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El-Araby AM, Jiménez-Faraco E, Feltzer R, Martin-Garcia JM, Karri BR, Ramachandran B, Kim C, Fisher JF, Hermoso JA, Mobashery S. Catalytic process of anhydro-N-acetylmuramic acid kinase from Pseudomonas aeruginosa. J Biol Chem 2023; 299:105198. [PMID: 37660917 PMCID: PMC10570956 DOI: 10.1016/j.jbc.2023.105198] [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: 05/27/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/05/2023] Open
Abstract
The bacterial cell envelope is the structure with which the bacterium engages with, and is protected from, its environment. Within this envelop is a conserved peptidoglycan polymer which confers shape and strength to the cell envelop. The enzymatic processes that build, remodel, and recycle the chemical components of this cross-linked polymer are preeminent targets of antibiotics and exploratory targets for emerging antibiotic structures. We report a comprehensive kinetic and structural analysis for one such enzyme, the Pseudomonas aeruginosa anhydro-N-acetylmuramic acid (anhNAM) kinase (AnmK). AnmK is an enzyme in the peptidoglycan-recycling pathway of this pathogen. It catalyzes the pairing of hydrolytic ring opening of anhNAM with concomitant ATP-dependent phosphoryl transfer. AnmK follows a random-sequential kinetic mechanism with respect to its anhNAM and ATP substrates. Crystallographic analyses of four distinct structures (apo AnmK, AnmK:AMPPNP, AnmK:AMPPNP:anhNAM, and AnmK:ATP:anhNAM) demonstrate that both substrates enter the active site independently in an ungated conformation of the substrate subsites, with protein loops acting as gates for anhNAM binding. Catalysis occurs within a closed conformational state for the enzyme. We observe this state crystallographically using ATP-mimetic molecules. A remarkable X-ray structure for dimeric AnmK sheds light on the precatalytic and postcatalytic ternary complexes. Computational simulations in conjunction with the high-resolution X-ray structures reveal the full catalytic cycle. We further report that a P. aeruginosa strain with disrupted anmK gene is more susceptible to the β-lactam imipenem compared to the WT strain. These observations position AnmK for understanding the nexus among peptidoglycan recycling, susceptibility to antibiotics, and bacterial virulence.
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Affiliation(s)
- Amr M El-Araby
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Eva Jiménez-Faraco
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jose M Martin-Garcia
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Bhaskara Rao Karri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Balajee Ramachandran
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.
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2
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Zhang Y, Chen W, Wu D, Liu Y, Wu Z, Li J, Zhang SY, Ji Q. Molecular basis for cell-wall recycling regulation by transcriptional repressor MurR in Escherichia coli. Nucleic Acids Res 2022; 50:5948-5960. [PMID: 35640608 PMCID: PMC9177960 DOI: 10.1093/nar/gkac442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/01/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
The cell-wall recycling process is important for bacterial survival in nutrient-limited conditions and, in certain cases, is directly involved in antibiotic resistance. In the sophisticated cell-wall recycling process in Escherichia coli, the transcriptional repressor MurR controls the expression of murP and murQ, which are involved in transporting and metabolizing N-acetylmuramic acid (MurNAc), generating N-acetylmuramic acid-6-phosphate (MurNAc-6-P) and N-acetylglucosamine-6-phosphate (GlcNAc-6-P). Here, we report that both MurNAc-6-P and GlcNAc-6-P can bind to MurR and weaken the DNA binding ability of MurR. Structural characterizations of MurR in complex with MurNAc-6-P or GlcNAc-6-P as well as in the apo form revealed the detailed ligand recognition chemistries. Further studies showed that only MurNAc-6-P, but not GlcNAc-6-P, is capable of derepressing the expression of murQP controlled by MurR in cells and clarified the substrate specificity through the identification of key residues responsible for ligand binding in the complex structures. In summary, this study deciphered the molecular mechanism of the cell wall recycling process regulated by MurR in E. coli.
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Affiliation(s)
- Ya Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weizhong Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Di Wu
- Shanghai Key Laboratory for Molecular Engineer of Chiral Drugs, School of Chemistry and Chemical Engineering & Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yushi Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhaowei Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jian Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shu-Yu Zhang
- Shanghai Key Laboratory for Molecular Engineer of Chiral Drugs, School of Chemistry and Chemical Engineering & Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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3
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Gil-Marqués ML, Moreno-Martínez P, Costas C, Pachón J, Blázquez J, McConnell MJ. Peptidoglycan recycling contributes to intrinsic resistance to fosfomycin in Acinetobacter baumannii. J Antimicrob Chemother 2019; 73:2960-2968. [PMID: 30124902 DOI: 10.1093/jac/dky289] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/25/2018] [Indexed: 12/15/2022] Open
Abstract
Background Acinetobacter baumannii is intrinsically resistant to fosfomycin; however, the mechanisms underlying this resistance are poorly understood. Objectives To identify and characterize genes that contribute to intrinsic fosfomycin resistance in A. baumannii. Methods More than 9000 individual transposon mutants of the A. baumannii ATCC 17978 strain (fosfomycin MIC ≥1024 mg/L) were screened to identify mutations conferring increased susceptibility to fosfomycin. In-frame deletion mutants were constructed for the identified genes and their susceptibility to fosfomycin was characterized by MIC determination and growth in the presence of fosfomycin. The effects of these mutations on membrane permeability and peptidoglycan integrity were characterized. Susceptibilities to 21 antibiotics were determined for the mutant strains. Results Screening of the transposon library identified mutants in the ampD and anmK genes, both encoding enzymes of the peptidoglycan recycling pathway, that demonstrated increased susceptibility to fosfomycin. MIC values for in-frame deletion mutants were ≥42-fold (ampD) and ≥8-fold (anmK) lower than those for the parental strain, and growth of the mutant strains in the presence of 32 mg/L fosfomycin was significantly reduced. Neither mutation resulted in increased cell permeability; however, the ampD mutant demonstrated decreased peptidoglycan integrity. Susceptibility to 21 antibiotics was minimally affected by mutations in ampD and anmK. Conclusions This study demonstrates that AmpD and AnmK of the peptidoglycan recycling pathway contribute to intrinsic fosfomycin resistance in A. baumannii, indicating that inhibitors of these enzymes could be used in combination with fosfomycin as a novel treatment approach for MDR A. baumannii.
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Affiliation(s)
- María Luisa Gil-Marqués
- Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Patricia Moreno-Martínez
- Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Coloma Costas
- Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Jerónimo Pachón
- Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain.,Department of Medicine, University of Seville, Seville, Spain
| | - Jesús Blázquez
- Centro Nacional de Biotecnología (CNB), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Michael J McConnell
- Clinical Unit of Infectious Diseases, Clinical Microbiology and Preventive Medicine, Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
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4
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Calvert MB, Mayer C, Titz A. An efficient synthesis of 1,6-anhydro- N-acetylmuramic acid from N-acetylglucosamine. Beilstein J Org Chem 2018; 13:2631-2636. [PMID: 30018663 PMCID: PMC5753053 DOI: 10.3762/bjoc.13.261] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/29/2017] [Indexed: 11/23/2022] Open
Abstract
A novel synthesis of 1,6-anhydro-N-acetylmuramic acid is described, which proceeds in only five steps from the cheap starting material N-acetylglucosamine. This efficient synthesis should enable future studies into the importance of 1,6-anhydromuramic acid in bacterial cell wall recycling processes.
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Affiliation(s)
- Matthew B Calvert
- Chemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig, Germany
| | - Christoph Mayer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Germany
| | - Alexander Titz
- Chemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany.,Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig, Germany.,Department of Pharmacy, Saarland University, Saarbrücken, Germany
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5
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Dik DA, Fisher JF, Mobashery S. Cell-Wall Recycling of the Gram-Negative Bacteria and the Nexus to Antibiotic Resistance. Chem Rev 2018; 118:5952-5984. [PMID: 29847102 PMCID: PMC6855303 DOI: 10.1021/acs.chemrev.8b00277] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The importance of the cell wall to the viability of the bacterium is underscored by the breadth of antibiotic structures that act by blocking key enzymes that are tasked with cell-wall creation, preservation, and regulation. The interplay between cell-wall integrity, and the summoning forth of resistance mechanisms to deactivate cell-wall-targeting antibiotics, involves exquisite orchestration among cell-wall synthesis and remodeling and the detection of and response to the antibiotics through modulation of gene regulation by specific effectors. Given the profound importance of antibiotics to the practice of medicine, the assertion that understanding this interplay is among the most fundamentally important questions in bacterial physiology is credible. The enigmatic regulation of the expression of the AmpC β-lactamase, a clinically significant and highly regulated resistance response of certain Gram-negative bacteria to the β-lactam antibiotics, is the exemplar of this challenge. This review gives a current perspective to this compelling, and still not fully solved, 35-year enigma.
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Affiliation(s)
- David A. Dik
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jed F. Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States
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6
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Rother C, Gutmann A, Gudiminchi R, Weber H, Lepak A, Nidetzky B. Biochemical Characterization and Mechanistic Analysis of the Levoglucosan Kinase from Lipomyces starkeyi. Chembiochem 2018; 19:596-603. [DOI: 10.1002/cbic.201700587] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Christina Rother
- Institute of Biotechnology and Biochemical Engineering; Graz University of Technology, NAWI Graz; Petersgasse 12 8010 Graz Austria
| | - Alexander Gutmann
- Institute of Biotechnology and Biochemical Engineering; Graz University of Technology, NAWI Graz; Petersgasse 12 8010 Graz Austria
| | - Ramakrishna Gudiminchi
- Institute of Biotechnology and Biochemical Engineering; Graz University of Technology, NAWI Graz; Petersgasse 12 8010 Graz Austria
- Austrian Centre of Industrial Biotechnology; Petersgasse 14 8010 Graz Austria
| | - Hansjörg Weber
- Graz University of Technology, NAWI Graz; Stremayrgasse 9 8010 Graz Austria
| | - Alexander Lepak
- Institute of Biotechnology and Biochemical Engineering; Graz University of Technology, NAWI Graz; Petersgasse 12 8010 Graz Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering; Graz University of Technology, NAWI Graz; Petersgasse 12 8010 Graz Austria
- Austrian Centre of Industrial Biotechnology; Petersgasse 14 8010 Graz Austria
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7
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Dhar S, Kumari H, Balasubramanian D, Mathee K. Cell-wall recycling and synthesis in Escherichia coli and Pseudomonas aeruginosa – their role in the development of resistance. J Med Microbiol 2018; 67:1-21. [DOI: 10.1099/jmm.0.000636] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Supurna Dhar
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Hansi Kumari
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | | | - Kalai Mathee
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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8
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Dai J. New insights into a hot environment for early life. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:203-210. [PMID: 28276199 DOI: 10.1111/1758-2229.12528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Investigating the physical-chemical setting of early life is a challenging task. In this contribution, the author attempted to introduce a provocative concept from cosmology - cosmic microwave background (CMB), which is the residual thermal radiation from a hot early Universe - to the field. For this purpose, the author revisited a recently deduced biomarker, the 1,6-anhydro bond of sugars in bacteria. In vitro, the 1,6-anhydro bond of sugars reflects and captures residual thermal radiation in thermochemical processes and therefore is somewhat analogous to CMB. In vivo, the formation process of the 1,6-anhydro bond of sugars on the peptidoglycan of prokaryotic cell wall is parallel to in vitro processes, suggesting that the 1,6-anhydro bond is an ideal CMB-like analogue that suggests a hot setting for early life. The CMB-like 1,6-anhydro bond is involved in the life cycle of viruses and the metabolism of eukaryotes, underlying this notion. From a novel perspective, the application of the concept of the CMB to microbial ecology may give new insights into a hot environment, such as hydrothermal vents, supporting early life and providing hypotheses to test in molecular palaeontology.
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Affiliation(s)
- Jianghong Dai
- School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, No. 68 Xuefu Road (S), Evergreen Garden, Wuhan, 430023, People's Republic of China
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9
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The N-Acetylmuramic Acid 6-Phosphate Phosphatase MupP Completes the Pseudomonas Peptidoglycan Recycling Pathway Leading to Intrinsic Fosfomycin Resistance. mBio 2017; 8:mBio.00092-17. [PMID: 28351914 PMCID: PMC5371407 DOI: 10.1128/mbio.00092-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bacterial cells are encased in and stabilized by a netlike peptidoglycan (PGN) cell wall that undergoes turnover during bacterial growth. PGN turnover fragments are frequently salvaged by the cells via a pathway referred to as PGN recycling. Two different routes for the recycling of the cell wall sugar N-acetylmuramic acid (MurNAc) have been recognized in bacteria. In Escherichia coli and related enterobacteria, as well as in most Gram-positive bacteria, MurNAc is recovered via a catabolic route requiring a MurNAc 6-phosphate etherase (MurQ in E. coli) enzyme. However, many Gram-negative bacteria, including Pseudomonas species, lack a MurQ ortholog and use an alternative, anabolic recycling route that bypasses the de novo biosynthesis of uridyldiphosphate (UDP)-MurNAc, the first committed precursor of PGN. Bacteria featuring the latter pathway become intrinsically resistant to the antibiotic fosfomycin, which targets the de novo biosynthesis of UDP-MurNAc. We report here the identification and characterization of a phosphatase enzyme, named MupP, that had been predicted to complete the anabolic recycling pathway of Pseudomonas species but has remained unknown so far. It belongs to the large haloacid dehalogenase family of phosphatases and specifically converts MurNAc 6-phosphate to MurNAc. A ΔmupP mutant of Pseudomonas putida was highly susceptible to fosfomycin, accumulated large amounts of MurNAc 6-phosphate, and showed lower levels of UDP-MurNAc than wild-type cells, altogether consistent with a role for MupP in the anabolic PGN recycling route and as a determinant of intrinsic resistance to fosfomycin. Many Gram-negative bacteria, but not E. coli, make use of a cell wall salvage pathway that contributes to the pool of UDP-MurNAc, the first committed precursor of cell wall synthesis in bacteria. This salvage pathway is of particular interest because it confers intrinsic resistance to the antibiotic fosfomycin, which blocks de novo UDP-MurNAc biosynthesis. Here we identified and characterized a previously missing enzyme within the salvage pathway, the MurNAc 6-phosphate phosphatase MupP of P. putida. MupP, together with the other enzymes of the anabolic recycling pathway, AnmK, AmgK, and MurU, yields UDP-MurNAc, renders bacteria intrinsically resistant to fosfomycin, and thus may serve as a novel drug target for antimicrobial therapy.
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10
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Bacik JP, Jarboe LR. Bioconversion of anhydrosugars: Emerging concepts and strategies. IUBMB Life 2016; 68:700-8. [PMID: 27416973 DOI: 10.1002/iub.1533] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 06/18/2016] [Indexed: 11/12/2022]
Abstract
As methods for the use of anhydrosugars in chemical and biofuel production continue to develop, our collective knowledge of anhydrosugar processing enzymes continues to improve, including their mechanistic details, structural dynamics and modes of substrate binding. Of particular interest, anhydrosugar kinases, such as levoglucosan kinase (LGK) and 1,6-anhydro-N-acetylmuramic acid kinase (AnmK), utilize an unusual mechanism whereby the sugar substrate is both cleaved and phosphorylated. The phosphorylated sugar can then be routed to other metabolic pathways, thereby allowing its further bioconversion. Advanced engineering efforts to improve the catalytic efficiency and stability of LGK have been steadily progressing. Other enzymes that cleave the glycosidic bond of disaccharide sugars containing an anhydrosugar component are also being identified and characterized. Accordingly, the potential future use of these enzymes in large-scale production strategies is becoming increasingly viable. Here, a mini-review of the observed characteristics of anhydrosugar processing enzymes is presented along with recent developments in the bioconversion of these sugars. © 2016 IUBMB Life 68(9):700-708, 2016.
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Affiliation(s)
- John-Paul Bacik
- Department of Chemistry, Princeton University, Princeton, New Jersey, 08544
| | - Laura R Jarboe
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa, 50011
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11
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Kim EM, Um Y, Bott M, Woo HM. Engineering ofCorynebacterium glutamicumfor growth and succinate production from levoglucosan, a pyrolytic sugar substrate. FEMS Microbiol Lett 2015; 362:fnv161. [DOI: 10.1093/femsle/fnv161] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2015] [Indexed: 01/03/2023] Open
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12
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Bacik JP, Klesmith JR, Whitehead TA, Jarboe LR, Unkefer CJ, Mark BL, Michalczyk R. Producing glucose 6-phosphate from cellulosic biomass: structural insights into levoglucosan bioconversion. J Biol Chem 2015; 290:26638-48. [PMID: 26354439 DOI: 10.1074/jbc.m115.674614] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 11/06/2022] Open
Abstract
The most abundant carbohydrate product of cellulosic biomass pyrolysis is the anhydrosugar levoglucosan (1,6-anhydro-β-d-glucopyranose), which can be converted to glucose 6-phosphate by levoglucosan kinase (LGK). In addition to the canonical kinase phosphotransfer reaction, the conversion requires cleavage of the 1,6-anhydro ring to allow ATP-dependent phosphorylation of the sugar O6 atom. Using x-ray crystallography, we show that LGK binds two magnesium ions in the active site that are additionally coordinated with the nucleotide and water molecules to result in ideal octahedral coordination. To further verify the metal binding sites, we co-crystallized LGK in the presence of manganese instead of magnesium and solved the structure de novo using the anomalous signal from four manganese atoms in the dimeric structure. The first metal is required for catalysis, whereas our work suggests that the second is either required or significantly promotes the catalytic rate. Although the enzyme binds its sugar substrate in a similar orientation to the structurally related 1,6-anhydro-N-acetylmuramic acid kinase (AnmK), it forms markedly fewer bonding interactions with the substrate. In this orientation, the sugar is in an optimal position to couple phosphorylation with ring cleavage. We also observed a second alternate binding orientation for levoglucosan, and in these structures, ADP was found to bind with lower affinity. These combined observations provide an explanation for the high Km of LGK for levoglucosan. Greater knowledge of the factors that contribute to the catalytic efficiency of LGK can be used to improve applications of this enzyme for levoglucosan-derived biofuel production.
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Affiliation(s)
- John-Paul Bacik
- From the Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545,
| | | | - Timothy A Whitehead
- Chemical Engineering and Materials Science, and Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824
| | - Laura R Jarboe
- the Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, and
| | - Clifford J Unkefer
- From the Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - Brian L Mark
- the Department of Microbiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Ryszard Michalczyk
- From the Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
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13
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Dai J, Qu H, Yu Z, Yang J, Zhang H. Computational analysis of AnmK-like kinase: New insights into the cell wall metabolism of fungi. J Theor Biol 2015; 379:59-65. [PMID: 25979372 DOI: 10.1016/j.jtbi.2015.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 04/13/2015] [Accepted: 05/02/2015] [Indexed: 02/02/2023]
Abstract
1,6-Anhydro-N-acetylmuramic acid kinase (AnmK) is the unique enzyme that marks the recycling of the cell wall of Escherichia coli. Here, 81 fungal AnmK-like kinase sequences from 57 fungal species were searched in the NCBI database and a phylogenetic tree was constructed. The three-dimensional structure of an AnmK-like kinase, levoglucosan kinase (LGK) of the yeast Lipomyces starkeyi, was modeled; molecular docking revealed that AnmK and LGK are conserved proteins, and 187Asp, 212Asp are enzymatic residues, respectively. Analysis suggests that 1,6-anhydro-N-acetylglucosamine (anhGlcNAc) and/or 1,6-anhydro-β-d-glucosamine (anhGlcN) would be the appropriate substrates of AnmK-like kinases. Also, the counterparts of other characteristic enzymes of cell wall recycling of bacteria were found in fungi. Taken together, it is proposed that a putative recycling of anhGlcNAc/anhGlcN, which is associated with the hydrolysis of cell walls, exists in fungi. This computational analysis will provide new insights into the metabolism of fungal cell walls.
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Affiliation(s)
- Jianghong Dai
- School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, No. 68 Xuefu Road (S), Evergreen Garden, Wuhan 430023, PR China; College of Resources & Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China.
| | - Hong Qu
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, No. 5 Yiheyuan Road, Beijing 100871, PR China.
| | - Zhisheng Yu
- College of Resources & Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China
| | - Jiangke Yang
- School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, No. 68 Xuefu Road (S), Evergreen Garden, Wuhan 430023, PR China
| | - Hongxun Zhang
- College of Resources & Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China
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14
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Epoxide-mediated differential packaging of Cif and other virulence factors into outer membrane vesicles. J Bacteriol 2014; 196:3633-42. [PMID: 25112474 DOI: 10.1128/jb.01760-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa produces outer membrane vesicles (OMVs) that contain a number of secreted bacterial proteins, including phospholipases, alkaline phosphatase, and the CFTR inhibitory factor (Cif). Previously, Cif, an epoxide hydrolase, was shown to be regulated at the transcriptional level by epoxides, which serve as ligands of the repressor, CifR. Here, we tested whether epoxides have an effect on Cif levels in OMVs. We showed that growth of P. aeruginosa in the presence of specific epoxides but not a hydrolysis product increased Cif packaging into OMVs in a CifR-independent fashion. The outer membrane protein, OprF, was also increased under these conditions, but alkaline phosphatase activity was not significantly altered. Additionally, we demonstrated that OMV shape and density were affected by epoxide treatment, with two distinct vesicle fractions present when cells were treated with epibromohydrin (EBH), a model epoxide. Vesicles isolated from the two density fractions exhibited different protein profiles in Western blotting and silver staining. We have shown that a variety of clinically or host-relevant treatments, including antibiotics, also alter the proteins packaged in OMVs. Proteomic analysis of purified OMVs followed by an analysis of transposon mutant OMVs yielded mutants with altered vesicle packaging. Finally, epithelial cell cytotoxicity was reduced in the vesicles formed in the presence of EBH, suggesting that this epoxide alters the function of the OMVs. Our data support a model whereby clinically or host-relevant signals mediate differential packaging of virulence factors in OMVs, which results in functional consequences for host-pathogen interactions.
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15
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Bacik JP, Tavassoli M, Patel TR, McKenna SA, Vocadlo DJ, Khajehpour M, Mark BL. Conformational itinerary of Pseudomonas aeruginosa 1,6-anhydro-N-acetylmuramic acid kinase during its catalytic cycle. J Biol Chem 2014; 289:4504-14. [PMID: 24362022 PMCID: PMC3924312 DOI: 10.1074/jbc.m113.521633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/29/2013] [Indexed: 11/06/2022] Open
Abstract
Anhydro-sugar kinases are unique from other sugar kinases in that they must cleave the 1,6-anhydro ring of their sugar substrate to phosphorylate it using ATP. Here we show that the peptidoglycan recycling enzyme 1,6-anhydro-N-acetylmuramic acid kinase (AnmK) from Pseudomonas aeruginosa undergoes large conformational changes during its catalytic cycle, with its two domains rotating apart by up to 32° around two hinge regions to expose an active site cleft into which the substrates 1,6-anhydroMurNAc and ATP can bind. X-ray structures of the open state bound to a nonhydrolyzable ATP analog (AMPPCP) and 1,6-anhydroMurNAc provide detailed insight into a ternary complex that forms preceding an operative Michaelis complex. Structural analysis of the hinge regions demonstrates a role for nucleotide binding and possible cross-talk between the bound ligands to modulate the opening and closing of AnmK. Although AnmK was found to exhibit similar binding affinities for ATP, ADP, and AMPPCP according to fluorescence spectroscopy, small angle x-ray scattering analyses revealed that AnmK adopts an open conformation in solution in the absence of ligand and that it remains in this open state after binding AMPPCP, as we had observed for our crystal structure of this complex. In contrast, the enzyme favored a closed conformation when bound to ADP in solution, consistent with a previous crystal structure of this complex. Together, our findings show that the open conformation of AnmK facilitates binding of both the sugar and nucleotide substrates and that large structural rearrangements must occur upon closure of the enzyme to correctly align the substrates and residues of the enzyme for catalysis.
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Affiliation(s)
| | - Marjan Tavassoli
- Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and
| | - Trushar R. Patel
- Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and
| | - Sean A. McKenna
- Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and
| | - David J. Vocadlo
- the Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5S 1P6, Canada
| | - Mazdak Khajehpour
- Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and
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16
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Schacherl M, Waltersperger S, Baumann U. Structural characterization of the ribonuclease H-like type ASKHA superfamily kinase MK0840 from Methanopyrus kandleri. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:2440-50. [PMID: 24311585 DOI: 10.1107/s0907444913022683] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 08/12/2013] [Indexed: 11/10/2022]
Abstract
Murein recycling is a process in which microorganisms recover peptidoglycan-degradation products in order to utilize them in cell wall biosynthesis or basic metabolic pathways. Methanogens such as Methanopyrus kandleri contain pseudomurein, which differs from bacterial murein in its composition and branching. Here, four crystal structures of the putative sugar kinase MK0840 from M. kandleri in apo and nucleotide-bound states are reported. MK0840 shows high similarity to bacterial anhydro-N-acetylmuramic acid kinase, which is involved in murein recycling. The structure shares a common fold with panthothenate kinase and the 2-hydroxyglutaryl-CoA dehydratase component A, both of which are members of the ASKHA (acetate and sugar kinases/Hsc70/actin) superfamily of phosphotransferases. Local conformational changes in the nucleotide-binding site between the apo and holo forms are observed upon nucleotide binding. Further insight is given into domain movements and putative active-site residues are identified.
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Affiliation(s)
- Magdalena Schacherl
- Institute of Biochemistry, University of Cologne, Otto-Fischer-Strasse 12-14, 50674 Cologne, Germany
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17
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A cell wall recycling shortcut that bypasses peptidoglycan de novo biosynthesis. Nat Chem Biol 2013; 9:491-3. [PMID: 23831760 DOI: 10.1038/nchembio.1289] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 06/05/2013] [Indexed: 11/09/2022]
Abstract
We report a salvage pathway in Gram-negative bacteria that bypasses de novo biosynthesis of UDP N-acetylmuramic acid (UDP-MurNAc), the first committed peptidoglycan precursor, and thus provides a rationale for intrinsic fosfomycin resistance. The anomeric sugar kinase AmgK and the MurNAc α-1-phosphate uridylyl transferase MurU, defining this new cell wall sugar-recycling route in Pseudomonas putida, were characterized and engineered into Escherichia coli, channeling external MurNAc directly to peptidoglycan biosynthesis.
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18
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Genes required for and effects of alginate overproduction induced by growth of Pseudomonas aeruginosa on Pseudomonas isolation agar supplemented with ammonium metavanadate. J Bacteriol 2013; 195:4020-36. [PMID: 23794622 DOI: 10.1128/jb.00534-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that can adapt to changing environments and can secrete an exopolysaccharide known as alginate as a protection response, resulting in a colony morphology and phenotype referred to as mucoid. However, how P. aeruginosa senses its environment and activates alginate overproduction is not fully understood. Previously, we showed that Pseudomonas isolation agar supplemented with ammonium metavanadate (PIAAMV) induces P. aeruginosa to overproduce alginate. Vanadate is a phosphate mimic and causes protein misfolding by disruption of disulfide bonds. Here we used PIAAMV to characterize the pathways involved in inducible alginate production and tested the global effects of P. aeruginosa growth on PIAAMV by a mutant library screen, by transcriptomics, and in a murine acute virulence model. The PA14 nonredundant mutant library was screened on PIAAMV to identify new genes that are required for the inducible alginate stress response. A functionally diverse set of genes encoding products involved in cell envelope biogenesis, peptidoglycan remodeling, uptake of phosphate and iron, phenazine biosynthesis, and other processes were identified as positive regulators of the mucoid phenotype on PIAAMV. Transcriptome analysis of P. aeruginosa cultures growing in the presence of vanadate showed differential expression of genes involved in virulence, envelope biogenesis, and cell stress pathways. In this study, it was observed that growth on PIAAMV attenuates P. aeruginosa in a mouse pneumonia model. Induction of alginate overproduction occurs as a stress response to protect P. aeruginosa, but it may be possible to modulate and inhibit these pathways based on the new genes identified in this study.
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19
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Abstract
Many Gram-negative and Gram-positive bacteria recycle a significant proportion of the peptidoglycan components of their cell walls during their growth and septation. In many--and quite possibly all--bacteria, the peptidoglycan fragments are recovered and recycled. Although cell-wall recycling is beneficial for the recovery of resources, it also serves as a mechanism to detect cell-wall-targeting antibiotics and to regulate resistance mechanisms. In several Gram-negative pathogens, anhydro-MurNAc-peptide cell-wall fragments regulate AmpC β-lactamase induction. In some Gram-positive organisms, short peptides derived from the cell wall regulate the induction of both β-lactamase and β-lactam-resistant penicillin-binding proteins. The involvement of peptidoglycan recycling with resistance regulation suggests that inhibitors of the enzymes involved in the recycling might synergize with cell-wall-targeted antibiotics. Indeed, such inhibitors improve the potency of β-lactams in vitro against inducible AmpC β-lactamase-producing bacteria. We describe the key steps of cell-wall remodeling and recycling, the regulation of resistance mechanisms by cell-wall recycling, and recent advances toward the discovery of cell-wall-recycling inhibitors.
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Affiliation(s)
- Jarrod W Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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20
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Novel molecular fossils of bacteria: insights into hydrothermal origin of life. J Theor Biol 2012; 310:249-56. [PMID: 22796638 DOI: 10.1016/j.jtbi.2012.06.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 06/27/2012] [Accepted: 06/28/2012] [Indexed: 11/21/2022]
Abstract
Hydrothermal vents, in particular, alkaline submarine vents, are potential systems for the origin of life. Early hydrothermal vents may have imprinted on biochemical processes and housekeeping proteins of life and have hallmarked key molecules. This essay introduces new information to this discussion by focusing on newly identified sulfur-modified DNA and a heretofore ignored anhydro bond of the cell wall peptidoglycan in bacteria. It is suggested that they are novel molecular fossils that are relevant to the settings of alkaline submarine vents and harbor clues of early life. As DNA and the cell wall are bound up with genetic information and the integrity of cell, respectively, these two molecular fossils may provide insights into hydrothermal origin of life from a new angle.
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21
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Mark BL, Vocadlo DJ, Oliver A. Providing β-lactams a helping hand: targeting the AmpC β-lactamase induction pathway. Future Microbiol 2012; 6:1415-27. [PMID: 22122439 DOI: 10.2217/fmb.11.128] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A major cause of the clinical failure of broad-spectrum β-lactam antibiotics against Pseudomonas aeruginosa and many Enterobacteriaceae species are chromosomal mutations that lead to the hyperproduction of AmpC β-lactamase. These mutations typically affect proteins within the peptidoglycan (PG) recycling pathway, as well as proteins that are modulated by metabolic intermediates of this pathway. Blocking PG recycling and associated sensing mechanisms with small-molecule inhibitors holds promise as a strategy for overcoming AmpC-mediated resistance that results from the selection of mutations during β-lactam therapy, or from the direct acquisition of infections by AmpC-producing mutants. Here we report on the structural and functional biology of potential drug targets within the Gram-negative PG recycling pathway and the utility of blocking PG recycling as a means of attenuating AmpC-mediated resistance in P. aeruginosa.
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Affiliation(s)
- Brian L Mark
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
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