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Accueil > Départements > Microbiologie > Nicolas BAYAN : Biologie Moléculaire des Corynebactéries et Mycobactéries

Les publications

Liste de publications : 2010 - Présent


  • E. Lesur, A. Baron, C. Dietrich, M. Buchotte, G. Doisneau, D. Urban, J. - M. Beau, N. Bayan, B. Vauzeilles, D. Guianvarc'h, et Y. Bourdreux, « First access to a mycolic acid-based bioorthogonal reporter for the study of the mycomembrane and mycoloyltransferases in Corynebacteria », Chemical Communications (Cambridge, England), oct. 2019.
    Résumé : In this study, we report the first synthesis of an alkyne-based trehalose monomycolate probe containing a β-hydroxylated fatty acid and an α-branched chain similar to those of the natural mycolic acid. We demonstrate its utility for the labeling of the mycomembrane of Corynebacteria as well as for the study of mycoloyltransferases.
    Mots-clés : CORYNE, MICROBIO.

  • F. Migliardo, Y. Bourdreux, M. Buchotte, G. Doisneau, J. - M. Beau, et N. Bayan, « Study of the conformational behaviour of trehalose mycolates by FT-IR spectroscopy », Chemistry and Physics of Lipids, vol. 223, p. 104789, juin 2019.
    Résumé : Mycolic acids are fundamental cell wall components, found in the outer membrane barrier (mycomembrane) of Mycobacterium related genera, that have shown antigenic, murine innate immunity inducting and inflammatory activity triggering action. The mycolic acid derivatives, such as the lipid extractable trehalose monomycolates (TMM) and dimycolates (TDM), have been extensively investigated by several biochemical and biological methods and, more recently, we have performed the first neutron scattering measurements on these molecules in order to characterize their dynamical behavior as well as their rigidity properties. In the present paper, we show the first systematic FT-IR study on TMM, TDM and glucose monomycolate (GMM). It includes the analysis of individual lipids but also mixtures of TMM/TDM (ratio of 1:1) or TMM/GMM (ratio of 1:2). The present work is aimed to the first characterization of the vibrational behavior of mycolates and their mixtures enabling us to elucidate the molecular mechanisms responsible for the capability of mycolic acids to affect the flexibility and permeability properties of the mycomembrane. As a whole, the present FT-IR findings provide information that have relevant biological implications, allowing to demonstrate that the membrane fluidity is not only linked to the chain length, but also to the specific conformational behavior adopted by mycolates, which in the mixtures is strongly affected by their mutual interactions. In addition, the capability of trehalose to drive the mycolate conformational behavior and then the chain order and packing is emphasized; due to the TDM relevant evidences shown by our data, this trehalose effect could be related to the TDM toxicity and inflammation action.
    Mots-clés : chain length, chain order, CORYNE, fluidity, Infrared spectroscopy, MICROBIO, mycomembrane, trehalose mycolates.


  • N. Dautin, C. de Sousa-d'Auria, F. Constantinesco-Becker, C. Labarre, J. Oberto, I. L. de la Sierra-Gallay, C. Dietrich, H. Issa, C. Houssin, et N. Bayan, « Mycoloyltransferases: A large and major family of enzymes shaping the cell envelope of Corynebacteriales », Biochimica et Biophysica Acta (BBA) - General Subjects, vol. 1861, nᵒ 1 Pt B, p. 3581-3592, janv. 2017.
    Résumé : Mycobacterium and Corynebacterium are important genera of the Corynebacteriales order, the members of which are characterized by an atypical diderm cell envelope. Indeed the cytoplasmic membrane of these bacteria is surrounded by a thick mycolic acid-arabinogalactan-peptidoglycan (mAGP) covalent polymer. The mycolic acid-containing part of this complex associates with other lipids (mainly trehalose monomycolate (TMM) and trehalose dimycolate (TDM)) to form an outer membrane. The metabolism of mycolates in the cell envelope is governed by esterases called mycoloyltransferases that catalyze the transfer of mycoloyl chains from TMM to another TMM molecule or to other acceptors such as the terminal arabinoses of arabinogalactan or specific polypeptides. In this review we present an overview of this family of Corynebacteriales enzymes, starting with their expression, localization, structure and activity to finally discuss their putative functions in the cell. In addition, we show that Corynebacteriales possess multiple mycoloyltransferases encoding genes in their genome. The reason for this multiplicity is not known, as their function in mycolates biogenesis appear to be only partially redundant. It is thus possible that, in some species living in specific environments, some mycoloyltransferases have evolved to gain some new functions. In any case, the few characterized mycoloyltransferases are very important for the bacterial physiology and are also involved in adaptation in the host where they constitute major secreted antigens. Although not discussed in this review, all these functions make them interesting targets for the discovery of new antibiotics and promising vaccines candidates. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.
    Mots-clés : Antigen 85, ARCHEE, CORYNE, Esterase, Fibronectin-binding protein, MICROBIO, Mycobacterium, Mycolyltransferases, Mycomembrane.

  • H. Issa, E. Huc-Claustre, T. Reddad, N. Bonadé Bottino, M. Tropis, C. Houssin, M. Daffé, N. Bayan, et N. Dautin, « Click-chemistry approach to study mycoloylated proteins: Evidence for PorB and PorC porins mycoloylation in Corynebacterium glutamicum », PloS One, vol. 12, nᵒ 2, p. e0171955, 2017.
    Résumé : Protein mycoloylation is a recently identified, new form of protein acylation. This post-translational modification consists in the covalent attachment of mycolic acids residues to serine. Mycolic acids are long chain, α-branched, β-hydroxylated fatty acids that are exclusively found in the cell envelope of Corynebacteriales, a bacterial order that includes important genera such as Mycobacterium, Nocardia or Corynebacterium. So far, only 3 mycoloylated proteins have been identified: PorA, PorH and ProtX from C. glutamicum. Whereas the identity and function of ProtX is unknown, PorH and PorA associate to form a membrane channel, the activity of which is dependent upon PorA mycoloylation. However, the exact role of mycoloylation and the generality of this phenomenon are still unknown. In particular, the identity of other mycoloylated proteins, if any, needs to be determined together with establishing whether such modification occurs in Corynebacteriales genera other than Corynebacterium. Here, we tested whether a metabolic labeling and click-chemistry approach could be used to detect mycoloylated proteins. Using a fatty acid alkyne analogue, we could indeed label PorA, PorH and ProtX and determine ProtX mycoloylation site. Importantly, we also show that two other porins from C. glutamicum, PorB and PorC are mycoloylated.
    Mots-clés : CORYNE, MICROBIO.


  • A. E. Grzegorzewicz, C. de Sousa-d'Auria, M. R. McNeil, E. Huc-Claustre, V. Jones, C. Petit, S. K. Angala, J. Zemanová, Q. Wang, J. M. Belardinelli, Q. Gao, Y. Ishizaki, K. Mikušová, P. J. Brennan, D. R. Ronning, M. Chami, C. Houssin, et M. Jackson, « Assembling of the Mycobacterium tuberculosis Cell Wall Core », The Journal of Biological Chemistry, vol. 291, nᵒ 36, p. 18867-18879, sept. 2016.
    Résumé : The unique cell wall of mycobacteria is essential to their viability and the target of many clinically used anti-tuberculosis drugs and inhibitors under development. Despite intensive efforts to identify the ligase(s) responsible for the covalent attachment of the two major heteropolysaccharides of the mycobacterial cell wall, arabinogalactan (AG) and peptidoglycan (PG), the enzyme or enzymes responsible have remained elusive. We here report on the identification of the two enzymes of Mycobacterium tuberculosis, CpsA1 (Rv3267) and CpsA2 (Rv3484), responsible for this function. CpsA1 and CpsA2 belong to the widespread LytR-Cps2A-Psr (LCP) family of enzymes that has been shown to catalyze a variety of glycopolymer transfer reactions in Gram-positive bacteria, including the attachment of wall teichoic acids to PG. Although individual cpsA1 and cpsA2 knock-outs of M. tuberculosis were readily obtained, the combined inactivation of both genes appears to be lethal. In the closely related microorganism Corynebacterium glutamicum, the ortholog of cpsA1 is the only gene involved in this function, and its conditional knockdown leads to dramatic changes in the cell wall composition and morphology of the bacteria due to extensive shedding of cell wall material in the culture medium as a result of defective attachment of AG to PG. This work marks an important step in our understanding of the biogenesis of the unique cell envelope of mycobacteria and opens new opportunities for drug development.
    Mots-clés : arabinogalactan, Cell Wall, CORYNE, cryo-electron microscopy, ligase, MICROBIO, Mycobacterium tuberculosis, outer membrane, Peptidoglycan, polysaccharide.


  • M. Levefaudes, D. Patin, C. de Sousa-d'Auria, M. Chami, D. Blanot, M. Hervé, M. Arthur, C. Houssin, et D. Mengin-Lecreulx, « Diaminopimelic Acid Amidation in Corynebacteriales: NEW INSIGHTS INTO THE ROLE OF LtsA IN PEPTIDOGLYCAN MODIFICATION », The Journal of Biological Chemistry, vol. 290, nᵒ 21, p. 13079-13094, mai 2015.
    Résumé : A gene named ltsA was earlier identified in Rhodococcus and Corynebacterium species while screening for mutations leading to increased cell susceptibility to lysozyme. The encoded protein belonged to a huge family of glutamine amidotransferases whose members catalyze amide nitrogen transfer from glutamine to various specific acceptor substrates. We here describe detailed physiological and biochemical investigations demonstrating the specific role of LtsA protein from Corynebacterium glutamicum (LtsACg) in the modification by amidation of cell wall peptidoglycan diaminopimelic acid (DAP) residues. A morphologically altered but viable ΔltsA mutant was generated, which displays a high susceptibility to lysozyme and β-lactam antibiotics. Analysis of its peptidoglycan structure revealed a total loss of DAP amidation, a modification that was found in 80% of DAP residues in the wild-type polymer. The cell peptidoglycan content and cross-linking were otherwise not modified in the mutant. Heterologous expression of LtsACg in Escherichia coli yielded a massive and toxic incorporation of amidated DAP into the peptidoglycan that ultimately led to cell lysis. In vitro assays confirmed the amidotransferase activity of LtsACg and showed that this enzyme used the peptidoglycan lipid intermediates I and II but not, or only marginally, the UDP-MurNAc pentapeptide nucleotide precursor as acceptor substrates. As is generally the case for glutamine amidotransferases, either glutamine or NH4(+) could serve as the donor substrate for LtsACg. The enzyme did not amidate tripeptide- and tetrapeptide-truncated versions of lipid I, indicating a strict specificity for a pentapeptide chain length.
    Mots-clés : Amides, Amino Acid Sequence, Anti-Bacterial Agents, Antibiotics, bacterial metabolism, Bacterial Proteins, Blotting, Western, Cell Wall, Cells, Cultured, CORYNE, Corynebacteriales, Corynebacterium, DAP amidation, Diaminopimelic Acid, ENVBAC, enzyme, gene knockout, glutaminase, Immunoenzyme Techniques, lysozyme, MICROBIO, Microscopy, Electron, Transmission, Molecular Sequence Data, Muramidase, Mutation, Peptidoglycan, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Sequence Homology, Amino Acid, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Transaminases.

  • F. Migliardo, C. Salmeron, et N. Bayan, « Mobility and temperature resistance of trehalose mycolates as key characteristics of the outer membrane of Mycobacterium tuberculosis », Journal of Biomolecular Structure & Dynamics, vol. 33, nᵒ 2, p. 447-459, 2015.
    Résumé : Trehalose mycolates are fundamental characteristics of the outer membrane (mycomembrane) of Mycobacterium tuberculosis and they are supposed to play a key role in the low permeability and high resistance of mycobacteria to many antibiotics; however, still, the molecular characteristics making mycolates so effective in their biological function are not fully understood. This work aims to investigate by quasi-elastic neutron scattering the diffusive dynamical properties of trehalose mycolates in water mixtures as a function of temperature, energy and exchanged wavevector Q in order to elucidate the dynamics-function relation in the mycomembrane. A comparison with lecithin lipids in water mixtures is performed since they are considered among the most rigid and resistant lipids. From the analysis of the data collected as a function of temperature, a lower temperature dependence of the mobility as well as a higher rigidity of trehalose mycolates in comparison with lecithin lipids are highlighted. The present findings provide detailed molecular information which allows to go ahead in the understanding at a molecular level of the resistance to stress and antibiotics by corynebacteria and mycobacteria.
    Mots-clés : Cell Membrane, Cell Wall, CORYNE, diffusion, Lecithins, MICROBIO, Models, Chemical, Mycobacterium tuberculosis, Mycolic Acids, quasi elastic neutron scattering, stability, Trehalose, trehalose mycolates, Water.
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Structure. 2014 Apr 8 ;22(4):582-9
Independent domain assembly in a trapped folding intermediate of multimeric outer membrane secretins. Authors : Guilvout I, Chami M, Disconzi E, Bayan N, Pugsley AP, Huysmans GH

J Bacteriol. 2014 Jan ;196(1):121-8
Bacterial secretins form constitutively open pores akin to general porins. Authors : Disconzi E, Guilvout I, Chami M, Masi M, Huysmans GH, Pugsley AP, Bayan N


J Bacteriol. 2013 Sep ;195(18):4121-8
Identification of a mycoloyl transferase selectively involved in O-acylation of polypeptides in Corynebacteriales. Authors : Huc E, de Sousa-D’Auria C, de la Sierra-Gallay IL, Salmeron C, van Tilbeurgh H, Bayan N, Houssin C, Daffé M, Tropis M


PLoS One. 2012 ;7(9):e46225
The ppm operon is essential for acylation and glycosylation of lipoproteins in Corynebacterium glutamicum. Authors : Mohiman N, Argentini M, Batt SM, Cornu D, Masi M, Eggeling L, Besra G, Bayan N

Structure. 2012 Jul 3 ;20(7):1233-43
Crystal structures of the outer membrane domain of intimin and invasin from enterohemorrhagic E. coli and enteropathogenic Y. pseudotuberculosis. Authors : Fairman JW, Dautin N, Wojtowicz D, Liu W, Noinaj N, Barnard TJ, Udho E, Przytycka TM, Cherezov V, Buchanan SK

J Bacteriol. 2012 Feb ;194(3):587-97
Biochemical disclosure of the mycolate outer membrane of Corynebacterium glutamicum. Authors : Marchand CH, Salmeron C, Bou Raad R, Méniche X, Chami M, Masi M, Blanot D, Daffé M, Tropis M, Huc E, Le Maréchal P, Decottignies P, Bayan N

J Mol Biol. 2012 Jan 6 ;415(1):128-42
Molecular basis for the activation of a catalytic asparagine residue in a self-cleaving bacterial autotransporter. Authors : Barnard TJ, Gumbart J, Peterson JH, Noinaj N, Easley NC, Dautin N, Kuszak AJ, Tajkhorshid E, Bernstein HD, Buchanan SK


J Bacteriol. 2011 Aug ;193(15):3748-56
Residues in a conserved α-helical segment are required for cleavage but not secretion of an Escherichia coli serine protease autotransporter passenger domain. Authors : Dautin N, Bernstein HD

Biochim Biophys Acta. 2011 Jan ;1808(1):41-6
Coupled cell-free synthesis and lipid vesicle insertion of a functional oligomeric channel MscL MscL does not need the insertase YidC for insertion in vitro. Authors : Berrier C, Guilvout I, Bayan N, Park KH, Mesneau A, Chami M, Pugsley AP, Ghazi A


Proc Natl Acad Sci U S A. 2010 Oct 12 ;107(41):17739-44
Secretion of a bacterial virulence factor is driven by the folding of a C-terminal segment. Authors : Peterson JH, Tian P, Ieva R, Dautin N, Bernstein HD

Toxins (Basel). 2010 Jun ;2(6):1179-206
Serine protease autotransporters of enterobacteriaceae (SPATEs) : biogenesis and function. Authors : Dautin N

J Biol Chem. 2010 Jul 16 ;285(29):21908-12
O-mycoloylated proteins from Corynebacterium : an unprecedented post-translational modification in bacteria. Authors : Huc E, Meniche X, Benz R, Bayan N, Ghazi A, Tropis M, Daffé M

J Bacteriol. 2010 Jun ;192(11):2691-700
A deficiency in arabinogalactan biosynthesis affects Corynebacterium glutamicum mycolate outer membrane stability. Authors : Bou Raad R, Méniche X, de Sousa-d’Auria C, Chami M, Salmeron C, Tropis M, Labarre C, Daffé M, Houssin C, Bayan N

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