Lanthionine is a nonproteinogenic amino acid with the chemical formula (HOOC-CH(NH2)-CH2-S-CH2-CH(NH2)-COOH). It is typically formed by a cysteine residue and a dehydrated serine residue. Despite its name, lanthionine does not contain the element lanthanum.
Dehydroalanine is a dehydroamino acid. It does not exist in its free form, but it occurs naturally as a residue found in peptides of microbial origin. As an amino acid residue, it is unusual because it has an unsaturated backbone.
Teicoplanin is an antibiotic used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and Enterococcus faecalis. It is a semisynthetic glycopeptide antibiotic with a spectrum of activity similar to vancomycin. Its mechanism of action is to inhibit bacterial cell wall synthesis.
Nonribosomal peptides (NRP) are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside these organisms. While there exist a wide range of peptides that are not synthesized by ribosomes, the term nonribosomal peptide typically refers to a very specific set of these as discussed in this article.
Daptomycin, sold under the brand name Cubicin among others, is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms.
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass.
Thiostrepton is a natural cyclic oligopeptide antibiotic of the thiopeptide class, derived from several strains of streptomycetes, such as Streptomyces azureus and Streptomyces laurentii. Thiostrepton is a natural product of the ribosomally synthesized and post-translationally modified peptide (RiPP) class.
Sparsomycin is a compound, initially discovered as a metabolite of the bacterium Streptomyces sparsogenes, which binds to the 50S ribosomal subunit and inhibits protein synthesis through peptidyl transferase inhibition. As it binds to the 50S ribosomal subunit, it induces translocation on the 30S subunit. It is a nucleotide analogue. It was also formerly thought to be a possible anti-tumor agent, but interest in this drug was later discarded after it was discovered that it resulted in retinopathy and as a tool to study protein synthesis; it is not specific for bacterial ribosomes and so not usable as an antibiotic.
Streptogramin A is a group of antibiotics within the larger family of antibiotics known as streptogramins. They are synthesized by the bacteria Streptomyces virginiae. The streptogramin family of antibiotics consists of two distinct groups: group A antibiotics contain a 23-membered unsaturated ring with lactone and peptide bonds while group B antibiotics are depsipeptides. While structurally different, these two groups of antibiotics act synergistically, providing greater antibiotic activity than the combined activity of the separate components. These antibiotics have until recently been commercially manufactured as feed additives in agriculture, although today there is increased interest in their ability to combat antibiotic-resistant bacteria, particularly vancomycin-resistant bacteria.
In biochemistry, non-coded or non-proteinogenic amino acids are distinct from the 22 proteinogenic amino acids 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:
Plantazolicin (PZN) is a natural antibiotic produced by the gram-positive soil bacterium Bacillus velezensis FZB42. PZN has specifically been identified as a selective bactericidal agent active against Bacillus anthracis, the causative agent of anthrax. This natural product is a ribosomally synthesized and post-translationally modified peptide (RiPP); it can be classified further as a thiazole/oxazole-modified microcin (TOMM) or a linear azole-containing peptide (LAP).
Bottromycin is a macrocyclic peptide with antibiotic activity. It was first discovered in 1957 as a natural product isolated from Streptomyces bottropensis. It has been shown to inhibit methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) among other Gram-positive bacteria and mycoplasma. Bottromycin is structurally distinct from both vancomycin, a glycopeptide antibiotic, and methicillin, a beta-lactam antibiotic.
YcaO is a protein found in bacteria which is involved in the synthesis of thiazole/oxazole modified microcin antibiotics, such as bottromycin. YcaO performs ATP dependent cyclodehydration to form the oxazole and thiazole moieties of the microcin.
Ribosomally synthesized and post-translationally modified peptides (RiPPs), also known as ribosomal natural products, are a diverse class of natural products of ribosomal origin. Consisting of more than 20 sub-classes, RiPPs are produced by a variety of organisms, including prokaryotes, eukaryotes, and archaea, and they possess a wide range of biological functions.
The cyclothiazomycins are a group of natural products, classified as thiopeptides, which are produced by various Streptomyces species of bacteria.
In biochemistry, a dehydroamino acid is an amino acids, usually with a C=C double bond in its side chain. Dehydroamino acids are not coded by DNA, but arise via post-translational modification.
Streptomyces actuosus is a bacterium species from the genus of Streptomyces. Streptomyces actuosus produces nosiheptide and staurosporin.
Thiopeptides are a class of peptide antibiotics produced by bacteria. They have antibiotic activity against Gram-positive bacteria, but little or no activity against Gram-negative bacteria. Many of the members of this class show activity against methicillin-resistant Staphylococcus aureus (MRSA) and are therefore subjects of research interest.
Klebsazolicin (KLB) is a peptide antibiotic encoded in the genome of a gram-negative bacterium Klebsiella pneumoniae subsp. ozonae and targeting prokaryotic ribosome. Klebsazolicin is a ribosomally synthesized and post-translationally modified peptide (RiPP) and a linear azol(in)e-containing peptide (LAP).
Cinnamycin is a tetracyclic antibacterial peptide produced by Streptomyces cinnamoneus containing 19 amino acid residues including the unusual amino acids threo-3-methyl-lanthionine, meso-lanthionine, lysinoalanine, and 3-hydroxyaspartic acid.
