title: [Microcins--peptide antibiotics of enterobacteria: genetic control of the synthesis, structure, and mechanism of action].
abstract: A general survey of the poorly studied peptide antibiotics, microcins, which are produced by enterobacteria and effect gram-negative bacteria is conducted. In most cases, plasmid genes are responsible for microcin synthesis and the host cell immunity to the produced microcin. A complex system of plasmid and chromosomal genes is involved in the production and immunity to microcins. The chemical structure of three studied microcins is unusual. It was shown that peptides of the microcin molecules are synthesized on ribosomes and often modified posttranslationally. New types of posttranslational modifications were revealed in the biosynthesis of the microcin B17. These modifications are related to the formation of the thiazole and oxazole rings in its molecule; plasmid genes are responsible for these modifications. It was demonstrated that the smallest gene (21 bp) of all known genes controls the synthesis of the heptapeptide contained in the microcins of the C type.
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology; D001430:Bacteriocins / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000737:chemistry* / Q000235:genetics; D010080:Oxazoles / Q000737:chemistry; D010455:Peptides; D010957:Plasmids; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D013844:Thiazoles / Q000737:chemistry