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vollmer The enlargement of the sacculus is facilitated by two synthetic reactions: the precursor molecule lipid II is oligomerized by transglycosylation to form the murein glycan strands, and the peptides of neighbouring glycans are cross-linked by transpeptidation. In vitro murein (peptidoglycan) synthesis by dimers of the bifunctional transglycosylase-transpeptidase PBP1B from Escherichia coli. Susceptibility to antibiotics and ß-lactamase induction in murein hydrolase mutants of Escherichia coli. www.uni-tuebingen.de /Mikrobiogen/vollmer.html   (900 words)

Growth of the Stress-Bearing and Shape-Maintaining Murein Sacculus of Escherichia coli -- Höltje 62 (1): 181 -- ... The murein triplet is covalently attached to the free amino groups present in the donor peptides of the cross-links on both sides of a strand, called the docking strand, that is substituted by acceptor peptides. It is assumed that in the presence of murein synthesis inhibitors, the multienzyme complex is still pushed along the murein strands by the action of the murein hydrolases processively degrading the docking strand while the synthases idle due to a block in the supply or utilization of the murein precursors (see the legend to Fig. The murein of the cylindrical middle part of a rod-shaped sacculus is schematically spread out inside the outlines of a cell, with the metabolically inert polar caps indicated by striped semicircles. mmbr.asm.org /cgi/content/full/62/1/181   (9025 words)

Murein – Wikipedia tiếng Việt Murein là thành phần sinh hóa cấu thành nên thành tế bào của các loài prokaryotes. Lớp murein nằm bên ngoài màng sinh chất thường dày từ 20 - 80 nm (vi khuẩn Gram dương) hoặc 7 - 8 nm (vi khuẩn Gram âm). Thành phần hóa học của murein là peptidoglycan, một loại polysacchride có chứa nitơ. vi.wikipedia.org /wiki/Murein   (266 words)

Science--Pharmacia Prize--Christine Jacobs Murein is an essential heteropolymer that protects the bacterium from osmotic rupture, dictates cell shape, and is intimately involved in cell growth and division. Therefore, the elucidation of the mechanisms that upset the control of the murein hydrolases should help identify the control devices themselves, which in turn has important consequences for the discovery of new antibacterial drugs. Escherichia coli degrades up to 50% of its murein per generation, but most of the liberated murein fragments (muropeptides) are transported from the periplasm into the cytoplasm and recycled for further murein biosynthesis (6). www.sciencemag.org /feature/data/pharmacia/1997/jacobs.dtl   (1092 words)

Constitutive Septal Murein Synthesis in Escherichia coli with Impaired Activity of the Morphogenetic Proteins RodA and ... new strands to the preexisting murein (15, 36, 48, 52). We were therefore interested in studying murein segregation in strains with impaired activity of the PBP2 and RodA proteins. Murein segregation in the rodA° mutant KJB24 as observed by immunoelectron microscopy. jb.asm.org /cgi/content/full/183/14/4115   (5432 words)

Structure and Function of Procaryotes The assembly of peptidoglycan on the outside of the plasma membrane is mediated by a group of periplasmic enzymes which are transglycosylases, transpeptidases and carboxypeptidases. Assembly of the interpeptide bridge in Gram-positive murein is inhibited by the beta lactam antibiotics in the same manner as the interpeptide bond in Gram-negative murein. Gram-negative bacteria may contain a single monomolecular layer of murein in their cell walls while Gram-positive bacteria are thought to have several layers or "wraps" of peptidoglycan. textbookofbacteriology.net /structure.html   (7723 words)

Antibiotic Attack The cell walls of gram-positive bacteria are made up of twenty times as much murein or peptidoglycan than gram-negative bacteria. As opposed to gram-positive cells, gram-negative cells are resistant to lysozyme and penicillin attack. They can stretch and change their shape because they lack murein or peptidoglycan in their cell walls. library.mtandao-afrika.org /TQA01074/english/bio.htm   (1068 words)

Cloning and Characterization of PBP 1C, a Third Member of the Multimodular Class A Penicillin-binding Proteins of ... The muropeptide structure of isolated murein sacculi was determined according to the procedure described by Glauner (41). An analysis of the length distribution of the glycan strands in the range from 1 to 27 disaccharide units in the murein (42) The murein composition of isolated murein sacculi was determined as described previously (41, 51). www.jbc.org /cgi/content/full/274/45/32031   (6341 words)

[No title]   (Site not responding. Last check: 2007-10-02) They may therefore be part of a tunneling device directing the flow of murein precursors to the membrane enzymes that insert the precursors into the preexisting murein sacculus. Holtje, J.V. Growth of the stress-bearing and shape-maintaining murein sacculus of Escherichia coli. Revised nucleotide sequence of the sporulation gene spoVE from Bacillus subtilis. www.tcdb.org /tcdb/family2.php?tc=9.B.3   (356 words)

Proteobacteria - MicrobeWiki Murein lipoprotein is a small protein at 7200 Da that exists in great numbers with 7x10 Three fatty acid groups penetrate the inner leaflet of the OM while the rest is hydrophilic and is most likely located in the periplasm. About one-third of the murein lipoprotein molecules are covalently bound to the peptidoglycan layer, thus fixing the OM to the underlying peptidoglycan and increasing stability of the envelope. microbewiki.kenyon.edu /index.php/Proteobacteria   (425 words)

Multiple Enzymatic Activities of the Murein Hydrolase from Staphylococcal Phage phi 11. IDENTIFICATION OF A ... The gene encoding the murein hydrolase of staphylococcal phage their solubilization with murein hydrolases (32, 35, 36). 11 murein hydrolase, and glycan strands were degraded by subsequent digestion of the solubilized muropeptides with mutanolysin (see "Experimental Procedures"). www.jbc.org /cgi/content/full/274/22/15847   (6086 words)

BioMed Central | Full text | Resistance of rumen bacteria murein to bovine gastric lysozyme This prompted us establish 2 hypotheses: 1 – there might be other abomasum peptides with antimicrobial activity in addition to lysozyme, that would also act against Gram negative bacteria; 2 – since rumen bacteria have been subject to the selective pressure of gastric antimicrobial secretions, rumen bacteria might have developed resistance to these compounds. The activity of BG lysozyme on purified murein was different to that of other c lysozymes in having lower optimal pH and L, D carboxypeptidase or Nacetyl muramyl L-ala amidase activity. However, the discovery of the capacity of bacteria to presumably modify its bacterial murein and become resistant to the lytic action of lysozymes, will surely be of concern in practical applications, as has bacterial antibiotic resistance. www.biomedcentral.com /1472-6785/4/7   (2501 words)

Tertiary Structure of Bacterial Murein: the Scaffold Model -- Dmitriev et al. 185 (11): 3458 -- The Journal of ... The functional zone, which comprises both assembled and mature murein, includes a compact and highly cross-linked narrow internal zone (zone 3) with a height of 4 disaccharides; this internal zone functions as a stress-bearing structure of the murein fabric. of murein and the degree of cross-linking being the characteristic On the architecture of the gram-negative bacterial murein sacculus. jb.asm.org /cgi/content/full/185/11/3458   (7543 words)

The signal peptide sequence of a lytic transglycosylase of Neisseria meningitidis is involved in regulation of gene ... Ehlert, K., Höltje, J.-V. and Templin, M. Cloning and expression of a murein hydrolase lipoprotein from Escherichia coli. Höltje, J.-V. Growth of the stress-bearing and shape-maintaining murein sacculus of Escherichia coli. Vollmer, W., von Rechenberg, M. and Höltje, J.-V. Demonstration of molecular interactions between the murein polymerase PBP1B, the lytic transglycosylase MltA, and the scaffolding protein MipA of Escherichia coli. mic.sgmjournals.org /cgi/content/full/150/5/1427   (5331 words)

Antimicrobial Agents Used in the Treatment of infectious Disease It is present in many topical antibiotic preparations, and since it is not absorbed by the gut, it is given to "sterilize" the bowel prior to surgery. Cycloserine inhibits the early stages of murein synthesis where D-alanyl-D-alanine is added to the growing peptide side chain. The antibiotic resembles D-alanine in spatial structure, and it competitively inhibits the racemase reaction that converts L-alanine to D-alanine and the synthetase reaction that joins two D-alanine molecules. textbookofbacteriology.net /antimicrobial.html   (5028 words)

Tertiary structure of Staphylococcus aureus cell wall murein. The recently described scaffold model of murein architecture depicts the gram-negative bacterial cell wall as a gel-like matrix composed of cross-linked glycan strands oriented perpendicularly to the plasma membrane while peptide bridges adopt a parallel orientation (B. Dmitriev, F. Toukach, K. Schaper, O. Holst, E. Rietschel, and S. Ehlers, J. Bacteriol. Based on the scaffold model, we now present computer simulation studies on the peptidoglycan arrangement of the gram-positive organism Staphylococcus aureus, which show that the orientation of peptide bridges is critical for the highly cross-linked murein architecture of this microorganism. According to the proposed refined model, staphylococcal murein is composed of glycan and oligopeptide chains, both running in a plane that is perpendicular to the plasma membrane, with oligopeptide chains adopting a zigzag conformation and zippering adjacent glycan strands along their lengths. staphylococcus.researchtoday.net /archive/1/2/768.htm   (228 words)

The Prototype Bacterial Cell Eubacteria (with the exception of the genera Mycoplasma and Chlamydia) possess peptidoglycan (synonyms: murein, mucopeptide, cell wall skeleton). Archaebacteria contain a pseudomurein that is different in structure from eubacterial murein. In view of the increasing number of similarities between the archaea and the eukaryotes, the term archaebacteria is no longer used. pathmicro.med.sc.edu /fox/protype.htm   (1344 words)

Structure and Function of Bacterial Cells Such a material is murein, the ubiquitous component of bacterial cell walls. This is one type of murein found in Gram-positive bacteria. The main difference between Gram-negative and Gram-positive peptidoglycans is the occurrence of a bridge of amino acids in the latter which links the peptide side chains to one another. www.bact.wisc.edu /themicrobialworld/structure.html   (6330 words)

In Vitro Synthesis of Cross-linked Murein and Its Attachment to Sacculi by PBP1A from Escherichia coli -- Born et al. ... In Vitro Synthesis of Cross-linked Murein and Its Attachment to Sacculi by PBP1A from Escherichia coli -- Born et al. Center of Biomembranes and Lipid Enzymology, Department of Biochemistry of Membranes, Institute for Biomembranes, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands murein synthesized from radioactive lipid II to nonlabeled murein www.jbc.org /cgi/content/short/281/37/26985?rss=1   (271 words)

Growth of the Stress-Bearing and Shape-Maintaining Murein Sacculus of Escherichia coli -- Höltje 62 (1): 181 -- ... Born, P., Breukink, E., Vollmer, W. In Vitro Synthesis of Cross-linked Murein and Its Attachment to Sacculi by PBP1A from Escherichia coli. Vollmer, W., Holtje, J.-V. The Architecture of the Murein (Peptidoglycan) in Gram-Negative Bacteria: Vertical Scaffold or Horizontal Layer(s)?. Vollmer, W., von Rechenberg, M., Holtje, J.-V. Demonstration of Molecular Interactions between the Murein Polymerase PBP1B, the Lytic Transglycosylase MltA, and the Scaffolding Protein MipA of Escherichia coli. mmbr.asm.org /cgi/content/abstract/62/1/181   (2532 words)

Cell Biology of Bacteria - Page 4 Has a thick peptidoglycan (murein) layer and 2 classes of teichoic acids. Lipoteichoic acid which is on the surface, embedded in the peptidoglycan layer and is linked to the cytoplasmic membrane. Has a thin peptidoglycan (murein) layer with an outer membrane attached to the peptidoglycan layer by lipoproteins. jan.ucc.nau.edu /~fpm/bio205/cellwall-4.html   (216 words)

The Bacterium's Way for Safe Enlargement and Division -- Koch 66 (9): 3657 -- Applied and Environmental Microbiology The layers of murein are added to the sidewall as shown on the sides of the figure. This wall is compact and unstressed until a central split exposes the septal wall to stress because the pressure inside the cell is higher than that outside. A new proposal for the primary and secondary structure of the glycan moiety of pseudomurein. aem.asm.org /cgi/content/full/66/9/3657   (5769 words)

Microbe Magazine I believe that bacteria emerged as a distinctive domain when its first members developed a murein cell wall, i.e., a sacculus or exoskeleton that protected individuals from turgor pressure. This strong, yet elastic structure covering the bacterial cell prevents cells from swelling or rupturing when the osmotic pressure is higher inside than outside. Koch, A. Simulation of the conformation of the murein fabric: I. The oligoglycan, penta-muropeptide, and crosslinked nona-muropeptide. www.asm.org /news/index.asp?bid=16349   (1593 words)

Pathology and Microbiology The role of membrane potential in the expression of the Staphylococcus aureus cid and lrg murein hydrolase regulators. Acetic acid induces expression of the Staphylococcus aureus cidABC and lrgAB murein hydrolase regulator operons. Transcription of the Staphylococcus aureus cid and lrg murein hydrolase regulators is affected by sigma factor B (s www.unmc.edu /Pathology/facultypages/baylesbio.htm   (460 words)

The Two Murein Lipoproteins of Salmonella enterica Serovar Typhimurium Contribute to the Virulence of the Organism -- ... The Two Murein Lipoproteins of Salmonella enterica Serovar Typhimurium Contribute to the Virulence of the Organism -- Sha et al. The Two Murein Lipoproteins of Salmonella enterica Serovar Typhimurium Contribute to the Virulence of the Organism Fadl, A. A., Sha, J., Klimpel, G. R., Olano, J. P., Niesel, D. W., Chopra, A. Murein Lipoprotein Is a Critical Outer Membrane Component Involved in Salmonella enterica Serovar Typhimurium Systemic Infection. iai.asm.org /cgi/content/abstract/72/7/3987   (662 words)

Abstract: Tertiary structure of bacterial murein   (Site not responding. Last check: 2007-10-02) In contrast, a scaffold model of murein architecture, which assumes that glycan strands extend perpendicularly to the plasma membrane, was found to accommodate published experimental evidence and yield a viable stress-bearing matrix. Moreover, this model is in accordance with the well-established principle of murein assembly in vivo, i.e., sequential attachment of strands to the preexisting structure. For the first time, the phenomenon of division plane alternation in dividing bacteria can be reconciled with a computer model of the molecular architecture of murein. nmr.ioc.ac.ru /Staff/ToukachPV/rus/abmur.htm   (238 words)

Lecture 2&3   (Site not responding. Last check: 2007-10-02) Also, the solvents cause the large amount of peptidoglycan in the Gram+ wall to dehydrate, shrink and hold the primary stain tenaciously. Peptidoglycan (murein) is the backbone of the bacterial cell wall of both G+ and G- bacteria * Fig. It is also the target of penicillin, which binds to transpeptidase enzyme and keeps it from constructing the pentaglycine bridge from glycine molecules. webpages.marshall.edu /~gain/bactnote/structure.html   (790 words)

Food Safety News - Iowa State University Extension This study was carried out to evaluate the effects of gamma radiation alone or in combination with oregano essential oil on the murein composition of Escherichia coli O157:H7 and on the intracellular and extracellular concentrations of ATP. The bacterial strain was treated with three radiation doses: 0.4 kGy to induce cell damage, 1.1 kGy to obtain a viable but nonculturable state, and 1.3 kGy to cause cell death. All treatments had a significant effect (P 0.05) on the murein composition, although some muropeptides did not seem to be affected by the treatment. www.extension.iastate.edu /foodsafety/news/fsnews.cfm?newsid=11378   (331 words)

Antibiotics attack The cell walls of a bacterium (fungi lack cell walls) are continuously expanding through the synthesis of peptidoglycan, a polymer of sugars and amino acids, otherwise known as murein. To grow, reproduce, and spread, the cell wall must be able to expand with the growing interior. By inhibiting cell wall synthesis, antibiotics cause the cell to undergo autolysis. www.hhmi.org /biointeractive/Antibiotics_Attack/pw_2.html   (150 words)

Murein Lipoprotein Is a Critical Outer Membrane Component Involved in Salmonella enterica Serovar Typhimurium Systemic ... Murein Lipoprotein Is a Critical Outer Membrane Component Involved in Salmonella enterica Serovar Typhimurium Systemic Infection -- Fadl et al. Murein Lipoprotein Is a Critical Outer Membrane Component Involved in Salmonella enterica Serovar Typhimurium Systemic Infection Mutation of htrB gene in a virulent Salmonella typhimurium strain by intergenic transduction: strain construction and phenotypic characterization. iai.asm.org /cgi/content/full/73/2/1081   (9153 words)

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