Search

Your search keyword '"Bougault, Catherine"' showing total 149 results
Start Over Author "Bougault, Catherine"
149 results on '"Bougault, Catherine"'

12. Recognition of Peptidoglycan Fragments by the Transpeptidase PBP4 From Staphylococcus aureus

Author

Maya-Martinez, Roberto, Alexander, J Andrew N, Otten, Christian, Ayala, Isabel, Vollmer, Daniela, Gray, Joe, Bougault, Catherine M, Burt, Alister, Laguri, Cédric, Fonvielle, Matthieu, Arthur, Michel, Strynadka, Natalie, Vollmer, Waldemar, Simorre, Jean-Pierre, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of Northern British Columbia [Prince George] (UNBC), The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Structure bactérienne et résistance aux antibiotiques (CRC - Inserm U1138), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), ANR-11-BSV5-0024,CarbaTub,Mécanisme d'inhibition d'une nouvelle cible des antibiotiques appartenant à la famille des bêta-lactamines(2011), Institut de biologie structurale (IBS - UMR 5075), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), University of Northern British Columbia (UNBC), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), ANR: CarbaTub,ANR-2011-BSV5-024-04, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), École Pratique des Hautes Études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École Pratique des Hautes Études (EPHE)

Subjects
Microbiology (medical), Glycan, Staphylococcus aureus, penicillin-binding protein 4, Mutant, lcsh:QR1-502, Peptide, peptidoglycan, medicine.disease_cause, Microbiology, lcsh:Microbiology, Bacterial cell structure, 03 medical and health sciences, chemistry.chemical_compound, Hydrolase, medicine, Original Research, 030304 developmental biology, X-ray crystallography, chemistry.chemical_classification, 0303 health sciences, biology, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], 030306 microbiology, NMR, cyclic muropeptides, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], chemistry, Biochemistry, biology.protein, Peptidoglycan, Cell envelope
Abstract

International audience; Peptidoglycan (PG) is an essential component of the cell envelope, maintaining bacterial cell shape and protecting it from bursting due to turgor pressure. The monoderm bacterium Staphylococcus aureus has a highly cross-linked PG, with ~90% of peptide stems participating in DD-cross-links and up to 15 peptide stems connected with each other. These cross-links are formed in transpeptidation reactions catalyzed by penicillin-binding proteins (PBPs) of classes A and B. Most S. aureus strains have three housekeeping PBPs with this function (PBP1, PBP2, and PBP3) but MRSA strains have acquired a third class B PBP, PBP2a, which is encoded by the mecA gene and required for the expression of high-level resistance to β-lactams. Another housekeeping PBP of S. aureus is PBP4, which belongs to the class C PBPs, and hence would be expected to have PG hydrolase (DD-carboxypeptidase or DD-endopeptidase) activity. However, previous works showed that, unexpectedly, PBP4 has transpeptidase activity that significantly contributes to both the high level of cross-linking in the PG of S. aureus and to the low level of β-lactam resistance in the absence of PBP2a. To gain insights into this unusual activity of PBP4, we studied by NMR spectroscopy its interaction in vitro with different substrates, including intact peptidoglycan, synthetic peptide stems, muropeptides, and long glycan chains with uncross-linked peptide stems. PBP4 showed no affinity for the complex, intact peptidoglycan or the smallest isolated peptide stems. Transpeptidase activity of PBP4 was verified with the disaccharide peptide subunits (muropeptides) in vitro, producing cyclic dimer and multimer products; these assays also showed a designed PBP4(S75C) nucleophile mutant to be inactive. Using this inactive but structurally highly similar variant, liquid-state NMR identified two interaction surfaces in close proximity to the central nucleophile position that can accommodate the potential donor and acceptor stems for the transpeptidation reaction. A PBP4:muropeptide model structure was built from these experimental restraints, which provides new mechanistic insights into mecA independent resistance to β-lactams in S. aureus.

Published
2019

13. Solution 1H NMR study of the electronic structure and magnetic properties of high-spin ferrous or deoxy myoglobins

Author

Bougault, Catherine M., Dou, Yi, Ikeda-Saito, Masao, Langry, Kevin C., Smith, Kevin M., and La Mar, Gerd N.

Subjects
Myoglobin -- Analysis, Anisotropy -- Analysis, Nuclear magnetic resonance spectroscopy -- Usage, Chemistry
Abstract

Solution 1D and 2D NMR, together with limited isotope labeling, have led to the assignment of the heme, axial His, and numerous heme contact residues in sperm whale, horse, and human deoxy myoglobin. The paramagnetic relaxivity leads to increased line widths and shorter [T.sub.1]s with little compensation in increased dispersion due to dipolar shifts. Hence only limited, but crucial F helix standard backbone sequence specific assignment could be made for heme cavity residues. Numerous other residues with significant dipolar shifts could be assigned from the characteristic scalar connectivities and dipolar contacts to the heme predicted by the crystal structure. It is concluded that the complete and unambiguous assignment of the heme pyrrole substituent signals is not attainable by 2D NMR alone without either partial deuterium labeling of the heme or parallel assignment of key residues in dipolar contact with the heme; hence the present study revises some earlier assignments. The resulting dipolar shifts for nonligated residues, together with the crystal coordinates of deoxy myoglobin, were used to determine the orientation relative to the heme and the anisotropy of the paramagnetic susceptibility tensor. The significant anisotropy, [absolute value of [Delta][Chi]] [similar to] 1 x [10.sup.-9] [m.sup.3]/mol, however, is shown to result in dipolar shift with reciprocal square, rather than just reciprocal, absolute temperature dependence, which is indicative of large zero field splitting rather than g-tensor anisotropy. The appropriate equation for a 5[B.sub.2] ground state allows an estimate of the zero-field splitting, D [similar to] -10 [cm.sup.-1] which is in good agreement with earlier results. The present NMR data favor a spin-only magnetic moment with S = 2 and D [similar to] -10 [cm.sup.-1] over a ground state with S < 2 and significant orbital contribution (Hendrich and Debrunner, 1989).

Published
1998

14. Interaction of lipopolysaccharides at intermolecular sites of the periplasmic Lpt transport assembly

Author

Laguri, Cédric, Sperandeo, Paola, Pounot, Kevin, Ayala, Isabel, Silipo, Alba, Bougault, Catherine M, Molinaro, Antonio, Polissi, Alessandra, Simorre, Jean-Pierre, Laguri, Cedric, Sperandeo, Paola, Pounot, Kevin, Ayala, Isabel, Silipo, Alba, Bougault, Catherine M, Molinaro, Antonio, Polissi, Alessandra, Simorre, Jean Pierre, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Pharmacological Sciences and Biomolecular, University of Milan, Dipartimento di Scienze Chimiche, Università degli studi di Napoli Federico II, ISBG, UMS 3518 CNRS-CEA-UJF-EMBL, ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Università degli Studi di Milano = University of Milan (UNIMI), and University of Naples Federico II = Università degli studi di Napoli Federico II

Subjects
Lipopolysaccharides, Models, Molecular, Magnetic Resonance Spectroscopy, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], lcsh:R, Intracellular Space, Molecular Conformation, lcsh:Medicine, Biological Transport, Models, Biological, Article, Structure-Activity Relationship, lcsh:Q, lipids (amino acids, peptides, and proteins), Periplasmic Proteins, lcsh:Science, Protein Binding
Abstract

International audience; Transport of lipopolysaccharides (LPS) to the surface of the outer membrane is essential for viability of Gram-negative bacteria. Periplasmic LptC and LptA proteins of the LPS transport system (Lpt) are responsible for LPS transfer between the Lpt inner and outer membrane complexes. Here, using a monomeric E. coli LptA mutant, we first show in vivo that a stable LptA oligomeric form is not strictly essential for bacteria. The LptC-LptA complex was characterized by a combination of SAXS and NMR methods and a low resolution model of the complex was determined. We were then able to observe interaction of LPS with LptC, the monomeric LptA mutant as well as with the LptC-LptA complex. A LptC-LPS complex was built based on NMR data in which the lipid moiety of the LPS is buried at the interface of the two β-jellyrolls of the LptC dimer. The selectivity of LPS for this intermolecular surface and the observation of such cavities at homo- or heteromolecular interfaces in LptC and LptA suggests that intermolecular sites are essential for binding LPS during its transport.

Published
2017

15. Induced conformational changes activate the peptidoglycan synthase PBP1B

Author

Egan, Alexander J. F., Maya‐Martinez, Roberto, Ayala, Isabel, Bougault, Catherine M., Banzhaf, Manuel, Breukink, Eefjan, Vollmer, Waldemar, Simorre, Jean‐Pierre, The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), European Molecular Biology Laboratory [Heidelberg] (EMBL), Bijvoet Center for Biomolecular Research [Utrecht], Utrecht University [Utrecht], Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Protein Conformation, Escherichia coli Proteins, Membrane Proteins, Peptidoglycan, Serine-Type D-Ala-D-Ala Carboxypeptidase, Allosteric Regulation, Escherichia coli, Penicillin-Binding Proteins, Peptidoglycan Glycosyltransferase, Research Articles, Research Article, Bacterial Outer Membrane Proteins, Protein Binding
Abstract

International audience; Bacteria surround their cytoplasmic membrane with an essential, stress-bearing peptidoglycan (PG) layer consisting of glycan chains linked by short peptides into a mesh-like structure. Growing and dividing cells expand their PG layer using inner-membrane anchored PG synthases, including Penicillin-binding proteins (PBPs), which participate in dynamic protein complexes to facilitate cell wall growth. In Escherichia coli, and presumably other Gram-negative bacteria, growth of the mainly single layered PG is regulated by outer membrane-anchored lipoproteins. The lipoprotein LpoB is required to activate PBP1B, which is a major, bi-functional PG synthase with glycan chain polymerising (glycosyltransferase) and peptide cross-linking (transpeptidase) activities. In this work we show how the binding of LpoB to the regulatory UB2H domain of PBP1B activates both activities. Binding induces structural changes in the UB2H domain, which transduce to the two catalytic domains by distinct allosteric pathways. We also show how an additional regulator protein, CpoB, is able to selectively modulate the TPase activation by LpoB without interfering with GTase activation.

Published
2018

17. Negative Impact of Carbapenem Methylation on the Reactivity of β-Lactams for Cysteine Acylation as Revealed by Quantum Calculations and Kinetic Analyses

Author

Bhattacharjee, Nicholus, primary, Triboulet, Sébastien, additional, Dubée, Vincent, additional, Fonvielle, Matthieu, additional, Edoo, Zainab, additional, Hugonnet, Jean-Emmanuel, additional, Ethève-Quelquejeu, Mélanie, additional, Simorre, Jean-Pierre, additional, Field, Martin J., additional, Arthur, Michel, additional, and Bougault, Catherine M., additional

Published
2019
Full Text
View/download PDF

18. Dynamics characterization of fully hydrated bacterial cell walls by solid-state NMR: evidence for cooperative binding of metal ions

Author

Kern, Thomas, Giffard, Mathilde, Hediger, Sabine, Amoroso, Ana, Giustini, Cecile, Nhat Khai Bui, Joris, Bernard, Bougault, Catherine, Vollmer, Waldemar, and Simorre, Jean-Pierre

Subjects
Carbonyl compounds -- Structure, Carbonyl compounds -- Chemical properties, Escherichia coli -- Physiological aspects, Hydration (Chemistry) -- Analysis, Nuclear magnetic resonance spectroscopy -- Usage, Peptidoglycans -- Structure, Peptidoglycans -- Chemical properties, Chemistry
Abstract

The flexibility and the organization of peptidoglycans from Gram-negative bacteria (Escherichia coli) are compared with its counterpart from different Gram-positive bacteria by using solid-state nuclear magnetic resonance spectroscopy (NMR) under magic-angle sample spinning (MAS). A new model is proposed for the interaction of divalent cations with both wall teichoic acids and carbonyl groups of peptidoglycan.

Published
2010

19. Surface organometallic chemistry: synthesis and characterization of a tris(neopentyl)zirconium(IV) complex grafted to the surface of a partially dehydroxylated silica

Author

Quignard, Francoise, Lecuyer, Christine, Bougault, Catherine, Lefebvre, Frederic, Choplin, Agnes, Olivier, Daniele, and Basset, Jean-Marie

Subjects
Zirconium -- Research, Silica -- Research, Chemistry
Abstract

Tetrakis(neopentyl)zirconium (ZrNp4) reacts with the surface of a silica dehydroxylated at 500 degrees centigrade to produce a surface molecular complex featuring a predetermined coordination sphere site and a selectivity of more than 90%. Furthermore, the presence of steric crowding at the Zr center promotes the stabilization of the ZrNp4 complex. The structure and reaction of the ZrNp4 complex has been examined using infrared and NMR spectroscopy.

Published
1992

20. Toward the characterization of peptidoglycan structure and protein-peptidoglycan interactions by solid-state NMR spectroscopy

Author

Kern, Thomas, Hediger, Sabine, Muller, Patrick, Giustini, Cecile, Joris, Bernard, Bougault, Catherine, Vollmer, Waldemar, and Simorre, Jean-Pierre

Subjects
Escherichia coli -- Composition, Hydration (Chemistry) -- Analysis, Nuclear magnetic resonance spectroscopy -- Usage, Peptidoglycans -- Chemical properties, Chemistry
Abstract

The application of the solid-state NMR spectroscopy to study intact hydrated and fully labeled Gram negative bacterium Escherichia coli sacculi is presented. The interaction of peptidoglycan sacculus with proteins is studied.

Published
2008

21. Hydrogen bonds in rubredoxins from mesophilic and hyperthermophilic organisms

Author

Bougault, Catherine M., Eidsness, Marly K., and Prestegard, James H.

Subjects
Biochemistry -- Research, Hydrogen bonding -- Physiological aspects, Bacteria, Thermophilic -- Physiological aspects, Nuclear magnetic resonance spectroscopy -- Usage, Biological sciences, Chemistry
Abstract

Research has been conducted on rubredoxins from hyperthermophilic bacteria Pyrococcus furiosus and its analogue. The authors report the study of the strength and extent of hydrogen bond networks in rubredoxins carried out via the use of NMR spectroscopy, and suggest that NMR hydrogen bond pattern which has been revealed in hyperthermophile rubredoxin leads to stabilization at the metal binding pocket.

Published
2003

22. Dynamics Characterization of Fully Hydrated Bacterial Cell Walls by Solid-State NMR: Evidence for Cooperative Binding of Metal Ions

Author

Kern, Thomas, Giffard, Mathilde, Hediger, Sabine, Amoroso, Ana, Giustini, Cécile, Bui, Nhat Khai, Joris, Bernard, Bougault, Catherine, Vollmer, Waldemar, and Simorre, Jean-Pierre

Abstract

The bacterial cell wall maintains a cell’s integrity while allowing growth and division. It is made up of peptidoglycan (PG), a biopolymer forming a multigigadalton bag-like structure, and, additionally in Gram-positive bacteria, of covalently linked anionic polymers collectively called teichoic acids. These anionic polymers are thought to play important roles in host−cell adhesion, inflammation, and immune activation. In this Article, we compare the flexibility and the organization of peptidoglycans from Gram-negative bacteria (E. coli) with its counterpart from different Gram-positive bacteria using solid-state nuclear magnetic resonance spectroscopy (NMR) under magic-angle sample spinning (MAS). The NMR fingerprints suggest an identical local conformation of the PG in all of these bacterial species. Dynamics in the peptidoglycan network decreases from E. colito B. subtilisand from B. subtilisto S. aureusand correlates mainly with the degree of peptide cross-linkage. For intact bacterial cells and isolated cell walls, we show that 31P solid-state NMR is particularly well adapted to characterize and differentiate wall teichoic acids of different species. We have further observed complexation with divalent ions, highlighting an important structural aspect of Gram-positive cell wall architecture. We propose a new model for the interaction of divalent cations with both wall teichoic acids and carbonyl groups of peptidoglycan.

Published
2024
Full Text
View/download PDF

23. Elongated structure of the outer-membrane activator of peptidoglycan synthesis LpoA: implications for PBP1A stimulation

Author

Jean, Nicolas L, Bougault, Catherine M, Lodge, Adam, Derouaux, Adeline, Callens, Gilles, Egan, Alexander J F, Ayala, Isabel, Lewis, Richard J, Vollmer, Waldemar, Simorre, Jean-Pierre, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Institute for Cell and Molecular Biosciences, Newcastle University, Laguri, Cedric, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Models, Molecular, Magnetic Resonance Spectroscopy, Sequence Homology, Amino Acid, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], [SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Escherichia coli Proteins, Lipoproteins, Molecular Sequence Data, Temperature, Peptidoglycan, Hydrogen-Ion Concentration, Protein Structure, Secondary, Protein Structure, Tertiary, Short Article, X-Ray Diffraction, Structural Biology, Periplasm, Scattering, Small Angle, Escherichia coli, Penicillin-Binding Proteins, Amino Acid Sequence, Molecular Biology, Bacterial Outer Membrane Proteins, Protein Binding
Abstract

Summary The bacterial cell envelope contains the stress-bearing peptidoglycan layer, which is enlarged during cell growth and division by membrane-anchored synthases guided by cytoskeletal elements. In Escherichia coli, the major peptidoglycan synthase PBP1A requires stimulation by the outer-membrane-anchored lipoprotein LpoA. Whereas the C-terminal domain of LpoA interacts with PBP1A to stimulate its peptide crosslinking activity, little is known about the role of the N-terminal domain. Herein we report its NMR structure, which adopts an all-α-helical fold comprising a series of helix-turn-helix tetratricopeptide-repeat (TPR)-like motifs. NMR spectroscopy of full-length LpoA revealed two extended flexible regions in the C-terminal domain and limited, if any, flexibility between the N- and C-terminal domains. Analytical ultracentrifugation and small-angle X-ray scattering results are consistent with LpoA adopting an elongated shape, with dimensions sufficient to span from the outer membrane through the periplasm to interact with the peptidoglycan synthase PBP1A., Graphical Abstract, Highlights • LpoA’s N-terminal domain features an all-α-helical fold similar to TPR domains • The C-terminal domain of E. coli LpoA contains two extensive flexible regions • Full-length LpoA adopts an elongated structure with low interdomain flexibility • LpoA can span the periplasm to stimulate the peptidoglycan synthase PBP1A, Jean et al. determine the NMR structure of LpoA N-terminal domain and identify two unique flexible regions in the C-terminal domain. SAXS data suggest little flexibility between the two domains leading to an elongated shape for the full-length protein, required in the activation of peptidoglycan synthase PBP1A.

Published
2014

27. Structure of Enterococcus faeciuml,d-transpeptidase acylated by ertapenem provides insight into the inactivation mechanism

Author

Lauriane Lecoq, Vincent Dubée, Sébastien Triboulet, Bougault, Catherine M., Jean-Emmanuel Hugonnet, Michel Arthur, Jean-Pierre Simorre, Thomas, Frank, Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Humans, MESH: Peptidyl Transferases, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], [SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], biochemical phenomena, metabolism, and nutrition, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], MESH: Protein Conformation, MESH: beta-Lactams, MESH: Anti-Bacterial Agents, polycyclic compounds, MESH: Enterococcus faecium, bacteria, MESH: Gram-Positive Bacterial Infections, MESH: Acetylation, MESH: Models, Molecular
Abstract

International audience; The maintenance of bacterial cell shape and integrity is largely attributed to peptidoglycan, a biopolymer highly cross-linked through d,d-transpeptidation. Peptidoglycan cross-linking is catalyzed by penicillin-binding proteins (PBPs) that are the essential target of β-lactam antibiotics. PBPs are functionally replaced by l,d-transpeptidases (Ldts) in ampicillin-resistant mutants of Enterococcus faecium and in wild-type Mycobacterium tuberculosis. Ldts are inhibited in vivo by a single class of β-lactams, the carbapenems, which act as a suicide substrate. We present here the first structure of a carbapenem-acylated l,d-transpeptidase, E. faecium Ldtfm acylated by ertapenem, which revealed key contacts between the carbapenem core and residues of the catalytic cavity of the enzyme. Significant reorganization of the antibiotic conformation occurs upon enzyme acylation. These results, together with the analysis of protein-to-carbapenem proton transfers, provide new insights into the mechanism of Ldt acylation by carbapenems.

Published
2012

29. Outer-membrane lipoprotein LpoB spans the periplasm to stimulate the peptidoglycan synthase PBP1B

Author

Egan, Alexander J F, Jean, Nicolas L., Koumoutsi, Alexandra, Bougault, Catherine M., Biboy, Jacob, Sassine, Jad, Solovyova, Alexandra S., Breukink, Eefjan, Typas, Athanasios, Vollmer, Waldemar, Simorre, Jean Pierre, Egan, Alexander J F, Jean, Nicolas L., Koumoutsi, Alexandra, Bougault, Catherine M., Biboy, Jacob, Sassine, Jad, Solovyova, Alexandra S., Breukink, Eefjan, Typas, Athanasios, Vollmer, Waldemar, and Simorre, Jean Pierre

Abstract

Bacteria surround their cytoplasmic membrane with an essential, stress-bearing peptidoglycan (PG) layer. Growing and dividing cells expand their PG layer by using membrane-anchored PG synthases, which are guided by dynamic cytoskeletal elements. In Escherichia coli, growth of the mainly single-layered PG is also regulated by outer membrane-anchored lipoproteins. The lipoprotein LpoB is required for the activation of penicillin-binding protein (PBP) 1B, which is a major, bifunctional PG synthase with glycan chain polymerizing (glycosyltransferase) and peptide cross-linking (transpeptidase) activities. Here, we report the structure of LpoB, determined by NMR spectroscopy, showing an N-terminal, 54-aa-long flexible stretch followed by a globular domain with similarity to the N-terminal domain of the prevalent periplasmic protein TolB. We have identified the interaction interface between the globular domain of LpoB and the noncatalytic UvrB domain 2 homolog domain of PBP1B and modeled the complex. Amino acid exchanges within this interface weaken the PBP1B-LpoB interaction, decrease the PBP1B stimulation in vitro, and impair its function in vivo. On the contrary, the N-terminal flexible stretch of LpoB is required to stimulate PBP1B in vivo, but is dispensable in vitro. This supports a model in which LpoB spans the periplasm to interact with PBP1B and stimulate PG synthesis.

Published
2014

30. Outer-membrane lipoprotein LpoB spans the periplasm to stimulate the peptidoglycan synthase PBP1B

Author

Sub Membrane Biochemistry & Biophysics, Membrane Biochemistry and Biophysics, Egan, Alexander J F, Jean, Nicolas L., Koumoutsi, Alexandra, Bougault, Catherine M., Biboy, Jacob, Sassine, Jad, Solovyova, Alexandra S., Breukink, Eefjan, Typas, Athanasios, Vollmer, Waldemar, Simorre, Jean Pierre, Sub Membrane Biochemistry & Biophysics, Membrane Biochemistry and Biophysics, Egan, Alexander J F, Jean, Nicolas L., Koumoutsi, Alexandra, Bougault, Catherine M., Biboy, Jacob, Sassine, Jad, Solovyova, Alexandra S., Breukink, Eefjan, Typas, Athanasios, Vollmer, Waldemar, and Simorre, Jean Pierre

Published
2014

36. Kinetic Features of L,D-Transpeptidase Inactivation Critical for β-Lactam Antibacterial Activity

Author

Triboulet, Sébastien, primary, Dubée, Vincent, additional, Lecoq, Lauriane, additional, Bougault, Catherine, additional, Mainardi, Jean-Luc, additional, Rice, Louis B., additional, Ethève-Quelquejeu, Mélanie, additional, Gutmann, Laurent, additional, Marie, Arul, additional, Dubost, Lionel, additional, Hugonnet, Jean-Emmanuel, additional, Simorre, Jean-Pierre, additional, and Arthur, Michel, additional

Published
2013
Full Text
View/download PDF

45. Structure and nuclear import function of the C-terminal domain of influenza virus polymerase PB2 subunit

Author

Tarendeau, Franck, primary, Boudet, Julien, additional, Guilligay, Delphine, additional, Mas, Philippe J, additional, Bougault, Catherine M, additional, Boulo, Sébastien, additional, Baudin, Florence, additional, Ruigrok, Rob W H, additional, Daigle, Nathalie, additional, Ellenberg, Jan, additional, Cusack, Stephen, additional, Simorre, Jean-Pierre, additional, and Hart, Darren J, additional

Published
2007
Full Text
View/download PDF

46. Acyl acceptor recognition by E nterococcus faecium l, d-transpeptidase Ldtfm.

Author

Triboulet, Sébastien, Bougault, Catherine M., Laguri, Cédric, Hugonnet, Jean‐Emmanuel, Arthur, Michel, and Simorre, Jean‐Pierre

Subjects
*ENTEROCOCCUS faecium, *MYCOBACTERIUM tuberculosis, *AMPICILLIN, *PEPTIDOGLYCANS, *BACTERIAL cell membranes, *OSMOTIC pressure, *NUCLEAR magnetic resonance
Abstract

In M ycobacterium tuberculosis and ampicillin-resistant mutants of E nterococcus faecium, the classical target of β-lactam antibiotics is bypassed by l, d-transpeptidases that form unusual 3 → 3 peptidoglycan cross-links. β-lactams of the carbapenem class, such as ertapenem, are mimics of the acyl donor substrate and inactivate l, d-transpeptidases by acylation of their catalytic cysteine. We have blocked the acyl donor site of E. faecium l, d-transpeptidase Ldtfm by ertapenem and identified the acyl acceptor site based on analyses of chemical shift perturbations induced by binding of peptidoglycan fragments to the resulting acylenzyme. An nuclear magnetic resonance ( NMR)-driven docking structure of the complex revealed key hydrogen interactions between the acyl acceptor and Ldtfm that were evaluated by site-directed mutagenesis and development of a cross-linking assay. Three residues are reported as critical for stabilisation of the acceptor in the Ldtfm active site and proper orientation of the nucleophilic nitrogen for the attack of the acylenzyme carbonyl. Identification of the catalytic pocket dedicated to the acceptor substrate opens new perspectives for the design of inhibitors with an original mode of action that could act alone or in synergy with β-lactams. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

47. Acyl acceptor recognition by E nterococcus faecium l, d-transpeptidase Ldtfm.

Author

Triboulet, Sébastien, Bougault, Catherine M., Laguri, Cédric, Hugonnet, Jean‐Emmanuel, Arthur, Michel, and Simorre, Jean‐Pierre

Subjects
ENTEROCOCCUS faecium, MYCOBACTERIUM tuberculosis, AMPICILLIN, PEPTIDOGLYCANS, BACTERIAL cell membranes, OSMOTIC pressure, NUCLEAR magnetic resonance
Abstract

In M ycobacterium tuberculosis and ampicillin-resistant mutants of E nterococcus faecium, the classical target of β-lactam antibiotics is bypassed by l, d-transpeptidases that form unusual 3 → 3 peptidoglycan cross-links. β-lactams of the carbapenem class, such as ertapenem, are mimics of the acyl donor substrate and inactivate l, d-transpeptidases by acylation of their catalytic cysteine. We have blocked the acyl donor site of E. faecium l, d-transpeptidase Ldtfm by ertapenem and identified the acyl acceptor site based on analyses of chemical shift perturbations induced by binding of peptidoglycan fragments to the resulting acylenzyme. An nuclear magnetic resonance ( NMR)-driven docking structure of the complex revealed key hydrogen interactions between the acyl acceptor and Ldtfm that were evaluated by site-directed mutagenesis and development of a cross-linking assay. Three residues are reported as critical for stabilisation of the acceptor in the Ldtfm active site and proper orientation of the nucleophilic nitrogen for the attack of the acylenzyme carbonyl. Identification of the catalytic pocket dedicated to the acceptor substrate opens new perspectives for the design of inhibitors with an original mode of action that could act alone or in synergy with β-lactams. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

48. Backbone and side-chain H, C, and N NMR assignments of the N-terminal domain of Escherichia coli LpoA.

Author

Jean, Nicolas, Bougault, Catherine, Derouaux, Adeline, Callens, Gilles, Vollmer, Waldemar, and Simorre, Jean-Pierre

Abstract

The peptidoglycan is a major component of the bacterial cell wall and is essential to maintain cellular integrity and cell shape. Penicillin-Binding Proteins (PBPs) catalyze the final biosynthetic steps of peptidoglycan synthesis from lipid II precursor and are the main targets of β-lactam antibiotics. The molecular details of peptidoglycan growth and its regulation are poorly understood. Presumably, PBPs are active in peptidoglycan synthesizing multi-enzyme complexes that are controlled from inside the cell by cytoskeletal elements. Recently, two outer-membrane lipoproteins, LpoA and LpoB, were shown to be required in Escherichia coli for the function of the main peptidoglycan synthases, PBP1A and PBP1B, by stimulating their transpeptidase activity. However, the mechanism of PBP-activation by Lpo proteins is not known, and the Lpo proteins await structural characterization at atomic resolution. Here we present the backbone and side-chain H, C, N NMR assignments of the N-terminal domain of LpoA from E. coli for structural and functional studies. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

49. Paramagnetic NMR investigations of high-spin nickel(II) complexes. Controlled synthesis, structural, electronic, and magnetic properties of dinuclear vs mononuclear species

Author

Belle, Catherine, Bougault, Catherine, Averbuch, Marie-Therese, Durif, Andre, Pierre, Jean-Louis, Latour, Jean-Marc, and Pape, Laurent Le

Subjects
Nickel compounds -- Research, Chemistry
Abstract

A description of the synthesis of nonsymmetric tertiary amines (N3SR) and preparation of mono- and dinuclear octahedral nickel(II) complexes is presented. Reaction with Ni(OAc)2.4H2O in alcohol permits the simple and controlled preparation of mono- and dinuclear nickel(II) complexes.

Published
2001

Catalog

Books, media, physical & digital resources
See catalog results