Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.

An enzyme that catalyses three sequential METHYLATION reactions for conversion of phosphatidylethanolamine to PHOSPHATIDYLCHOLINE.

A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.

An enzyme that catalyzes the transfer of a methyl group from S-ADENOSYLMETHIONINE to the 5-position of CYTOSINE residues in DNA.

Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.

Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)

Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.

A viscous, hygroscopic amino alcohol with an ammoniacal odor. It is widely distributed in biological tissue and is a component of lecithin. It is used as a surfactant, fluorimetric reagent, and to remove CO2 and H2S from natural gas and other gases.

Enzymes that catalyze the methylation of amino acids after their incorporation into a polypeptide chain. S-Adenosyl-L-methionine acts as the methylating agent. EC 2.1.1.

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

An enzyme that catalyzes the methylation of the epsilon-amino group of lysine residues in proteins to yield epsilon mono-, di-, and trimethyllysine. EC 2.1.1.43.

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

Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)

Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a serine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and serine and 2 moles of fatty acids.

Enzymes that catalyze the methylation of arginine residues of proteins to yield N-mono- and N,N-dimethylarginine. This enzyme is found in many organs, primarily brain and spleen.

Methylases that are specific for CYTOSINE residues found on DNA.

Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.

A PROTEIN O-METHYLTRANSFERASE that recognizes and catalyzes the methyl esterification of ISOASPARTIC ACID and D-ASPARTIC ACID residues in peptides and proteins. It initiates the repair of proteins damaged by the spontaneous decomposition of normal L-aspartic acid and L-asparagine residues.

Enzymes that are part of the restriction-modification systems. They are responsible for producing a species-characteristic methylation pattern, on either adenine or cytosine residues, in a specific short base sequence in the host cell's own DNA. This methylated sequence will occur many times in the host-cell DNA and remain intact for the lifetime of the cell. Any DNA from another species which gains entry into a living cell and lacks the characteristic methylation pattern will be recognized by the restriction endonucleases of similar specificity and destroyed by cleavage. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms.

An enzyme that catalyzes the METHYLATION of phosphatidyl-N-methylethanolamine to produce phosphatidyl-N-dimethylethanolamine. This enzyme can also methylate phosphatidyl-N-dimethylethanolamine to produce phosphatidyl-N-trimethylethanolamine (PHOSPHATIDYLCHOLINE).

Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)

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

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.

Cytidine 5'-(trihydrogen diphosphate). A cytosine nucleotide containing two phosphate groups esterified to the sugar moiety. Synonyms: CRPP; cytidine pyrophosphate.

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

AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.

5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions.

A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.

An enzyme that catalyzes reversibly the transfer of phosphoethanolamine from CDP-ethanolamine to diacylglycerol to yield phosphatidylethanolamine (cephalin) and CMP. The enzyme is found in the endoplasmic reticulum. EC 2.7.8.1.

Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

Acidic phospholipids composed of two molecules of phosphatidic acid covalently linked to a molecule of glycerol. They occur primarily in mitochondrial inner membranes and in bacterial plasma membranes. They are the main antigenic components of the Wassermann-type antigen that is used in nontreponemal SYPHILIS SERODIAGNOSIS.

A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.

Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.

An enzyme that catalyzes the formation of phosphatidylserine and CMP from CDPdiglyceride plus serine. EC 2.7.8.8.

The rate dynamics in chemical or physical systems.

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.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

Donor of choline in biosynthesis of choline-containing phosphoglycerides.

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

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.

Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.

Derivatives of phosphatidic acid in which the hydrophobic regions are composed of two fatty acids and a polar alcohol is joined to the C-3 position of glycerol through a phosphodiester bond. They are named according to their polar head groups, such as phosphatidylcholine and phosphatidylethanolamine.

A ZINC metalloenzyme that catalyzes the transfer of a methyl group from BETAINE to HOMOCYSTEINE to produce dimethylglycine and METHIONINE, respectively. This enzyme is a member of a family of ZINC-dependent METHYLTRANSFERASES that use THIOLS or selenols as methyl acceptors.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

An enzyme that catalyzes the transfer of methyl groups from S-adenosylmethionine to free carboxyl groups of a protein molecule forming methyl esters. EC 2.1.1.-.

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.

Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.

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

A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)

Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.

GLYCEROPHOSPHOLIPIDS in which one of the two acyl chains is attached to glycerol with an ether alkenyl linkage instead of an ester as with the other glycerophospholipids.

A pyrimidine analogue that inhibits DNA methyltransferase, impairing DNA methylation. It is also an antimetabolite of cytidine, incorporated primarily into RNA. Azacytidine has been used as an antineoplastic agent.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

A phospholipase that hydrolyzes the acyl group attached to the 1-position of PHOSPHOGLYCERIDES.

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

An enzyme that catalyzes the synthesis of phosphatidylcholines from CDPcholine and 1,2-diacylglycerols. EC 2.7.8.2.

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.

Fatty acid derivatives of glycerophosphates. They are composed of glycerol bound in ester linkage with 1 mole of phosphoric acid at the terminal 3-hydroxyl group and with 2 moles of fatty acids at the other two hydroxyl groups.

A species of halophilic archaea whose organisms are nonmotile. Habitats include freshwater and marine mud, animal-waste lagoons, and the rumens of ungulates.

An antidepressive agent that has also been used in the treatment of movement disorders. The mechanism of action is not well understood.

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.

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

Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.

This enzyme catalyzes the last step of CREATINE biosynthesis by catalyzing the METHYLATION of guanidinoacetate to CREATINE.

A multisubunit polycomb protein complex that catalyzes the METHYLATION of chromosomal HISTONE H3. It works in conjunction with POLYCOMB REPRESSIVE COMPLEX 1 to effect EPIGENETIC REPRESSION.

A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.

A class of sphingolipids found largely in the brain and other nervous tissue. They contain phosphocholine or phosphoethanolamine as their polar head group so therefore are the only sphingolipids classified as PHOSPHOLIPIDS.

Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.

Enzymes that catalyze the transfer of nitrogenous groups, primarily amino groups, from a donor, generally an amino acid, to an acceptor, usually a 2-oxoacid. EC 2.6.

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.

Cyclic TETRAPYRROLES based on the corrin skeleton.

The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.

Phospholipases that hydrolyze the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.

Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.

Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.

Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.

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.

Hydrocarbon rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.

An essential amino acid. It is often added to animal feed.

Interruption or suppression of the expression of a gene at transcriptional or translational levels.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

A genetic process by which the adult organism is realized via mechanisms that lead to the restriction in the possible fates of cells, eventually leading to their differentiated state. Mechanisms involved cause heritable changes to cells without changes to DNA sequence such as DNA METHYLATION; HISTONE modification; DNA REPLICATION TIMING; NUCLEOSOME positioning; and heterochromatization which result in selective gene expression or repression.

FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.

A pyrimidine base that is a fundamental unit of nucleic acids.

Compounds possessing both a hydroxyl (-OH) and an amino group (-NH2).

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

Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.

An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.

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.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Stable phosphorus atoms that have the same atomic number as the element phosphorus, but differ in atomic weight. P-31 is a stable phosphorus isotope.

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.

A group of substances similar to VITAMIN K 1 which contains a ring of 2-methyl-1,4-naphthoquinione and an isoprenoid side chain of varying number of isoprene units. In vitamin K 2, each isoprene unit contains a double bond. They are produced by bacteria including the normal intestinal flora.

An enzyme that catalyzes the transfer of cytidylate (CMP) to choline phosphate to form CDPcholine. It is the rate-limiting enzyme in the choline pathway for the biosynthesis of phosphatidylcholine. Its activity is increased by glucocorticoids. EC 2.7.7.15.

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

Diglycerides are a type of glyceride, specifically a form of lipid, that contains two fatty acid chains linked to a glycerol molecule by ester bonds.

A class of enzymes that transfers substituted phosphate groups. EC 2.7.8.

Established cell cultures that have the potential to propagate indefinitely.

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

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.

Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)

The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.

A family of gram-negative, asporogenous rods or ovoid cells, aerobic or facultative anaerobic chemoorganotrophs. They are commonly isolated from SOIL, activated sludge, or marine environments.

The process of cleaving a chemical compound by the addition of a molecule of water.

A condition produced by a deficiency of CHOLINE in animals. Choline is known as a lipotropic agent because it has been shown to promote the transport of excess fat from the liver under certain conditions in laboratory animals. Combined deficiency of choline (included in the B vitamin complex) and all other methyl group donors causes liver cirrhosis in some animals. Unlike compounds normally considered as vitamins, choline does not serve as a cofactor in enzymatic reactions. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)

An order of gram-positive, primarily aerobic BACTERIA that tend to form branching filaments.

Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.

Areas of increased density of the dinucleotide sequence cytosine--phosphate diester--guanine. They form stretches of DNA several hundred to several thousand base pairs long. In humans there are about 45,000 CpG islands, mostly found at the 5' ends of genes. They are unmethylated except for those on the inactive X chromosome and some associated with imprinted genes.

Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.

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

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.

Nucleic acid structures found on the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear RNAs. These structures, which are positively charged, protect the above specified RNAs at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA CAP ANALOGS), which lack the positive charge, inhibit the initiation of protein synthesis.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome has not been identified in man. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1379) Inositol phospholipids are important in signal transduction.

The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.

An antibiotic purine ribonucleoside that readily substitutes for adenosine in the biological system, but its incorporation into DNA and RNA has an inhibitory effect on the metabolism of these nucleic acids.

A nonfluorescent reagent for the detection of primary amines, peptides and proteins. The reaction products are highly fluorescent.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.

Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.

A family of gram-positive, saprophytic bacteria occurring in soil and aquatic environments.

Arachidonic acids are polyunsaturated fatty acids, specifically a type of omega-6 fatty acid, that are essential for human nutrition and play crucial roles in various biological processes, including inflammation, immunity, and cell signaling. They serve as precursors to eicosanoids, which are hormone-like substances that mediate a wide range of physiological responses.

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

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.

Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

Proteins prepared by recombinant DNA technology.

A benzofuran derivative used as a protein reagent since the terminal N-NBD-protein conjugate possesses interesting fluorescence and spectral properties. It has also been used as a covalent inhibitor of both beef heart mitochondrial ATPase and bacterial ATPase.

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.

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).

A ubiquitous family of proteins that transport PHOSPHOLIPIDS such as PHOSPHATIDYLINOSITOL and PHOSPHATIDYLCHOLINE between membranes. They play an important role in phospholipid metabolism during vesicular transport and SIGNAL TRANSDUCTION.

An antineoplastic agent. It has significant activity against melanomas. (from Martindale, The Extra Pharmacopoeia, 31st ed, p564)

Proteins found in any species of bacterium.

A ubiquitous sodium salt that is commonly used to season food.

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.

A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.

A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumor efficacy and the presence in their chemical structures of N-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumor cells are not completely understood. (From AMA, Drug Evaluations Annual, 1994, p2026)

Myeloid-lymphoid leukemia protein is a transcription factor that maintains high levels of HOMEOTIC GENE expression during development. The GENE for myeloid-lymphoid leukemia protein is commonly disrupted in LEUKEMIA and combines with over 40 partner genes to form FUSION ONCOGENE PROTEINS.

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.

Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.

The addition of an organic acid radical into a molecule.

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

Guanine is a purine nucleobase, one of the four nucleobases in the nucleic acid of DNA and RNA, involved in forming hydrogen bonds between complementary base pairs in double-stranded DNA molecules.

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

Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Proteins obtained from ESCHERICHIA COLI.

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.

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.

Diaminopimelic acid (DAP) is a crucial intermediate in the biosynthesis of L-lysine, an essential amino acid, and is also a significant component of peptidoglycan, a cell wall polymer in bacteria.

The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.

A ubiquitously found basic protein that binds to phosphatidylethanolamine and NUCLEOTIDES. It is an endogenous inhibitor of RAF KINASES and may play a role in regulating SIGNAL TRANSDUCTION. Phosphatidylethanolamine-binding protein is the precursor of hippocampal cholinergic neurostimulating peptide, which is cleaved from the N-terminal region of the protein.

Peptidoglycan immunoadjuvant originally isolated from bacterial cell wall fragments; also acts as pyrogen and may cause arthritis; stimulates both humoral and cellular immunity.

The ester of diacylglycerol with the terminal phosphate of cytidine diphosphate. It serves as an intermediate in the biosynthesis of phosphatidylethanolamine and phosphatidylserine in bacteria.

A group of 16-carbon fatty acids that contain no double bonds.

The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.

A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, and sweetening agent.

The characteristic three-dimensional shape of a molecule.

An ASPARTIC ACID residue in polypeptide chains that is linked at the beta-carboxyl group instead of at the normal, alpha-carboxyl group, polypeptide linkage. It is a result of the spontaneous decomposition of aspartic acid or ASPARAGINE residues.

A family in the order Rhodobacterales, class ALPHAPROTEOBACTERIA.

The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.

The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.

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

Elements of limited time intervals, contributing to particular results or situations.

A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)

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.

A hydrocarbon used as an industrial solvent. It has been used as an aerosal propellent, as a refrigerant and as a local anesthetic. (From Martindale, The Extra Pharmacopoeia, 31st ed, p1403)

Former kingdom, located on Korea Peninsula between Sea of Japan and Yellow Sea on east coast of Asia. In 1948, the kingdom ceased and two independent countries were formed, divided by the 38th parallel.

An enzyme that is active in the first step of choline phosphoglyceride (lecithin) biosynthesis by catalyzing the phosphorylation of choline to phosphorylcholine in the presence of ATP. Ethanolamine and its methyl and ethyl derivatives can also act as acceptors. EC 2.7.1.32.

Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.

Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

A cell line derived from cultured tumor cells.

A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.

A methylated nucleotide base found in eukaryotic DNA. In ANIMALS, the DNA METHYLATION of CYTOSINE to form 5-methylcytosine is found primarily in the palindromic sequence CpG. In PLANTS, the methylated sequence is CpNpGp, where N can be any base.

Life or metabolic reactions occurring in an environment containing oxygen.

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).

Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognize specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.4.

Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

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)

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

The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.

An unsaturated, essential fatty acid. It is found in animal and human fat as well as in the liver, brain, and glandular organs, and is a constituent of animal phosphatides. It is formed by the synthesis from dietary linoleic acid and is a precursor in the biosynthesis of prostaglandins, thromboxanes, and leukotrienes.

Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.

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.

A genus of anaerobic, irregular spheroid-shaped METHANOSARCINALES whose organisms are nonmotile. Endospores are not formed. These archaea derive energy via formation of methane from acetate, methanol, mono-, di-, and trimethylamine, and possibly, carbon monoxide. Organisms are isolated from freshwater and marine environments.

Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.

An enzyme that catalyzes the demethylation of L-homocysteine to L-METHIONINE.

Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.

The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

A reagent that is used to neutralize peptide terminal amino groups.

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

An enzyme that transfers acyl groups from acyl-CoA to glycerol-3-phosphate to form monoglyceride phosphates. It acts only with CoA derivatives of fatty acids of chain length above C-10. Also forms diglyceride phosphates. EC 2.3.1.15.

Organic compounds that contain the (-NH2OH) radical.

The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.

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

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)

An order of anaerobic methanogens in the kingdom EURYARCHAEOTA. They are pseudosarcina, coccoid or sheathed rod-shaped and catabolize methyl groups. The cell wall is composed of protein. The order includes one family, METHANOCOCCACEAE. (From Bergey's Manual of Systemic Bacteriology, 1989)