Architecture of Microcin B17 Synthetase: An Octameric Protein Complex Converting a Ribosomally Synthesized Peptide into a DNA Gyrase Poison.

The introduction of azole heterocycles into a peptide backbone is the principal step in the biosynthesis of numerous compounds with therapeutic potential. One of them is microcin B17, a bacterial topoisomerase inhibitor whose activity depends on the conversion of selected serine and cysteine residues of the precursor peptide to oxazoles and thiazoles by the McbBCD synthetase complex. Crystal structures of McbBCD reveal an octameric BCD complex with two bound substrate peptides.

The Product of Yersinia pseudotuberculosis mcc Operon Is a Peptide-Cytidine Antibiotic Activated Inside Producing Cells by the TldD/E Protease.

Microcin C is a heptapeptide-adenylate antibiotic produced by some strains of Escherichia coli. Its peptide part is responsible for facilitated transport inside sensitive cells where it is proteolyzed with release of a toxic warhead-a nonhydrolyzable aspartamidyl-adenylate, which inhibits aspartyl-tRNA synthetase. Recently, a microcin C homologue from Bacillus amyloliquefaciens containing a longer peptide part modified with carboxymethyl-cytosine instead of adenosine was described, but no biological activity of this compound was revealed.

Expression of genes involved in carbohydrate-lipid metabolism in muscle and fat tissues in the initial stage of adult-age obesity in fed and fasted mice.

C57Bl mice exhibit impaired glucose metabolism by the late adult age under standard living conditions. The aim of this study was to evaluate white adipose tissue (WAT), brown adipose tissue (BAT), and skeletal muscle expression of genes involved in carbohydrate-lipid metabolism at postpubertal stages preceding the late adult age in C57Bl mice. Muscle mRNA levels of uncoupling protein 3 () and carnitine palmitoyltransferase 1 () (indicators of FFA oxidation), WAT mRNA levels of hormone-sensitive lipase () and lipoprotein lipase () (indicators of lipolysis and lipogenesis), muscle and WAT mRNA levels of the type 4 glucose transporter (indicators of insulin-dependent glucose uptake), and BAT mRNA levels of uncoupling protein 1 () (indicator of thermogenesis) were measured in fed and 16 h-fasted mice in three age groups: 10-week-old (young), 15-week-old (early adult), and 30-week-old (late adult).

Peptide-nucleotide antibiotic Microcin C is a potent inducer of stringent response and persistence in both sensitive and producing cells.

Microcin C (McC) is a peptide-nucleotide antibiotic that inhibits aspartyl-tRNA synthetase. Here, we show that McC is a strong inducer of persistence in Escherichia coli. Persistence induced by McC is mediated by (p)ppGpp and requires chromosomally encoded toxin-antitoxin modules.