Acetyl Coenzyme A: Acetyl CoA participates in the biosynthesis of fatty acids and sterols, in the oxidation of fatty acids and in the metabolism of many amino acids. It also acts as a biological acetylating agent.Acetate-CoA Ligase: An enzyme that catalyzes the formation of CoA derivatives from ATP, acetate, and CoA to form AMP, pyrophosphate, and acetyl CoA. It acts also on propionates and acrylates. EC ACoenzymes: Small molecules that are required for the catalytic function of ENZYMES. Many VITAMINS are coenzymes.Acetyl-CoA Carboxylase: A carboxylating enzyme that catalyzes the conversion of ATP, acetyl-CoA, and HCO3- to ADP, orthophosphate, and malonyl-CoA. It is a biotinyl-protein that also catalyzes transcarboxylation. The plant enzyme also carboxylates propanoyl-CoA and butanoyl-CoA (From Enzyme Nomenclature, 1992) EC Kinase: An enzyme that catalyzes reversibly the phosphorylation of acetate in the presence of a divalent cation and ATP with the formation of acetylphosphate and ADP. It is important in the glycolysis process. EC Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.Phosphate Acetyltransferase: An enzyme that catalyzes the synthesis of acetylphosphate from acetyl-CoA and inorganic phosphate. Acetylphosphate serves as a high-energy phosphate compound. EC Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.Coenzyme A Ligases: Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.Acetyl-CoA Hydrolase: An enzyme that catalyzes reversibly the hydrolysis of acetyl-CoA to yield CoA and acetate. The enzyme is involved in the oxidation of fatty acids. EC A drug that is derived from opium, which contains from 0.3-1.5% thebaine depending on its origin. It produces strychnine-like convulsions rather than narcosis. It may be habit-forming and is a controlled substance (opiate) listed in the U.S. Code of Federal Regulations, Title 21 Part 1308.12 (1985). (From Merck Index, 11th ed)Ubiquinone: A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.Carbon-Nitrogen Ligases: Enzymes that catalyze the joining of two molecules by the formation of a carbon-nitrogen bond. EC 6.3.Arylamine N-Acetyltransferase: An enzyme that catalyzes the transfer of acetyl groups from ACETYL-COA to arylamines. It can also catalyze acetyl transfer between arylamines without COENZYME A and has a wide specificity for aromatic amines, including SEROTONIN. However, arylamine N-acetyltransferase should not be confused with the enzyme ARYLALKYLAMINE N-ACETYLTRANSFERASE which is also referred to as SEROTONIN ACETYLTRANSFERASE.Carboxyl and Carbamoyl Transferases: A group of enzymes that catalyze the transfer of carboxyl- or carbamoyl- groups. EC 2.1.3.Ligases: A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.Aldehyde Oxidoreductases: Oxidoreductases that are specific for ALDEHYDES.Acetyl-CoA C-Acetyltransferase: An enzyme that catalyzes the formation of acetoacetyl-CoA from two molecules of ACETYL COA. Some enzymes called thiolase or thiolase-I have referred to this activity or to the activity of ACETYL-COA C-ACYLTRANSFERASE.Acetylation: Formation of an acetyl derivative. (Stedman, 25th ed)Kinetics: The rate dynamics in chemical or physical systems.Oxo-Acid-Lyases: Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.Carnitine O-Acetyltransferase: An enzyme that catalyzes the formation of O-acetylcarnitine from acetyl-CoA plus carnitine. EC 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.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.Hydroxybutyrates: Salts and esters of hydroxybutyric acid.4-Aminobenzoic Acid: An aminobenzoic acid isomer that combines with pteridine and GLUTAMIC ACID to form FOLIC ACID. The fact that 4-aminobenzoic acid absorbs light throughout the UVB range has also resulted in its use as an ingredient in SUNSCREENS.Organic Chemistry Phenomena: The conformation, properties, reaction processes, and the properties of the reactions of carbon compounds.Adipates: Derivatives of adipic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,6-carboxy terminated aliphatic structure.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)GlyoxylatesMalonyl Coenzyme A: A coenzyme A derivative which plays a key role in the fatty acid synthesis in the cytoplasmic and microsomal systems.PyruvatesAmino 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.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Acetic Acid: Product of the oxidation of ethanol and of the destructive distillation of wood. It is used locally, occasionally internally, as a counterirritant and also as a reagent. (Stedman, 26th ed)Acyltransferases: 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.Citric Acid Cycle: A series of oxidative reactions in the breakdown of acetyl units derived from GLUCOSE; FATTY ACIDS; or AMINO ACIDS by means of tricarboxylic acid intermediates. The end products are CARBON DIOXIDE, water, and energy in the form of phosphate bonds.Bacterial Proteins: Proteins found in any species of bacterium.Carbon: A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.ATP Citrate (pro-S)-Lyase: An enzyme that, in the presence of ATP and COENZYME A, catalyzes the cleavage of citrate to yield acetyl CoA, oxaloacetate, ADP, and ORTHOPHOSPHATE. This reaction represents an important step in fatty acid biosynthesis. This enzyme was formerly listed as EC A-Transferases: Enzymes which transfer coenzyme A moieties from acyl- or acetyl-CoA to various carboxylic acceptors forming a thiol ester. Enzymes in this group are instrumental in ketone body metabolism and utilization of acetoacetate in mitochondria. EC 2.8.3.Polyesters: Polymers of organic acids and alcohols, with ester linkages--usually polyethylene terephthalate; can be cured into hard plastic, films or tapes, or fibers which can be woven into fabrics, meshes or velours.Genes, Bacterial: The functional hereditary units of BACTERIA.CobamidesCloning, 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.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Fatty Acids: 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)Clostridium: A genus of motile or nonmotile gram-positive bacteria of the family Clostridiaceae. Many species have been identified with some being pathogenic. They occur in water, soil, and in the intestinal tract of humans and lower animals.Acetylesterase: An enzyme that catalyzes the conversion of acetate esters and water to alcohols and acetate. EC A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.Hydroxymethylglutaryl CoA Reductases: Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.Acyl Coenzyme A: S-Acyl coenzyme A. Fatty acid coenzyme A derivatives that are involved in the biosynthesis and oxidation of fatty acids as well as in ceramide formation.CitratesMultienzyme Complexes: Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Mesna: A sulfhydryl compound used to prevent urothelial toxicity by inactivating metabolites from ANTINEOPLASTIC AGENTS, such as IFOSFAMIDE or CYCLOPHOSPHAMIDE.Citrate (si)-Synthase: Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.Pyruvic Acid: An intermediate compound in the metabolism of carbohydrates, proteins, and fats. In thiamine deficiency, its oxidation is retarded and it accumulates in the tissues, especially in nervous structures. (From Stedman, 26th ed)Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Organophosphates: Carbon-containing phosphoric acid derivatives. Included under this heading are compounds that have CARBON atoms bound to one or more OXYGEN atoms of the P(=O)(O)3 structure. Note that several specific classes of endogenous phosphorus-containing compounds such as NUCLEOTIDES; PHOSPHOLIPIDS; and PHOSPHOPROTEINS are listed elsewhere.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)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.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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Gene Expression Regulation, Enzymologic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Pantothenic Acid: A butyryl-beta-alanine that can also be viewed as pantoic acid complexed with BETA ALANINE. It is incorporated into COENZYME A and protects cells against peroxidative damage by increasing the level of GLUTATHIONE.Histone Acetyltransferases: Enzymes that catalyze acyl group transfer from ACETYL-CoA to HISTONES forming CoA and acetyl-histones.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.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.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.Molecular Weight: The sum of the weight of all the atoms in a molecule.Euryarchaeota: A phylum of ARCHAEA comprising at least seven classes: Methanobacteria, Methanococci, Halobacteria (extreme halophiles), Archaeoglobi (sulfate-reducing species), Methanopyri, and the thermophiles: Thermoplasmata, and Thermococci.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Cell-Free System: A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)Propanediol Dehydratase: An enzyme that catalyzes the dehydration of 1,2-propanediol to propionaldehyde. EC A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.NADP: Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th 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.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Acetylcarnitine: An acetic acid ester of CARNITINE that facilitates movement of ACETYL COA into the matrices of mammalian MITOCHONDRIA during the oxidation of FATTY ACIDS.Mevalonic AcidSequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Fungal Proteins: Proteins found in any species of fungus.Methanosarcina barkeri: A species of halophilic archaea whose organisms are nonmotile. Habitats include freshwater and marine mud, animal-waste lagoons, and the rumens of ungulates.Pantetheine: An intermediate in the pathway of coenzyme A formation in mammalian liver and some microorganisms.Alcohol Oxidoreductases: A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.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.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.Hydroxymethylglutaryl-CoA Reductase Inhibitors: Compounds that inhibit HMG-CoA reductases. They have been shown to directly lower cholesterol synthesis.Riboflavin: Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as FLAVIN MONONUCLEOTIDE and FLAVIN-ADENINE DINUCLEOTIDE.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).Phenylacetates: Derivatives of phenylacetic acid. Included under this heading are a variety of acid forms, salts, esters, and amides that contain the benzeneacetic acid structure. Note that this class of compounds should not be confused with derivatives of phenyl acetate, which contain the PHENOL ester of ACETIC ACID.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.Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Palmitoyl Coenzyme A: A fatty acid coenzyme derivative which plays a key role in fatty acid oxidation and biosynthesis.Methanobacterium: A genus of anaerobic, rod-shaped METHANOBACTERIACEAE. Its organisms are nonmotile and use ammonia as the sole source of nitrogen. These methanogens are found in aquatic sediments, soil, sewage, and the gastrointestinal tract of animals.Lovastatin: A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Methanosarcina: 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.Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Pyridoxal Phosphate: This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent: Specific hydroxymethylglutaryl CoA reductases that utilize the cofactor NAD. In liver enzymes of this class are involved in cholesterol biosynthesis.Methylmalonyl-CoA Mutase: An enzyme that catalyzes the conversion of methylmalonyl-CoA to succinyl-CoA by transfer of the carbonyl group. It requires a cobamide coenzyme. A block in this enzymatic conversion leads to the metabolic disease, methylmalonic aciduria. EC Synthase: An enzyme that catalyzes the synthesis of hydroxymethylglutaryl-CoA from acetyl-CoA and acetoacetyl-CoA. This is a key enzyme in steroid biosynthesis. This enzyme was formerly listed as EC A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.