Mining Translation Inhibitors by a Unique Peptidyl-Aminonucleoside Synthetase Reveals Cystocin Biosynthesis and Self-Resistance.

Puromycin (Puro) is a natural aminonucleoside antibiotic that inhibits protein synthesis by its incorporation into elongating peptide chains. The unique mechanism of Puro finds diverse applications in molecular biology, including the selection of genetically engineered cell lines, in situ protein synthesis monitoring, and studying ribosome functions. However, the key step of Puro biosynthesis remains enigmatic.

Pyruvylated cell wall glycopolymers of Promicromonospora citrea VKM A≿-665 and Promicromonospora sp. VKM A≿-1028.

The cell walls of two strains of the genus Promicromonospora (phylum Actinobacteria) were found to include non-phosphorylated anionic glycopolymers with pyruvic acid acetals of R-configuration. The cell wall of the type strain P. citrea 665 contains two glycopolymers of the sort, including the Kdn-teichulosonic acid with the repeating unit →6)-α-d-Gl≿p/→6)-α-d-Gl≿p3SO-(1 → 4)-α-[7,9Pyr]-Kdn-(2→, and the galactan with the repeating unit →3)-α-[4,6Pyr]-d-Galp-2OAc-(1 → .

Cell Wall Glycopolymers of Type Strains from Three Species of the Genus Actinoplanes.

The structures of cell wall glycopolymers from the type strains of three Actinoplanes species were investigated using chemical methods, NMR spectroscopy, and mass spectrometry. Actinoplanes digitatis VKM Ac-649(T) contains two phosphate-containing glycopolymers: poly(diglycosyl-1-phosphate) →6)-α-D-GlcpNAc-(1-P-6)-α-D-GlcpN-(1→ and teichoic acid →1)-sn-Gro-(3-P-3)-β-[β-D-GlcpNAc-(1→2]-D-Galp-(1→. Two glycopolymers were identified in A.

Teichulosonic acid, an anionic polymer of a new class from the cell wall of Actinoplanes utahensis VKM Ac-674(T).

The cell wall of Actinoplanes utahensis VKM Ac-674(T) contains two anionic polymers: teichoic acid 1,3-poly(glycerol phosphate) that is widespread in cell walls of Gram-positive bacteria; and a unique teichulosonic acid belonging to a new class of bioglycans described only in microorganisms of the Actinomycetales order. The latter polymer contains residues of di-N-acyl derivative of sialic acid-like monosaccharide - 5,7-diamino-3,5,7,9-tetradeoxy-L-glycero-β-L-manno-non-2-ulosonic or pseudaminic acid (Pse) which bears the N-(3,4-dihydroxybutanoyl) group (Dhb) at C7. This polymer has irregular structure and consists of fragments of two types, which differ in substitution of the Dhb residues at O4 either with β-D-glucopyranose or with β-Pse residues.