan, DNA'daki çeşitli azotlu bazların miktarları arasındaki ilişkileri ifade eden empirik kurallardır.[1][2][3][4][5][6]. Chargaff'ın çalışmasına kadar "tetranükleotit" teorisi hakimdi, bu teoriye göre DNA dört farklı azotlu bazın ( adenin, timin, guanin ve sitozin) tekrar eden birimlerinden oluşmaktaydı. Chargaff ve yardımcıları DNA nükleotitlerini kâğıt kromatografisi ile ayrıştırıp farklı tiplerden nükleotitlerin miktarlarını ölçtüler. Eğer dört baz tekrar eden birimler içinde olsaydı oranlarının eşit olması beklenirdi, oysa ölçümler bunu doğrulamadı. Chargaff tarafından bulunan ilişkiler aşağıdaki gibiydi:[7]. ...
Chihayafuru (Japonca: ちはやふる), Yuki Suetsugu tarafından yazılan bir manga serisidir. Hikâye, yeni sınıf arkadaşı sayesinde karuta ile tanışan Chihaya Ayase adında lise öğrencisi hakkındadır. Manga serisi 2007 yılından bu yana Be Love dergisinde yayınlanmaktadır.[1] Serinin Madhouse tarafından üretilen anime adaptasyonu[2] Ekim 2011[3] ile Mart 2012 tarihleri arasında Nippon TV'de yayınlanmış olup ikinci sezonu Ocak ve Haziran 2013 tarihleri arasında yayınlandı. Ayrıca 19 Mart 2016 tarihinde Chihayafuru: Kami no Ku ile 29 Nisan 2016 tarihinde Chihayafuru: Shimo no Ku olmak üzere iki canlı aksiyon filmi uyarlaması yayınlandı.[4] Manga, Manga Taishō Ödülü ve Kodansha Manga Ödülü'nü kazandı. Dördüncü cildi Mart 2009 tarihinde piyasaya çıktığından beri düzenli olarak Japon Çizgi Roman Sıralaması tablosunda yer aldı ve Ağustos 2011'de 4.5 milyon kopya sattığı tahmin edildi. Popülerliği Japonya'daki rekabetçi karuta profilini ...
አር ኤን ኤ ( RNA ) እንደ ዲ ኤን ኤ ( DNA ) ከኒክሉኢክ አሲድ ( Nucleic acid ) የተሠራ ነው። እንደ ዲ ኤን ኤ አራት ቤዝ (base) አለው። እነሱም አዴናዪን ( A, adenine) ፤ ዩራሲል ( U, uracil ) ( ዲ ኤን ኤ ግን በዩራሲል ፋንታ ታያሚን ( T, thymine ) ነው ያለው) ጓኒን ( G, guanine ) እና ሳይቶሲን ( C, Cytosine )። ኑክሌይክ አሲዶች ደግሞ ሶስት መሰረታዊ አካላቶች አላቸው። ቤዝ፡ ሱካሩ ( sugar group ) እና ፎስፌት ግሩፑ ( the phosphate group ) ናቸው። አር ኤን ኤን ከዲ ኤን ኤ የሚለየዉ ሌላው ነገር የአር ኤን ኤ ስኳር ሁለተኛ ካርቦን ሀይድሮክሲል ( hydroxyl group (-OH )) ሲኖረው ዲ ኤን ኤ ግን ያለው ኤች ( H ) ብቻ ነው። ይህም አር ኤን ኤን በጣም ተለካካፊ ( reactive ) አድርጎታል። ...
Another key to finding the correct structure of DNA was the so-called Chargaff ratios, experimentally determined ratios of the nucleotide subunits of DNA: the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England in 1952 reinforced the salience of this important fact for Watson and Crick.[43] The significance of these ratios for the structure of DNA were not recognized until Watson, persisting in building structural models, realized that A:T and C:G pairs are structurally similar. In particular, the length of each base pair is the same. Chargaff had also pointed out to Watson that, in the aqueous, saline environment of the cell, the predominant tautomers of the pyrimidine (C and T) bases would be the amine and keto configurations of cytosine and thymine, rather than the imino and enol forms that Crick and Watson had assumed. They consulted Jerry Donohue who ...
Uracil is a base found in RNA. It pairs with adenine and replaces thymine in DNA. Uracil, a pyrimidine, was originally discovered in 1900. ...
These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. ... Involved in the de novo synthesis of guanine nucleotides which are not only essential for DNA and RNA synthesis, but also ... Dephosphorylates specifically the 5 and 2(3)-phosphates of uracil and thymine deoxyribonucleotides, and so protects ... a structural basis for the random-in ordered-out kinetic mechanism. J Mol Biol. 2003 Feb 14;326(2):517-27. [PubMed:12559919 ] ...
Each nucleotide can be adenine, thymine, cytosine or guanine. Genetic information is read in sequence of three bases called ... The rungs of the ladder are nucleotide base pairs, which are the genetic information of the DNA. ... A: The pattern of base pairs in the DNA double helix encodes the instructions for building the proteins necessary to construct ... RNA is transported out of the cells nucleus where proteins are built based upon translation of the RNA code. Proteins are an ...
Which is not a nucleotide base in DNA? a. adenine c. glutamine e. cytosine b. guanine d. thymine f. All are in .... BIOLOGY: ... How many base units are there in the SI? (a) four (b) five (c) six (d) seven. An Introduction to Physical Science ... 47 Is tert-butoxide anion a strong enough base to react significantly with water? In other words, can a solutio.... Organic ... 3.74 Are most proposals to carry out carbon sequestration based on chemical or physical properties of CO2? Defe.... Chemistry ...
Also known as nucleotides, they are composed of a five-carbon sugar, a nitrogenous base and a phosphate... ... There are five different types of nucleotides: uracil, cytosine, guanine, adenine and thymine. ... Also known as nucleotides, they are composed of a five-carbon sugar, a nitrogenous base and a phosphate group. ... A: The elements of nucleic acids are phosphate groups, sugar molecules and nitrogenous bases; together, these elements make up ...
Which is not a nucleotide base in DNA? a. adenine b. glutamine c. guanine d. thymine e. cytosine f. all are in .... Biology: ...
There are four nucleotide bases: adenine, guanine, cytosine and thymine. It is the sequence of base pairs, arranged in discrete ... linked on the inside of the helix by complementary pairs of nucleotide bases (bars). ... There are four nucleotide bases: adenine, guanine, cytosine and thymine. It is the sequence of base pairs, arranged in discrete ... Keywords: artwork, base, bases, biochemical, biochemistry, bond, bonding, bonds, cut out, cut outs, cut-out, cut-outs, cutout, ...
... consist of two pairs of complementary nucleotide bases (adenine/thymine, guanine/cytosine).. ... Genealogy based on genetics is, it seems, as limited as genealogy based on physical features. Yet these are the very techniques ... thymine, guanine, and cytosine-and they are complementary in that adenine always pairs with thymine, and guanine always pairs ... Figure 3. Comparison of human and ape DNA sequences (C = cytosine, G = guanine, A = adenine, T = thymine). Arrangement 1 shows ...
A nucleotide consists of a base (adenine, thymine or uracil, guanine, cytosine). plus a molecule of sugar and one of phosphoric ... The basis of the story line in this video is based on information from the cuneiform tablets from ancient Sumeria. The ... Youve mixed up "nucleotide" with nucleosynthesis, ie the formation of the nuclei of atoms (elements) heavier than H and He in ... "Earth-based catastrophes such as large-scale volcanism and global warming can destroy the ozone layer, too, but evidence for ...
... guanine n. A nucleic acid that carries the genetic information in cells and some viruses, consisting of two long... ... DNA A. adenine T. thymine C. cytosine G. ... the base pairs are adenine with thymine and guanine with ... of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or ... There are four kinds of nucleotides in a DNA molecule: cytosine, guanine, adenine, and thymine-C, G, A, and T, for short. ...
It consists of base pairs known as nucleotides adenine, cytosine, guanine and thymine. The human genome consists of 3.2 billion ... bases of DNA. Other organisms have different genome sizes.. In relation, while the study of the properties of genes is termed ...
Make research projects and school reports about nucleotide easy with credible articles from our FREE, online encyclopedia and ... guanine nucleotides are base-paired opposite cytosine nucleotides. Adenine nucleotides are base-paired opposite thymine ... The most important nucleotides are those derived from the bases adenine, guanine, cytosine, thymine, and uracil. ... The two purine bases found in both DNA and in RNA are guanine (G) and adenine (A). The two pyrimidine bases found in DNA are ...
... for determining the content of a first hemoglobin in a blood sample which also contains other forms of hemoglobin is based on ... This absorption is due to the heterocyclic rings in the nucleotide bases adenine, cytosine, guanine, and thymine (or uracil for ... CD4-IgG2-based salvage therapy of HIV-1 infection. US20030212317 *. Mar 29, 2001. Nov 13, 2003. Kovatchev Boris P.. Method, ... A calorimetric method has been devised based on the observation that Hb A1c, when subject to mild acid hydrolysis, releases 5- ...
... guanine and thymine nucleotide bases in 1950. He discovered that there were always equal amounts of thymine and adenine or ... This is what we now refer to as DNA and forms the base of the genomics field. ... Albert Kossel was awarded the Nobel Prize in Physiology and Medicine in 1910 for the discovery of the five nucleotide bases, ... As a result, he deduced that adenosine forms chromosome pairs with thymine and cytosine forms chromosome pairs with guanine. ...
Researchers reveal how the alteration of a single nucleotide-the basic building block of DNA-could initiate fragile X syndrome ... Nucleotides in DNA include one of four bases (cytosine, thymine, adenine, or guanine). The researchers found that normal ... These cells had a thymine base and a normal replication pattern and, accordingly, showed no tendency to expand their repeat ... embryonic stem cells had a thymine base at the SNP site and an active replication origin. Fragile X cells, in contrast, had a ...
... which are called nucleotides. Learn about DNA structure and see pictures of DNA structure. ... The steps are formed by the nitrogen bases of the nucleotides where adenine pairs with thymine and cytosine with guanine. ... The base pairs in DNA are adenine with thymine and cytosine with guanine. ... The nitrogenous bases point inward on the ladder and form pairs with bases on the other side, like rungs. Each base pair is ...
Nitrogen-containingt base -Part of a nucleotide. In DNA, the bases are adenine, guanine, thymine, and cytosine. In RNA, the ... Part of a nucleotide; in DNA, the bases are adenine, guanine, thymine, and cytosine; in RNA, the bases are adenine, guanine, ... The nucleotides in DNA have four kinds of nitrogen containing bases: adenine (A), guanine (G), cytosine (C), and thymine (T). ... The nucleotides in DNA have four kinds of nitrogen-containing bases: adenine, guanine, cytosine, and thy-mine. Within DNA, each ...
A new technique which marks individual DNA bases with dye could slash the cost of gene-sequencing ten-thousandfold in just 10 ... guanine, cytosine and thymine - the nucleotides contained. Then they induced a single, 12-base strand of DNA from the human p53 ... Touching bases. One commercially available alternative is pyrosequencing, which also detects nucleotides as they are added to a ... In contrast, Jus modified nucleotides contain a blocker that ensures that only one base can be measured at a time, even if ...
Each of the four nucleotides (adenine, cytosine, guanine, thymine) has a unique fluorescence emission profile. So each unique ... These include methods based on deterministic photoswitching in space and time, as pioneered by Stefan Hell. Examples of this ... As the bases are sequentially added in this sequencing by synthesis method, the fluorescence wavelength signature from each ... Compact plug-and-play laser modules based on OPSL technology, such as Coherents OBIS product family, are proving to be very ...
the genetic alphabet, the DNA molecules contain only the four nucleotide bases, that is,. adenine, thymine, guanine and ... Worse, how do we conclude that only things that are based on a code represent information? Again, just an assertion - but an ... On the basis of Shannons information theory, which can now be regarded as. being mathematically complete, we have extended the ... Theorem 8: Only those structures that are based on a code can represent. information (because of Theorem 4). This is a ...
There are four types of nucleotide base; adenine, guanine, cytosine and thymine. The sequence of base pairs, arranged in ... It is composed of two twisting strands (white/blue) of sugar-phosphate molecules, linked by complementary pairs of nucleotide ... linked by complementary pairs of nucleotide bases (coloured spheres). There are four types of nucleotide base; adenine, guanine ... cytosine and thymine. The sequence of base pairs, arranged in discrete segments known as genes, determines the genetic code. ...
This process is used to determine the order of nucleotide bases. Each molecule of DNA is made from adenine, guanine, cytosine ... Sequencing methods have evolved from relatively laborious gel-based procedures to modern automated protocols based on dye ... guanine, cytosine, and thymine, in a DNA oligonucleotide. By generating a DNA sequence for a particular organism, you are ... DNA sequencing encompasses biochemical methods for determining the order of the nucleotide bases, adenine, ...
Cytosine and Guanine. A nucleotide is sort of like a small block in the assembly of a DNA... ... different nucleotides within a molecule of DNA called Thymine, Adenine, ... base pairing. Thymine and Adenine pair together and Cytosine and Guanine pair together. The order in which these base pairs ... What is DNA? Nucleotides, Bases and Information Storage. by Rhys Baker. 11 ...
G: Guanine. A: Adenine. T: Thymine. C: Cytosine. U: Uracil (which is not present in DNA, but takes the place of thymine in RNA) ... and a heterocyclic base (blue). The structures of some of the common bases, which are derivatives of either purine or ... The nitrogen-containing base of a nucleotide (also called the nucleobase) is typically a derivative of either purine or ... A nucleotide is a chemical compound with three components: a nitrogen-containing base, a pentose (five-carbon) sugar ( ...
... a sequencing-by-synthesis reaction by using a nucleotide derivative that forms a hydrogen bond with a complementary nucleotide ... Other nucleotides useful in the invention comprise an adenine, cytosine, guanine, thymine base, an xanthine or hypoxanthine; 5- ... by exhibiting base-complementarity with one or more bases that occur in DNA or RNA and/or being capable of base-complementary ... A nucleotide corresponds to a specific nucleotide species if they share base-complementarity with respect to at least one base ...
The purines (adenine and guanine) are chemicals used to build the nucleotides of DNA and RNA. The other class of base, the ... The addition of methyl is required for the conversion of the uracil nucleotide into the thymine nucleotide, and without this ... This alteration results in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases (frame 3 ... They can inhibit the production of the purine containing nucleotides, adenine and guanine. If a cell doesnt have sufficient ...
  • Intriguingly, a specific alteration in the DNA sequence near the FMR1 gene-a "single-nucleotide polymorphism" or SNP-has been linked to an increased risk of repeat expansion in some premutation carriers. (newswise.com)
  • Students use authentic data to uncover the single nucleotide polymorphism (SNP) responsible for long hair in dogs. (bioedonline.org)
  • When a single nucleotide at the same location differs between individuals, the variation is called a "snip" (short for single nucleotide polymorphism or SNP). (bioedonline.org)
  • Unprecedented advances in molecular and cellular biology, in bio- chemistry, in genetics, and in structural biology-occurring at an accelerating rate over the past decade define this as a unique and opportune moment in our history: For the first time we can envision obtaining easy access to the complete sequence of the 3 billion nucleotides in human DNA and deciphering much of the information contained therein. (nap.edu)
  • In many cases of HCC in China and Africa, a double mutation in the HBV genome, an adenine-to-thymine transversion at nucleotide 1762 and a guanine-to-adenine transition at nucleotide 1764 (1762 T /1764 A ), has been found in tumors ( 5 , 10 , 11 ). (pnas.org)
  • To reap the benefits of personalized medicine, the billions of nucleotide bases that comprise an individual's genome must be sequenced - and done so at an affordable price. (photonics.com)
  • Today, the task of sequencing some 3 billion chemical base pairs of the genome, enough information to fill a 20-volume encyclopedia, remains a daunting challenge, thus far accomplished largely through brute force means. (thaindian.com)
  • The invention provides methods for correcting misincorporation of a nucleotide in a primer during a sequencing-by-synthesis reaction by using both a polymerase substantially lacking in exonuclease activity and an enzyme, preferably a polymerase, having exonuclease activity. (google.es)