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Booth S, Lewis RJ. Structural basis for the coordination of cell division with the synthesis of the bacterial cell envelope. Protein Sci 2019; 28:2042-2054. [PMID: 31495975 PMCID: PMC6863701 DOI: 10.1002/pro.3722] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 01/02/2023]
Abstract
Bacteria are surrounded by a complex cell envelope made up of one or two membranes supplemented with a layer of peptidoglycan (PG). The envelope is responsible for the protection of bacteria against lysis in their oft-unpredictable environments and it contributes to cell integrity, morphology, signaling, nutrient/small-molecule transport, and, in the case of pathogenic bacteria, host-pathogen interactions and virulence. The cell envelope requires considerable remodeling during cell division in order to produce genetically identical progeny. Several proteinaceous machines are responsible for the homeostasis of the cell envelope and their activities must be kept coordinated in order to ensure the remodeling of the envelope is temporally and spatially regulated correctly during multiple cycles of cell division and growth. This review aims to highlight the complexity of the components of the cell envelope, but focusses specifically on the molecular apparatuses involved in the synthesis of the PG wall, and the degree of cross talk necessary between the cell division and the cell wall remodeling machineries to coordinate PG remodeling during division. The current understanding of many of the proteins discussed here has relied on structural studies, and this review concentrates particularly on this structural work.
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Affiliation(s)
- Simon Booth
- Institute for Cell and Molecular Biosciences, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Richard J. Lewis
- Institute for Cell and Molecular Biosciences, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
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2
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Phospholipid retention in the absence of asymmetry strengthens the outer membrane permeability barrier to last-resort antibiotics. Proc Natl Acad Sci U S A 2018; 115:E8518-E8527. [PMID: 30087182 DOI: 10.1073/pnas.1806714115] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The outer membrane of Gram-negative bacteria is a critical barrier that prevents entry of noxious compounds. Integral to this functionality is the presence of lipopolysaccharide (LPS) or lipooligosaccharide (LOS), a molecule that is located exclusively in the outer leaflet of the outer membrane. Its lipid anchor, lipid A, is a glycolipid whose hydrophobicity and net negative charge are primarily responsible for the robustness of the membrane. Because of this, lipid A is a hallmark of Gram-negative physiology and is generally essential for survival. Rare exceptions have been described, including Acinetobacter baumannii, which can survive in the absence of lipid A, albeit with significant growth and membrane permeability defects. Here, we show by an evolution experiment that LOS-deficient A. baumannii can rapidly improve fitness over the course of only 120 generations. We identified two factors which negatively contribute to fitness in the absence of LOS, Mla and PldA. These proteins are involved in glycerophospholipid transport (Mla) and lipid degradation (PldA); both are active only on mislocalized, surface-exposed glycerophospholipids. Elimination of these two mechanisms was sufficient to cause a drastic fitness improvement in LOS-deficient A. baumannii The LOS-deficient double mutant grows as robustly as LOS-positive wild-type bacteria while remaining resistant to the last-resort polymyxin antibiotics. These data provide strong biological evidence for the directionality of Mla-mediated glycerophospholipid transport in Gram-negative bacteria and furthers our knowledge of asymmetry-maintenance mechanisms in the context of the outer membrane barrier.
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Lee JK, Park SC, Hahm KS, Park Y. A helix-PXXP-helix peptide with antibacterial activity without cytotoxicity against MDRPA-infected mice. Biomaterials 2013; 35:1025-39. [PMID: 24176194 DOI: 10.1016/j.biomaterials.2013.10.035] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 10/08/2013] [Indexed: 10/26/2022]
Abstract
In response to the growing problem of multidrug-resistant pathogenic microbes, much attention is being paid to naturally occurring and synthetic antimicrobial peptides (AMPs) and the effects of their structural modification. Among these modifications, amino acid substitution is a simple approach to enhancing biological activity and reducing cytotoxicity. An earlier study indicated that HPA3, an analog of HP (2-20) derived from the N-terminus of Helicobacter pylori ribosomal protein L1, forms large pores and shows considerable cytotoxicity. However, HPA3P, in which a proline (Pro) is substituted for glutamic acid (Glu) at position 9 of HPA3, shows markedly less cytotoxicity. This may be attributable to the presence of a Pro-kink into middle of the HPA3P structure within the membrane environment. Unfortunately, HPA3P is not an effective antibacterial agent in vivo. We therefore designed a helix-PXXP-helix structure (HPA3P2), in which Pro was substituted for the Glu and phenylalanine (Phe) at positions 9 and 12 of HPA3, yielding a molecule with a flexible central hinge. As compared to HPA3P, HPA3P3 exhibited dramatically increased antibacterial activity in vivo. ICR mice infected with clinically isolated multidrug-resistant Pseudomonas aeruginosa showed 100% survival when administered one 0.5-mg/kg dose of HPA3P2 or three 0.1-mg/kg doses of HPA3P2. Moreover, in a mouse model of septic shock induced by P. aeruginosa LPS, HPA3P2 reduced production of pro-inflammatory mediators and correspondingly reduced lung (alveolar) and liver tissue damage. The changes in HPA3 behavior with the introduction of Pro likely reflects alterations of the mechanism of action: i) HPA3 forms pores in the bacterial cell membranes, ii) HPA3P permeates the cell membranes and binds to intracellular RNA and DNA, and iii) HPA3P2 acts on the outer cellular membrane component LPS. Collectively, these results suggest HPA3P2 has the potential to be an effective antibiotic for use against multidrug-resistant bacterial strains.
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Affiliation(s)
- Jong-Kook Lee
- Research Center for Proteinaceous Materials (RCPM), Chosun University, Kwangju 501-759, Republic of Korea
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Smoum R, Rubinstein A, Dembitsky VM, Srebnik M. Boron containing compounds as protease inhibitors. Chem Rev 2012; 112:4156-220. [PMID: 22519511 DOI: 10.1021/cr608202m] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Reem Smoum
- The School of Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel.
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5
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The role of antimicrobial peptides in preventing multidrug-resistant bacterial infections and biofilm formation. Int J Mol Sci 2011; 12:5971-92. [PMID: 22016639 PMCID: PMC3189763 DOI: 10.3390/ijms12095971] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/05/2011] [Accepted: 09/06/2011] [Indexed: 01/21/2023] Open
Abstract
Over the last decade, decreasing effectiveness of conventional antimicrobial-drugs has caused serious problems due to the rapid emergence of multidrug-resistant pathogens. Furthermore, biofilms, which are microbial communities that cause serious chronic infections and dental plaque, form environments that enhance antimicrobial resistance. As a result, there is a continuous search to overcome or control such problems, which has resulted in antimicrobial peptides being considered as an alternative to conventional drugs. Antimicrobial peptides are ancient host defense effector molecules in living organisms. These peptides have been identified in diverse organisms and synthetically developed by using peptidomimic techniques. This review was conducted to demonstrate the mode of action by which antimicrobial peptides combat multidrug-resistant bacteria and prevent biofilm formation and to introduce clinical uses of these compounds for chronic disease, medical devices, and oral health. In addition, combinations of antimicrobial peptides and conventional drugs were considered due to their synergetic effects and low cost for therapeutic treatment.
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Ostash B, Walker S. Moenomycin family antibiotics: chemical synthesis, biosynthesis, and biological activity. Nat Prod Rep 2010; 27:1594-617. [PMID: 20730219 PMCID: PMC2987538 DOI: 10.1039/c001461n] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The review (with 214 references cited) is devoted to moenomycins, the only known group of antibiotics that directly inhibit bacterial peptidoglycan glycosytransferases. Naturally occurring moenomycins and chemical and biological approaches to their derivatives are described. The biological properties of moenomycins and plausible mechanisms of bacterial resistance to them are also covered here, portraying a complete picture of the chemistry and biology of these fascinating natural products
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Affiliation(s)
- Bohdan Ostash
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Ave., Armenise Bldg. 2, Rm 630, Boston, MA 02115, USA
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Kawai F, Clarke TB, Roper DI, Han GJ, Hwang KY, Unzai S, Obayashi E, Park SY, Tame JR. Crystal Structures of Penicillin-Binding Proteins 4 and 5 from Haemophilus influenzae. J Mol Biol 2010; 396:634-45. [DOI: 10.1016/j.jmb.2009.11.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 11/20/2009] [Accepted: 11/22/2009] [Indexed: 10/20/2022]
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8
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Amagliani G, Omiccioli E, Andreoni F, Boiani R, Bianconi I, Zaccone R, Mancuso M, Magnani M. Development of a multiplex PCR assay for Photobacterium damselae subsp. piscicida identification in fish samples. JOURNAL OF FISH DISEASES 2009; 32:645-653. [PMID: 19500208 DOI: 10.1111/j.1365-2761.2009.01027.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A multiplex polymerase chain reaction protocol for the detection of Photobacterium damselae and subspecies piscicida and damselae discrimination, with internal amplification control, was developed. Assay specificity was assessed by testing 19 target and 25 non-target pure cultures. The detection limit was 500 fg, corresponding to 100 genome equivalents. The optimized protocol was also prevalidated with spleen, kidney and blood samples from infected and uninfected sea bass, without any culture step, and it can be proposed as a valid alternative to culture standard methods for the rapid and specific diagnosis of photobacteriosis in fish.
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Affiliation(s)
- G Amagliani
- Centro di Biotecnologie, Università di Urbino, via T. Campanella 1, Fano (PU), Italy.
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Domain requirement of moenomycin binding to bifunctional transglycosylases and development of high-throughput discovery of antibiotics. Proc Natl Acad Sci U S A 2008; 105:431-6. [PMID: 18182485 DOI: 10.1073/pnas.0710868105] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Moenomycin inhibits bacterial growth by blocking the transglycosylase activity of class A penicillin-binding proteins (PBPs), which are key enzymes in bacterial cell wall synthesis. We compared the binding affinities of moenomycin A with various truncated PBPs by using surface plasmon resonance analysis and found that the transmembrane domain is important for moenomycin binding. Full-length class A PBPs from 16 bacterial species were produced, and their binding activities showed a correlation with the antimicrobial activity of moenomycin against Enterococcus faecalis and Staphylococcus aureus. On the basis of these findings, a fluorescence anisotropy-based high-throughput assay was developed and used successfully for identification of transglycosylase inhibitors.
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Offant J, Michoux F, Dermiaux A, Biton J, Bourne Y. Functional characterization of the glycosyltransferase domain of penicillin-binding protein 1a from Thermotoga maritima. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:1036-42. [PMID: 16725395 DOI: 10.1016/j.bbapap.2006.03.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 03/16/2006] [Accepted: 03/23/2006] [Indexed: 11/26/2022]
Abstract
Class A penicillin-binding proteins (A-PBPs) are high-molecular weight membrane-bound bifunctional enzymes that catalyze the penicillin-sensitive transpeptidation and transglycosylation reaction steps involved in peptidoglycan assembling. We have over-expressed and characterized a soluble form of the glycosyltransferase domain of PBP1a (GT-PBP1a*) from the hyperthermophilic bacteria Thermotoga maritima. GT-PBP1a* efficiently catalyses peptidoglycan biosynthesis, as shown using an in vitro biosynthetized dansylated-lipid II substrate and a HPLC-coupled assay, and is specifically inhibited by moenomycin. GT-PBP1a* tends to spontaneously aggregate in detergent-free solution, a feature that supports existence of a secondary site for membrane association, distinct from the N-terminal transmembrane anchoring region. Overall, our preliminary data document the biochemical properties of GT-PBP1a* and should guide further studies aimed at deciphering the structural determinants involved into membrane binding by this class of enzymes.
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Affiliation(s)
- Julien Offant
- Architecture et Fonction des Macromolécules Biologiques, Case 932, Campus de Luminy, F13288 Marseille Cedex 09, France
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Affiliation(s)
- Peter Welzel
- Institut für Organische Chemie, Universität Leipzig, Germany.
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12
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Ostash B, Walker S. Bacterial transglycosylase inhibitors. Curr Opin Chem Biol 2006; 9:459-66. [PMID: 16118062 DOI: 10.1016/j.cbpa.2005.08.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Accepted: 08/12/2005] [Indexed: 12/01/2022]
Abstract
The spread of bacterial resistance to known antibiotics has inspired interest in previously under-exploited drug targets. The transglycosylation reaction remains a 'black box' in the generally well-studied process of bacterial peptidoglycan biosynthesis, which is a very attractive target for chemotherapeutic intervention. Here, we summarize recent progress in the study of bacterial transglycosylases and the compounds that inhibit them. The transglycosylation reaction is readily targeted by several different classes of natural products, implying that it should be possible to develop drugs that inhibit this process once efficient high-throughput screens and appropriate compound libraries have been developed.
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Affiliation(s)
- Bohdan Ostash
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
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Affiliation(s)
- Dan Kahne
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
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Di Guilmi AM, Dessen A, Dideberg O, Vernet T. The glycosyltransferase domain of penicillin-binding protein 2a from Streptococcus pneumoniae catalyzes the polymerization of murein glycan chains. J Bacteriol 2003; 185:4418-23. [PMID: 12867450 PMCID: PMC165775 DOI: 10.1128/jb.185.15.4418-4423.2003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2003] [Accepted: 04/05/2003] [Indexed: 11/20/2022] Open
Abstract
The bacterial peptidoglycan consists of glycan chains of repeating beta-1,4-linked N-acetylglucosaminyl-N-acetylmuramyl units cross-linked through short peptide chains. The polymerization of the glycans, or glycosyltransfer (GT), and transpeptidation (TP) are catalyzed by bifunctional penicillin-binding proteins (PBPs). The beta-lactam antibiotics inhibit the TP reaction, but their widespread use led to the development of drug resistance in pathogenic bacteria. In this context, the GT catalytic domain represents a potential target in the antibacterial fight. In this work, the in vitro polymerization of glycan chains by the extracellular region of recombinant Streptococcus pneumoniae PBP2a, namely, PBP2a* (the asterisk indicates the soluble form of the protein) is presented. Dansylated lipid II was used as the substrate, and the kinetic parameters K(m) and k(cat)/K(m) were measured at 40.6 micro M (+/- 15.5) and 1 x 10(-3) M(-1) s(-1), respectively. The GT reaction catalyzed by PBP2a* was inhibited by moenomycin and vancomycin. Furthermore, the sequence between Lys 78 and Ser 156 is required for enzymatic activity, whereas it is dispensable for lipid II binding. In addition, we confirmed that this region of the protein is also involved in membrane interaction, independently of the transmembrane anchor. The characterization of the catalytically active GT domain of S. pneumoniae PBP2a may contribute to the development of new inhibitors, which are urgently needed to renew the antibiotic arsenal.
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Affiliation(s)
- Anne Marie Di Guilmi
- Laboratoire d'Ingénierie des Macromolécules, Institut de Biologie Structurale Jean-Pierre Ebel, (CEA, CNRS, UMR5075, UJF), 38027 Grenoble cedex 1, France
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Di Guilmi AM, Dessen A, Dideberg O, Vernet T. Functional characterization of penicillin-binding protein 1b from Streptococcus pneumoniae. J Bacteriol 2003; 185:1650-8. [PMID: 12591883 PMCID: PMC148077 DOI: 10.1128/jb.185.5.1650-1658.2003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2002] [Accepted: 12/02/2002] [Indexed: 11/20/2022] Open
Abstract
The widespread use of antibiotics has encouraged the development of drug resistance in pathogenic bacteria. In order to overcome this problem, the modification of existing antibiotics and/or the identification of targets for the design of new antibiotics is currently being undertaken. Bifunctional penicillin-binding proteins (PBPs) are membrane-associated molecules whose transpeptidase (TP) activity is irreversibly inhibited by beta-lactam antibiotics and whose glycosyltransferase (GT) activity represents a potential target in the antibacterial fight. In this work, we describe the expression and the biochemical characterization of the soluble extracellular region of Streptococcus pneumoniae PBP1b (PBP1b*). The acylation efficiency for benzylpenicillin and cefotaxime was characterized by stopped-flow fluorometry and a 40-kDa stable TP domain was generated after limited proteolysis. In order to analyze the GT activity of PBP1b*, we developed an electrophoretic assay which monitors the fluorescence signal from PBP1b*-bound dansylated lipid II. This binding was inhibited by the antibiotic moenomycin and was specific for the GT domain, since no signal was observed in the presence of the purified functional TP domain. Binding studies performed with truncated forms of PBP1b* demonstrated that the first conserved motif of the GT domain is not required for the recognition of lipid II, whereas the second motif is necessary for such interaction.
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Affiliation(s)
- Anne Marie Di Guilmi
- Laboratoire d'Ingénierie des Macromolécules, Institut de Biologie Structurale Jean-Pierre Ebel, CEA, CNRS, UJF, UMR5075, 38027 Grenoble cedex 1, France
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