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Methods in Enzymology 2002
Topics: Bacterial Proteins; Cell Membrane; Chromatography, High Pressure Liquid; Indicators and Reagents; Peptidoglycan; Salmonella; Salmonella typhimurium; Solubility; Virulence
PubMed: 12474403
DOI: 10.1016/s0076-6879(02)58105-2 -
FEMS Microbiology Letters Jan 1995Muropeptide composition of peptidoglycan from the Gram-negative bacteria Aeromonas sp., Acinetobacter acetoaceticus, Agrobacterium tumefaciens, Enterobacter cloacae,... (Comparative Study)
Comparative Study
Muropeptide composition of peptidoglycan from the Gram-negative bacteria Aeromonas sp., Acinetobacter acetoaceticus, Agrobacterium tumefaciens, Enterobacter cloacae, Proteus morganii, Pseudomonas aeruginosa, Pseudomonas putida, Vibrio parahaemolyticus Yersinia enterocolitica and Escherichia coli, was analyzed by HPLC. In all instances peptidoglycan was built up from the same subunits. A wide disparity in the relative abundance of muropeptides and all structural parameters was observed. The contribution of LD-A2pm-A2pm cross-linked muropeptides was extremely variable; from 1 to 45% of cross-linked muropeptides. Muropeptides with the dipeptides Lys-Lys or Arg-Lys, indicative of murein-bound (lipo)proteins, were detected in all instances although abundance was very variable.
Topics: Amino Acid Sequence; Carbohydrate Sequence; Chromatography, High Pressure Liquid; Dipeptides; Gram-Negative Bacteria; Macromolecular Substances; Molecular Sequence Data; Oligopeptides; Peptidoglycan; Species Specificity
PubMed: 7867925
DOI: 10.1111/j.1574-6968.1995.tb07341.x -
ACS Chemical Biology Apr 2023Antibiotic resistance of pathogenic bacteria needs to be urgently addressed by the development of new antibacterial entities. Although the prokaryotic cell wall...
Antibiotic resistance of pathogenic bacteria needs to be urgently addressed by the development of new antibacterial entities. Although the prokaryotic cell wall comprises a valuable target for this purpose, development of novel cell wall-active antibiotics is mostly missing today. This is mainly caused by hindrances in the assessment of isolated enzymes of the co-dependent murein synthesis machineries, e.g., the elongasome and divisome. We therefore present imaging methodologies to evaluate inhibitors of bacterial cell wall synthesis by high-resolution atomic force microscopy on isolated murein sacculi. With the ability to elucidate the peptidoglycan ultrastructure of cells, unprecedented molecular insights into the mechanisms of antibiotics were established. The nanoscopic impairments introduced by ampicillin, amoxicillin, and fosfomycin were not only identified by AFM but readily correlated with their known mechanism of action. These valuable in vitro capabilities will facilitate the identification and evaluation of new antibiotic leads in the future.
Topics: Anti-Bacterial Agents; Escherichia coli; Peptidoglycan; Bacteria; Cell Wall; Molecular Imaging
PubMed: 36893440
DOI: 10.1021/acschembio.2c00945 -
Journal of the American Chemical Society Aug 2019The bacterial cell wall is composed of peptidoglycan, and its biosynthesis is an established target for antibiotics. Peptidoglycan is assembled from a glycopeptide...
The bacterial cell wall is composed of peptidoglycan, and its biosynthesis is an established target for antibiotics. Peptidoglycan is assembled from a glycopeptide precursor, Lipid II, that is polymerized by peptidoglycan glycosyltransferases into glycan strands that are subsequently cross-linked to form the mature cell wall. For decades bacteria were thought to contain only one family of enzymes that polymerize Lipid II, but recently, the ubiquitous Shape, Elongation, Division, and Sporulation (SEDS)-family proteins RodA and FtsW were shown to be peptidoglycan polymerases. Because RodA and FtsW are essential in nearly all bacteria, these enzymes are promising targets for new antibiotics. However, almost nothing is known about the mechanisms of these polymerases. Here, we report that SEDS proteins synthesize peptidoglycan by adding new Lipid II monomers to the reducing end of the growing glycan chain. Using substrates that can only react at the reducing end, we also show that the glycosyl donor and acceptor in the polymerization reaction have distinct lipid requirements. These findings provide the first fundamental insights into the mechanism of SEDS-family polymerases and lay the groundwork for future biochemical and structural studies.
Topics: Bacterial Proteins; Biosynthetic Pathways; Humans; Peptidoglycan; Peptidoglycan Glycosyltransferase; Staphylococcal Infections; Staphylococcus aureus; Substrate Specificity
PubMed: 31386359
DOI: 10.1021/jacs.9b06358 -
MBio Sep 2017Peptidoglycan (PG), a polymer cross-linked by d-amino acid-containing peptides, is an essential component of the bacterial cell wall. We found that a fluorescent...
Peptidoglycan (PG), a polymer cross-linked by d-amino acid-containing peptides, is an essential component of the bacterial cell wall. We found that a fluorescent d-alanine analog (FDAA) incorporates chiefly at one of the two poles in but that polar dominance varies as a function of the cell cycle in : immediately after cytokinesis, FDAAs are incorporated chiefly at one of the two poles, but just before cytokinesis, FDAAs are incorporated comparably at both. These observations suggest that mycobacterial PG-synthesizing enzymes are localized in functional compartments at the poles and septum and that the capacity for PG synthesis matures at the new pole in Deeper knowledge of the biology of mycobacterial PG synthesis may help in discovering drugs that disable previously unappreciated steps in the process. People are dying all over the world because of the rise of antimicrobial resistance to medicines that could previously treat bacterial infections, including tuberculosis. Here, we used fluorescent d-alanine analogs (FDAAs) that incorporate into peptidoglycan (PG)-the synthesis of which is an attractive drug target-combined with high- and super-resolution microscopy to investigate the spatiotemporal dynamics of PG synthesis in and FDAA incorporation predominates at one of the two poles in In contrast, while FDAA incorporation into is also polar, there are striking variations in polar dominance as a function of the cell cycle. This suggests that enzymes involved in PG synthesis are localized in functional compartments in mycobacteria and that possesses a mechanism for maturation of the capacity for PG synthesis at the new pole. This may help in discovering drugs that cripple previously unappreciated steps in the process.
Topics: Alanine; Bacterial Proteins; Cell Division; Cell Wall; Cytokinesis; Mycobacterium smegmatis; Mycobacterium tuberculosis; Peptidoglycan; Tuberculosis
PubMed: 28900018
DOI: 10.1128/mBio.01183-17 -
Environmental Research Jun 2020The power generation performance of a microbial fuel cell (MFC) greatly depends on the relative amount of electricigens in the anodic microbial community. Running the...
The power generation performance of a microbial fuel cell (MFC) greatly depends on the relative amount of electricigens in the anodic microbial community. Running the MFC multiple times can practically enrich the electricigens, and thus improve its power generation efficiency. However, Gram-positive electricigens cannot be enriched well because of their thick non-conductive peptidoglycan layer. Herein, we report a new Gram-positive electricigen enrichment method by regulating the peptidoglycan layer of the bacteria using lysozyme. Lysozyme can partially hydrolyze the peptidoglycans layer of Gram-positive Firmicutes to improve the permeability of cell wall, and thus enhance its electricity generation activity. The stimulation of Gram-positive electricigen endows MFCs a high power generation community structure, which results in the power density 42% higher than that of the control sample. Our work has provided a new and simple method for optimizing the anode community structure by regulating weak electricigens in the community with lysozyme.
Topics: Bioelectric Energy Sources; Cell Wall; Electricity; Muramidase; Peptidoglycan
PubMed: 32247147
DOI: 10.1016/j.envres.2020.109463 -
The New Microbiologica Apr 1993Peptidoglycan synthesis and its fine chemical composition were studied in dividing and in non-dividing Klebsiella pneumoniae cocci and compared with rods. The... (Comparative Study)
Comparative Study
Peptidoglycan synthesis and its fine chemical composition were studied in dividing and in non-dividing Klebsiella pneumoniae cocci and compared with rods. The beta-lactam mecillinam, a specific inhibitor of lateral wall elongation which causes rod-to-sphere transition in rods, showed 50% inhibition of the peptidoglycan in normal rods of the parent Mir A12 only if added at an early stage of the cell cycle and no effect if added later or during septation. In the rods of the mutant Mir M7, mecillinam was shown to inhibit 50% of peptidoglycan synthesis until rods become cocci, and thereafter to be absolutely devoid of effects. On the contrary, piperacillin, a specific inhibitor of septum formation, was active on all strains regardless of their cell shape, only if added at 20 and removed at 40 min of the cell cycle. As regards the analysis of peptidoglycan fine chemical composition, bacteria dividing as cocci showed alterations in the muropeptide composition consisting in a 50-fold increase in the tetramer family. This alteration was not seen in the cocci that did not divide as such. These results confirm our previous claim that septum formation and lateral wall elongation are mutually exclusive in normal rods and that septum formation requires the synthesis of a peptidoglycan of different chemical composition.
Topics: Amdinocillin; Cell Division; Klebsiella pneumoniae; Morphogenesis; Muramidase; Peptide Fragments; Peptidoglycan
PubMed: 8510570
DOI: No ID Found -
Journal of General Microbiology Dec 1985Muramidase digests of alkali-treated SDS-insoluble peptidoglycan from two strains of Neisseria gonorrhoeae were examined. Both strains contained disaccharide peptide...
Muramidase digests of alkali-treated SDS-insoluble peptidoglycan from two strains of Neisseria gonorrhoeae were examined. Both strains contained disaccharide peptide monomers that had intramolecular 1,6-anhydro-muramyl ends. In contrast to strain 1L260, in which 50% of the monomer fraction is O-acetylated, the monomer fraction from strain RD5 was completely devoid of O-acetyl groups, as shown by HPLC. Penicillin decreased the O-acetylation of peptidoglycan but did not affect the proportion of anhydro-muramyl residues.
Topics: Acetylation; Chromatography, High Pressure Liquid; Muramidase; Neisseria gonorrhoeae; Peptidoglycan
PubMed: 3938476
DOI: 10.1099/00221287-131-12-3397 -
Molecular Microbiology Dec 2011Cell morphology and viability in Eubacteria is dictated by the architecture of peptidoglycan, the major and essential structural component of the cell wall. Although the...
Cell morphology and viability in Eubacteria is dictated by the architecture of peptidoglycan, the major and essential structural component of the cell wall. Although the biochemical composition of peptidoglycan is well understood, how the peptidoglycan architecture can accommodate the dynamics of growth and division while maintaining cell shape remains largely unknown. Here, we elucidate the peptidoglycan architecture and dynamics of bacteria with ovoid cell shape (ovococci), which includes a number of important pathogens, by combining biochemical analyses with atomic force and super-resolution microscopies. Atomic force microscopy analysis showed preferential orientation of the peptidoglycan network parallel to the short axis of the cell, with distinct architectural features associated with septal and peripheral wall synthesis. Super-resolution three-dimensional structured illumination fluorescence microscopy was applied for the first time in bacteria to unravel the dynamics of peptidoglycan assembly in ovococci. The ovococci have a unique peptidoglycan architecture and growth mode not observed in other model organisms.
Topics: Bacteria; Cell Wall; Microscopy, Atomic Force; Microscopy, Fluorescence; Peptidoglycan
PubMed: 22059678
DOI: 10.1111/j.1365-2958.2011.07871.x -
EMBO Reports Apr 2005The Drosophila immune system is able to discriminate between classes of bacteria. Detection of Gram-positive bacteria involves a complex of two pattern recognition... (Comparative Study)
Comparative Study
The Drosophila immune system is able to discriminate between classes of bacteria. Detection of Gram-positive bacteria involves a complex of two pattern recognition receptors: peptidoglycan recognition protein SA (PGRP-SA) and Gram-negative binding protein 1 (GNBP1). These activate the Toll signalling pathway. To define the cell wall components sensed by the host, we used highly purified peptidoglycan fragments of two principal Gram-positive bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae. We report that in both peptidoglycans, the minimal structure needed to activate the Toll pathway is a muropeptide dimer and that the free reducing end of the N-acetyl muramic acid residues of the muropeptides is essential for activity. Monomeric muropeptides were inactive and inhibitory in combination with dimers. Finally, peptidoglycan was degraded by the haemolymph of wild-type but not GNBP1 mutant flies. We suggest a model whereby GNBP1 is involved in the hydrolysis of Gram-positive peptidoglycan producing new glycan reducing ends, which are subsequently detected by PGRP-SA.
Topics: Animals; Carrier Proteins; Cell Wall; Chromatography, High Pressure Liquid; Drosophila; Drosophila Proteins; Hemolymph; Models, Biological; Muramic Acids; Peptidoglycan; Receptors, Cell Surface; Signal Transduction; Staphylococcus aureus; Streptococcus pneumoniae; Toll-Like Receptors
PubMed: 15791270
DOI: 10.1038/sj.embor.7400371