1
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Hart EM, Lyerly E, Bernhardt TG. The conserved σD envelope stress response monitors multiple aspects of envelope integrity in corynebacteria. PLoS Genet 2024; 20:e1011127. [PMID: 38829907 PMCID: PMC11175481 DOI: 10.1371/journal.pgen.1011127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/13/2024] [Accepted: 05/15/2024] [Indexed: 06/05/2024] Open
Abstract
The cell envelope fortifies bacterial cells against antibiotics and other insults. Species in the Mycobacteriales order have a complex envelope that includes an outer layer of mycolic acids called the mycomembrane (MM) and a cell wall composed of peptidoglycan and arabinogalactan. This envelope architecture is unique among bacteria and contributes significantly to the virulence of pathogenic Mycobacteriales like Mycobacterium tuberculosis. Characterization of pathways that govern envelope biogenesis in these organisms is therefore critical in understanding their biology and for identifying new antibiotic targets. To better understand MM biogenesis, we developed a cell sorting-based screen for mutants defective in the surface exposure of a porin normally embedded in the MM of the model organism Corynebacterium glutamicum. The results revealed a requirement for the conserved σD envelope stress response in porin export and identified MarP as the site-1 protease, respectively, that activate the response by cleaving the membrane-embedded anti-sigma factor. A reporter system revealed that the σD pathway responds to defects in mycolic acid and arabinogalactan biosynthesis, suggesting that the stress response has the unusual property of being induced by activating signals that arise from defects in the assembly of two distinct envelope layers. Our results thus provide new insights into how C. glutamicum and related bacteria monitor envelope integrity and suggest a potential role for members of the σD regulon in protein export to the MM.
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Affiliation(s)
- Elizabeth M. Hart
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Evan Lyerly
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Thomas G. Bernhardt
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
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2
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Banahene N, Peters-Clarke TM, Biegas KJ, Shishkova E, Hart EM, McKitterick AC, Kambitsis NH, Johnson UG, Bernhardt TG, Coon JJ, Swarts BM. Chemical Proteomics Strategies for Analyzing Protein Lipidation Reveal the Bacterial O-Mycoloylome. J Am Chem Soc 2024; 146:12138-12154. [PMID: 38635392 PMCID: PMC11066868 DOI: 10.1021/jacs.4c02278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/20/2024]
Abstract
Protein lipidation dynamically controls protein localization and function within cellular membranes. A unique form of protein O-fatty acylation in Corynebacterium, termed protein O-mycoloylation, involves the attachment of mycolic acids─unusually large and hydrophobic fatty acids─to serine residues of proteins in these organisms' outer mycomembrane. However, as with other forms of protein lipidation, the scope and functional consequences of protein O-mycoloylation are challenging to investigate due to the inherent difficulties of enriching and analyzing lipidated peptides. To facilitate the analysis of protein lipidation and enable the comprehensive profiling and site mapping of protein O-mycoloylation, we developed a chemical proteomics strategy integrating metabolic labeling, click chemistry, cleavable linkers, and a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method employing LC separation and complementary fragmentation methods tailored to the analysis of lipophilic, MS-labile O-acylated peptides. Using these tools in the model organism Corynebacterium glutamicum, we identified approximately 30 candidate O-mycoloylated proteins, including porins, mycoloyltransferases, secreted hydrolases, and other proteins with cell envelope-related functions─consistent with a role for O-mycoloylation in targeting proteins to the mycomembrane. Site mapping revealed that many of the proteins contained multiple spatially proximal modification sites, which occurred predominantly at serine residues surrounded by conformationally flexible peptide motifs. Overall, this study (i) discloses the putative protein O-mycoloylome for the first time, (ii) yields new insights into the undercharacterized proteome of the mycomembrane, which is a hallmark of important pathogens (e.g., Corynebacterium diphtheriae, Mycobacterium tuberculosis), and (iii) provides generally applicable chemical strategies for the proteomic analysis of protein lipidation.
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Affiliation(s)
- Nicholas Banahene
- Department
of Chemistry and Biochemistry, Central Michigan
University, Mount
Pleasant, Michigan 48859, United States
- Biochemistry,
Cell, and Molecular Biology Graduate Programs, Central Michigan University, Mount
Pleasant, Michigan 48859, United States
| | - Trenton M. Peters-Clarke
- Department
of Chemistry, University of Wisconsin, Madison, Wisconsin 53562, United States
- Department
of Biomolecular Chemistry, University of
Wisconsin, Madison, Wisconsin 53562, United States
- National
Center for Quantitative Biology of Complex Systems, University of Wisconsin, Madison, Wisconsin 53562, United States
| | - Kyle J. Biegas
- Department
of Chemistry and Biochemistry, Central Michigan
University, Mount
Pleasant, Michigan 48859, United States
- Biochemistry,
Cell, and Molecular Biology Graduate Programs, Central Michigan University, Mount
Pleasant, Michigan 48859, United States
| | - Evgenia Shishkova
- Department
of Biomolecular Chemistry, University of
Wisconsin, Madison, Wisconsin 53562, United States
- National
Center for Quantitative Biology of Complex Systems, University of Wisconsin, Madison, Wisconsin 53562, United States
| | - Elizabeth M. Hart
- Department
of Microbiology, Harvard Medical School, Boston, Massachusetts 02115 United States
- Howard
Hughes Medical Institute, Chevy
Chase, Maryland 20815, United States
| | - Amelia C. McKitterick
- Department
of Microbiology, Harvard Medical School, Boston, Massachusetts 02115 United States
- Howard
Hughes Medical Institute, Chevy
Chase, Maryland 20815, United States
| | - Nikolas H. Kambitsis
- Department
of Chemistry and Biochemistry, Central Michigan
University, Mount
Pleasant, Michigan 48859, United States
| | - Ulysses G. Johnson
- Department
of Chemistry and Biochemistry, Central Michigan
University, Mount
Pleasant, Michigan 48859, United States
- Biochemistry,
Cell, and Molecular Biology Graduate Programs, Central Michigan University, Mount
Pleasant, Michigan 48859, United States
| | - Thomas G. Bernhardt
- Department
of Microbiology, Harvard Medical School, Boston, Massachusetts 02115 United States
- Howard
Hughes Medical Institute, Chevy
Chase, Maryland 20815, United States
| | - Joshua J. Coon
- Department
of Chemistry, University of Wisconsin, Madison, Wisconsin 53562, United States
- Department
of Biomolecular Chemistry, University of
Wisconsin, Madison, Wisconsin 53562, United States
- National
Center for Quantitative Biology of Complex Systems, University of Wisconsin, Madison, Wisconsin 53562, United States
- Morgridge
Institute for Research, Madison, Wisconsin 53562, United States
| | - Benjamin M. Swarts
- Department
of Chemistry and Biochemistry, Central Michigan
University, Mount
Pleasant, Michigan 48859, United States
- Biochemistry,
Cell, and Molecular Biology Graduate Programs, Central Michigan University, Mount
Pleasant, Michigan 48859, United States
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3
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Jeong H, Kim Y, Lee HS. CdbC: a disulfide bond isomerase involved in the refolding of mycoloyltransferases in Corynebacterium glutamicum cells exposed to oxidative conditions. J Biochem 2024; 175:457-470. [PMID: 38227582 DOI: 10.1093/jb/mvae005] [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: 11/09/2023] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 01/18/2024] Open
Abstract
In Corynebacterium glutamicum cells, cdbC, which encodes a protein containing the CysXXCys motif, is regulated by the global redox-responsive regulator OsnR. In this study, we assessed the role of the periplasmic protein CdbC in disulfide bond formation and its involvement in mycomembrane biosynthesis. Purified CdbC efficiently refolded scrambled RNaseA, exhibiting prominent disulfide bond isomerase activity. The transcription of cdbC was decreased in cells grown in the presence of the reductant dithiothreitol (DTT). Moreover, unlike wild-type and cdbC-deleted cells, cdbC-overexpressing (P180-cdbC) cells grown in the presence of DTT exhibited retarded growth, abnormal cell morphology, increased cell surface hydrophobicity and altered mycolic acid composition. P180-cdbC cells cultured in a reducing environment accumulated trehalose monocorynomycolate, indicating mycomembrane deformation. Similarly, a two-hybrid analysis demonstrated the interaction of CdbC with the mycoloyltransferases MytA and MytB. Collectively, our findings suggest that CdbC, a periplasmic disulfide bond isomerase, refolds misfolded MytA and MytB and thereby assists in mycomembrane biosynthesis in cells exposed to oxidative conditions.
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Affiliation(s)
- Haeri Jeong
- Department of Biotechnology and Bioinformatics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
| | - Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon, 65, Semyeong-ro, Chungbuk 27136, Republic of Korea
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
- Interdisciplinary Graduate Program for Artificial Intelligence Smart Convergence Technology, Korea University, 2511, Sejong-ro, Sejong 30019, Republic of Korea
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4
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de Sousa-d'Auria C, Constantinesco F, Bayan N, Constant P, Tropis M, Daffé M, Graille M, Houssin C. Cg1246, a new player in mycolic acid biosynthesis in Corynebacterium glutamicum. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35394419 DOI: 10.1099/mic.0.001171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycolic acids are key components of the complex cell envelope of Corynebacteriales. These fatty acids, conjugated to trehalose or to arabinogalactan form the backbone of the mycomembrane. While mycolic acids are essential to the survival of some species, such as Mycobacterium tuberculosis, their absence is not lethal for Corynebacterium glutamicum, which has been extensively used as a model to depict their biosynthesis. Mycolic acids are first synthesized on the cytoplasmic side of the inner membrane and transferred onto trehalose to give trehalose monomycolate (TMM). TMM is subsequently transported to the periplasm by dedicated transporters and used by mycoloyltransferase enzymes to synthesize all the other mycolate-containing compounds. Using a random transposition mutagenesis, we recently identified a new uncharacterized protein (Cg1246) involved in mycolic acid metabolism. Cg1246 belongs to the DUF402 protein family that contains some previously characterized nucleoside phosphatases. In this study, we performed a functional and structural characterization of Cg1246. We showed that absence of the protein led to a significant reduction in the pool of TMM in C. glutamicum, resulting in a decrease in all other mycolate-containing compounds. We found that, in vitro, Cg1246 has phosphatase activity on organic pyrophosphate substrates but is most likely not a nucleoside phosphatase. Using a computational approach, we identified important residues for phosphatase activity and constructed the corresponding variants in C. glutamicum. Surprisingly complementation with these non-functional proteins fully restored the defect in TMM of the Δcg1246 mutant strain, suggesting that in vivo, the phosphatase activity is not involved in mycolic acid biosynthesis.
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Affiliation(s)
- Célia de Sousa-d'Auria
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Florence Constantinesco
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Nicolas Bayan
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Patricia Constant
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Maryelle Tropis
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau Cedex, Paris, France
| | - Christine Houssin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
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5
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Banahene N, Kavunja HW, Swarts BM. Chemical Reporters for Bacterial Glycans: Development and Applications. Chem Rev 2022; 122:3336-3413. [PMID: 34905344 PMCID: PMC8958928 DOI: 10.1021/acs.chemrev.1c00729] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacteria possess an extraordinary repertoire of cell envelope glycans that have critical physiological functions. Pathogenic bacteria have glycans that are essential for growth and virulence but are absent from humans, making them high-priority targets for antibiotic, vaccine, and diagnostic development. The advent of metabolic labeling with bioorthogonal chemical reporters and small-molecule fluorescent reporters has enabled the investigation and targeting of specific bacterial glycans in their native environments. These tools have opened the door to imaging glycan dynamics, assaying and inhibiting glycan biosynthesis, profiling glycoproteins and glycan-binding proteins, and targeting pathogens with diagnostic and therapeutic payload. These capabilities have been wielded in diverse commensal and pathogenic Gram-positive, Gram-negative, and mycobacterial species─including within live host organisms. Here, we review the development and applications of chemical reporters for bacterial glycans, including peptidoglycan, lipopolysaccharide, glycoproteins, teichoic acids, and capsular polysaccharides, as well as mycobacterial glycans, including trehalose glycolipids and arabinan-containing glycoconjugates. We cover in detail how bacteria-targeting chemical reporters are designed, synthesized, and evaluated, how they operate from a mechanistic standpoint, and how this information informs their judicious and innovative application. We also provide a perspective on the current state and future directions of the field, underscoring the need for interdisciplinary teams to create novel tools and extend existing tools to support fundamental and translational research on bacterial glycans.
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Affiliation(s)
- Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, United States
- Biochemistry, Cell, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, United States
| | - Herbert W. Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, United States
- Biochemistry, Cell, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, United States
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6
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Biegas KJ, Swarts BM. Chemical probes for tagging mycobacterial lipids. Curr Opin Chem Biol 2021; 65:57-65. [PMID: 34216933 DOI: 10.1016/j.cbpa.2021.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/20/2021] [Indexed: 12/13/2022]
Abstract
Mycobacteria, which cause tuberculosis and related diseases, possess a diverse set of complex envelope lipids that provide remarkable tolerance to antibiotics and are major virulence factors that drive pathogenesis. Recently, metabolic labeling and bio-orthogonal chemistry have been harnessed to develop chemical probes for tagging specific lipids in live mycobacteria, enabling a range of new basic and translational research avenues. A toolbox of probes has been developed for labeling mycolic acids and their derivatives, including trehalose-, arabinogalactan-, and protein-linked mycolates, as well as newer probes for labeling phthiocerol dimycocerosates (PDIMs) and potentially other envelope lipids. These lipid-centric tools have yielded fresh insights into mycobacterial growth and host interactions, provided new avenues for drug target discovery and characterization, and inspired innovative diagnostic and therapeutic strategies.
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Affiliation(s)
- Kyle J Biegas
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, USA
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, USA.
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7
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Genome-wide identification of novel genes involved in Corynebacteriales cell envelope biogenesis using Corynebacterium glutamicum as a model. PLoS One 2021; 15:e0240497. [PMID: 33383576 PMCID: PMC7775120 DOI: 10.1371/journal.pone.0240497] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/16/2020] [Indexed: 01/06/2023] Open
Abstract
Corynebacteriales are Actinobacteria that possess an atypical didermic cell envelope. One of the principal features of this cell envelope is the presence of a large complex made up of peptidoglycan, arabinogalactan and mycolic acids. This covalent complex constitutes the backbone of the cell wall and supports an outer membrane, called mycomembrane in reference to the mycolic acids that are its major component. The biosynthesis of the cell envelope of Corynebacteriales has been extensively studied, in particular because it is crucial for the survival of important pathogens such as Mycobacterium tuberculosis and is therefore a key target for anti-tuberculosis drugs. In this study, we explore the biogenesis of the cell envelope of Corynebacterium glutamicum, a non-pathogenic Corynebacteriales, which can tolerate dramatic modifications of its cell envelope as important as the loss of its mycomembrane. For this purpose, we used a genetic approach based on genome-wide transposon mutagenesis. We developed a highly effective immunological test based on the use of anti-cell wall antibodies that allowed us to rapidly identify bacteria exhibiting an altered cell envelope. A very large number (10,073) of insertional mutants were screened by means of this test, and 80 were finally selected, representing 55 different loci. Bioinformatics analyses of these loci showed that approximately 60% corresponded to genes already characterized, 63% of which are known to be directly involved in cell wall processes, and more specifically in the biosynthesis of the mycoloyl-arabinogalactan-peptidoglycan complex. We identified 22 new loci potentially involved in cell envelope biogenesis, 76% of which encode putative cell envelope proteins. A mutant of particular interest was further characterized and revealed a new player in mycolic acid metabolism. Because a large proportion of the genes identified by our study is conserved in Corynebacteriales, the library described here provides a new resource of genes whose characterization could lead to a better understanding of the biosynthesis of the envelope components of these bacteria.
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8
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Dietrich C, Li de la Sierra-Gallay I, Masi M, Girard E, Dautin N, Constantinesco-Becker F, Tropis M, Daffé M, van Tilbeurgh H, Bayan N. The C-terminal domain of Corynebacterium glutamicum mycoloyltransferase A is composed of five repeated motifs involved in cell wall binding and stability. Mol Microbiol 2020; 114:1-16. [PMID: 32073722 DOI: 10.1111/mmi.14492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/07/2020] [Indexed: 12/29/2022]
Abstract
The genomes of Corynebacteriales contain several genes encoding mycoloyltransferases (Myt) that are specific cell envelope enzymes essential for the biogenesis of the outer membrane. MytA is a major mycoloyltransferase of Corynebacterium glutamicum, displaying an N-terminal domain with esterase activity and a C-terminal extension containing a conserved repeated Leu-Gly-Phe-Pro (LGFP) sequence motif of unknown function. This motif is highly conserved in Corynebacteriales and found associated with cell wall hydrolases and with proteins of unknown function. In this study, we determined the crystal structure of MytA and found that its C-terminal domain is composed of five LGFP motifs and forms a long stalk perpendicular to the N-terminal catalytic α/β-hydrolase domain. The LGFP motifs are composed of a 4-stranded β-fold and occupy alternating orientations along the axis of the stalk. Multiple acetate binding pockets were identified in the stalk, which could correspond to putative ligand-binding sites. By using various MytA mutants and complementary in vitro and in vivo approaches, we provide evidence that the C-terminal LGFP domain interacts with the cell wall peptidoglycan-arabinogalactan polymer. We also show that the C-terminal LGFP domain is not required for the activity of MytA but rather contributes to the overall integrity of the cell envelope.
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Affiliation(s)
- Christiane Dietrich
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Ines Li de la Sierra-Gallay
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Muriel Masi
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Eric Girard
- University of Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | | | - Maryelle Tropis
- Institut de Pharmacologie et de Biologie Structurale, CNRS UMR 5089, Toulouse Cedex, France
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, CNRS UMR 5089, Toulouse Cedex, France
| | - Herman van Tilbeurgh
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
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9
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Fiolek TJ, Banahene N, Kavunja HW, Holmes NJ, Rylski AK, Pohane AA, Siegrist MS, Swarts BM. Engineering the Mycomembrane of Live Mycobacteria with an Expanded Set of Trehalose Monomycolate Analogues. Chembiochem 2019; 20:1282-1291. [PMID: 30589191 PMCID: PMC6614877 DOI: 10.1002/cbic.201800687] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Indexed: 01/20/2023]
Abstract
Mycobacteria and related organisms in the Corynebacterineae suborder are characterized by a distinctive outer membrane referred to as the mycomembrane. Biosynthesis of the mycomembrane occurs through an essential process called mycoloylation, which involves antigen 85 (Ag85)-catalyzed transfer of mycolic acids from the mycoloyl donor trehalose monomycolate (TMM) to acceptor carbohydrates and, in some organisms, proteins. We recently described an alkyne-modified TMM analogue (O-AlkTMM-C7) which, in conjunction with click chemistry, acted as a chemical reporter for mycoloylation in intact cells and allowed metabolic labeling of mycoloylated components of the mycomembrane. Here, we describe the synthesis and evaluation of a toolbox of TMM-based reporters bearing alkyne, azide, trans-cyclooctene, and fluorescent tags. These compounds gave further insight into the substrate tolerance of mycoloyltransferases (e.g., Ag85s) in a cellular context and they provide significantly expanded experimental versatility by allowing one- or two-step cell labeling, live cell labeling, and rapid cell labeling via tetrazine ligation. Such capabilities will facilitate research on mycomembrane composition, biosynthesis, and dynamics. Moreover, because TMM is exclusively metabolized by Corynebacterineae, the described probes may be valuable for the specific detection and cell-surface engineering of Mycobacterium tuberculosis and related pathogens. We also performed experiments to establish the dependence of probe incorporation on mycoloyltransferase activity, results from which suggested that cellular labeling is a function not only of metabolic incorporation (and likely removal) pathway(s), but also accessibility across the envelope. Thus, whole-cell labeling experiments with TMM reporters should be carefully designed and interpreted when envelope permeability may be compromised. On the other hand, this property of TMM reporters can potentially be exploited as a convenient way to probe changes in envelope integrity and permeability, facilitating drug development studies.
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Affiliation(s)
- Taylor J Fiolek
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Herbert W Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Nathan J Holmes
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Adrian K Rylski
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Amol Arunrao Pohane
- Department of Microbiology, University of Massachusetts, 639 N. Pleasant Street, Amherst, MA, 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, 639 N. Pleasant Street, Amherst, MA, 01003, USA
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
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Lesur E, Baron A, Dietrich C, Buchotte M, Doisneau G, Urban D, Beau JM, Bayan N, Vauzeilles B, Guianvarc’h D, Bourdreux Y. First access to a mycolic acid-based bioorthogonal reporter for the study of the mycomembrane and mycoloyltransferases in Corynebacteria. Chem Commun (Camb) 2019; 55:13074-13077. [DOI: 10.1039/c9cc05754d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study we describe the first synthesis of an alkyne-based trehalose monomycolate probe closely mimicking the complex pattern of mycolic acids and its utility for the study of mycomembrane and mycoloyltransferases in Corynebacteria.
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11
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The role of corynomycolic acids in Corynebacterium-host interaction. Antonie Van Leeuwenhoek 2018; 111:717-725. [PMID: 29435693 DOI: 10.1007/s10482-018-1036-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/29/2018] [Indexed: 10/18/2022]
Abstract
Within the Actinobacteria, the genera Corynebacterium, Mycobacterium, Nocardia and Rhodococcus form the so-called CMNR group, also designated as mycolic acid-containing actinomycetes. Almost all members of this group are characterized by a mycolic acid layer, the mycomembrane, which covers the cell wall and is responsible for a high resistance of these bacteria against chemical and antibiotic stress. Furthermore, components of the mycomembrane are crucial for the interaction of bacteria with host cells. This review summarizes the current knowledge of mycolic acid synthesis and interaction with components of the immune system for the genus Corynebacterium with an emphasis on the pathogenic species Corynebacterium diphtheriae, Corynebacterium pseudotuberculosis and Corynebacterium ulcerans as well as the biotechnology workhorse Corynebacterium glutamicum.
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12
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Toyoda K, Inui M. Extracytoplasmic function sigma factor σDconfers resistance to environmental stress by enhancing mycolate synthesis and modifying peptidoglycan structures inCorynebacterium glutamicum. Mol Microbiol 2017; 107:312-329. [DOI: 10.1111/mmi.13883] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Koichi Toyoda
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawa; Kyoto 619-0292 Japan
| | - Masayuki Inui
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawa; Kyoto 619-0292 Japan
- Graduate School of Biological Sciences; Nara Institute of Science and Technology, 8916-5; Takayama, Ikoma, Nara 630-0101 Japan
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O'Neill MK, Piligian BF, Olson CD, Woodruff PJ, Swarts BM. Tailoring Trehalose for Biomedical and Biotechnological Applications. PURE APPL CHEM 2017; 89:1223-1249. [PMID: 29225379 PMCID: PMC5718624 DOI: 10.1515/pac-2016-1025] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Trehalose is a non-reducing sugar whose ability to stabilize biomolecules has brought about its widespread use in biological preservation applications. Trehalose is also an essential metabolite in a number of pathogens, most significantly the global pathogen Mycobacterium tuberculosis, though it is absent in humans and other mammals. Recently, there has been a surge of interest in modifying the structure of trehalose to generate analogues that have applications in biomedical research and biotechnology. Non-degradable trehalose analogues could have a number of advantages as bioprotectants and food additives. Trehalose-based imaging probes and inhibitors are already useful as research tools and may have future value in the diagnosis and treatment of tuberculosis, among other uses. Underlying the advancements made in these areas are novel synthetic methods that facilitate access to and evaluation of trehalose analogues. In this review, we focus on both aspects of the development of this class of molecules. First, we consider the chemical and chemoenzymatic methods that have been used to prepare trehalose analogues and discuss their prospects for synthesis on commercially relevant scales. Second, we describe ongoing efforts to develop and deploy detectable trehalose analogues, trehalose-based inhibitors, and non-digestible trehalose analogues. The current and potential future uses of these compounds are discussed, with an emphasis on their roles in understanding and combatting mycobacterial infection.
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Affiliation(s)
- Mara K O'Neill
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Brent F Piligian
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Claire D Olson
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Peter J Woodruff
- Department of Chemistry, University of Southern Maine, Portland, ME, USA
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI 48859, USA
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14
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Taniguchi H, Busche T, Patschkowski T, Niehaus K, Pátek M, Kalinowski J, Wendisch VF. Physiological roles of sigma factor SigD in Corynebacterium glutamicum. BMC Microbiol 2017; 17:158. [PMID: 28701150 PMCID: PMC5508688 DOI: 10.1186/s12866-017-1067-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/04/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Sigma factors are one of the components of RNA polymerase holoenzymes, and an essential factor of transcription initiation in bacteria. Corynebacterium glutamicum possesses seven genes coding for sigma factors, most of which have been studied to some detail; however, the role of SigD in transcriptional regulation in C. glutamicum has been mostly unknown. RESULTS In this work, pleiotropic effects of sigD overexpression at the level of phenotype, transcripts, proteins and metabolites were investigated. Overexpression of sigD decreased the growth rate of C. glutamicum cultures, and induced several physiological effects such as reduced culture foaming, turbid supernatant and cell aggregation. Upon overexpression of sigD, the level of Cmt1 (corynomycolyl transferase) in the supernatant was notably enhanced, and carbohydrate-containing compounds were excreted to the supernatant. The real-time PCR analysis revealed that sigD overexpression increased the expression of genes related to corynomycolic acid synthesis (fadD2, pks), genes encoding corynomycolyl transferases (cop1, cmt1, cmt2, cmt3), L, D-transpeptidase (lppS), a subunit of the major cell wall channel (porH), and the envelope lipid regulation factor (elrF). Furthermore, overexpression of sigD resulted in trehalose dicorynomycolate accumulation in the cell envelope. CONCLUSIONS This study demonstrated that SigD regulates the synthesis of corynomycolate and related compounds, and expanded the knowledge of regulatory functions of sigma factors in C. glutamicum.
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Affiliation(s)
- Hironori Taniguchi
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Tobias Busche
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Thomas Patschkowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
- Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Karsten Niehaus
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
- Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Miroslav Pátek
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
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Identification of specific posttranslational O-mycoloylations mediating protein targeting to the mycomembrane. Proc Natl Acad Sci U S A 2017; 114:4231-4236. [PMID: 28373551 DOI: 10.1073/pnas.1617888114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The outer membranes (OMs) of members of the Corynebacteriales bacterial order, also called mycomembranes, harbor mycolic acids and unusual outer membrane proteins (OMPs), including those with α-helical structure. The signals that allow precursors of such proteins to be targeted to the mycomembrane remain uncharacterized. We report here the molecular features responsible for OMP targeting to the mycomembrane of Corynebacterium glutamicum, a nonpathogenic member of the Corynebacteriales order. To better understand the mechanisms by which OMP precursors were sorted in C. glutamicum, we first investigated the partitioning of endogenous and recombinant PorA, PorH, PorB, and PorC between bacterial compartments and showed that they were both imported into the mycomembrane and secreted into the extracellular medium. A detailed investigation of cell extracts and purified proteins by top-down MS, NMR spectroscopy, and site-directed mutagenesis revealed specific and well-conserved posttranslational modifications (PTMs), including O-mycoloylation, pyroglutamylation, and N-formylation, for mycomembrane-associated and -secreted OMPs. PTM site sequence analysis from C. glutamicum OMP and other O-acylated proteins in bacteria and eukaryotes revealed specific patterns. Furthermore, we found that such modifications were essential for targeting to the mycomembrane and sufficient for OMP assembly into mycolic acid-containing lipid bilayers. Collectively, it seems that these PTMs have evolved in the Corynebacteriales order and beyond to guide membrane proteins toward a specific cell compartment.
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16
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Issa H, Huc-Claustre E, Reddad T, Bonadé Bottino N, Tropis M, Houssin C, Daffé M, Bayan N, Dautin N. Click-chemistry approach to study mycoloylated proteins: Evidence for PorB and PorC porins mycoloylation in Corynebacterium glutamicum. PLoS One 2017; 12:e0171955. [PMID: 28199365 PMCID: PMC5310785 DOI: 10.1371/journal.pone.0171955] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/27/2017] [Indexed: 01/23/2023] Open
Abstract
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.
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Affiliation(s)
- Hanane Issa
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
- Holy Spirit University of Kaslik (USEK), Jounieh, Mount Lebanon, Lebanon
| | | | - Thamila Reddad
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nolwenn Bonadé Bottino
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Maryelle Tropis
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Christine Houssin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Mamadou Daffé
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
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18
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Dautin N, de Sousa-d'Auria C, Constantinesco-Becker F, Labarre C, Oberto J, Li de la Sierra-Gallay I, Dietrich C, Issa H, Houssin C, Bayan N. Mycoloyltransferases: A large and major family of enzymes shaping the cell envelope of Corynebacteriales. Biochim Biophys Acta Gen Subj 2016; 1861:3581-3592. [PMID: 27345499 DOI: 10.1016/j.bbagen.2016.06.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 12/31/2022]
Abstract
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.
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Affiliation(s)
- Nathalie Dautin
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Célia de Sousa-d'Auria
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Florence Constantinesco-Becker
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Cécile Labarre
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Jacques Oberto
- Cell Biology of Archaea, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Ines Li de la Sierra-Gallay
- Function and Architecture of Macromolecular Assemblies, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Christiane Dietrich
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Hanane Issa
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France; Faculty of Sciences, Department of Life and Earth Sciences, Holy Spirit University of Kaslik (USEK), Kaslik, B.P. 446, Jounieh, Lebanon
| | - Christine Houssin
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
| | - Nicolas Bayan
- Molecular Biology of Corynebacteria and Mycobacteria, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France.
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Kavunja HW, Piligian BF, Fiolek TJ, Foley HN, Nathan TO, Swarts BM. A chemical reporter strategy for detecting and identifying O-mycoloylated proteins in Corynebacterium. Chem Commun (Camb) 2016; 52:13795-13798. [DOI: 10.1039/c6cc07143k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A trehalose monomycolate (TMM)-mimicking chemical reporter facilitated the investigation of a recently discovered class of lipidated proteins in the Corynebacterineae.
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Affiliation(s)
- Herbert W. Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
| | - Brent F. Piligian
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
| | - Taylor J. Fiolek
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
| | - Hannah N. Foley
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
| | - Temitope O. Nathan
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
| | - Benjamin M. Swarts
- Department of Chemistry and Biochemistry, Central Michigan University
- Mount Pleasant
- USA
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Lanéelle MA, Tropis M, Daffé M. Current knowledge on mycolic acids in Corynebacterium glutamicum and their relevance for biotechnological processes. Appl Microbiol Biotechnol 2013; 97:9923-30. [PMID: 24113823 DOI: 10.1007/s00253-013-5265-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/12/2013] [Accepted: 09/14/2013] [Indexed: 11/29/2022]
Abstract
Corynebacterium glutamicum is the world's largest producer of glutamate and lysine. Industrial glutamate overproduction is induced by empirical processes, such as biotin limitation, supplementation with specific surfactants or addition of sublethal concentration of certain antibiotics to the culture media. Although Gram-positive bacteria, C. glutamicum and related bacterial species and genera contain, in addition to the plasma membrane, an outer permeability membrane similar to that of Gram-negative microorganisms. As the amino acids have to cross both membranes, their integrity, composition and fluidity influence the export process. While the precise mechanism of the export of the amino acids by C. glutamicum is not fully understood, the excretion of amino acids through the inner membrane involved at least a major export system mechanosensitive channel MscS family (MscCG) encoded by NCgl1221. As the various industrial treatments have been shown to affect the lipid content of the bacterial cell, it is strongly believed that defects in the hallmark of the outer membrane, 2-alkyl, 3-hydroxylated long-chain fatty acids (mycolic acids), could be key factors in the glutamate overproduction. This review aims at giving an overview of the current knowledge on mycolic acids structure, biosynthesis and transfer in C. glutamicum and their relevance for amino acid biotechnological production.
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Affiliation(s)
- Marie-Antoinette Lanéelle
- Team « Mycobacterial Cell Envelopes: Structure, Biosynthesis and Roles », Département "Mécanismes Moléculaires des Infections Mycobactériennes", Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie et Biologie Structurale (IPBS), UMR 5089, BP 64182, 205, Route de Narbonne, 31077, Toulouse Cedex 04, France
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