Isoleucine
An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.
Valine
Threonine Dehydratase
A pyridoxal-phosphate protein that catalyzes the deamination of THREONINE to 2-ketobutyrate and AMMONIA. The role of this enzyme can be biosynthetic or biodegradative. In the former role it supplies 2-ketobutyrate required for ISOLEUCINE biosynthesis, while in the latter it is only involved in the breakdown of threonine to supply energy. This enzyme was formerly listed as EC 4.2.1.16.
Amino Acids
Threonine
Isoleucine-tRNA Ligase
Peptide PHI
A 27-amino acid peptide with histidine at the N-terminal and isoleucine amide at the C-terminal. The exact amino acid composition of the peptide is species dependent. The peptide is secreted in the intestine, but is found in the nervous system, many organs, and in the majority of peripheral tissues. It has a wide range of biological actions, affecting the cardiovascular, gastrointestinal, respiratory, and central nervous systems.
Acetolactate Synthase
A flavoprotein enzyme that catalyzes the formation of acetolactate from 2 moles of PYRUVATE in the biosynthesis of VALINE and the formation of acetohydroxybutyrate from pyruvate and alpha-ketobutyrate in the biosynthesis of ISOLEUCINE. This enzyme was formerly listed as EC 4.1.3.18.
Hydro-Lyases
RNA, Transfer, Ile
Amino Acids, Essential
Transaminases
Valerates
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.
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.
Mutation
Enzyme Repression
Keto Acids
'Keto acids', also known as ketone bodies, are water-soluble compounds - acetoacetic acid, beta-hydroxybutyric acid, and acetone - that are produced during fat metabolism when liver glycogen stores are depleted, providing an alternative energy source for the brain and other organs in states of carbohydrate restriction or intense physical exertion.
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.
Amino Acyl-tRNA Synthetases
A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.
Oxo-Acid-Lyases
Homoserine Dehydrogenase
An enzyme that catalyzes the reduction of aspartic beta-semialdehyde to homoserine, which is the branch point in biosynthesis of methionine, lysine, threonine and leucine from aspartic acid. EC 1.1.1.3.
Phenylalanine
2-Isopropylmalate Synthase
An enzyme that catalyzes the first step in the biosynthetic pathway to LEUCINE, forming isopropyl malate from acetyl-CoA and alpha-ketoisovaleric acid. This enzyme was formerly listed as EC 4.1.3.12.
Nitrosoguanidines
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.
Base Sequence
Ketol-Acid Reductoisomerase
Butyrates
Mutagenesis, Site-Directed
1-Sarcosine-8-Isoleucine Angiotensin II
Nutritional Requirements
Pyruvates
Pyruvates, in the context of medical and biochemistry definitions, are molecules that result from the final step of glycolysis, containing a carboxylic acid group and an aldehyde group, playing a crucial role in cellular metabolism, including being converted into Acetyl-CoA to enter the Krebs cycle or lactate under anaerobic conditions.
Amino Acid Substitution
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
Alanine
Aspartate Kinase
Norleucine
An unnatural amino acid that is used experimentally to study protein structure and function. It is structurally similar to METHIONINE, however it does not contain SULFUR.
Nitrogen
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
Aminobutyrates
Dietary Proteins
Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.
Genetics, Microbial
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)