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Enduracididine
Enduracididine is a non-proteinogenic α-amino acid that is a cyclic analogue of arginine. It is not genetically encoded into peptide sequences, but rather is generated as a posttranslational modification In molecular biology, post-translational modification (PTM) is the covalent process of changing proteins following protein biosynthesis. PTMs may involve enzymes or occur spontaneously. Proteins are created by ribosomes, which translate mRNA .... Biological roles Enduracididine occurs rarely in nature, appearing principally in peptide antibiotics such as the antibacterial compounds enramycin and teixobactin. References {{Amino acids Non-proteinogenic amino acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teixobactin
Teixobactin () is a peptide-like secondary metabolite of some species of bacteria, that kills some gram-positive bacteria. It appears to belong to a new class of antibiotics, and harms bacteria by binding to lipid II and lipid III, important precursor molecules for forming the cell wall. Teixobactin was discovered using a new method of culturing bacteria in soil, which allowed researchers to grow a previously unculturable bacterium now named '' Eleftheria terrae'', which produces the antibiotic. Teixobactin was shown to kill ''Staphylococcus aureus'' and ''Mycobacterium tuberculosis''. History In January 2015, a collaboration of four institutes in the US and Germany together with two pharmaceutical companies, reported that they had isolated and characterized a new antibiotic, killing "without detectable resistance." Teixobactin was discovered by screening previously unculturable bacteria present in a sample of soil from "a grassy field in Maine," using the isolation chip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-proteinogenic Amino Acids
In biochemistry, non-coded or non-proteinogenic amino acids are distinct from the 22 proteinogenic amino acids (21 in eukaryotesplus formylmethionine in eukaryotes with prokaryote organelles like mitochondria), which are naturally encoded in the genome of organisms for the assembly of proteins. However, over 140 non-proteinogenic amino acids occur naturally in proteins and thousands more may occur in nature or be synthesized in the laboratory. Chemically synthesized amino acids can be called unnatural amino acids. Unnatural amino acids can be synthetically prepared from their native analogs via modifications such as amine alkylation, side chain substitution, structural bond extension cyclization, and isosteric replacements within the amino acid backbone. Many non-proteinogenic amino acids are important: * intermediates in biosynthesis, * in post-translational formation of proteins, * in a physiological role (e.g. components of Peptidoglycan, bacterial cell walls, neurotransmitters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidinium, guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. Only the -arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is Genetic code, encoded by the DNA codon table, codons CGU, CGC, CGA, CGG, AGA, and AGG. The guanidine group in arginine is the Precursor (chemistry), precursor for the biosynthesis of nitric oxide. Like all amino acids, it is a white, water-soluble solid. The one-letter symbol R was assigned to arginine for its phonetic similarity. History Arginine was first isolated in 1886 from Lupinus luteus, yellow lupin seedlings by the German chemist Ernst Schulze (chemist), Ernst Schulze and his assistant Ernst Steiger. He named it from the Greek ''árg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posttranslational Modification
In molecular biology, post-translational modification (PTM) is the covalent process of changing proteins following protein biosynthesis. PTMs may involve enzymes or occur spontaneously. Proteins are created by ribosomes, which translate mRNA into polypeptide chains, which may then change to form the mature protein product. PTMs are important components in cell signalling, as for example when prohormones are converted to hormones. Post-translational modifications can occur on the amino acid side chains or at the protein's C- or N- termini. They can expand the chemical set of the 22 amino acids by changing an existing functional group or adding a new one such as phosphate. Phosphorylation is highly effective for controlling the enzyme activity and is the most common change after translation. Many eukaryotic and prokaryotic proteins also have carbohydrate molecules attached to them in a process called glycosylation, which can promote protein folding and improve stability a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enramycin
Enramycin (also known as enduracidin) is a polypeptide antibiotic produced by '' Streptomyces fungicidus''. Enramycin is widely used as a feed additive for pigs and chickens to prevent necrotic enteritis induced by Gram-positive gut pathogens. Mechanism of action Enramycin acts as an inhibitor of the enzyme MurG, which is essential for cell wall biosynthesis in Gram-positive bacteria. MurG catalyzes the transglycosylation reaction in the last step of peptidoglycan biosynthesis. Inhibiting this step greatly compromises cell wall integrity leading to cell lysis. Spectrum of susceptibility Enramycin has been found to be very effective against Gram-positive gut pathogens, most notably, ''Clostridium perfringens ''Clostridium perfringens'' (formerly known as ''C. welchii'', or ''Bacillus welchii'') is a Gram-positive, bacillus (rod-shaped), anaerobic, spore-forming pathogenic bacterium of the genus '' Clostridium''. ''C. perfringens'' is ever-present ...''; a leading caus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
