1
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Rambaher MH, Zdovc I, Glavač NK, Gobec S, Frlan R. Mur ligase F as a new target for the flavonoids quercitrin, myricetin, and (-)-epicatechin. J Comput Aided Mol Des 2023; 37:721-733. [PMID: 37796382 PMCID: PMC10618370 DOI: 10.1007/s10822-023-00535-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
MurC, D, E, and F are ATP-dependent ligases involved in the stepwise assembly of the tetrapeptide stem of forming peptidoglycan. As highly conserved targets found exclusively in bacterial cells, they are of significant interest for antibacterial drug discovery. In this study, we employed a computer-aided molecular design approach to identify potential inhibitors of MurF. A biochemical inhibition assay was conducted, screening twenty-four flavonoids and related compounds against MurC-F, resulting in the identification of quercitrin, myricetin, and (-)-epicatechin as MurF inhibitors with IC50 values of 143 µM, 139 µM, and 92 µM, respectively. Notably, (-)-epicatechin demonstrated mixed type inhibition with ATP and uncompetitive inhibition with D-Ala-D-Ala dipeptide and UM3DAP substrates. Furthermore, in silico analysis using Sitemap and subsequent docking analysis using Glide revealed two plausible binding sites for (-)-epicatechin. The study also investigated the crucial structural features required for activity, with a particular focus on the substitution pattern and hydroxyl group positions, which were found to be important for the activity. The study highlights the significance of computational approaches in targeting essential enzymes involved in bacterial peptidoglycan synthesis.
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Affiliation(s)
- Martina Hrast Rambaher
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Irena Zdovc
- Veterinary Faculty, Institute of Microbiology and Parasitology, University of Ljubljana, Gerbičeva ul. 60, Ljubljana, Slovenia
| | - Nina Kočevar Glavač
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Stanislav Gobec
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia.
| | - Rok Frlan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia.
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2
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Dowson AJ, Lloyd AJ, Cuming AC, Roper DI, Frigerio L, Dowson CG. Plant peptidoglycan precursor biosynthesis: Conservation between moss chloroplasts and Gram-negative bacteria. PLANT PHYSIOLOGY 2022; 190:165-179. [PMID: 35471580 PMCID: PMC9434261 DOI: 10.1093/plphys/kiac176] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
Accumulating evidence suggests that peptidoglycan, consistent with a bacterial cell wall, is synthesized around the chloroplasts of many photosynthetic eukaryotes, from glaucophyte algae to early-diverging land plants including pteridophyte ferns, but the biosynthetic pathway has not been demonstrated. Here, we employed mass spectrometry and enzymology in a two-fold approach to characterize the synthesis of peptidoglycan in chloroplasts of the moss Physcomitrium (Physcomitrella) patens. To drive the accumulation of peptidoglycan pathway intermediates, P. patens was cultured with the antibiotics fosfomycin, D-cycloserine, and carbenicillin, which inhibit key peptidoglycan pathway proteins in bacteria. Mass spectrometry of the trichloroacetic acid-extracted moss metabolome revealed elevated levels of five of the predicted intermediates from uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) through the uridine diphosphate N-acetylmuramic acid (UDP-MurNAc)-D,L-diaminopimelate (DAP)-pentapeptide. Most Gram-negative bacteria, including cyanobacteria, incorporate meso-diaminopimelic acid (D,L-DAP) into the third residue of the stem peptide of peptidoglycan, as opposed to L-lysine, typical of most Gram-positive bacteria. To establish the specificity of D,L-DAP incorporation into the P. patens precursors, we analyzed the recombinant protein UDP-N-acetylmuramoyl-L-alanyl-D-glutamate-2,6-diaminopimelate ligase (MurE) from both P. patens and the cyanobacterium Anabaena sp. (Nostoc sp. strain PCC 7120). Both ligases incorporated D,L-DAP in almost complete preference to L-Lys, consistent with the mass spectrophotometric data, with catalytic efficiencies similar to previously documented Gram-negative bacterial MurE ligases. We discuss how these data accord with the conservation of active site residues common to DL-DAP-incorporating bacterial MurE ligases and of the probability of a horizontal gene transfer event within the plant peptidoglycan pathway.
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Affiliation(s)
- Amanda J Dowson
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Adrian J Lloyd
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Andrew C Cuming
- Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - David I Roper
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Lorenzo Frigerio
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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3
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Funes Chabán M, Hrast M, Frlan R, Graikioti DG, Athanassopoulos CM, Carpinella MC. Inhibition of MurA Enzyme from Escherichia coli and Staphylococcus aureus by Diterpenes from Lepechinia meyenii and Their Synthetic Analogs. Antibiotics (Basel) 2021; 10:1535. [PMID: 34943747 PMCID: PMC8698320 DOI: 10.3390/antibiotics10121535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 12/11/2022] Open
Abstract
Enzymes MurA and MurF, involved in bacterial cell wall synthesis, have been validated as targets for the discovery of novel antibiotics. A panel of plant-origin antibacterial diterpenes and synthetic analogs derived therefrom were investigated for their inhibitory properties on these enzymes from Escherichia coli and Staphylococcus aureus. Six compounds were proven to be effective for inhibiting MurA from both bacteria, with IC50 values ranging from 1.1 to 25.1 µM. To further mechanistically investigate the nature of binding and to explain the activity, these compounds were docked into the active site of MurA from E. coli. The aromatic ring of the active compounds showed a T-shaped π-π interaction with the phenyl ring of Phe328, and at least one hydrogen bond was formed between the hydroxy groups and Arg120 and/or Arg91. The results disclosed here establish new chemical scaffolds for the development of novel entities targeting MurA as potential antibiotics to combat the threat of pathogenic bacteria, particularly resistant strains.
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Affiliation(s)
- Macarena Funes Chabán
- Fine Chemical and Natural Products Laboratory, IRNASUS CONICET-UCC, Universidad Católica de Córdoba, Córdoba 5016, Argentina;
| | - Martina Hrast
- Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.H.); (R.F.)
| | - Rok Frlan
- Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.H.); (R.F.)
| | - Dafni G. Graikioti
- Synthetic Organic Chemistry Laboratory, Department of Chemistry, University of Patras, 26504 Patras, Greece; (D.G.G.); (C.M.A.)
| | - Constantinos M. Athanassopoulos
- Synthetic Organic Chemistry Laboratory, Department of Chemistry, University of Patras, 26504 Patras, Greece; (D.G.G.); (C.M.A.)
| | - María Cecilia Carpinella
- Fine Chemical and Natural Products Laboratory, IRNASUS CONICET-UCC, Universidad Católica de Córdoba, Córdoba 5016, Argentina;
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4
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Amanat S, Ashraf A, Hussain W, Rasool N, Khan YD. Identification of Lysine Carboxylation Sites in Proteins by Integrating Statistical Moments and Position Relative Features via General PseAAC. Curr Bioinform 2020. [DOI: 10.2174/1574893614666190723114923] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background:
Carboxylation is one of the most biologically important post-translational
modifications and occurs on lysine, arginine, and glutamine residues of a protein. Among all these
three, the covalent attachment of the carboxyl group with the lysine side chain is the most frequent
and biologically important type of carboxylation. For studying such biological functions, it is essential
to correctly determine the lysine sites sensitive to carboxylation.
Objective:
Herein, we present a computational model for the prediction of the carboxylysine site
which is based on machine learning.
Methods:
Various position and composition relative features have been incorporated into the Pse-
AAC for construction of feature vectors and a neural network is employed as a classifier. The
model is validated by jackknife, cross-validation, self-consistency, and independent testing.
Results:
The results of the self-consistency test elaborated that model has 99.76% Acc, 99.76% Sp,
99.76% Sp, and 0.99 MCC. Using the jackknife method, prediction model validation gave 97.07%
Acc, while for 10-fold cross-validation, prediction model validation gave 95.16% Acc.
Conclusion:
The results of independent dataset testing were 94.3% which illustrated that the proposed
model has better performance as compared to the existing model PreLysCar; however, the
accuracy can be improved further, in the future, due to the increasing number of carboxylysine
sites in proteins.
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Affiliation(s)
- Saba Amanat
- Department of Computer Science, School of Systems and Technology, University of Management and Technology, Lahore, Pakistan
| | - Adeel Ashraf
- Department of Computer Science, School of Systems and Technology, University of Management and Technology, Lahore, Pakistan
| | - Waqar Hussain
- Department of Computer Science, School of Systems and Technology, University of Management and Technology, Lahore, Pakistan
| | - Nouman Rasool
- Department of Life Sciences, School of Science University of Management and Technology, Lahore, Pakistan
| | - Yaser D. Khan
- Department of Computer Science, School of Systems and Technology, University of Management and Technology, Lahore, Pakistan
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5
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MurE inhibitors as antibacterial agents: a review. J INCL PHENOM MACRO 2020. [DOI: 10.1007/s10847-020-01018-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Hrast M, Rožman K, Ogris I, Škedelj V, Patin D, Sova M, Barreteau H, Gobec S, Grdadolnik SG, Zega A. Evaluation of the published kinase inhibitor set to identify multiple inhibitors of bacterial ATP-dependent mur ligases. J Enzyme Inhib Med Chem 2019; 34:1010-1017. [PMID: 31072165 PMCID: PMC6522912 DOI: 10.1080/14756366.2019.1608981] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
The Mur ligases form a series of consecutive enzymes that participate in the intracellular steps of bacterial peptidoglycan biosynthesis. They therefore represent interesting targets for antibacterial drug discovery. MurC, D, E and F are all ATP-dependent ligases. Accordingly, with the aim being to find multiple inhibitors of these enzymes, we screened a collection of ATP-competitive kinase inhibitors, on Escherichia coli MurC, D and F, and identified five promising scaffolds that inhibited at least two of these ligases. Compounds 1, 2, 4 and 5 are multiple inhibitors of the whole MurC to MurF cascade that act in the micromolar range (IC50, 32-368 µM). NMR-assisted binding studies and steady-state kinetics studies performed on aza-stilbene derivative 1 showed, surprisingly, that it acts as a competitive inhibitor of MurD activity towards D-glutamic acid, and additionally, that its binding to the D-glutamic acid binding site is independent of the enzyme closure promoted by ATP.
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Affiliation(s)
- Martina Hrast
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia
| | - Kaja Rožman
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia.,b Department of Medicinal Chemistry , University of Minnesota , Minneapolis , MN , USA
| | - Iza Ogris
- c Molecular Structural Dynamics, Theory Department , National Institute of Chemistry , Ljubljana , Slovenia
| | - Veronika Škedelj
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia
| | - Delphine Patin
- d Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay , Gif-Sur-Yvette Cedex , France
| | - Matej Sova
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia
| | - Hélène Barreteau
- d Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay , Gif-Sur-Yvette Cedex , France
| | - Stanislav Gobec
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia
| | - Simona Golič Grdadolnik
- c Molecular Structural Dynamics, Theory Department , National Institute of Chemistry , Ljubljana , Slovenia
| | - Anamarija Zega
- a Faculty of Pharmacy , University of Ljubljana , Ljubljana , Slovenia
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7
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Lohans CT, Wang DY, Jorgensen C, Cahill ST, Clifton IJ, McDonough MA, Oswin HP, Spencer J, Domene C, Claridge TDW, Brem J, Schofield CJ. 13C-Carbamylation as a mechanistic probe for the inhibition of class D β-lactamases by avibactam and halide ions. Org Biomol Chem 2018; 15:6024-6032. [PMID: 28678295 DOI: 10.1039/c7ob01514c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The class D (OXA) serine β-lactamases are a major cause of resistance to β-lactam antibiotics. The class D enzymes are unique amongst β-lactamases because they have a carbamylated lysine that acts as a general acid/base in catalysis. Previous crystallographic studies led to the proposal that β-lactamase inhibitor avibactam targets OXA enzymes in part by promoting decarbamylation. Similarly, halide ions are proposed to inhibit OXA enzymes via decarbamylation. NMR analyses, in which the carbamylated lysines of OXA-10, -23 and -48 were 13C-labelled, indicate that reaction with avibactam does not ablate lysine carbamylation in solution. While halide ions did not decarbamylate the 13C-labelled OXA enzymes in the absence of substrate or inhibitor, avibactam-treated OXA enzymes were susceptible to decarbamylation mediated by halide ions, suggesting halide ions may inhibit OXA enzymes by promoting decarbamylation of acyl-enzyme complex. Crystal structures of the OXA-10 avibactam complex were obtained with bromide, iodide, and sodium ions bound between Trp-154 and Lys-70. Structures were also obtained wherein bromide and iodide ions occupy the position expected for the 'hydrolytic water' molecule. In contrast with some solution studies, Lys-70 was decarbamylated in these structures. These results reveal clear differences between crystallographic and solution studies on the interaction of class D β-lactamases with avibactam and halides, and demonstrate the utility of 13C-NMR for studying lysine carbamylation in solution.
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Affiliation(s)
| | - David Y Wang
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
| | | | - Samuel T Cahill
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
| | - Ian J Clifton
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
| | | | - Henry P Oswin
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - James Spencer
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Carmen Domene
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK. and Department of Chemistry, King's College London, London, SE1 1DB, UK
| | | | - Jürgen Brem
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
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8
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Šink R, Kotnik M, Zega A, Barreteau H, Gobec S, Blanot D, Dessen A, Contreras-Martel C. Crystallographic Study of Peptidoglycan Biosynthesis Enzyme MurD: Domain Movement Revisited. PLoS One 2016; 11:e0152075. [PMID: 27031227 PMCID: PMC4816537 DOI: 10.1371/journal.pone.0152075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 03/08/2016] [Indexed: 11/30/2022] Open
Abstract
The biosynthetic pathway of peptidoglycan, an essential component of bacterial cell wall, is a well-recognized target for antibiotic development. Peptidoglycan precursors are synthesized in the bacterial cytosol by various enzymes including the ATP-hydrolyzing Mur ligases, which catalyze the stepwise addition of amino acids to a UDP-MurNAc precursor to yield UDP-MurNAc-pentapeptide. MurD catalyzes the addition of D-glutamic acid to UDP-MurNAc-L-Ala in the presence of ATP; structural and biochemical studies have suggested the binding of the substrates with an ordered kinetic mechanism in which ligand binding inevitably closes the active site. In this work, we challenge this assumption by reporting the crystal structures of intermediate forms of MurD either in the absence of ligands or in the presence of small molecules. A detailed analysis provides insight into the events that lead to the closure of MurD and reveals that minor structural modifications contribute to major overall conformation alterations. These novel insights will be instrumental in the development of new potential antibiotics designed to target the peptidoglycan biosynthetic pathway.
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Affiliation(s)
- Roman Šink
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia
| | - Miha Kotnik
- Lek Pharmaceuticals d. d., Verovškova 57, Ljubljana, Slovenia
| | - Anamarija Zega
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia
| | - Hélène Barreteau
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette, France
| | - Stanislav Gobec
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia
| | - Didier Blanot
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette, France
| | - Andréa Dessen
- Univ. Grenoble Alpes, Institut de Biologie Structurale, Grenoble, France
- CNRS, IBS, Grenoble, France
- CEA, IBS, Grenoble, France
- Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, São Paulo, Brazil
| | - Carlos Contreras-Martel
- Univ. Grenoble Alpes, Institut de Biologie Structurale, Grenoble, France
- CNRS, IBS, Grenoble, France
- CEA, IBS, Grenoble, France
- * E-mail:
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9
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Patin D, Turk S, Barreteau H, Mainardi JL, Arthur M, Gobec S, Mengin-Lecreulx D, Blanot D. Unusual substrate specificity of the peptidoglycan MurE ligase from Erysipelothrix rhusiopathiae. Biochimie 2015; 121:209-18. [PMID: 26700151 DOI: 10.1016/j.biochi.2015.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/06/2015] [Indexed: 01/23/2023]
Abstract
Erysipelothrix rhusiopathiae is a Gram-positive bacterium pathogenic to many species of birds and mammals, including humans. The main feature of its peptidoglycan is the presence of l-alanine at position 3 of the peptide stem. In the present work, we cloned the murE gene from E. rhusiopathiae and purified the corresponding protein as His6-tagged form. Enzymatic assays showed that E. rhusiopathiae MurE was indeed an l-alanine-adding enzyme. Surprisingly, it was also able, although to a lesser extent, to add meso-diaminopimelic acid, the amino acid found at position 3 in many Gram-negative bacteria, Bacilli and Mycobacteria. Sequence alignment of MurE enzymes from E. rhusiopathiae and Escherichia coli revealed that the DNPR motif that is characteristic of meso-diaminopimelate-adding enzymes was replaced by HDNR. The role of the latter motif in the interaction with l-alanine and meso-diaminopimelic acid was demonstrated by site-directed mutagenesis experiments and the construction of a homology model. The overexpression of the E. rhusiopathiae murE gene in E. coli resulted in the incorporation of l-alanine at position 3 of the peptide part of peptidoglycan.
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Affiliation(s)
- Delphine Patin
- Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198 CEA/CNRS/Université Paris-Sud, 91405 Orsay, France.
| | - Samo Turk
- Fakulteta za Farmacijo, Univerza v Ljubljani, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Hélène Barreteau
- Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198 CEA/CNRS/Université Paris-Sud, 91405 Orsay, France
| | - Jean-Luc Mainardi
- Laboratoire de Recherche Moléculaire sur les Antibiotiques, Centre de Recherche des Cordeliers, Equipe 12, INSERM U1138, 75006 Paris, France; Université Pierre et Marie Curie - Paris 6, UMR S1138, 15 Rue de l'Ecole de Médecine, 75006 Paris, France; Université Paris-Descartes, Sorbonne Paris Cité, UMR S1138, 75006 Paris, France
| | - Michel Arthur
- Laboratoire de Recherche Moléculaire sur les Antibiotiques, Centre de Recherche des Cordeliers, Equipe 12, INSERM U1138, 75006 Paris, France; Université Pierre et Marie Curie - Paris 6, UMR S1138, 15 Rue de l'Ecole de Médecine, 75006 Paris, France; Université Paris-Descartes, Sorbonne Paris Cité, UMR S1138, 75006 Paris, France
| | - Stanislav Gobec
- Fakulteta za Farmacijo, Univerza v Ljubljani, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Dominique Mengin-Lecreulx
- Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198 CEA/CNRS/Université Paris-Sud, 91405 Orsay, France
| | - Didier Blanot
- Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198 CEA/CNRS/Université Paris-Sud, 91405 Orsay, France
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10
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Cha SS, An YJ, Jeong CS, Yu JH, Chung KM. ATP-binding mode including a carbamoylated lysine and two Mg(2+) ions, and substrate-binding mode in Acinetobacter baumannii MurF. Biochem Biophys Res Commun 2014; 450:1045-50. [PMID: 24978312 DOI: 10.1016/j.bbrc.2014.06.108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 06/22/2014] [Indexed: 11/24/2022]
Abstract
MurF adds d-Ala-d-Ala dipeptide to UDP-N-acetylmuramyl-l-Ala-γ-d-Glu-m-DAP (or l-Lys) in an ATP-dependent manner, which is the last step in the biosynthesis of monomeric precursor of peptidoglycan. Here we report crystal structures of two MurF-ATP complexes: the MurF-ATP complex and the MurF-ATP-UDP complex. The ATP-binding mode revealed by the crystal structure of the MurF-ATP complex confirms the previous biochemical demonstration that a carbamoylated lysine and two Mg(2+) ions are required for enzyme activity of MurF. The UDP-MurF interactions observed in the crystal structure of the MurF-ATP-UDP complex depict the characteristic substrate-binding mode of MurF. The emergence and dissemination of multidrug-resistant Acinetobacter baumannii strains are great threats to public health. Therefore, the structural information on A. baumannii MurF as a validated target for drug discovery will provide a framework to develop antibacterial agents against multidrug-resistant A. baumannii infections as well as to understand the reaction mechanism of MurF.
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Affiliation(s)
- Sun-Shin Cha
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea; Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Pusan 606-791, Republic of Korea; Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea.
| | - Young Jun An
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea
| | - Chang-Sook Jeong
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea
| | - Jeong Hee Yu
- Department of Microbiology and Immunology, Chonbuk National University Medical School, Jeonju 561-756, Republic of Korea
| | - Kyung Min Chung
- Department of Microbiology and Immunology, Chonbuk National University Medical School, Jeonju 561-756, Republic of Korea; Institute for Medical Science, Chonbuk National University Medical School, Jeonju 561-756, Republic of Korea.
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11
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Hrast M, Anderluh M, Knez D, Randall CP, Barreteau H, O'Neill AJ, Blanot D, Gobec S. Design, synthesis and evaluation of second generation MurF inhibitors based on a cyanothiophene scaffold. Eur J Med Chem 2014; 73:83-96. [DOI: 10.1016/j.ejmech.2013.11.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/15/2013] [Accepted: 11/24/2013] [Indexed: 11/29/2022]
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12
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Combination of site directed mutagenesis and secondary structure analysis predicts the amino acids essential for stability of M. leprae MurE. Interdiscip Sci 2014; 6:40-7. [PMID: 24464703 DOI: 10.1007/s12539-014-0185-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 03/22/2013] [Accepted: 04/23/2013] [Indexed: 10/25/2022]
Abstract
The life-threatening infections caused by Mycobacterium leprae (Mle) remain a major challenge in developing countries as well as globe and there is a need to design potent anti-leprosy drugs. In our previous studies, ATP-dependent Mle-MurE ligase involved in biosynthesis of peptidoglycan was identified as one of the common drug targets, homology modeled and reported. In this work in silico site directed mutagenesis study was carried out on the homology modeled Mle-MurE ligase. This predicted the amino acids essential for stability. In addition, the distribution of these residues in different secondary structures and in active sites was analyzed. Finally, the role of the conserved residues in stability and function was analyzed. The availability of Mle-MurE ligase built model together with insights gained from stability studies and docking studies will promote the rational design of potent and selective Mle-MurE ligase inhibitors as anti-leprosy therapeutics.
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13
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Jimenez-Morales D, Adamian L, Shi D, Liang J. Lysine carboxylation: unveiling a spontaneous post-translational modification. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:48-57. [PMID: 24419378 PMCID: PMC3919261 DOI: 10.1107/s139900471302364x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 08/22/2013] [Indexed: 11/10/2022]
Abstract
The carboxylation of lysine residues is a post-translational modification (PTM) that plays a critical role in the catalytic mechanisms of several important enzymes. It occurs spontaneously under certain physicochemical conditions, but is difficult to detect experimentally. Its full impact is unknown. In this work, the signature microenvironment of lysine-carboxylation sites has been characterized. In addition, a computational method called Predictor of Lysine Carboxylation (PreLysCar) for the detection of lysine carboxylation in proteins with available three-dimensional structures has been developed. The likely prevalence of lysine carboxylation in the proteome was assessed through large-scale computations. The results suggest that about 1.3% of large proteins may contain a carboxylated lysine residue. This unexpected prevalence of lysine carboxylation implies an enrichment of reactions in which it may play functional roles. The results also suggest that by switching enzymes on and off under appropriate physicochemical conditions spontaneous PTMs may serve as an important and widely used efficient biological machinery for regulation.
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Affiliation(s)
- David Jimenez-Morales
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Room 218, Chicago, IL 60607, USA
| | - Larisa Adamian
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Room 218, Chicago, IL 60607, USA
| | - Dashuang Shi
- Children’s National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue NW, Washington, DC 20010-2970, USA
| | - Jie Liang
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Room 218, Chicago, IL 60607, USA
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Burghout P, Quintero B, Bos L, Beilharz K, Veening JW, de Jonge MI, van der Linden M, van der Ende A, Hermans PWM. A single amino acid substitution in the MurF UDP-MurNAc-pentapeptide synthetase renders Streptococcus pneumoniae dependent on CO2 and temperature. Mol Microbiol 2013; 89:494-506. [PMID: 23750975 DOI: 10.1111/mmi.12292] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2013] [Indexed: 11/30/2022]
Abstract
The respiratory tract pathogen Streptococcus pneumoniae encounters different levels of environmental CO2 during transmission, host colonization and disease. About 8% of all pneumococcal isolates are capnophiles that require CO2 -enriched growth conditions. The underlying molecular mechanism for caphnophilic behaviour, as well as its biological function is unknown. Here, we found that capnophilic S. pneumoniae isolates from clonal complex (CC) 156 (i.e. Spain(9V) -3 ancestry) and CC344 (i.e. Norway(NT) -42 ancestry) have a valine at position 179 in the MurF UDP-MurNAc-pentapeptide synthetase. At ≤ 30°C, the growth characteristics of capnophilic and non-capnophilic CC156 strains were equal, but at > 30°C growth and survival of MurF(V) (179) strains was dependent on > 0.1% CO2 -enriched conditions. Expression of MurF(V) (179) in S. pneumoniae R6 and G54 rendered these, otherwise non-capnophilic strains, capnophilic. Time-lapse microscopy revealed that a capnophilic CC156 strain undergoes rapid autolysis upon exposure to CO2 -poor conditions at 37°C, and staining with fluorescently labelled vancomycin showed a defect in de novo cell wall synthesis. In summary, in capnophilic S. pneumoniae strains from CC156 and CC344 cell wall synthesis is placed under control of environmental CO2 levels and temperature. This mechanism might represent a novel strategy of the pneumococcus to rapidly adapt and colonize its host under changing environmental conditions.
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Affiliation(s)
- Peter Burghout
- Laboratory of Pediatric Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
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15
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Hrast M, Turk S, Sosič I, Knez D, Randall CP, Barreteau H, Contreras-Martel C, Dessen A, O'Neill AJ, Mengin-Lecreulx D, Blanot D, Gobec S. Structure-activity relationships of new cyanothiophene inhibitors of the essential peptidoglycan biosynthesis enzyme MurF. Eur J Med Chem 2013; 66:32-45. [PMID: 23786712 DOI: 10.1016/j.ejmech.2013.05.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 10/26/2022]
Abstract
Peptidoglycan is an essential component of the bacterial cell wall, and enzymes involved in its biosynthesis represent validated targets for antibacterial drug discovery. MurF catalyzes the final intracellular peptidoglycan biosynthesis step: the addition of D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc-L-Ala-γ-D-Glu-meso-DAP (or L-Lys). As MurF has no human counterpart, it represents an attractive target for the development of new antibacterial drugs. Using recently published cyanothiophene inhibitors of MurF from Streptococcus pneumoniae as a starting point, we designed and synthesized a series of structurally related derivatives and investigated their inhibition of MurF enzymes from different bacterial species. Systematic structural modifications of the parent compounds resulted in a series of nanomolar inhibitors of MurF from S. pneumoniae and micromolar inhibitors of MurF from Escherichia coli and Staphylococcus aureus. Some of the inhibitors also show antibacterial activity against S. pneumoniae R6. These findings, together with two new co-crystal structures, represent an excellent starting point for further optimization toward effective novel antibacterials.
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Affiliation(s)
- Martina Hrast
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
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16
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Streptococcus pneumoniae folate biosynthesis responds to environmental CO2 levels. J Bacteriol 2013; 195:1573-82. [PMID: 23354753 DOI: 10.1128/jb.01942-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Although carbon dioxide (CO2) is known to be essential for Streptococcus pneumoniae growth, it is poorly understood how this respiratory tract pathogen adapts to the large changes in environmental CO2 levels it encounters during transmission, host colonization, and disease. To identify the molecular mechanisms that facilitate pneumococcal growth under CO2-poor conditions, we generated a random S. pneumoniae R6 mariner transposon mutant library representing mutations in 1,538 different genes and exposed it to CO2-poor ambient air. With Tn-seq, we found mutations in two genes that were involved in S. pneumoniae adaptation to changes in CO2 availability. The gene pca, encoding pneumococcal carbonic anhydrase (PCA), was absolutely essential for S. pneumoniae growth under CO2-poor conditions. PCA catalyzes the reversible hydration of endogenous CO2 to bicarbonate (HCO3(-)) and was previously demonstrated to facilitate HCO3(-)-dependent fatty acid biosynthesis. The gene folC that encodes the dihydrofolate/folylpolyglutamate synthase was required at the initial phase of bacterial growth under CO2-poor culture conditions. FolC compensated for the growth-phase-dependent decrease in S. pneumoniae intracellular long-chain (n > 3) polyglutamyl folate levels, which was most pronounced under CO2-poor growth conditions. In conclusion, S. pneumoniae adaptation to changes in CO2 availability involves the retention of endogenous CO2 and the preservation of intracellular long-chain polyglutamyl folate pools.
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17
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Fonvielle M, Mellal D, Patin D, Lecerf M, Blanot D, Bouhss A, Santarem M, Mengin-Lecreulx D, Sollogoub M, Arthur M, Ethève-Quelquejeu M. Efficient access to peptidyl-RNA conjugates for picomolar inhibition of non-ribosomal FemX(Wv) aminoacyl transferase. Chemistry 2012. [PMID: 23197408 DOI: 10.1002/chem.201201999] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peptidyl-RNA conjugates have various applications in studying the ribosome and enzymes participating in tRNA-dependent pathways such as Fem transferases in peptidoglycan synthesis. Herein a convergent synthesis of peptidyl-RNAs based on Huisgen-Sharpless cycloaddition for the final ligation step is developed. Azides and alkynes are introduced into tRNA and UDP-MurNAc-pentapeptide, respectively. Synthesis of 2'-azido RNA helix starts from 2'-azido-2'-deoxyadenosine that is coupled to deoxycytidine by phosphoramidite chemistry. The resulting dinucleotide is deprotected and ligated to a 22-nt RNA helix mimicking the acceptor arm of Ala-tRNA(Ala) by T4 RNA ligase. For alkyne UDP-MurNAc-pentapeptide, meso-cystine is enzymatically incorporated into the peptidoglycan precursor and reduced, and L-Cys is converted to dehydroalanine with O-(mesitylenesulfonyl)hydroxylamine. Reaction of but-3-yne-1-thiol with dehydroalanine affords the alkyne-containing UDP-MurNAc-pentapeptide. The Cu(I)-catalyzed azide alkyne cycloaddition reaction in the presence of tris[(1-hydroxypropyl-1H-1,2,3-triazol-4-yl)methyl]amine provided the peptidyl-RNA conjugate, which was tested as an inhibitor of non-ribosomal FemX(Wv) aminoacyl transferase. The bi-substrate analogue was found to inhibit FemX(Wv) with an IC(50) of (89±9) pM, as both moieties of the peptidyl-RNA conjugate contribute to high-affinity binding.
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Affiliation(s)
- Matthieu Fonvielle
- Centre de Recherche des Cordeliers, LRMA, Equipe 12, Université Pierre et Marie Curie - Paris 6, UMR S 872, Paris 75006, France
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18
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Patin D, Bostock J, Chopra I, Mengin-Lecreulx D, Blanot D. Biochemical characterisation of the chlamydial MurF ligase, and possible sequence of the chlamydial peptidoglycan pentapeptide stem. Arch Microbiol 2012; 194:505-12. [DOI: 10.1007/s00203-011-0784-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 12/01/2011] [Accepted: 12/09/2011] [Indexed: 10/14/2022]
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19
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Das D, Hervé M, Feuerhelm J, Farr CL, Chiu HJ, Elsliger MA, Knuth MW, Klock HE, Miller MD, Godzik A, Lesley SA, Deacon AM, Mengin-Lecreulx D, Wilson IA. Structure and function of the first full-length murein peptide ligase (Mpl) cell wall recycling protein. PLoS One 2011; 6:e17624. [PMID: 21445265 PMCID: PMC3060825 DOI: 10.1371/journal.pone.0017624] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/03/2011] [Indexed: 11/18/2022] Open
Abstract
Bacterial cell walls contain peptidoglycan, an essential polymer made by enzymes in the Mur pathway. These proteins are specific to bacteria, which make them targets for drug discovery. MurC, MurD, MurE and MurF catalyze the synthesis of the peptidoglycan precursor UDP-N-acetylmuramoyl-L-alanyl-γ-D-glutamyl-meso-diaminopimelyl-D-alanyl-D-alanine by the sequential addition of amino acids onto UDP-N-acetylmuramic acid (UDP-MurNAc). MurC-F enzymes have been extensively studied by biochemistry and X-ray crystallography. In gram-negative bacteria, ∼30-60% of the bacterial cell wall is recycled during each generation. Part of this recycling process involves the murein peptide ligase (Mpl), which attaches the breakdown product, the tripeptide L-alanyl-γ-D-glutamyl-meso-diaminopimelate, to UDP-MurNAc. We present the crystal structure at 1.65 Å resolution of a full-length Mpl from the permafrost bacterium Psychrobacter arcticus 273-4 (PaMpl). Although the Mpl structure has similarities to Mur enzymes, it has unique sequence and structure features that are likely related to its role in cell wall recycling, a function that differentiates it from the MurC-F enzymes. We have analyzed the sequence-structure relationships that are unique to Mpl proteins and compared them to MurC-F ligases. We have also characterized the biochemical properties of this enzyme (optimal temperature, pH and magnesium binding profiles and kinetic parameters). Although the structure does not contain any bound substrates, we have identified ∼30 residues that are likely to be important for recognition of the tripeptide and UDP-MurNAc substrates, as well as features that are unique to Psychrobacter Mpl proteins. These results provide the basis for future mutational studies for more extensive function characterization of the Mpl sequence-structure relationships.
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Affiliation(s)
- Debanu Das
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, United States of America
| | - Mireille Hervé
- Université Paris-Sud, Laboratoire des Enveloppes Bactériennes et Antibiotiques, Orsay, France
- Centre National de la Recherche Scientifique, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Orsay, France
| | - Julie Feuerhelm
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Carol L. Farr
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Hsiu-Ju Chiu
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, United States of America
| | - Marc-André Elsliger
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Mark W. Knuth
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Heath E. Klock
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Mitchell D. Miller
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, United States of America
| | - Adam Godzik
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Center for Research in Biological Systems, University of California San Diego, La Jolla, California, United States of America
- Program on Bioinformatics and Systems Biology, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Scott A. Lesley
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Ashley M. Deacon
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, United States of America
| | - Dominique Mengin-Lecreulx
- Université Paris-Sud, Laboratoire des Enveloppes Bactériennes et Antibiotiques, Orsay, France
- Centre National de la Recherche Scientifique, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Orsay, France
| | - Ian A. Wilson
- Joint Center for Structural Genomics (http://www.jcsg.org)
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
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20
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Essential residues for the enzyme activity of ATP-dependent MurE ligase from Mycobacterium tuberculosis. Protein Cell 2010; 1:1011-22. [PMID: 21153518 DOI: 10.1007/s13238-010-0132-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 10/31/2010] [Indexed: 10/18/2022] Open
Abstract
The emergence of total drug-resistant tuberculosis (TDRTB) has made the discovery of new therapies for tuberculosis urgent. The cytoplasmic enzymes of peptidoglycan biosynthesis have generated renewed interest as attractive targets for the development of new anti-mycobacterials. One of the cytoplasmic enzymes, uridine diphosphate (UDP)-MurNAc-tripeptide ligase (MurE), catalyses the addition of meso-diaminopimelic acid (m-DAP) into peptidoglycan in Mycobacterium tuberculosis coupled to the hydrolysis of ATP. Mutants of M. tuberculosis MurE were generated by replacing K157, E220, D392, R451 with alanine and N449 with aspartate, and truncating the first 24 amino acid residues at the N-terminus of the enzyme. Analysis of the specific activity of these proteins suggested that apart from the 24 N-terminal residues, the other mutated residues are essential for catalysis. Variations in K(m) values for one or more substrates were observed for all mutants, except the N-terminal truncation mutant, indicating that these residues are involved in binding substrates and form part of the active site structure. These mutant proteins were also tested for their specificity for a wide range of substrates. Interestingly, the mutations K157A, E220A and D392A showed hydrolysis of ATP uncoupled from catalysis. The ATP hydrolysis rate was enhanced by at least partial occupation of the uridine nucleotide dipeptide binding site. This study provides an insight into the residues essential for the catalytic activity and substrate binding of the ATP-dependent MurE ligase. Since ATP-dependent MurE ligase is a novel drug target, the understanding of its function may lead to development of novel inhibitors against resistant forms of M. tuberculosis.
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21
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Gautam A, Vyas R, Tewari R. Peptidoglycan biosynthesis machinery: a rich source of drug targets. Crit Rev Biotechnol 2010; 31:295-336. [PMID: 21091161 DOI: 10.3109/07388551.2010.525498] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The range of antibiotic therapy for the control of bacterial infections is becoming increasingly limited because of the rapid rise in multidrug resistance in clinical bacterial isolates. A few diseases, such as tuberculosis, which were once thought to be under control, have re-emerged as serious health threats. These problems have resulted in intensified research to look for new inhibitors for bacterial pathogens. Of late, the peptidoglycan (PG) layer, the most important component of the bacterial cell wall has been the subject of drug targeting because, first, it is essential for the survivability of eubacteria and secondly, it is absent in humans. The last decade has seen tremendous inputs in deciphering the 3-D structures of the PG biosynthetic enzymes. Many inhibitors against these enzymes have been developed using virtual and high throughput screening techniques. This review discusses the mechanistic and structural properties of the PG biosynthetic enzymes and inhibitors developed in the last decade.
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Affiliation(s)
- Ankur Gautam
- Department of Biotechnology, Panjab University, Chandigarh, India
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22
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Li Y, Yu X, Ho J, Fushman D, Allewell NM, Tuchman M, Shi D. Reversible post-translational carboxylation modulates the enzymatic activity of N-acetyl-L-ornithine transcarbamylase. Biochemistry 2010; 49:6887-95. [PMID: 20695527 DOI: 10.1021/bi1007386] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Acetyl-l-ornithine transcarbamylase (AOTCase), rather than ornithine transcarbamylase (OTCase), is the essential carbamylase enzyme in the arginine biosynthesis of several plant and human pathogens. The specificity of this unique enzyme provides a potential target for controlling the spread of these pathogens. Recently, several crystal structures of AOTCase from Xanthomonas campestris (xc) have been determined. In these structures, an unexplained electron density at the tip of the Lys302 side chain was observed. Using (13)C NMR spectroscopy, we show herein that Lys302 is post-translationally carboxylated. The structure of wild-type AOTCase in a complex with the bisubstrate analogue N(delta)-(phosphonoacetyl)-N(alpha)-acetyl-l-ornithine (PALAO) indicates that the carboxyl group on Lys302 forms a strong hydrogen bonding network with surrounding active site residues, Lys252, Ser253, His293, and Glu92 from the adjacent subunit either directly or via a water molecule. Furthermore, the carboxyl group is involved in binding N-acetyl-l-ornithine via a water molecule. Activity assays with the wild-type enzyme and several mutants demonstrate that the post-translational modification of lysine 302 has an important role in catalysis.
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Affiliation(s)
- Yongdong Li
- Research Center for Genetic Medicine and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, DC 20010, USA
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23
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Patin D, Boniface A, Kovač A, Hervé M, Dementin S, Barreteau H, Mengin-Lecreulx D, Blanot D. Purification and biochemical characterization of Mur ligases from Staphylococcus aureus. Biochimie 2010; 92:1793-800. [PMID: 20659527 DOI: 10.1016/j.biochi.2010.07.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 07/15/2010] [Indexed: 10/19/2022]
Abstract
The Mur ligases (MurC, MurD, MurE and MurF) catalyze the stepwise synthesis of the UDP-N-acetylmuramoyl-pentapeptide precursor of peptidoglycan. The murC, murD, murE and murF genes from Staphylococcus aureus, a major pathogen, were cloned and the corresponding proteins were overproduced in Escherichia coli and purified as His(6)-tagged forms. Their biochemical properties were investigated and compared to those of the E. coli enzymes. Staphylococcal MurC accepted L-Ala, L-Ser and Gly as substrates, as the E. coli enzyme does, with a strong preference for L-Ala. S. aureus MurE was very specific for L-lysine and in particular did not accept meso-diaminopimelic acid as a substrate. This mirrors the E. coli MurE specificity, for which meso-diaminopimelic acid is the preferred substrate and L-lysine a very poor one. S. aureus MurF appeared less specific and accepted both forms (L-lysine and meso-diaminopimelic acid) of UDP-MurNAc-tripeptide, as the E. coli MurF does. The inverse and strict substrate specificities of the two MurE orthologues is thus responsible for the presence of exclusively meso-diaminopimelic acid and L-lysine at the third position of the peptide in the peptidoglycans of E. coli and S. aureus, respectively. The specific activities of the four Mur ligases were also determined in crude extracts of S. aureus and compared to cell requirements for peptidoglycan biosynthesis.
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Affiliation(s)
- Delphine Patin
- Univ Paris-Sud, Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619, Orsay F-91405, France
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24
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Štefane B, Gobec S, Sosič I, Kovač A, Turk S, Blanot D. The Synthesis of Novel 2,4,6-Trisubstituted 1,3,5-Triazines: A Search for Potential MurF Enzyme Inhibitors. HETEROCYCLES 2010. [DOI: 10.3987/com-09-11839] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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25
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Baurin S, Vercheval L, Bouillenne F, Falzone C, Brans A, Jacquamet L, Ferrer JL, Sauvage E, Dehareng D, Frère JM, Charlier P, Galleni M, Kerff F. Critical role of tryptophan 154 for the activity and stability of class D beta-lactamases. Biochemistry 2009; 48:11252-63. [PMID: 19860471 DOI: 10.1021/bi901548c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The catalytic efficiency of the class D beta-lactamase OXA-10 depends critically on an unusual carboxylated lysine as the general base residue for both the enzyme acylation and deacylation steps of catalysis. Evidence is presented that the interaction between the indole group of Trp154 and the carboxylated lysine is essential for the stability of the posttranslationally modified Lys70. Substitution of Trp154 by Gly, Ala, or Phe yielded noncarboxylated enzymes which displayed poor catalytic efficiencies and reduced stability when compared to the wild-type OXA-10. The W154H mutant was partially carboxylated. In addition, the maximum values of k(cat) and k(cat)/K(M) were shifted toward pH 7, indicating that the carboxylation state of Lys70 is dependent on the protonation level of the histidine. A comparison of the three-dimensional structures of the different proteins also indicated that the Trp154 mutations did not modify the overall structures of OXA-10 but induced an increased flexibility of the Omega-loop in the active site. Finally, the deacylation-impaired W154A mutant was used to determine the structure of the acyl-enzyme complex with benzylpenicillin. These results indicate a role of the Lys70 carboxylation during the deacylation step and emphasize the importance of Trp154 for the ideal positioning of active site residues leading to an optimum activity.
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Affiliation(s)
- Stéphane Baurin
- Laboratory of Biological Macromolecules, Center for Protein Engineering, University of Liège, Institut de Chimie B6a, Belgium
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26
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Sova M, Kovac A, Turk S, Hrast M, Blanot D, Gobec S. Phosphorylated hydroxyethylamines as novel inhibitors of the bacterial cell wall biosynthesis enzymes MurC to MurF. Bioorg Chem 2009; 37:217-22. [PMID: 19804894 DOI: 10.1016/j.bioorg.2009.09.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 10/20/2022]
Abstract
Enzymes involved in the biosynthesis of bacterial peptidoglycan represent important targets for development of new antibacterial drugs. Among them, Mur ligases (MurC to MurF) catalyze the formation of the final cytoplasmic precursor UDP-N-acetylmuramyl-pentapeptide from UDP-N-acetylmuramic acid. We present the design, synthesis and biological evaluation of a series of phosphorylated hydroxyethylamines as new type of small-molecule inhibitors of Mur ligases. We show that the phosphate group attached to the hydroxyl moiety of the hydroxyethylamine core is essential for good inhibitory activity. The IC(50) values of these inhibitors were in the micromolar range, which makes them a promising starting point for the development of multiple inhibitors of Mur ligases as potential antibacterial agents. In addition, 1-(4-methoxyphenylsulfonamido)-3-morpholinopropan-2-yl dihydrogen phosphate 7a was discovered as one of the best inhibitors of MurE described so far.
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Affiliation(s)
- Matej Sova
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
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27
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Kristan K, Kotnik M, Oblak M, Urleb U. New high-throughput fluorimetric assay for discovering inhibitors of UDP-N-acetylmuramyl-L-alanine: D-glutamate (MurD) ligase. ACTA ACUST UNITED AC 2009; 14:412-8. [PMID: 19403924 DOI: 10.1177/1087057109332597] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A novel assay for monitoring the activity of the bacterial enzyme UDP-N-acetylmuramyl-L-alanine:D-glutamate ligase (MurD ligase) is presented. MurD, which belongs to an enzyme family of Mur ligases, is essential for the synthesis of bacterial peptidoglycan and therefore represents an attractive target for the discovery of novel antibacterial agents. The inhibition assay described in this article is amenable to high-throughput screening. It is based on the detection of the accumulation of adenosine 5'-diphosphate (ADP), a product of the reaction catalyzed by MurD ligase, by conversion to a fluorescent signal via a coupled enzyme system, using the ADP Quest assay kit from DiscoveRx. The novel assay has been validated by obtaining KM,app values for substrates D-Glu, UDP- N-acetylmuramyl-L-alanine (UMA) and ATP that are in agreement with the data reported in the literature. A counterscreen assay was introduced to eliminate false positives, and some of the known MurD inhibitors have been retested to compare the data measured with different methods. Moreover, a focused library of around 1000 compounds was screened for the inhibition of MurD to assess the performance and robustness of the assay. Finally, a novel MurD inhibitor belonging to a new structural class, with an IC50 value of 105 microM, was discovered.
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Affiliation(s)
- Katja Kristan
- Drug Discovery, Lek Pharmaceuticals d.d., Ljubljana, Slovenia.
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Mandrich L, Manco G. Evolution in the Amidohydrolase Superfamily: Substrate-Assisted Gain of Function in the E183K Mutant of a Phosphotriesterase-like Metal-Carboxylesterase. Biochemistry 2009; 48:5602-12. [DOI: 10.1021/bi801932x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Luigi Mandrich
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Giuseppe Manco
- Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131, Naples, Italy
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Turk S, Kovac A, Boniface A, Bostock JM, Chopra I, Blanot D, Gobec S. Discovery of new inhibitors of the bacterial peptidoglycan biosynthesis enzymes MurD and MurF by structure-based virtual screening. Bioorg Med Chem 2009; 17:1884-9. [PMID: 19223185 DOI: 10.1016/j.bmc.2009.01.052] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2008] [Revised: 01/19/2009] [Accepted: 01/22/2009] [Indexed: 11/18/2022]
Abstract
The ATP-dependent Mur ligases (MurC, MurD, MurE and MurF) successively add L-Ala, D-Glu, meso-A(2)pm or L-Lys, and D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc, and they represent promising targets for antibacterial drug discovery. We have used the molecular docking programme eHiTS for the virtual screening of 1990 compounds from the National Cancer Institute 'Diversity Set' on MurD and MurF. The 50 top-scoring compounds from screening on each enzyme were selected for experimental biochemical evaluation. Our approach of virtual screening and subsequent in vitro biochemical evaluation of the best ranked compounds has provided four novel MurD inhibitors (best IC(50)=10 microM) and one novel MurF inhibitor (IC(50)=63 microM).
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Affiliation(s)
- Samo Turk
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
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Paradis-Bleau C, Lloyd A, Sanschagrin F, Clarke T, Blewett A, Bugg TDH, Levesque RC. Phage display-derived inhibitor of the essential cell wall biosynthesis enzyme MurF. BMC BIOCHEMISTRY 2008; 9:33. [PMID: 19099588 PMCID: PMC2626591 DOI: 10.1186/1471-2091-9-33] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 12/19/2008] [Indexed: 11/10/2022]
Abstract
BACKGROUND To develop antibacterial agents having novel modes of action against bacterial cell wall biosynthesis, we targeted the essential MurF enzyme of the antibiotic resistant pathogen Pseudomonas aeruginosa. MurF catalyzes the formation of a peptide bond between D-Alanyl-D-Alanine (D-Ala-D-Ala) and the cell wall precursor uridine 5'-diphosphoryl N-acetylmuramoyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid (UDP-MurNAc-Ala-Glu-meso-A2pm) with the concomitant hydrolysis of ATP to ADP and inorganic phosphate, yielding UDP-N-acetylmuramyl-pentapeptide. As MurF acts on a dipeptide, we exploited a phage display approach to identify peptide ligands having high binding affinities for the enzyme. RESULTS Screening of a phage display 12-mer library using purified P. aeruginosa MurF yielded to the identification of the MurFp1 peptide. The MurF substrate UDP-MurNAc-Ala-Glumeso-A2pm was synthesized and used to develop a sensitive spectrophotometric assay to quantify MurF kinetics and inhibition. MurFp1 acted as a weak, time-dependent inhibitor of MurF activity but was a potent inhibitor when MurF was pre-incubated with UDP-MurNAc-Ala-Glu-meso-A2pm or ATP. In contrast, adding the substrate D-Ala-D-Ala during the pre-incubation nullified the inhibition. The IC50 value of MurFp1 was evaluated at 250 microM, and the Ki was established at 420 microM with respect to the mixed type of inhibition against D-Ala-D-Ala. CONCLUSION MurFp1 exerts its inhibitory action by interfering with the utilization of D-Ala-D-Ala by the MurF amide ligase enzyme. We propose that MurFp1 exploits UDP-MurNAc-Ala-Glu-meso-A2pm-induced structural changes for better interaction with the enzyme. We present the first peptide inhibitor of MurF, an enzyme that should be exploited as a target for antimicrobial drug development.
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Barreteau H, Kovac A, Boniface A, Sova M, Gobec S, Blanot D. Cytoplasmic steps of peptidoglycan biosynthesis. FEMS Microbiol Rev 2008; 32:168-207. [PMID: 18266853 DOI: 10.1111/j.1574-6976.2008.00104.x] [Citation(s) in RCA: 479] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The biosynthesis of bacterial cell wall peptidoglycan is a complex process that involves enzyme reactions that take place in the cytoplasm (synthesis of the nucleotide precursors) and on the inner side (synthesis of lipid-linked intermediates) and outer side (polymerization reactions) of the cytoplasmic membrane. This review deals with the cytoplasmic steps of peptidoglycan biosynthesis, which can be divided into four sets of reactions that lead to the syntheses of (1) UDP-N-acetylglucosamine from fructose 6-phosphate, (2) UDP-N-acetylmuramic acid from UDP-N-acetylglucosamine, (3) UDP-N-acetylmuramyl-pentapeptide from UDP-N-acetylmuramic acid and (4) D-glutamic acid and dipeptide D-alanyl-D-alanine. Recent data concerning the different enzymes involved are presented. Moreover, special attention is given to (1) the chemical and enzymatic synthesis of the nucleotide precursor substrates that are not commercially available and (2) the search for specific inhibitors that could act as antibacterial compounds.
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Affiliation(s)
- Hélène Barreteau
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Univ Paris-Sud, Orsay, France
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Perdih A, Kotnik M, Hodoscek M, Solmajer T. Targeted molecular dynamics simulation studies of binding and conformational changes in E. coli MurD. Proteins 2007; 68:243-54. [PMID: 17427948 DOI: 10.1002/prot.21374] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Enzymes involved in the biosynthesis of bacterial peptidoglycan, an essential cell wall polymer unique to prokaryotic cells, represent a highly interesting target for antibacterial drug design. Structural studies of E. coli MurD, a three-domain ATP hydrolysis driven muramyl ligase revealed two inactive open conformations of the enzyme with a distinct C-terminal domain position. It was hypothesized that the rigid body rotation of this domain brings the enzyme to its closed active conformation, a structure, which was also determined experimentally. Targeted molecular dynamics 1 ns-length simulations were performed in order to examine the substrate binding process and gain insight into structural changes in the enzyme that occur during the conformational transitions into the active conformation. The key interactions essential for the conformational transitions and substrate binding were identified. The results of such studies provide an important step toward more powerful exploitation of experimental protein structures in structure-based inhibitor design.
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Affiliation(s)
- Andrej Perdih
- Laboratory for Molecular Modelling and NMR Spectroscopy, National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia
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Füser G, Steinbüchel A. Analysis of genome sequences for genes of cyanophycin metabolism: identifying putative cyanophycin metabolizing prokaryotes. Macromol Biosci 2007; 7:278-96. [PMID: 17390395 DOI: 10.1002/mabi.200600207] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
CGP, a copolymer of aspartate and arginine, serves as a storage compound for nitrogen, carbon and energy in many cyanobacteria. Analysis of available genome sequences from prokaryotes identified ORFs putatively encoding proteins of high similarity to known cyanophycin synthetases and cyanophycinases from cyanobacteria in various strains of bacteria belonging to different phylogenetic taxa and not closely related to cyanobacteria. Genes of CGP metabolism occur in a wide range of bacteria exhibiting diverse metabolic capabilities, including aerobic and anaerobic respiration, fermentation, phototrophy and chemolithoautotrophy. This study identified different groups of cyanophycin synthetases and cyanophycinases, respectively, and proposes a collective terminology for the putative genes and enzymes of cyanophycin metabolism. Among 570 different microbial strains, whose genomes have been partially or completely sequenced and are publicly accessible, we identified 44 prokaryotes which possess a cyanophycin synthetase and are putatively able to synthesize CGP. From these, 31 prokaryotes harbor also a cyanophycinase enabling them to degrade CGP to dipeptides. From the latter, 24 strains possess in addition a dipeptidase necessary to hydrolyze beta-Asp-Arg dipeptides, thereby enabling them to completely utilize CGP. Therefore, CGP seems to have a much wider distribution among prokaryotes than previously recognized. Genes putatively encoding cyanophycin synthetase homologues were not identified in the genomes of Eukarya and Archaea and are therefore obviously only occurring in Eubacteria. In addition, the outcome of this detailed in silico analysis proposes to distinguish 10 different groups of cyanophycin synthetases.
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Affiliation(s)
- Gregor Füser
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, Münster, Germany
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Antonkine ML, Maes EM, Czernuszewicz RS, Breitenstein C, Bill E, Falzone CJ, Balasubramanian R, Lubner C, Bryant DA, Golbeck JH. Chemical rescue of a site-modified ligand to a [4Fe–4S] cluster in PsaC, a bacterial-like dicluster ferredoxin bound to Photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:712-24. [PMID: 17434441 DOI: 10.1016/j.bbabio.2007.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 01/21/2007] [Accepted: 02/02/2007] [Indexed: 10/23/2022]
Abstract
Chemical rescue of site-modified amino acids using externally supplied organic molecules represents a powerful method to investigate structure-function relationships in proteins. Here we provide definitive evidence that aryl and alkyl thiolates, reagents typically used for in vitro iron-sulfur cluster reconstitutions, serve as rescue ligands to a site-specifically modified [4Fe-4S](1+,2+) cluster in PsaC, a bacterial dicluster ferredoxin-like subunit of Photosystem I. PsaC binds two low-potential [4Fe-4S](1+,2+) clusters termed F(A) and F(B). In the C13G/C33S variant of PsaC, glycine has replaced cysteine at position 13 creating a protein that is missing one of the ligating amino acids to iron-sulfur cluster F(B). Using a variety of analytical techniques, including non-heme iron and acid-labile sulfur assays, and EPR, resonance Raman, and Mössbauer spectroscopies, we showed that the C13G/C33S variant of PsaC binds two [4Fe-4S](1+,2+) clusters, despite the absence of one of the biological ligands. (19)F NMR spectroscopy indicated that the external thiolate replaces cysteine 13 as a substitute ligand to the F(B) cluster. The finding that site-modified [4Fe-4S](1+,2+) clusters can be chemically rescued with external thiolates opens new opportunities for modulating their properties in proteins. In particular, it provides a mechanism to attach an additional electron transfer cofactor to the protein via a bound, external ligand.
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Affiliation(s)
- Mikhail L Antonkine
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
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Structural and functional characterization of enantiomeric glutamic acid derivatives as potential transition state analogue inhibitors of MurD ligase. J Mol Biol 2007; 370:107-15. [PMID: 17507028 DOI: 10.1016/j.jmb.2007.04.048] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 04/06/2007] [Accepted: 04/17/2007] [Indexed: 10/23/2022]
Abstract
Mur ligases play an essential role in the intracellular biosynthesis of bacterial peptidoglycan, the main component of the bacterial cell wall, and represent attractive targets for the design of novel antibacterials. UDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase (MurD) catalyses the addition of D-glutamic acid to the cytoplasmic intermediate UDP-N-acetylmuramoyl-L-alanine (UMA) and is the second in the series of Mur ligases. MurD ligase is highly stereospecific for its substrate, D-glutamic acid (D-Glu). Here, we report the high resolution crystal structures of MurD in complexes with two novel inhibitors designed to mimic the transition state of the reaction, which contain either the D-Glu or the L-Glu moiety. The binding modes of N-sulfonyl-D-Glu and N-sulfonyl-L-Glu derivatives were also characterised kinetically. The results of this study represent an excellent starting point for further development of novel inhibitors of this enzyme.
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Hervé M, Boniface A, Gobec S, Blanot D, Mengin-Lecreulx D. Biochemical characterization and physiological properties of Escherichia coli UDP-N-acetylmuramate:L-alanyl-gamma-D-glutamyl-meso-diaminopimelate ligase. J Bacteriol 2007; 189:3987-95. [PMID: 17384195 PMCID: PMC1913392 DOI: 10.1128/jb.00087-07] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The UDP-N-acetylmuramate:L-alanyl-gamma-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-gamma-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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Affiliation(s)
- Mireille Hervé
- CNRS Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619, 91405 Orsay Cedex, France.
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Chaput C, Ecobichon C, Cayet N, Girardin SE, Werts C, Guadagnini S, Prévost MC, Mengin-Lecreulx D, Labigne A, Boneca IG. Role of AmiA in the morphological transition of Helicobacter pylori and in immune escape. PLoS Pathog 2006; 2:e97. [PMID: 17002496 PMCID: PMC1574363 DOI: 10.1371/journal.ppat.0020097] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Accepted: 08/07/2006] [Indexed: 12/17/2022] Open
Abstract
The human gastric pathogen Helicobacter pylori is responsible for peptic ulcers and neoplasia. Both in vitro and in the human stomach it can be found in two forms, the bacillary and coccoid forms. The molecular mechanisms of the morphological transition between these two forms and the role of coccoids remain largely unknown. The peptidoglycan (PG) layer is a major determinant of bacterial cell shape, and therefore we studied H. pylori PG structure during the morphological transition. The transition correlated with an accumulation of the N-acetyl-D-glucosaminyl-β(1,4)-N-acetylmuramyl-L-Ala–D-Glu (GM-dipeptide) motif. We investigated the molecular mechanisms responsible for the GM-dipeptide motif accumulation, and studied the role of various putative PG hydrolases in this process. Interestingly, a mutant strain with a mutation in the amiA gene, encoding a putative PG hydrolase, was impaired in accumulating the GM-dipeptide motif and transforming into coccoids. We investigated the role of the morphological transition and the PG modification in the biology of H. pylori. PG modification and transformation of H. pylori was accompanied by an escape from detection by human Nod1 and the absence of NF-κB activation in epithelial cells. Accordingly, coccoids were unable to induce IL-8 secretion by AGS gastric epithelial cells. amiA is, to our knowledge, the first genetic determinant discovered to be required for this morphological transition into the coccoid forms, and therefore contributes to modulation of the host response and participates in the chronicity of H. pylori infection. Helicobacter pylori is a human pathogen responsible for gastric diseases such as ulcers and gastric cancers. Despite the host's vigorous immune response, H. pylori is capable of persisting for decades in its human host. H. pylori is found in biopsies in two distinct forms, a spiral rod form and a coccoid form. Chaput et al. investigated the molecular mechanisms leading to the transition of H. pylori from a spiral rod–shaped organism to a coccoid organism. The morphological transition is accompanied by modifications of the bacterial cell wall peptidoglycan. The authors have identified the AmiA protein as essential for this morphological transition and modification of the cell wall peptidoglycan. Additionally, the authors show that the cell wall modifications and morphological transition allow these coccoid forms to escape detection by the immune system and therefore could participate in the persistence of H. pylori infection during the lifetime of its human host.
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Affiliation(s)
- Catherine Chaput
- Unité de Pathogénie Bactérienne des Muqueuses, Institut Pasteur, Paris, France
| | - Chantal Ecobichon
- Unité de Pathogénie Bactérienne des Muqueuses, Institut Pasteur, Paris, France
| | - Nadège Cayet
- Plate-Forme de Microscopie Électronique, Institut Pasteur, Paris, France
| | - Stephen E Girardin
- Groupe Avenir, INSERM U389, Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
| | - Catherine Werts
- Groupe Immunité Innée et Signalisation, Institut Pasteur, Paris, France
| | | | | | | | - Agnès Labigne
- Unité de Pathogénie Bactérienne des Muqueuses, Institut Pasteur, Paris, France
| | - Ivo G Boneca
- Unité de Pathogénie Bactérienne des Muqueuses, Institut Pasteur, Paris, France
- * To whom correspondence should be addressed. E-mail:
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Humljan J, Kotnik M, Boniface A, Šolmajer T, Urleb U, Blanot D, Gobec S. A new approach towards peptidosulfonamides: synthesis of potential inhibitors of bacterial peptidoglycan biosynthesis enzymes MurD and MurE. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.08.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Smith CA. Structure, function and dynamics in the mur family of bacterial cell wall ligases. J Mol Biol 2006; 362:640-55. [PMID: 16934839 DOI: 10.1016/j.jmb.2006.07.066] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 07/23/2006] [Accepted: 07/26/2006] [Indexed: 10/24/2022]
Abstract
For bacteria, the structural integrity of its cell wall is of utmost importance for survival, and to this end, a rigid scaffold called peptidoglycan, comprised of sugar molecules and peptides, is synthesized and located outside the cytoplasmic membrane of the cell. Disruption of this peptidoglycan layer has for many years been a prime target for effective antibiotics, namely the penicillins and cephalosporins. Because this rigid layer is synthesized by a multi-step pathway numerous additional targets also exist that have no counterpart in the animal cell. Central to this pathway are four similar ligase enzymes, which add peptide groups to the sugar molecules, and interrupting these steps would ultimately prove fatal to the bacterial cell. The mechanisms of these ligases are well understood and the structures of all four of these ligases are now known. A detailed comparison of these four enzymes shows that considerable conformational changes are possible and that these changes, along with the recruitment of two different N-terminal binding domains, allows these enzymes to bind a substrate which at one end is identical and at the other has the growing polypeptide tail. Some insights into the structure-function relationships in these enzymes is presented.
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Affiliation(s)
- Clyde A Smith
- Stanford Synchrotron Radiation Laboratory, Menlo Park, CA 94025, USA.
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Mayer KM, McCorkle SR, Shanklin J. Linking enzyme sequence to function using Conserved Property Difference Locator to identify and annotate positions likely to control specific functionality. BMC Bioinformatics 2005; 6:284. [PMID: 16318626 PMCID: PMC1326233 DOI: 10.1186/1471-2105-6-284] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 11/30/2005] [Indexed: 11/21/2022] Open
Abstract
Background Families of homologous enzymes evolved from common progenitors. The availability of multiple sequences representing each activity presents an opportunity for extracting information specifying the functionality of individual homologs. We present a straightforward method for the identification of residues likely to determine class specific functionality in which multiple sequence alignments are converted to an annotated graphical form by the Conserved Property Difference Locator (CPDL) program. Results Three test cases, each comprised of two groups of funtionally-distinct homologs, are presented. Of the test cases, one is a membrane and two are soluble enzyme families. The desaturase/hydroxylase data was used to design and test the CPDL algorithm because a comparative sequence approach had been successfully applied to manipulate the specificity of these enzymes. The other two cases, ATP/GTP cyclases, and MurD/MurE synthases were chosen because they are well characterized structurally and biochemically. For the desaturase/hydroxylase enzymes, the ATP/GTP cyclases and the MurD/MurE synthases, groups of 8 (of ~400), 4 (of ~150) and 10 (of >400) residues, respectively, of interest were identified that contain empirically defined specificity determining positions. Conclusion CPDL consistently identifies positions near enzyme active sites that include those predicted from structural and/or biochemical studies to be important for specificity and/or function. This suggests that CPDL will have broad utility for the identification of potential class determining residues based on multiple sequence analysis of groups of homologous proteins. Because the method is sequence, rather than structure, based it is equally well suited for designing structure-function experiments to investigate membrane and soluble proteins.
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Affiliation(s)
- Kimberly M Mayer
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Sean R McCorkle
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Stubbe J, Tian J, He A, Sinskey AJ, Lawrence AG, Liu P. NONTEMPLATE-DEPENDENT POLYMERIZATION PROCESSES: Polyhydroxyalkanoate Synthases as a Paradigm. Annu Rev Biochem 2005; 74:433-80. [PMID: 15952894 DOI: 10.1146/annurev.biochem.74.082803.133013] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review focuses on nontemplate-dependent polymerases that use water-soluble substrates and convert them into water-insoluble polymers that form granules or inclusions within the cell. The initial part of the review summarizes briefly the current knowledge of polymer formation catalyzed by starch and glycogen synthases, polyphosphate kinase (a polymerase), cyanophycin synthetases, and rubber synthases. Specifically, our current understanding of their mechanisms of initiation, elongation (including granule formation), termination, remodeling, and polymer reutilization will be presented. General underlying principles that govern these types of polymerization reactions will be enumerated as a paradigm for all nontemplate-dependent polymerizations. The bulk of the review then focuses on polyhydroxyalkanoate (PHA) synthases that generate polyoxoesters. These enzymes are of interest as they generate biodegradable polymers. Our current knowledge of PHA production and utilization in vitro and in vivo as well as the contribution of many proteins to these processes will be reviewed.
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Affiliation(s)
- Joanne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Mathieu M, Debousker G, Vincent S, Viviani F, Bamas-Jacques N, Mikol V. Escherichia coli FolC structure reveals an unexpected dihydrofolate binding site providing an attractive target for anti-microbial therapy. J Biol Chem 2005; 280:18916-22. [PMID: 15705579 DOI: 10.1074/jbc.m413799200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In some bacteria, such as Escherichia coli, the addition of L-glutamate to dihydropteroate (dihydrofolate synthetase activity) and the subsequent additions of L-glutamate to tetrahydrofolate (folylpolyglutamate synthetase (FPGS) activity) are catalyzed by the same enzyme, FolC. The crystal structure of E. coli FolC is described in this paper. It showed strong similarities to that of the FPGS enzyme of Lactobacillus casei within the ATP binding site and the catalytic site, as do all other members of the Mur synthethase superfamily. FolC structure revealed an unexpected dihydropteroate binding site very different from the folate site identified previously in the FPGS structure. The relevance of this site is exemplified by the presence of phosphorylated dihydropteroate, a reaction intermediate in the DHFS reaction. L. casei FPGS is considered a relevant model for human FPGS. As such, the presence of a folate binding site in E. coli FolC, which is different from the one seen in FPGS enzymes, provides avenues for the design of specific inhibitors of this enzyme in antimicrobial therapy.
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Affiliation(s)
- Magali Mathieu
- Department of Structural Biology, Aventis Pharma, 13 Quai J. Guesde, F-94403 Vitry/Seine, France.
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Bouhss A, Crouvoisier M, Blanot D, Mengin-Lecreulx D. Purification and characterization of the bacterial MraY translocase catalyzing the first membrane step of peptidoglycan biosynthesis. J Biol Chem 2004; 279:29974-80. [PMID: 15131133 DOI: 10.1074/jbc.m314165200] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MraY translocase catalyzes the first membrane step of bacterial cell wall peptidoglycan synthesis (i.e. the transfer of the phospho-N-acetylmuramoyl-pentapeptide motif onto the undecaprenyl phosphate carrier lipid), a reversible reaction yielding undecaprenylpyrophosphoryl-N-acetylmuramoyl-pentapeptide (lipid intermediate I). This essential integral membrane protein, which is considered as a very promising target for the search of new antibacterial compounds, has thus far been clearly underexploited due to its intrinsic refractory nature to overexpression and purification. We here report conditions for the high level overproduction and for the first time the purification to homogeneity of milligram quantities of MraY protein. The kinetic parameters and effects of pH, salts, cations, and detergents on enzyme activity are described, taking the Bacillus subtilis MraY translocase as a model.
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Affiliation(s)
- Ahmed Bouhss
- Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université Paris-Sud, Bât. 430, 91405 Orsay, France.
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El Zoeiby A, Sanschagrin F, Levesque RC. Structure and function of the Mur enzymes: development of novel inhibitors. Mol Microbiol 2003; 47:1-12. [PMID: 12492849 DOI: 10.1046/j.1365-2958.2003.03289.x] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One of the biggest challenges for recent medical research is the continuous development of new antibiotics interacting with bacterial essential mechanisms. The machinery for peptidoglycan biosynthesis is a rich source of crucial targets for antibacterial chemotherapy. The cytoplasmic steps of the biosynthesis of peptidoglycan precursor, catalysed by a series of Mur enzymes, are excellent candidates for drug development. There has been growing interest in these bacterial enzymes over the last decade. Many studies attempted to understand the detailed mechanisms and structural features of the key enzymes MurA to MurF. Only MurA is inhibited by a known antibiotic, fosfomycin. Several attempts made to develop novel inhibitors of this pathway are discussed in this review. Three novel inhibitors of MurA were identified recently. 4-Thiazolidinone compounds were designed as MurB inhibitors. Many phosphinic acid derivatives and substrate analogues were identified as inhibitors of the MurC to MurF amino acid ligases.
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Affiliation(s)
- Ahmed El Zoeiby
- Centre de Recherche sur la Fonction, Structure et Ingénierie des Protéines, Faculté de Médecine, Pavillon Charles-Eugène Marchand, Université Laval, Ste-Foy, Québec, Canada, G1K 7P4
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