Artykuły w czasopismach: „Peptidoglycan metabolism”

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Garcia, Daniel L., i Joseph P. Dillard. "Mutations in ampG or ampD Affect Peptidoglycan Fragment Release from Neisseria gonorrhoeae". Journal of Bacteriology 190, nr 11 (4.04.2008): 3799–807. http://dx.doi.org/10.1128/jb.01194-07.

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ABSTRACT Neisseria gonorrhoeae releases peptidoglycan fragments during growth. The majority of the fragments released are peptidoglycan monomers, molecules known to increase pathogenesis through the induction of proinflammatory cytokines and responsible for the killing of ciliated epithelial cells. In other gram-negative bacteria such as Escherichia coli, these peptidoglycan fragments are efficiently degraded and recycled. Peptidoglycan fragments enter the cytoplasm from the periplasm via the AmpG permease. The amidase AmpD degrades peptidoglycan monomers by removing the disaccharide from the peptide. The disaccharide and the peptide are further degraded and are then used for new peptidoglycan synthesis or general metabolism. We examined the possibility that peptidoglycan fragment release by N. gonorrhoeae results from defects in peptidoglycan recycling. The deletion of ampG caused a large increase in peptidoglycan monomer release. Analysis of cytoplasmic material showed peptidoglycan fragments as recycling intermediates in the wild-type strain but absent from the ampG mutant. An ampD deletion reduced the release of all peptidoglycan fragments and nearly eliminated the release of free disaccharide. The ampD mutant also showed a large buildup of peptidoglycan monomers in the cytoplasm. The introduction of an ampG mutation in the ampD background restored peptidoglycan fragment release, indicating that events in the cytoplasm (metabolic or transcriptional regulation) affect peptidoglycan fragment release. The ampD mutant showed increased metabolism of exogenously added free disaccharide derived from peptidoglycan. These results demonstrate that N. gonorrhoeae has an active peptidoglycan recycling pathway and can regulate peptidoglycan fragment metabolism, dependent on the intracellular concentration of peptidoglycan fragments.

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Strating, Hendrik, Chris Vandenende i Anthony J. Clarke. "Changes in peptidoglycan structure and metabolism during differentiation ofProteus mirabilisinto swarmer cells". Canadian Journal of Microbiology 58, nr 10 (październik 2012): 1183–94. http://dx.doi.org/10.1139/w2012-102.

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The O-acetylation of peptidoglycan in Gram-negative bacteria occurs specifically at the C-6 hydroxyl group of muramoyl residues. The level of peptidoglycan O-acetylation was found to decrease from 51% to 29% upon differentiation of Proteus mirabilis vegetative cells to swarmers. This decrease was accompanied by a change in the muropeptide composition of the peptidoglycan. In particular, the content of anhydromuropeptides increased, while the amount of Lys-Lys-muropeptides arising from bound lipoprotein decreased. These changes together with a shift in proportion of larger muropeptides suggested a decrease in average chain length of the muropeptides from swarmer cells. Zymography using SDS–PAGE gels containing either O-acetylated or chemically de-O-acetylated peptidoglycan was used to monitor the activity of specific autolysins during the differentiation of vegetative to swarming cells of P. mirabilis. A 43 kDa autolysin with increased specificity for O-acetylated peptidoglycan was detected in vegetative cells, but its activity appeared to decrease as the cells began to differentiate, while the levels of 3 other autolysins with apparent specificity for non-O-acetylated peptidoglycan increased. These changes are discussed in relation to the autolysin profile of the bacteria and the changes in peptidoglycan composition with cell differentiation.

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Pérez Medina, Krizia, i Joseph Dillard. "Antibiotic Targets in Gonococcal Cell Wall Metabolism". Antibiotics 7, nr 3 (21.07.2018): 64. http://dx.doi.org/10.3390/antibiotics7030064.

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The peptidoglycan cell wall that encloses the bacterial cell and provides structural support and protection is remodeled by multiple enzymes that synthesize and cleave the polymer during growth. This essential and dynamic structure has been targeted by multiple antibiotics to treat gonococcal infections. Up until now, antibiotics have been used against the biosynthetic machinery and the therapeutic potential of inhibiting enzymatic activities involved in peptidoglycan breakdown has not been explored. Given the major antibiotic resistance problems we currently face, it is crucial to identify other possible targets that are key to maintaining cell integrity and contribute to disease development. This article reviews peptidoglycan as an antibiotic target, how N. gonorrhoeae has developed resistance to currently available antibiotics, and the potential of continuing to target this essential structure to combat gonococcal infections by attacking alternative enzymatic activities involved in cell wall modification and metabolism.

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Vasudevan, Pradeep, Jessica McElligott, Christa Attkisson, Michael Betteken i David L. Popham. "Homologues of the Bacillus subtilis SpoVB Protein Are Involved in Cell Wall Metabolism". Journal of Bacteriology 191, nr 19 (31.07.2009): 6012–19. http://dx.doi.org/10.1128/jb.00604-09.

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ABSTRACT Members of the COG2244 protein family are integral membrane proteins involved in synthesis of a variety of extracellular polymers. In several cases, these proteins have been suggested to move lipid-linked oligomers across the membrane or, in the case of Escherichia coli MviN, to flip the lipid II peptidoglycan precursor. Bacillus subtilis SpoVB was the first member of this family implicated in peptidoglycan synthesis and is required for spore cortex polymerization. Three other COG2244 members with high similarity to SpoVB are encoded within the B. subtilis genome. Mutant strains lacking any or all of these genes (yabM, ykvU, and ytgP) in addition to spoVB are viable and produce apparently normal peptidoglycan, indicating that their function is not essential in B. subtilis. Phenotypic changes associated with loss of two of these genes suggest that they function in peptidoglycan synthesis. Mutants lacking YtgP produce long cells and chains of cells, suggesting a role in cell division. Mutants lacking YabM exhibit sensitivity to moenomycin, an antibiotic that blocks peptidoglycan polymerization by class A penicillin-binding proteins. This result suggests that YabM may function in a previously observed alternate pathway for peptidoglycan strand synthesis.

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Dörries, Kirsten, Rabea Schlueter i Michael Lalk. "Impact of Antibiotics with Various Target Sites on the Metabolome of Staphylococcus aureus". Antimicrobial Agents and Chemotherapy 58, nr 12 (15.09.2014): 7151–63. http://dx.doi.org/10.1128/aac.03104-14.

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ABSTRACTIn this study, global intra- and extracellular metabolic profiles were exploited to investigate the impact of antibiotic compounds with different cellular targets on the metabolome ofStaphylococcus aureusHG001. Primary metabolism was largely covered, yet uncommon staphylococcal metabolites were detected in the cytosol ofS. aureus, including sedoheptulose-1,7-bisphosphate and the UDP-MurNAc-pentapeptide with an alanine-seryl residue. By comparing the metabolic profiles of unstressed and stressed staphylococcal cells in a time-dependent manner, we found far-ranging effects within the metabolome. For each antibiotic compound, accumulation as well as depletion of metabolites was detected, often comprising whole biosynthetic pathways, such as central carbon and amino acid metabolism and peptidoglycan, purine, and pyrimidine synthesis. Ciprofloxacin altered the pool of (deoxy)nucleotides as well as peptidoglycan precursors, thus linking stalled DNA and cell wall synthesis. Erythromycin tended to increase the amounts of intermediates of the pentose phosphate pathway and lysine. Fosfomycin inhibited the first enzymatic step of peptidoglycan synthesis, which was followed by decreased levels of peptidoglycan precursors but enhanced levels of substrates such as UDP-GlcNAc and alanine-alanine. In contrast, vancomycin and ampicillin inhibited the last stage of peptidoglycan construction on the outer cell surface. As a result, the amounts of UDP-MurNAc-peptides drastically increased, resulting in morphological alterations in the septal region and in an overall decrease in central metabolite levels. Moreover, each antibiotic affected intracellular levels of tricarboxylic acid cycle intermediates.

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Fernández, Ana, Astrid Pérez, Juan A. Ayala, Susana Mallo, Soraya Rumbo-Feal, Maria Tomás, Margarita Poza i Germán Bou. "Expression of OXA-Type and SFO-1 β-Lactamases Induces Changes in Peptidoglycan Composition and Affects Bacterial Fitness". Antimicrobial Agents and Chemotherapy 56, nr 4 (30.01.2012): 1877–84. http://dx.doi.org/10.1128/aac.05402-11.

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ABSTRACTβ-Lactamases and penicillin-binding proteins (PBPs) have evolved from a common ancestor. β-Lactamases are enzymes that degrade β-lactam antibiotics, whereas PBPs are involved in the synthesis and processing of peptidoglycan, which forms an elastic network in the bacterial cell wall. This study analyzed the interaction between β-lactamases and peptidoglycan and the impact on fitness and biofilm production. A representative set of all classes of β-lactamases was cloned in the expression vector pBGS18 under the control of the CTX-M promoter and expressed inEscherichia coliMG1655. The peptidoglycan composition of all clones was evaluated, and quantitative changes were found inE. colistrains expressing OXA-24, OXA-10-like, and SFO-1 (with its upstream regulator AmpR) β-lactamases; the level of cross-linked muropeptides decreased, and their average length increased. These changes were associated with a statistically significant fitness cost, which was demonstrated in bothin vitroandin vivoexperiments. The observed changes in peptidoglycan may be explained by the presence of residualdd-endopeptidase activity in these β-lactamases, which may result in hydrolysis of the peptide cross bridge. The biological cost associated with these changes provides important data regarding the interaction between β-lactamases and the metabolism of peptidoglycan and may provide an explanation for the epidemiology of these β-lactamases inEnterobacteriaceae.

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Maitra, Arundhati, Tulika Munshi, Jess Healy, Liam T. Martin, Waldemar Vollmer, Nicholas H. Keep i Sanjib Bhakta. "Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles’ heel for the TB-causing pathogen". FEMS Microbiology Reviews 43, nr 5 (10.06.2019): 548–75. http://dx.doi.org/10.1093/femsre/fuz016.

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ABSTRACTTuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis, remains one of the leading causes of mortality across the world. There is an urgent requirement to build a robust arsenal of effective antimicrobials, targeting novel molecular mechanisms to overcome the challenges posed by the increase of antibiotic resistance in TB. Mycobacterium tuberculosis has a unique cell envelope structure and composition, containing a peptidoglycan layer that is essential for maintaining cellular integrity and for virulence. The enzymes involved in the biosynthesis, degradation, remodelling and recycling of peptidoglycan have resurfaced as attractive targets for anti-infective drug discovery. Here, we review the importance of peptidoglycan, including the structure, function and regulation of key enzymes involved in its metabolism. We also discuss known inhibitors of ATP-dependent Mur ligases, and discuss the potential for the development of pan-enzyme inhibitors targeting multiple Mur ligases.

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Chan, Jia Mun, i Joseph P. Dillard. "Neisseria gonorrhoeae Crippled Its Peptidoglycan Fragment Permease To Facilitate Toxic Peptidoglycan Monomer Release". Journal of Bacteriology 198, nr 21 (22.08.2016): 3029–40. http://dx.doi.org/10.1128/jb.00437-16.

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ABSTRACTNeisseria gonorrhoeae(gonococci) andNeisseria meningitidis(meningococci) are human pathogens that cause gonorrhea and meningococcal meningitis, respectively. BothN. gonorrhoeaeandN. meningitidisrelease a number of small peptidoglycan (PG) fragments, including proinflammatory PG monomers, althoughN. meningitidisreleases fewer PG monomers. The PG fragments released byN. gonorrhoeaeandN. meningitidisare generated in the periplasm during cell wall remodeling, and a majority of these fragments are transported into the cytoplasm by an inner membrane permease, AmpG; however, a portion of the PG fragments are released into the extracellular environment through unknown mechanisms. We previously reported that the expression of meningococcalampGinN. gonorrhoeaereduced PG monomer release by gonococci. This finding suggested that the efficiency of AmpG-mediated PG fragment recycling regulates the amount of PG fragments released into the extracellular milieu. We determined that three AmpG residues near the C-terminal end of the protein modulate AmpG's efficiency. We also investigated the association between PG fragment recycling and release in two species of human-associated nonpathogenicNeisseria:N. siccaandN. mucosa. BothN. siccaandN. mucosarelease lower levels of PG fragments and are more efficient at recycling PG fragments thanN. gonorrhoeae. Our results suggest thatN. gonorrhoeaehas evolved to increase the amounts of toxic PG fragments released by reducing its PG recycling efficiency.IMPORTANCENeisseria gonorrhoeaeandNeisseria meningitidisare human pathogens that cause highly inflammatory diseases, althoughN. meningitidisis also frequently found as a normal member of the nasopharyngeal microbiota. NonpathogenicNeisseria, such asN. siccaandN. mucosa, also colonize the nasopharynx without causing disease. Although all four species release peptidoglycan fragments,N. gonorrhoeaeis the least efficient at recycling and releases the largest amount of proinflammatory peptidoglycan monomers, partly due to differences in the recycling permease AmpG. Studying the interplay between bacterial physiology (peptidoglycan metabolism) and pathogenesis (release of toxic monomers) leads to an increased understanding of how different bacterial species maintain asymptomatic colonization or cause disease and may contribute to efforts to mitigate disease.

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Rojony, Rajoana, Lia Danelishvili, Anaamika Campeau, Jacob M. Wozniak, David J. Gonzalez i Luiz E. Bermudez. "Exposure of Mycobacterium abscessus to Environmental Stress and Clinically Used Antibiotics Reveals Common Proteome Response among Pathogenic Mycobacteria". Microorganisms 8, nr 5 (9.05.2020): 698. http://dx.doi.org/10.3390/microorganisms8050698.

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Mycobacterium abscessus subsp. abscessus (MAB) is a clinically important nontuberculous mycobacterium (NTM) causing pulmonary infection in patients such as cystic fibrosis and bronchiectasis. MAB is naturally resistant to the majority of available antibiotics. In attempts to identify the fundamental response of MAB to aerobic, anaerobic, and biofilm conditions (as it is encountered in patients) and during exposure to antibiotics, we studied bacterial proteome using tandem mass tag mass spectrometry sequencing. Numerous de novo synthesized proteins belonging to diverse metabolic pathways were found in anaerobic and biofilm conditions, including glycolysis/gluconeogenesis, tricarboxylic acid (TCA) cycle, oxidative phosphorylation, nitrogen metabolism, and glyoxylate and dicarboxylate metabolism. Upon exposure to amikacin and linezolid under stress environments, MAB displayed metabolic enrichment for glycerophospholipid metabolism and oxidative phosphorylation. By comparing proteomes of two significant NTMs, MAB and M. avium subsp. hominissuis, we found highly synthesized shared enzymes of oxidative phosphorylation, TCA cycle, glycolysis/gluconeogenesis, glyoxylate/dicarboxylate, nitrogen metabolism, peptidoglycan biosynthesis, and glycerophospholipid/glycerolipid metabolism. The activation of peptidoglycan and fatty acid biosynthesis pathways indicates the attempt of bacteria to modify the cell wall, influencing the susceptibility to antibiotics. This study establishes global changes in the synthesis of enzymes promoting the metabolic shift and enhancing the pathogen resistance to antibiotics within different environments.

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PAYIE, KENNETH G., HENRI STRATING i ANTHONY J. CLARKE. "The Role ofO-Acetylation in the Metabolism of Peptidoglycan inProvidencia stuartii". Microbial Drug Resistance 2, nr 1 (styczeń 1996): 135–40. http://dx.doi.org/10.1089/mdr.1996.2.135.

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Kurek, Anna, Anna M. Grudniak, Magdalena Szwed, Anna Klicka, Lukasz Samluk, Krystyna I. Wolska, Wirginia Janiszowska i Magdalena Popowska. "Oleanolic acid and ursolic acid affect peptidoglycan metabolism in Listeria monocytogenes". Antonie van Leeuwenhoek 97, nr 1 (6.11.2009): 61–68. http://dx.doi.org/10.1007/s10482-009-9388-6.

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Bonis, Mathilde, Allison Williams, Stephanie Guadagnini, Catherine Werts i Ivo G. Boneca. "The Effect of Bulgecin A on Peptidoglycan Metabolism and Physiology ofHelicobacter pylori". Microbial Drug Resistance 18, nr 3 (czerwiec 2012): 230–39. http://dx.doi.org/10.1089/mdr.2011.0231.

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Rodionov, D. G., i E. E. Ishiguro. "Dependence of peptidoglycan metabolism on phospholipid synthesis during growth of Escherichia coli". Microbiology 142, nr 10 (1.10.1996): 2871–77. http://dx.doi.org/10.1099/13500872-142-10-2871.

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Miao, Jiatong, Hanrui Liu, Yushan Qu, Weizhe Fu, Kangwei Qi, Shizhu Zang, Jiajia He, Shijia Zhao, Shixing Chen i Tao Jiang. "Effect of peptidoglycan amidase MSMEG_6281 on fatty acid metabolism in Mycobacterium smegmatis". Microbial Pathogenesis 140 (marzec 2020): 103939. http://dx.doi.org/10.1016/j.micpath.2019.103939.

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Henze, U., T. Sidow, J. Wecke, H. Labischinski i B. Berger-Bächi. "Influence of femB on methicillin resistance and peptidoglycan metabolism in Staphylococcus aureus." Journal of Bacteriology 175, nr 6 (1993): 1612–20. http://dx.doi.org/10.1128/jb.175.6.1612-1620.1993.

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Giefing-Kröll, Carmen, Kira E. Jelencsics, Siegfried Reipert i Eszter Nagy. "Absence of pneumococcal PcsB is associated with overexpression of LysM domain-containing proteins". Microbiology 157, nr 7 (1.07.2011): 1897–909. http://dx.doi.org/10.1099/mic.0.045211-0.

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The streptococcal protein required for cell separation B (PcsB) is predicted to play an important role in peptidoglycan metabolism, based on sequence motifs and altered phenotypes of gene deletion mutant cells exhibiting defects in cell separation. However, no enzymic activity has been demonstrated for PcsB so far. By generating gene deletion mutant strains in four different genetic backgrounds we could demonstrate that pcsB is not essential for cell survival in Streptococcus pneumoniae, but is essential for proper cell division. Deletion mutant cells displayed cluster formation due to aberrant cell division, reduced growth and antibiotic sensitivity that were fully reverted by transformation with a plasmid carrying pcsB. Immunofluorescence staining revealed that PcsB was localized to the cell poles, similarly to PBP3 and LytB, enzymes with demonstrated peptidoglycan-degrading activity required for daughter cell separation. Similarly to other studies with PcsB homologues, we could not detect peptidoglycan-lytic activity with recombinant or native pneumococcal PcsB in vitro. In addition to defects in septum placement and separation, the absence of PcsB induced an increased release of several proteins, such as enolase, MalX and the SP0107 LysM domain protein. Interestingly, genes encoding both LysM domain-containing proteins that are present in the pneumococcal genome (SP0107 and SP2063) and predicted to be involved in cell wall metabolism were found to be highly overexpressed (14–33-fold increase) in ΔpcsB cells in two different genetic backgrounds. Otherwise, we detected very few changes in the global gene expression profile of cells lacking PcsB. Thus our data suggest that LysM domain proteins partially compensate for the lack of PcsB function and allow the survival and slow growth of the pneumococcus.

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Alvarez, Laura, Sara B. Hernandez i Felipe Cava. "Cell Wall Biology of Vibrio cholerae". Annual Review of Microbiology 75, nr 1 (8.10.2021): 151–74. http://dx.doi.org/10.1146/annurev-micro-040621-122027.

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Most bacteria are protected from environmental offenses by a cell wall consisting of strong yet elastic peptidoglycan. The cell wall is essential for preserving bacterial morphology and viability, and thus the enzymes involved in the production and turnover of peptidoglycan have become preferred targets for many of our most successful antibiotics. In the past decades, Vibrio cholerae, the gram-negative pathogen causing the diarrheal disease cholera, has become a major model for understanding cell wall genetics, biochemistry, and physiology. More than 100 articles have shed light on novel cell wall genetic determinants, regulatory links, and adaptive mechanisms. Here we provide the first comprehensive review of V. cholerae’s cell wall biology and genetics. Special emphasis is placed on the similarities and differences with Escherichia coli, the paradigm for understanding cell wall metabolism and chemical structure in gram-negative bacteria.

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Bæk, Kristoffer T., Angelika Gründling, René G. Mogensen, Louise Thøgersen, Andreas Petersen, Wilhelm Paulander i Dorte Frees. "β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus USA300 Is Increased by Inactivation of the ClpXP Protease". Antimicrobial Agents and Chemotherapy 58, nr 8 (27.05.2014): 4593–603. http://dx.doi.org/10.1128/aac.02802-14.

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ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) has acquired themecAgene encoding a peptidoglycan transpeptidase, penicillin binding protein 2a (PBP2a), which has decreased affinity for β-lactams. Quickly spreading and highly virulent community-acquired (CA) MRSA strains recently emerged as a frequent cause of infection in individuals without exposure to the health care system. In this study, we found that the inactivation of the components of the ClpXP protease substantially increased the β-lactam resistance level of a CA-MRSA USA300 strain, suggesting that the proteolytic activity of ClpXP controls one or more pathways modulating β-lactam resistance. These pathways do not involve the control ofmecAexpression, as the cellular levels of PBP2a were unaltered in theclpmutants. An analysis of the cell envelope properties of theclpXandclpPmutants revealed a number of distinct phenotypes that may contribute to the enhanced β-lactam tolerance. Both mutants displayed significantly thicker cell walls, increased peptidoglycan cross-linking, and altered composition of monomeric muropeptide species compared to those of the wild types. Moreover, changes in Sle1-mediated peptidoglycan hydrolysis and altered processing of the major autolysin Atl were observed in theclpmutants. In conclusion, the results presented here point to an important role for the ClpXP protease in controlling cell wall metabolism and add novel insights into the molecular factors that determine strain-dependent β-lactam resistance.

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Rousseau, N., M. Dargis, P. Gourde, D. Beauchamp i F. Malouin. "Effect of beta-lactams on peptidoglycan metabolism of Haemophilus influenzae grown in animals." Antimicrobial Agents and Chemotherapy 36, nr 10 (1.10.1992): 2147–55. http://dx.doi.org/10.1128/aac.36.10.2147.

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Fujimoto, David F., i Kenneth W. Bayles. "Opposing Roles of the Staphylococcus aureus Virulence Regulators, Agr and Sar, in Triton X-100- and Penicillin-Induced Autolysis". Journal of Bacteriology 180, nr 14 (15.07.1998): 3724–26. http://dx.doi.org/10.1128/jb.180.14.3724-3726.1998.

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ABSTRACT The regulation of murein hydrolases is a critical aspect of peptidoglycan growth and metabolism. In the present study, we demonstrate that mutations within the Staphylococcus aureusvirulence factor regulatory genes, agr and sar, affect autolysis, resulting in decreased and increased autolysis rates, respectively. Zymographic analyses of these mutant strains suggest thatagr and sar exert their effects on autolysis, in part, by modulating murein hydrolase expression and/or activity.

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Zhang, Xinshuai, Yao Ruan, Wukang Liu, Qian Chen, Lihong Gu i Ailing Guo. "Transcriptome Analysis of Gene Expression in Dermacoccus abyssi HZAU 226 under Lysozyme Stress". Microorganisms 8, nr 5 (11.05.2020): 707. http://dx.doi.org/10.3390/microorganisms8050707.

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Lysozyme acts as a kind of cationic antimicrobial protein and effectively hydrolyzes bacterial peptidoglycan to have a bactericidal effect, which also plays an important role in protecting eggs from microbial contamination. Dermacoccus abyssi HZAU 226, a Gram-positive bacterium isolated from spoiled eggs, has egg white and lysozyme tolerance, but its survival mechanism is unknown, especially from a transcriptomics point of view. In this study, the high lysozyme tolerance of D. abyssi HZAU 226 was characterized by three independent experiments, and then the Illumina RNA-seq was used to compare the transcriptional profiles of this strain in Luria–Bertani (LB) medium with and without 5 mg/mL lysozyme to identify differentially expressed genes (DEGs); 1024 DEGs were identified by expression analysis, including 544 up-regulated genes and 480 down-regulated genes in response to lysozyme treatment. The functional annotation analysis results of DEGs showed that these genes were mainly involved in glutathione biosynthesis and metabolism, ion transport, energy metabolism pathways, and peptidoglycan biosynthesis. This study is the first report of bacterial-related lysozyme RNA-seq, and our results help in understanding the lysozyme-tolerance mechanism of bacteria from a new perspective and provide transcriptome resources for subsequent research in related fields.

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Luan, Jun-Bo. "Insect Bacteriocytes: Adaptation, Development, and Evolution". Annual Review of Entomology 69, nr 1 (25.01.2024): 81–98. http://dx.doi.org/10.1146/annurev-ento-010323-124159.

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Bacteriocytes are host cells specialized to harbor symbionts in certain insect taxa. The adaptation, development, and evolution of bacteriocytes underlie insect symbiosis maintenance. Bacteriocytes carry enriched host genes of insect and bacterial origin whose transcription can be regulated by microRNAs, which are involved in host–symbiont metabolic interactions. Recognition proteins of peptidoglycan, the bacterial cell wall component, and autophagy regulate symbiont abundance in bacteriocytes. Horizontally transferred genes expressed in bacteriocytes influence the metabolism of symbiont peptidoglycan, which may affect the bacteriocyte immune response against symbionts. Bacteriocytes release or transport symbionts into ovaries for symbiont vertical transmission. Bacteriocyte development and death, regulated by transcriptional factors, are variable in different insect species. The evolutionary origin of insect bacteriocytes remains unclear. Future research should elucidate bacteriocyte cell biology, the molecular interplay between bacteriocyte metabolic and immune functions, the genetic basis of bacteriocyte origin, and the coordination between bacteriocyte function and host biology in diverse symbioses.

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de Oliveira, Amanda C. P., Rafael M. Ferreira, Maria Inês T. Ferro, Jesus A. Ferro, Caio Zamuner, Henrique Ferreira i Alessandro M. Varani. "XAC4296 Is a Multifunctional and Exclusive Xanthomonadaceae Gene Containing a Fusion of Lytic Transglycosylase and Epimerase Domains". Microorganisms 10, nr 5 (11.05.2022): 1008. http://dx.doi.org/10.3390/microorganisms10051008.

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Microorganisms have a limited and highly adaptable repertoire of genes capable of encoding proteins containing single or variable multidomains. The phytopathogenic bacteria Xanthomonas citri subsp. citri (X. citri) (Xanthomonadaceae family), the etiological agent of Citrus Canker (CC), presents a collection of multidomain and multifunctional enzymes (MFEs) that remains to be explored. Recent studies have shown that multidomain enzymes that act on the metabolism of the peptidoglycan and bacterial cell wall, belonging to the Lytic Transglycosylases (LTs) superfamily, play an essential role in X. citri biology. One of these LTs, named XAC4296, apart from the Transglycosylase SLT_2 and Peptidoglycan binding-like domains, contains an unexpected aldose 1-epimerase domain linked to the central metabolism; therefore, resembling a canonical MFE. In this work, we experimentally characterized XAC4296 revealing its role as an MFE and demonstrating its probable gene fusion origin and evolutionary history. The XAC4296 is expressed during plant-pathogen interaction, and the Δ4296 mutant impacts CC progression. Moreover, Δ4296 exhibited chromosome segregation and cell division errors, and sensitivity to ampicillin, suggesting not only LT activity but also that the XAC4296 may also contribute to resistance to β-lactams. However, both Δ4296 phenotypes can be restored when the mutant is supplemented with sucrose or glutamic acid as a carbon and nitrogen source, respectively; therefore, supporting the epimerase domain’s functional relationship with the central carbon and cell wall metabolism. Taken together, these results elucidate the role of XAC4296 as an MFE in X. citri, also bringing new insights into the evolution of multidomain proteins and antimicrobial resistance in the Xanthomonadaceae family.

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MARKOWSKA, KATARZYNA, ANNA MARIA GRUDNIAK, BARBARA MILCZAREK i KRYSTYNA IZABELLA WOLSKA. "The Effect of Silver Nanoparticles on Listeria monocytogenes PCM2191 Peptidoglycan Metabolism and Cell Permeability". Polish Journal of Microbiology 67, nr 3 (2018): 315–20. http://dx.doi.org/10.21307/pjm-2018-037.

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Arthur, Michel, Florence Depardieu, Peter Reynolds i Patrice Courvalin. "Quantitative analysis of the metabolism of soluble cytoplasmic peptidoglycan precursors of glycopeptide‐resistant enterococci". Molecular Microbiology 21, nr 1 (lipiec 1996): 33–44. http://dx.doi.org/10.1046/j.1365-2958.1996.00617.x.

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Hervé, Mireille, Audrey Boniface, Stanislav Gobec, Didier Blanot i Dominique Mengin-Lecreulx. "Biochemical Characterization and Physiological Properties of Escherichia coli UDP-N-Acetylmuramate:l-Alanyl-γ-d-Glutamyl-meso- Diaminopimelate Ligase". Journal of Bacteriology 189, nr 11 (23.03.2007): 3987–95. http://dx.doi.org/10.1128/jb.00087-07.

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ABSTRACT The UDP-N-acetylmuramate:l-alanyl-γ-d-glutamyl-meso-diaminopimelate ligase (murein peptide ligase [Mpl]) is known to be a recycling enzyme allowing reincorporation into peptidoglycan (murein) of the tripeptide l-alanyl-γ-d-glutamyl-meso-diaminopimelate released during the maturation and constant remodeling of this bacterial cell wall polymer that occur during cell growth and division. Mpl adds this peptide to UDP-N-acetylmuramic acid, thereby providing an economical additional source of UDP-MurNAc-tripeptide available for de novo peptidoglycan biosynthesis. The Mpl enzyme from Escherichia coli was purified to homogeneity as a His-tagged form, and its kinetic properties and parameters were determined. Mpl was found to accept tri-, tetra-, and pentapeptides as substrates in vitro with similar efficiencies, but it accepted the dipeptide l-Ala-d-Glu and l-Ala very poorly. Replacement of meso-diaminopimelic acid by l-Lys resulted in a significant decrease in the catalytic efficacy. The effects of disruption of the E. coli mpl gene and/or the ldcA gene encoding the ld-carboxypeptidase on peptidoglycan metabolism were investigated. The differences in the pools of UDP-MurNAc peptides and of free peptides between the wild-type and mutant strains demonstrated that the recycling activity of Mpl is not restricted to the tripeptide and that tetra- and pentapeptides are also directly reused by this process in vivo. The relatively broad substrate specificity of the Mpl ligase indicates that it is an interesting potential target for antibacterial compounds.

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Quintanilla, Samantha Y., Neda Habibi Arejan, Parthvi B. Patel i Cara C. Boutte. "PlrA (MSMEG_5223) is an essential polar growth regulator in Mycobacterium smegmatis". PLOS ONE 18, nr 1 (12.01.2023): e0280336. http://dx.doi.org/10.1371/journal.pone.0280336.

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Mycobacteria expand their cell walls at the cell poles in a manner that is not well described at the molecular level. In this study, we identify a new polar factor, PlrA, that is involved in restricting peptidoglycan metabolism to the cell poles in Mycobacterium smegmatis. We establish that only the N-terminal membrane domain of PlrA is essential. We show that depletion of plrA pheno-copies depletion of polar growth factor Wag31, and that PlrA is involved in regulating the Wag31 polar foci.

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Papadopoulos, Andrea Olga, Christopher Ealand, Bhavna Gowan Gordhan, Michael VanNieuwenhze i Bavesh Davandra Kana. "Characterisation of a putative M23-domain containing protein in Mycobacterium tuberculosis". PLOS ONE 16, nr 11 (16.11.2021): e0259181. http://dx.doi.org/10.1371/journal.pone.0259181.

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Mycobacterium tuberculosis, the causative agent of tuberculosis remains a global health concern, further compounded by the high rates of HIV-TB co-infection and emergence of multi- and extensive drug resistant TB, all of which have hampered efforts to eradicate this disease. As a result, novel anti-tubercular interventions are urgently required, with the peptidoglycan component of the M. tuberculosis cell wall emerging as an attractive drug target. Peptidoglycan M23 endopeptidases can function as active cell wall hydrolases or degenerate activators of hydrolases in a variety of bacteria, contributing to important processes such as bacterial growth, division and virulence. Herein, we investigate the function of the Rv0950-encoded putative M23 endopeptidase in M. tuberculosis. In silico analysis revealed that this protein is conserved in mycobacteria, with a zinc-binding catalytic site predictive of hydrolytic activity. Transcript analysis indicated that expression of Rv0950c was elevated during lag and log phases of growth and reduced in stationary phase. Deletion of Rv0950c yielded no defects in growth, colony morphology, antibiotic susceptibility or intracellular survival but caused a reduction in cell length. Staining with a monopeptide-derived fluorescent D-amino acid, which spatially reports on sites of active PG biosynthesis or repair, revealed an overall reduction in uptake of the probe in ΔRv0950c. When stained with a dipeptide probe in the presence of cell wall damaging agents, the ΔRv0950c mutant displayed reduced sidewall labelling. As bacterial peptidoglycan metabolism is important for survival and pathogenesis, the role of Rv0950c and other putative M23 endopeptidases in M. tuberculosis should be explored further.

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Sieradzki, Krzysztof, i Alexander Tomasz. "Gradual Alterations in Cell Wall Structure and Metabolism in Vancomycin-Resistant Mutants ofStaphylococcus aureus". Journal of Bacteriology 181, nr 24 (15.12.1999): 7566–70. http://dx.doi.org/10.1128/jb.181.24.7566-7570.1999.

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ABSTRACT In five vancomycin-resistant laboratory step mutants selected from the highly and homogeneously methicillin-resistant Staphylococcus aureus strain COL (MIC of methicillin, 800 μg/ml; MIC of vancomycin, 1.5 μg/ml), the gradually increasing levels of resistance to vancomycin were accompanied by parallel decreases in the levels of methicillin resistance and abnormalities in cell wall metabolism. The latter included a gradual reduction in the proportion of highly cross-linked muropeptide species in peptidoglycan, down-regulation of the production of penicillin-binding protein 2A (PBP2A) and PBP4, and hypersensitivity to β-lactam antibiotics each with a relatively selective affinity for the various staphylococcal PBPs; the PBP2-specific inhibitor ceftizoxime was particularly effective.

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Oliveira, Amanda C. P., Rafael M. Ferreira, Maria Inês T. Ferro, Jesus A. Ferro, Mick Chandler i Alessandro M. Varani. "Transposons and pathogenicity inXanthomonas: acquisition of murein lytic transglycosylases by TnXax1enhancesXanthomonas citrisubsp.citri306 virulence and fitness". PeerJ 6 (19.12.2018): e6111. http://dx.doi.org/10.7717/peerj.6111.

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Xanthomonas citrisubsp.citri306 (XccA) is the causal agent of type A citrus canker (CC), one of the most significant citriculture diseases. Murein lytic transglycosylases (LT), potentially involved in XccA pathogenicity, are enzymes responsible for peptidoglycan structure assembly, remodeling and degradation. They directly impact cell wall expansion during bacterial growth, septum division allowing cell separation, cell wall remodeling allowing flagellar assembly, bacterial conjugation, muropeptide recycling, and secretion system assembly, in particular the Type 3 Secretion System involved in bacterial virulence, which play a fundamental role in XccA pathogenicity. Information about the XccA LT arsenal is patchy: little is known about family diversity, their exact role or their connection to virulence in this bacterium. Among the LTs with possible involvement in virulence, two paralogue open reading frames (ORFs) (one on the chromosome and one in plasmid pXAC64) are passenger genes of the Tn3family transposon TnXax1, known to play a significant role in the evolution and emergence of pathogenicity inXanthomonadalesand to carry a variety of virulence determinants. This study addresses LT diversity in the XccA genome and examines the role of plasmid and chromosomal TnXax1LT passenger genes using site-directed deletion mutagenesis and functional characterization. We identified 13 XccA LTs: 12 belong to families 1A, 1B, 1C, 1D (two copies), 1F, 1G, 3A, 3B (two copies), 5A, 6A and one which is non-categorized. The non-categorized LT is exclusive to theXanthomonasgenus and related to the 3B family but contains an additional domain linked to carbohydrate metabolism. The categorized LTs are probably involved in cell wall remodeling to allow insertion of type 3, 4 and 6 secretion systems, flagellum assembly, division and recycling of cell wall and degradation and control of peptidoglycan production. The TnXax1passenger LT genes (3B family) are not essential to XccA or for CC development but are implicated in peptidoglycan metabolism, directly impacting bacterial fitness and CC symptom enhancement in susceptible hosts (e.g.,Citrus sinensis). This underlines the role of TnXax1as a virulence and pathogenicity-propagating agent in XccA and suggests that LT acquisition by horizontal gene transfer mediated by TnXax1may improve bacterial fitness, conferring adaptive advantages to the plant-pathogen interaction process.

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Daugelavičius, Rimantas, Virginija Cvirkaitė, Aušra Gaidelytė, Elena Bakienė, Rasa Gabrėnaitė-Verkhovskaya i Dennis H. Bamford. "Penetration of Enveloped Double-Stranded RNA Bacteriophages φ13 and φ6 into Pseudomonas syringae Cells". Journal of Virology 79, nr 8 (15.04.2005): 5017–26. http://dx.doi.org/10.1128/jvi.79.8.5017-5026.2005.

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ABSTRACT Bacteriophages φ6 and φ13 are related enveloped double-stranded RNA viruses that infect gram-negative Pseudomonas syringae cells. φ6 uses a pilus as a receptor, and φ13 attaches to the host lipopolysaccharide. We compared the entry-related events of these two viruses, including receptor binding, envelope fusion, peptidoglycan penetration, and passage through the plasma membrane. The infection-related events are dependent on the multiplicity of infection in the case of φ13 but not with φ6. A temporal increase of host outer membrane permeability to lipophilic ions was observed from 1.5 to 4 min postinfection in both virus infections. This enhanced permeability period coincided with the fast dilution of octadecyl rhodamine B-labeled virus-associated lipid molecules. This result is in agreement with membrane fusion, and the presence of temporal virus-derived membrane patches on the outer membrane. Similar to φ6, φ13 contains a thermosensitive lytic enzyme involved in peptidoglycan penetration. The phage entry also caused a limited depolarization of the plasma membrane. Inhibition of host respiration considerably decreased the efficiency of irreversible virus binding and membrane fusion. An active role of cell energy metabolism in restoring the infection-induced defects in the cell envelope was also observed.

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Heywood, Astra, i Iain L. Lamont. "Cell envelope proteases and peptidases of Pseudomonas aeruginosa: multiple roles, multiple mechanisms". FEMS Microbiology Reviews 44, nr 6 (17.08.2020): 857–73. http://dx.doi.org/10.1093/femsre/fuaa036.

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ABSTRACT Pseudomonas aeruginosa is a Gram-negative bacterium that is commonly isolated from damp environments. It is also a major opportunistic pathogen, causing a wide range of problematic infections. The cell envelope of P. aeruginosa, comprising the cytoplasmic membrane, periplasmic space, peptidoglycan layer and outer membrane, is critical to the bacteria's ability to adapt and thrive in a wide range of environments. Over 40 proteases and peptidases are located in the P. aeruginosa cell envelope. These enzymes play many crucial roles. They are required for protein secretion out of the cytoplasm to the periplasm, outer membrane, cell surface or the environment; for protein quality control and removal of misfolded proteins; for controlling gene expression, allowing adaptation to environmental changes; for modification and remodelling of peptidoglycan; and for metabolism of small molecules. The key roles of cell envelope proteases in ensuring normal cell functioning have prompted the development of inhibitors targeting some of these enzymes as potential new anti-Pseudomonas therapies. In this review, we summarise the current state of knowledge across the breadth of P. aeruginosa cell envelope proteases and peptidases, with an emphasis on recent findings, and highlight likely future directions in their study.

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Dillard, Joseph P., i Kathleen T. Hackett. "Mutations Affecting Peptidoglycan Acetylation in Neisseria gonorrhoeae and Neisseria meningitidis". Infection and Immunity 73, nr 9 (wrzesień 2005): 5697–705. http://dx.doi.org/10.1128/iai.73.9.5697-5705.2005.

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ABSTRACT Neisseria gonorrhoeae acetylates its cell wall peptidoglycan (PG) at the C-6 position on N-acetylmuramic acid. To understand the effects of PG acetylation on PG metabolism and release of PG fragments, we have made mutations in the genes responsible for PG acetylation. An insertion mutation in a putative PG acetylase gene (designated pacA) resulted in loss of PG acetylation as detected by a high-performance liquid chromatography-based assay. Sequence analysis of a naturally occurring nonacetylating strain revealed the presence of a 26-bp deletion in pacA. Introduction of the deletion mutation into wild-type gonococci resulted in lack of acetylation, and the phenotype was complemented by the addition of a wild-type copy of pacA at a distant location on the chromosome. Mutations were also introduced into three genes downstream of pacA. The gene directly downstream of pacA was required for acetylation and was designated pacB, whereas the next two genes were not required. Sequences highly similar to pacA and pacB were also found in N. meningitidis and N. lactamica strains, and an insertion in the meningococcal pacA eliminated PG acetylation. Phenotypic analyses of an N. gonorrhoeae pacA mutant did not show any decrease in lysozyme resistance or serum resistance, and the release of PG fragments during growth was unchanged. However, purified PG from the wild-type strain was significantly more resistant to the action of human lysozyme than was PG purified from the pacA mutant. Interestingly, the pacA mutant was more sensitive to EDTA, a compound known to trigger autolysis.

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Aliev, R. B., N. V. Stryzhak, A. S. Shapovalova, S. I. Abuvatfa, O. S. Kunytska i P. G. Kovalenko. "CLINICAL SIGNIFICANCE OF THE INFLUENCE OF CELL WALL ANTIGENS OF STAPHYLOCOCCUS AUREUS ON PHAGOCYTIC CELLS OF THE PERIPHERAL BLOOD IN CHILDREN WITH PURULENT AND INFLAMMATORY DISEASES OF STAPHYLOCOCCAL ETIOLOGY". Medical and Ecological Problems 27, nr 3-4 (31.08.2023): 13–16. http://dx.doi.org/10.31718/mep.2023.27.3-4.02.

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The paper examines the features of oxygen-dependent metabolism of peripheral blood phagocytes and the nature of its exposure to peptidoglycan and teichoic acid of Staphylococcus aureus. The study included 86 children with purulent and inflammatory processes of staphylococcal etiology aged from 7 months to 12 years and 14 apparently healthy children. The results of the study showed that in most children at the onset of the disease, an increase in the intensity of the oxygen-dependent metabolism of neutrophil granulocytes and monocytes was observed, which was manifested by elevated indicators of the spontaneous HCT test of these cells compared to healthy children. During the period of clinical recovery in children with an acute course of the disease, a significant decrease in spontaneous HST-test indicators was observed. In addition to the spontaneous HCT test, we also studied the indicators of the oxygen-dependent metabolism of neutrophil granulocytes and monocytes after incubation of these cells with cell wall antigens of Staphylococcus aureus – peptidoglycans and teichoic acids. The results of the study showed that after incubation, no significant difference was found between them and the indicators of the spontaneous HCT test. In the period of convalescence in children with acute bronchopneumonia, acute purulent otitis media, acute tonsillitis, a decrease in indicators of oxygen-dependent metabolism was observed after incubation of monocytes with teichoic acids compared to spontaneous indicators. Thus, the effect of cell wall antigens of Staphylococcus aureus on the oxygen-dependent metabolism of neutrophil granulocytes and monocytes of peripheral blood was different. At the beginning of the development of the pathological process, reliable inhibition of the oxygen-dependent metabolism of phagocytes by antigens of the cell wall of Staphylococcus aureus was observed in all clinical groups. In the acute course at the beginning of the disease, the suppression of HST-test indicators was somewhat greater than in the exacerbation of the chronic process. During the recovery of patients with an acute purulent-inflammatory process, reliable inhibition of the oxygen-dependent metabolism of neutrophil granulocytes and monocytes by cell wall antigens of Staphylococcus aureus was not observed, and in children with an exacerbation of the chronic pathological process, the inhibition of the indicators of the HCT test of neutrophil granulocytes and monocytes remained reliably higher and almost did not change compared to the onset of the disease.

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Rajeeve, Karthika, Nadine Vollmuth, Sudha Janaki-Raman, Thomas F. Wulff, Apoorva Baluapuri, Francesca R. Dejure, Claudia Huber i in. "Reprogramming of host glutamine metabolism during Chlamydia trachomatis infection and its key role in peptidoglycan synthesis". Nature Microbiology 5, nr 11 (3.08.2020): 1390–402. http://dx.doi.org/10.1038/s41564-020-0762-5.

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DE ROUBIN, M. R., D. MENGIN-LECREULX i J. VAN HEIJENOORT. "Peptidoglycan biosynthesis in Escherichia coli: variations in the metabolism of alanine and D-alanyl-D-alanine". Journal of General Microbiology 138, nr 8 (1.08.1992): 1751–57. http://dx.doi.org/10.1099/00221287-138-8-1751.

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Bancroft, Peter J., Obolbek Turapov, Heena Jagatia, Kristine B. Arnvig, Galina V. Mukamolova i Jeffrey Green. "Coupling of Peptidoglycan Synthesis to Central Metabolism in Mycobacteria: Post-transcriptional Control of CwlM by Aconitase". Cell Reports 32, nr 13 (wrzesień 2020): 108209. http://dx.doi.org/10.1016/j.celrep.2020.108209.

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Bannikova, Svetlana, Tamara Khlebodarova, Asya Vasilieva, Irina Mescheryakova, Alla Bryanskaya, Elizaveta Shedko, Vasily Popik, Tatiana Goryachkovskaya i Sergey Peltek. "Specific Features of the Proteomic Response of Thermophilic Bacterium Geobacillus icigianus to Terahertz Irradiation". International Journal of Molecular Sciences 23, nr 23 (2.12.2022): 15216. http://dx.doi.org/10.3390/ijms232315216.

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Studying the effects of terahertz (THz) radiation on the proteome of temperature-sensitive organisms is limited by a number of significant technical difficulties, one of which is maintaining an optimal temperature range to avoid thermal shock as much as possible. In the case of extremophilic species with an increased temperature tolerance, it is easier to isolate the effects of THz radiation directly. We studied the proteomic response to terahertz radiation of the thermophilic Geobacillus icigianus, persisting under wide temperature fluctuations with a 60 °C optimum. The experiments were performed with a terahertz free-electron laser (FEL) from the Siberian Center for Synchrotron and Terahertz Radiation, designed and employed by the Institute of Nuclear Physics of the SB of the RAS. A G. icigianus culture in LB medium was THz-irradiated for 15 min with 0.23 W/cm2 and 130 μm, using a specially designed cuvette. The life cycle of this bacterium proceeds under conditions of wide temperature and osmotic fluctuations, which makes its enzyme systems stress-resistant. The expression of several proteins was shown to change immediately after fifteen minutes of irradiation and after ten minutes of incubation at the end of exposure. The metabolic systems of electron transport, regulation of transcription and translation, cell growth and chemotaxis, synthesis of peptidoglycan, riboflavin, NADH, FAD and pyridoxal phosphate cofactors, Krebs cycle, ATP synthesis, chaperone and protease activity, and DNA repair, including methylated DNA, take part in the fast response to THz radiation. When the response developed after incubation, the systems of the cell’s anti-stress defense, chemotaxis, and, partially, cell growth were restored, but the respiration and energy metabolism, biosynthesis of riboflavin, cofactors, peptidoglycan, and translation system components remained affected and the amino acid metabolism system was involved.

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Pavelić, K., R. J. Bernacki i S. Vuk-Pavlović. "Insulin-modulated interleukin-2 production by murine splenocytes and a T-cell hybridoma". Journal of Endocrinology 114, nr 1 (lipiec 1987): 89–94. http://dx.doi.org/10.1677/joe.0.1140089.

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ABSTRACT Murine interleukin-2 (IL-2)-producing AOFS 21 T-cell hybridoma cells and normal murine splenocytes were stimulated in serum-free media by 16 potential mitogens/growth factors. Only insulin, concanavalin A (Con A), peptidoglycan monomer and a tumour-derived insulinoid stimulated [3H]thymidine incorporation by AOFS 21 cells and splenocytes. Supernatants of these stimulated cultures were tested for IL-2 activity which generally followed the pattern of growth stimulation. Both the mitogenicity and stimulation of IL-2 secretion by insulin were second only to the effects of Con A. J. Endocr. (1987) 114, 89–94

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Chaput, Catherine, Chantal Ecobichon, Nadine Pouradier, Jean-Claude Rousselle, Abdelkader Namane i Ivo G. Boneca. "Role of theN-Acetylmuramoyl-l-Alanyl Amidase, AmiA, ofHelicobacter pyloriin Peptidoglycan Metabolism, Daughter Cell Separation, and Virulence". Microbial Drug Resistance 22, nr 6 (wrzesień 2016): 477–86. http://dx.doi.org/10.1089/mdr.2016.0070.

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van Heijenoort, Y., M. Gómez, M. Derrien, J. Ayala i J. van Heijenoort. "Membrane intermediates in the peptidoglycan metabolism of Escherichia coli: possible roles of PBP 1b and PBP 3." Journal of Bacteriology 174, nr 11 (1992): 3549–57. http://dx.doi.org/10.1128/jb.174.11.3549-3557.1992.

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Mengin-Lecreulx, Dominique, i Bruno Lemaitre. "Structure and metabolism of peptidoglycan and molecular requirements allowing its detection by the Drosophila innate immune system". Journal of Endotoxin Research 11, nr 2 (kwiecień 2005): 105–11. http://dx.doi.org/10.1177/09680519050110020601.

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Bisicchia, Paola, Efthimia Lioliou, David Noone, Letal I. Salzberg, Eric Botella, Sebastian Hübner i Kevin M. Devine. "Peptidoglycan metabolism is controlled by the WalRK (YycFG) and PhoPR two-component systems in phosphate-limitedBacillus subtiliscells". Molecular Microbiology 75, nr 4 (luty 2010): 972–89. http://dx.doi.org/10.1111/j.1365-2958.2009.07036.x.

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de Sarrau, Benoît, Thierry Clavel, Isabelle Bornard i Christophe Nguyen-the. "Low temperatures and fermentative metabolism limit peptidoglycan digestion of Bacillus cereus. Impact on colony forming unit counts". Food Microbiology 33, nr 2 (kwiecień 2013): 213–20. http://dx.doi.org/10.1016/j.fm.2012.09.019.

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Valinger, Zdenka, Branko Ladešić, Ivo Hršak i Jelka Tomašić. "Relationship of metabolism and immunostimulating activity of peptidoglycan monomer in mice after three different routes of administration". International Journal of Immunopharmacology 9, nr 3 (styczeń 1987): 325–32. http://dx.doi.org/10.1016/0192-0561(87)90057-9.

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Miyamoto, Tetsuya, Masumi Katane, Yasuaki Saitoh, Masae Sekine i Hiroshi Homma. "Cystathionine β-lyase is involved in d-amino acid metabolism". Biochemical Journal 475, nr 8 (23.04.2018): 1397–410. http://dx.doi.org/10.1042/bcj20180039.

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Non-canonical d-amino acids play important roles in bacteria including control of peptidoglycan metabolism and biofilm disassembly. Bacteria appear to produce non-canonical d-amino acids to adapt to various environmental changes, and understanding the biosynthetic pathways is important. We identified novel amino acid racemases possessing the ability to produce non-canonical d-amino acids in Escherichia coli and Bacillus subtilis in our previous study, whereas the biosynthetic pathways of these d-amino acids still remain unclear. In the present study, we demonstrated that two cystathionine β-lyases (MetC and MalY) from E. coli produce non-canonical d-amino acids including non-proteinogenic amino acids. Furthermore, MetC displayed d- and l-serine (Ser) dehydratase activity. We characterised amino acid racemase, Ser dehydratase and cysteine lyase activities, and all were higher for MetC. Interestingly, all three activities were at a comparable level for MetC, although optimal conditions for each reaction were distinct. These results indicate that MetC and MalY are multifunctional enzymes involved in l-methionine metabolism and the production of d-amino acids, as well as d- and l-Ser metabolism. To our knowledge, this is the first evidence that cystathionine β-lyase is a multifunctional enzyme with three different activities.

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Briers, Yves, Maarten Walmagh, Barbara Grymonprez, Manfred Biebl, Jean-Paul Pirnay, Valerie Defraine, Jan Michiels i in. "Art-175 Is a Highly Efficient Antibacterial against Multidrug-Resistant Strains and Persisters of Pseudomonas aeruginosa". Antimicrobial Agents and Chemotherapy 58, nr 7 (21.04.2014): 3774–84. http://dx.doi.org/10.1128/aac.02668-14.

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ABSTRACTArtilysins constitute a novel class of efficient enzyme-based antibacterials. Specifically, they covalently combine a bacteriophage-encoded endolysin, which degrades the peptidoglycan, with a targeting peptide that transports the endolysin through the outer membrane of Gram-negative bacteria. Art-085, as well as Art-175, its optimized homolog with increased thermostability, are each composed of the sheep myeloid 29-amino acid (SMAP-29) peptide fused to the KZ144 endolysin. In contrast to KZ144, Art-085 and Art-175 pass the outer membrane and killPseudomonas aeruginosa, including multidrug-resistant strains, in a rapid and efficient (∼5 log units) manner. Time-lapse microscopy confirms that Art-175 punctures the peptidoglycan layer within 1 min, inducing a bulging membrane and complete lysis. Art-175 is highly refractory to resistance development by naturally occurring mutations. In addition, the resistance mechanisms against 21 therapeutically used antibiotics do not show cross-resistance to Art-175. Since Art-175 does not require an active metabolism for its activity, it has a superior bactericidal effect againstP. aeruginosapersisters (up to >4 log units compared to that of the untreated controls). In summary, Art-175 is a novel antibacterial that is well suited for a broad range of applications in hygiene and veterinary and human medicine, with a unique potential to target persister-driven chronic infections.

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Barreteau, Hélène, Ahmed Bouhss, Martine Fourgeaud, Jean-Luc Mainardi, Thierry Touzé, Fabien Gérard, Didier Blanot, Michel Arthur i Dominique Mengin-Lecreulx. "Human- and Plant-Pathogenic Pseudomonas Species Produce Bacteriocins Exhibiting Colicin M-Like Hydrolase Activity towards Peptidoglycan Precursors". Journal of Bacteriology 191, nr 11 (3.04.2009): 3657–64. http://dx.doi.org/10.1128/jb.01824-08.

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ABSTRACT Genes encoding proteins that exhibit similarity to the C-terminal domain of Escherichia coli colicin M were identified in the genomes of some Pseudomonas species, namely, P. aeruginosa, P. syringae, and P. fluorescens. These genes were detected only in a restricted number of strains. In P. aeruginosa, for instance, the colicin M homologue gene was located within the ExoU-containing genomic island A, a large horizontally acquired genetic element and virulence determinant. Here we report the cloning of these genes from the three Pseudomonas species and the purification and biochemical characterization of the different colicin M homologues. All of them were shown to exhibit Mg2+-dependent diphosphoric diester hydrolase activity toward the two undecaprenyl phosphate-linked peptidoglycan precursors (lipids I and II) in vitro. In all cases, the site of cleavage was localized between the undecaprenyl and pyrophospho-MurNAc moieties of these precursors. These enzymes were not active on the cytoplasmic precursor UDP-MurNAc-pentapeptide or (or only very poorly) on undecaprenyl pyrophosphate. These colicin M homologues have a narrow range of antibacterial activity. The P. aeruginosa protein at low concentrations was shown to inhibit growth of sensitive P. aeruginosa strains. These proteins thus represent a new class of bacteriocins (pyocins), the first ones reported thus far in the genus Pseudomonas that target peptidoglycan metabolism.

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Mir, Mushtaq, Sladjana Prisic, Choong-Min Kang, Shichun Lun, Haidan Guo, Jeffrey P. Murry, Eric J. Rubin i Robert N. Husson. "Mycobacterial GenecuvAIs Required for Optimal Nutrient Utilization and Virulence". Infection and Immunity 82, nr 10 (21.07.2014): 4104–17. http://dx.doi.org/10.1128/iai.02207-14.

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ABSTRACTTo persist and cause disease in the host,Mycobacterium tuberculosismust adapt to its environment during infection. Adaptations include changes in nutrient utilization and alterations in growth rate.M. tuberculosisRv1422 is a conserved gene of unknown function that was found in a genetic screen to interact with themce4cholesterol uptake locus. The Rv1422 protein is phosphorylated by theM. tuberculosisSer/Thr kinases PknA and PknB, which regulate cell growth and cell wall synthesis.Bacillus subtilisstrains lacking the Rv1422 homologueyvcKgrow poorly on several carbon sources, andyvcKis required for proper localization of peptidoglycan synthesis. Here we show thatMycobacterium smegmatisandM. tuberculosisstrains lacking Rv1422 have growth defects in minimal medium containing limiting amounts of several different carbon sources. These strains also have morphological abnormalities, including shortened and bulging cells, suggesting a cell wall defect. In both mycobacterial species, the Rv1422 protein localizes uniquely to the growing cell pole, the site of peptidoglycan synthesis in mycobacteria. AnM. tuberculosisΔRv1422 strain is markedly attenuated for virulence in a mouse infection model, where it elicits decreased inflammation in the lungs and shows impaired bacterial persistence. These findings led us to name this genecuvA(carbonutilization andvirulence proteinA) and to suggest a model in which deletion ofcuvAleads to changes in nutrient uptake and/or metabolism that affect cell wall structure, morphology, and virulence. Its role in virulence suggests that CuvA may be a useful target for novel inhibitors ofM. tuberculosisduring infection.

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Kim, Jungman, Jae Ho Choi, Taehwan Oh, Byungjae Ahn i Tatsuya Unno. "Codium fragile Ameliorates High-Fat Diet-Induced Metabolism by Modulating the Gut Microbiota in Mice". Nutrients 12, nr 6 (21.06.2020): 1848. http://dx.doi.org/10.3390/nu12061848.

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Codium fragile (CF) is a functional seaweed food that has been used for its health effects, including immunostimulatory, anti-inflammatory, anti-obesity and anti-cancer activities, but the effect of CF extracts on obesity via regulation of intestinal microflora is still unknown. This study investigated anti-obesity effects of CF extracts on gut microbiota of diet-induced obese mice. C57BL/6 mice fed a high-fat (HF) diet were given CF extracts intragastrically for 12 weeks. CF extracts significantly decreased animal body weight and the size of adipocytes, while reducing serum levels of cholesterol and glucose. In addition, CF extracts significantly shifted the gut microbiota of mice by increasing the abundance of Bacteroidetes and decreasing the abundance of Verrucomicrobia species, in which the portion of beneficial bacteria (i.e., Ruminococcaceae, Lachnospiraceae and Acetatifactor) were increased. This resulted in shifting predicted intestinal metabolic pathways involved in regulating adipocytes (i.e., mevalonate metabolism), energy harvest (i.e., pyruvate fermentation and glycolysis), appetite (i.e., chorismate biosynthesis) and metabolic disorders (i.e., isoprene biosynthesis, urea metabolism, and peptidoglycan biosynthesis). In conclusion, our study showed that CF extracts ameliorate intestinal metabolism in HF-induced obese mice by modulating the gut microbiota.

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