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Liang Y, Zhao Y, Kwan J, Wang Y, Qiao Y. Escherichia coli has robust regulatory mechanisms against elevated peptidoglycan cleavage by lytic transglycosylases. J Biol Chem 2023; 299:104615. [PMID: 36931392 PMCID: PMC10139938 DOI: 10.1016/j.jbc.2023.104615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/25/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023] Open
Abstract
Peptidoglycan (PG) is an essential and conserved exoskeletal component in all bacteria that protects cells from lysis. Gram-negative bacteria such as Escherichia coli encode multiple redundant lytic transglycosylases (LTs) that engage in PG cleavage, a potentially lethal activity requiring proper regulation to prevent autolysis. To elucidate the potential effects and cellular regulatory mechanisms of elevated LT activity, we individually cloned the periplasmic domains of two membrane-bound LTs, MltA and MltB under the control of the arabinose-inducible system for overexpression in the periplasmic space in E. coli. Interestingly, upon induction, the culture undergoes an initial period of cell lysis followed by robust growth restoration. The LT-overexpressing E. coli exhibits altered morphology with larger spherical cells, which is in line with the weakening of the PG layer due to aberrant LT activity. On the other hand, the restored cells display a similar rod shape and peptidoglycan profile that is indistinguishable from the uninduced control. Quantitative proteomics analysis of the restored cells identified significant protein enrichment in the regulator of capsule synthesis (Rcs) regulon, a two-component stress response known to be specifically activated by PG damage. We showed that LT-overexpressing E. coli with an inactivated Rcs system partially impairs the growth restoration process, supporting the involvement of the Rcs system in countering aberrant PG cleavage. Furthermore, we demonstrated that the elevated LT activity specifically potentiates β-lactam antibiotics against E. coli with a defective Rcs regulon, suggesting the dual effects of augmented PG cleavage and blocked PG synthesis as a potential antimicrobial strategy.
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Affiliation(s)
- Yaquan Liang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technical University, Singapore 637371
| | - Yilin Zhao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technical University, Singapore 637371
| | - JericMunChung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technical University, Singapore 637371
| | - Yue Wang
- A*STAR Infectious Disease Labs, Singapore 138648
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technical University, Singapore 637371.
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2
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Yu M, Zhao Y. Spectinomycin resistance in Lysobacter enzymogenes is due to its rRNA target but also relies on cell-wall recycling and purine biosynthesis. Front Microbiol 2022; 13:988110. [PMID: 36118211 PMCID: PMC9471086 DOI: 10.3389/fmicb.2022.988110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Resistance to spectinomycin emerged after widely used for treatment of gonorrhea. Previous studies revealed that Lysobacter enzymogenes strain C3 (LeC3) exhibited elevated level of intrinsic resistance to spectinomycin. In this study, we screened a Tn5 transposon mutant library of LeC3 to elucidate the underlying molecular mechanisms of spectinomycin resistance. Insertion sites in 15 out of 19 mutants recovered with decreased spectinomycin resistance were located on two ribosomal RNA operons at different loci, indicating the pivotal role of ribosomal RNAs in conferring spectinomycin resistance in L. enzymogenes. The other mutants harbored mutations in the tuf, rpoD, mltB, and purB genes. Among them, the tuf and rpoD genes, respectively, encode a translation elongation factor Tu and an RNA polymerase primary sigma factor. They both contribute to protein biosynthesis, where ribosomal RNAs play essential roles. The mltB gene, whose product is involved in cell-wall recycling, was not only associated with resistance against spectinomycin, but also conferred resistance to osmotic stress and ampicillin. In addition, mutation of the purB gene, for which its product is involved in the biosynthesis of inosine and adenosine monophosphates, led to decreased spectinomycin resistance. Addition of exogenous adenine at lower concentration in medium restored the growth deficiency in the purB mutant and increased bacterial resistance to spectinomycin. These results suggest that while cell-wall recycling and purine biosynthesis might contribute to spectinomycin resistance, target rRNAs play critical role in spectinomycin resistance in L. enzymogenes.
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Affiliation(s)
- Menghao Yu
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Department of Plant Pathology, WSU-IAREC, Prosser, WA, United States
- *Correspondence: Youfu Zhao,
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3
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Vacariu CM, Tanner ME. Recent Advances in the Synthesis and Biological Applications of Peptidoglycan Fragments. Chemistry 2022; 28:e202200788. [PMID: 35560956 DOI: 10.1002/chem.202200788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Indexed: 11/09/2022]
Abstract
The biosynthesis, breakdown, and modification of peptidoglycan (PG) play vital roles in both bacterial viability and in the response of human physiology to bacterial infection. Studies on PG biochemistry are hampered by the fact that PG is an inhomogeneous insoluble macromolecule. Chemical synthesis is therefore an important means to obtain PG fragments that may serve as enzyme substrates and elicitors of the human immune response. This review outlines the recent advances in the synthesis and biochemical studies of PG fragments, PG biosynthetic intermediates (such as Park's nucleotides and PG lipids), and PG breakdown products (such as muramyl dipeptides and anhydro-muramic acid-containing fragments). A rich variety of synthetic approaches has been applied to preparing such compounds since carbohydrate, peptide, and phospholipid chemical methodologies must all be applied.
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Affiliation(s)
- Condurache M Vacariu
- Department of Chemistry, University of British Columbia, V6T 1Z1, Vancouver, British Columbia, Canada
| | - Martin E Tanner
- Department of Chemistry, University of British Columbia, V6T 1Z1, Vancouver, British Columbia, Canada
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4
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Utsunomiya H, Saiki N, Kadoguchi H, Fukudome M, Hashimoto S, Ueda M, Takechi K, Takano H. Genes encoding lipid II flippase MurJ and peptidoglycan hydrolases are required for chloroplast division in the moss Physcomitrella patens. PLANT MOLECULAR BIOLOGY 2021; 107:405-415. [PMID: 33078277 DOI: 10.1007/s11103-020-01081-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Homologous genes for the peptidoglycan precursor flippase MurJ, and peptidoglycan hydrolases: lytic transglycosylase MltB, and DD-carboxypeptidase VanY are required for chloroplast division in the moss Physcomitrella patens. The moss Physcomitrella patens is used as a model plant to study plastid peptidoglycan biosynthesis. In bacteria, MurJ flippase transports peptidoglycan precursors from the cytoplasm to the periplasm. In this study, we identified a MurJ homolog (PpMurJ) in the P. patens genome. Bacteria employ peptidoglycan degradation and recycling pathways for cell division. We also searched the P. patens genome for genes homologous to bacterial peptidoglycan hydrolases and identified genes homologous for the lytic transglycosylase mltB, N-acetylglucosaminidase nagZ, and LD-carboxypeptidase ldcA in addition to a putative DD-carboxypeptidase vanY reported previously. Moreover, we found a ß-lactamase-like gene (Pplactamase). GFP fusion proteins with either PpMltB or PpVanY were detected in the chloroplasts, whereas fusion proteins with PpNagZ, PpLdcA, or Pplactamase localized in the cytoplasm. Experiments seeking PpMurJ-GFP fusion proteins failed. PpMurJ gene disruption in P. patens resulted in the appearance of macrochloroplasts in protonemal cells. Compared with the numbers of chloroplasts in wild-type plants (38.9 ± 4.9), PpMltB knockout and PpVanY knockout had lower numbers of chloroplasts (14.3 ± 6.7 and 28.1 ± 5.9, respectively). No differences in chloroplast numbers were observed after PpNagZ, PpLdcA, or Pplactamase single-knockout. Chloroplast numbers in PpMltB/PpVanY double-knockout cells were similar to those in PpMltB single-knockout cells. Zymogram analysis of the recombinant PpMltB protein revealed its peptidoglycan hydrolase activity. Our results imply that PpMurJ, PpMltB and PpVanY play a critical role in chloroplast division in the moss P. patens.
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Affiliation(s)
- Hanae Utsunomiya
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Nozomi Saiki
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Hayato Kadoguchi
- Faculty of Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Masaya Fukudome
- Faculty of Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Satomi Hashimoto
- Faculty of Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Mami Ueda
- Faculty of Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Katsuaki Takechi
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.
| | - Hiroyoshi Takano
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.
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5
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Nakamura T, Shimizu T, Inagaki F, Okazaki S, Saha SS, Uda A, Watanabe K, Watarai M. Identification of Membrane-Bound Lytic Murein Transglycosylase A (MltA) as a Growth Factor for Francisella novicida in a Silkworm Infection Model. Front Cell Infect Microbiol 2021; 10:581864. [PMID: 33553001 PMCID: PMC7862118 DOI: 10.3389/fcimb.2020.581864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022] Open
Abstract
Francisella tularensis, the causative agent of tularemia, is transmitted by arthropod vectors within mammalian hosts. The detailed mechanisms contributing to growth and survival of Francisella within arthropod remain poorly understood. To identify novel factors supporting growth and survival of Francisella within arthropods, a transposon mutant library of F. tularensis subsp. novicida (F. novicida) was screened using an F. novicida-silkworm infection model. Among 750 transposon mutants screened, the mltA-encoding membrane-bound lytic murein transglycosylase A (MltA) was identified as a novel growth factor of F. novicida in silkworms. Silkworms infection with an mltA deletion mutant (ΔmltA) resulted in a reduction in the number of bacteria and prolonged survival. The ΔmltA strain exhibited limited intracellular growth and cytotoxicity in BmN4 silkworm ovary cells. Moreover, the ΔmltA strain induced higher expression of the antimicrobial peptide in silkworms compared to the wild-type strain. These results suggest that F. novicida MltA contributes to the survival of F. novicida in silkworms via immune suppression-related mechanisms. Intracellular growth of the ΔmltA strain was also reduced in human monocyte THP-1 cells. These results also suggest the contribution of MltA to pathogenicity in humans and utility of the F. novicida-silkworm infection model to explore Francisella infection.
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Affiliation(s)
- Takemasa Nakamura
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Takashi Shimizu
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Fumiya Inagaki
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Shoma Okazaki
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Shib Shankar Saha
- Department of Pathology and Parasitology, Patuakhali Science and Technology University, Barisal, Bangladesh
| | - Akihiko Uda
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenta Watanabe
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Masahisa Watarai
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
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6
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Min K, An DR, Yoon HJ, Rana N, Park JS, Kim J, Lee M, Hesek D, Ryu S, Kim BM, Mobashery S, Suh SW, Lee HH. Peptidoglycan reshaping by a noncanonical peptidase for helical cell shape in Campylobacter jejuni. Nat Commun 2020; 11:458. [PMID: 31974386 PMCID: PMC6978369 DOI: 10.1038/s41467-019-13934-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 12/10/2019] [Indexed: 12/27/2022] Open
Abstract
Assembly of the peptidoglycan is crucial in maintaining viability of bacteria and in defining bacterial cell shapes, both of which are important for existence in the ecological niche that the organism occupies. Here, eight crystal structures for a member of the cell-shape-determining class of Campylobacter jejuni, the peptidoglycan peptidase 3 (Pgp3), are reported. Characterization of the turnover chemistry of Pgp3 reveals cell wall d,d-endopeptidase and d,d-carboxypeptidase activities. Catalysis is accompanied by large conformational changes upon peptidoglycan binding, whereby a loop regulates access to the active site. Furthermore, prior hydrolysis of the crosslinked peptide stem from the saccharide backbone of the peptidoglycan on one side is a pre-requisite for its recognition and turnover by Pgp3. These analyses reveal the noncanonical nature of the transformations at the core of the events that define the morphological shape for C. jejuni as an intestinal pathogen. Peptidoglycans (PG) define bacterial cell shapes. Here, the authors provide mechanistic insights into the peptidoglycan peptidase 3 (Pgp3) from the spiral shaped human pathogen Campylobacter jejuni by determining its crystal structure alone and in complex with synthetic cell-wall PG derivatives, and they further show that the enzyme has both d,d-endopeptidase and d,d-carboxypeptidase activities
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Affiliation(s)
- Kyungjin Min
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Doo Ri An
- Department of Biophysics and Chemical Biology, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea.,Hazardous Substances Analysis Division, Gyeongin Regional Office of Food and Drug Safety, Incheon, 22133, Korea
| | - Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Neha Rana
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, IN, 46556, USA
| | - Ji Su Park
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jinshil Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, IN, 46556, USA
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, IN, 46556, USA
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.,Center for Food and Bioconvergence, Seoul National University, Seoul, 08826, Korea
| | - B Moon Kim
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, IN, 46556, USA.
| | - Se Won Suh
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea. .,Department of Biophysics and Chemical Biology, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea.
| | - Hyung Ho Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea.
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7
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Broendum SS, Buckle AM, McGowan S. Catalytic diversity and cell wall binding repeats in the phage-encoded endolysins. Mol Microbiol 2018; 110:879-896. [DOI: 10.1111/mmi.14134] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Sebastian S. Broendum
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology; Monash University; Victoria 3800 Australia
- Biomedicine Discovery Institute, Department of Microbiology; Monash University; Victoria 3800 Australia
| | - Ashley M. Buckle
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology; Monash University; Victoria 3800 Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute, Department of Microbiology; Monash University; Victoria 3800 Australia
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8
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Dik DA, Batuecas MT, Lee M, Mahasenan KV, Marous DR, Lastochkin E, Fisher JF, Hermoso JA, Mobashery S. A Structural Dissection of the Active Site of the Lytic Transglycosylase MltE from Escherichia coli. Biochemistry 2018; 57:6090-6098. [PMID: 30256085 DOI: 10.1021/acs.biochem.8b00800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Lytic transglycosylases (LTs) are bacterial enzymes that catalyze the cleavage of the glycan strands of the bacterial cell wall. The mechanism of this cleavage is a remarkable intramolecular transacetalization reaction, accomplished by an ensemble of active-site residues. Because the LT reaction occurs in parallel with the cell wall bond-forming reactions catalyzed by the penicillin-binding proteins, simultaneous inhibition of both enzymes can be particularly bactericidal to Gram-negative bacteria. The MltE lytic transglycosylase is the smallest of the eight LTs encoded by the Escherichia coli genome. Prior crystallographic and computational studies identified four active-site residues-E64, S73, S75, and Y192-as playing roles in catalysis. Each of these four residues was individually altered by mutation to give four variant enzymes (E64Q, S73A, S75A, and Y192F). All four variants showed reduced catalytic activity [soluble wild type (100%) > soluble Y192F and S75A (both 40%) > S73A (4%) > E64Q (≤1%)]. The crystal structure of each variant protein was determined at the resolution of 2.12 Å for E64Q, 2.33 Å for Y192F, 1.38 Å for S73A, and 1.35 Å for S75A. These variants show alteration of the hydrogen-bond interactions of the active site. Within the framework of a prior computational study of the LT mechanism, we suggest the mechanistic role of these four active-site residues in MltE catalysis.
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Affiliation(s)
- David A Dik
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - María T Batuecas
- Department of Crystallography and Structural Biology , Inst. Química-Física "Rocasolano", CSIC , Serrano 119 , 28006 Madrid , Spain
| | - Mijoon Lee
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - Kiran V Mahasenan
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - Daniel R Marous
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - Jed F Fisher
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology , Inst. Química-Física "Rocasolano", CSIC , Serrano 119 , 28006 Madrid , Spain
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry , University of Notre Dame , 352 McCourtney Hall , Notre Dame , Indiana 46556 , United States
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9
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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: 116] [Impact Index Per Article: 19.3] [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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10
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Bao Y, Tian M, Li P, Liu J, Ding C, Yu S. Characterization of Brucella abortus mutant strain Δ22915, a potential vaccine candidate. Vet Res 2017; 48:17. [PMID: 28376905 PMCID: PMC5381064 DOI: 10.1186/s13567-017-0422-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/07/2017] [Indexed: 11/25/2022] Open
Abstract
Brucellosis, caused by Brucella spp., is an important zoonosis worldwide. Vaccination is an effective strategy for protection against Brucella infection in livestock in developing countries and in wildlife in developed countries. However, current vaccine strains including S19 and RB51 are pathogenic to humans and pregnant animals, limiting their use. In this study, we constructed the Brucella abortus (B. abortus) S2308 mutant strain Δ22915, in which the putative lytic transglycosylase gene BAB_RS22915 was deleted. The biological properties of mutant strain Δ22915 were characterized and protection of mice against virulent S2308 challenge was evaluated. The mutant strain Δ22915 showed reduced survival within RAW264.7 cells and survival in vivo in mice. In addition, the mutant strain Δ22915 failed to escape fusion with lysosomes within host cells, and caused no observable pathological damage. RNA-seq analysis indicated that four genes associated with amino acid/nucleotide transport and metabolism were significantly upregulated in mutant strain Δ22915. Furthermore, inoculation of ∆22915 at 105 colony forming units induced effective host immune responses and long-term protection of BALB/c mice. Therefore, mutant strain ∆22915 could be used as a novel vaccine candidate in the future to protect animals against B. abortus infection.
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Affiliation(s)
- Yanqing Bao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Mingxing Tian
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Peng Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Jiameng Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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11
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Suzuki S, Kaidow A, Meya T, Masuya A, Shiina T. Phenotypic difference between Δ(srl-recA)306 and ΔrecA::Km elucidated by next-generation sequencing combined with a long-PCR system. J GEN APPL MICROBIOL 2017; 63:22-27. [PMID: 27990000 DOI: 10.2323/jgam.2016.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Many significant gene mutations in E. coli have contributed to the development of genetics. Among these, a commonly used recA mutation, Δ(srl-recA)306 has been sequenced by a next-generation sequencer combined with a long PCR. An original report described that Δ(srl-recA)306 cells were deleted from srlR to recA genes in their genome. The next-generation sequencer enables more accurate details to be determined. We ask whether both surrounding genes from hypF to norV for srlR and alaS for recA is there first. The long PCR was carried out with primers, norR and alaS, and amplified DNA fragments differed in length from wild to Δ(srl-recA)306 cells, suggesting that an entire Δ(srl-recA)306 mutation was included. Sequences of those DNA fragments indicated that 9147 bp, from srlR to recA including 10 genes, were replaced by a Tn10 DNA sequence. Junction points at both srlR-Tn10 and Tn10-recA were determined precisely. The results indicate that the first 97% of recA gene sequences were lost with a downstream recX gene remaining intact. The phenotypic difference between Δ(srl-recA)306 and ΔrecA::Km is discussed.
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Affiliation(s)
- Shingo Suzuki
- Department of Molecular Life Science, Division of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine
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12
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Dik DA, Domínguez-Gil T, Lee M, Hesek D, Byun B, Fishovitz J, Boggess B, Hellman LM, Fisher JF, Hermoso JA, Mobashery S. Muropeptide Binding and the X-ray Structure of the Effector Domain of the Transcriptional Regulator AmpR of Pseudomonas aeruginosa. J Am Chem Soc 2017; 139:1448-1451. [PMID: 28079369 DOI: 10.1021/jacs.6b12819] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A complex link exists between cell-wall recycling/repair and the manifestation of resistance to β-lactam antibiotics in many Enterobacteriaceae and Pseudomonas aeruginosa. This process is mediated by specific cell-wall-derived muropeptide products. These muropeptides are internalized into the cytoplasm and bind to the transcriptional regulator AmpR, which controls the cytoplasmic events that lead to expression of β-lactamase, an antibiotic-resistance determinant. The effector-binding domain (EBD) of AmpR was purified to homogeneity. We document that the EBD exists exclusively as a dimer, even at a concentration as low as 1 μM. The EBD binds to the suppressor ligand UDP-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-meso-DAP-d-Ala-d-Ala and binds to two activator muropeptides, N-acetyl-β-d-glucosamine-(1→4)-1,6-anhydro-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-meso-DAP-d-Ala-d-Ala and 1,6-anhydro-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-meso-DAP-d-Ala-d-Ala, as assessed by non-denaturing mass spectrometry. The EBD does not bind to 1,6-anhydro-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-meso-DAP. This binding selectivity revises the dogma in the field. The crystal structure of the EBD dimer was solved to 2.2 Å resolution. The EBD crystallizes in a "closed" conformation, in contrast to the "open" structure required to bind the muropeptides. Structural issues of this ligand recognition are addressed by molecular dynamics simulations, which reveal significant differences among the complexes with the effector molecules.
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Affiliation(s)
- David A Dik
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Teresa Domínguez-Gil
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas , 28006 Madrid, Spain
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Byungjin Byun
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Jennifer Fishovitz
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Bill Boggess
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Lance M Hellman
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas , 28006 Madrid, Spain
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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13
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Schaub RE, Chan YA, Lee M, Hesek D, Mobashery S, Dillard JP. Lytic transglycosylases LtgA and LtgD perform distinct roles in remodeling, recycling and releasing peptidoglycan in Neisseria gonorrhoeae. Mol Microbiol 2016; 102:865-881. [PMID: 27608412 DOI: 10.1111/mmi.13496] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2016] [Indexed: 12/17/2022]
Abstract
Neisseria gonorrhoeae releases peptidoglycan (PG) fragments during infection that provoke a large inflammatory response and, in pelvic inflammatory disease, this response leads to the death and sloughing of ciliated cells of the Fallopian tube. We characterized the biochemical functions and localization of two enzymes responsible for the release of proinflammatory PG fragments. The putative lytic transglycosylases LtgA and LtgD were shown to create the 1,6-anhydromuramyl moieties, and both enzymes were able to digest a small, synthetic tetrasaccharide dipeptide PG fragment into the cognate 1,6-anhydromuramyl-containing reaction products. Degradation of tetrasaccharide PG fragments by LtgA is the first demonstration of a family 1 lytic transglycosylase exhibiting this activity. Pulse-chase experiments in gonococci demonstrated that LtgA produces a larger amount of PG fragments than LtgD, and a vast majority of these fragments are recycled. In contrast, LtgD was necessary for wild-type levels of PG precursor incorporation and produced fragments predominantly released from the cell. Additionally, super-resolution microscopy established that LtgA localizes to the septum, whereas LtgD is localized around the cell. This investigation suggests a model where LtgD produces PG monomers in such a way that these fragments are released, whereas LtgA creates fragments that are mostly taken into the cytoplasm for recycling.
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Affiliation(s)
- Ryan E Schaub
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Yolande A Chan
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Mijoon Lee
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Dusan Hesek
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Joseph P Dillard
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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14
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Substrate recognition and catalysis by LytB, a pneumococcal peptidoglycan hydrolase involved in virulence. Sci Rep 2015; 5:16198. [PMID: 26537571 PMCID: PMC4633669 DOI: 10.1038/srep16198] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022] Open
Abstract
Streptococcus pneumoniae is a major cause of life-threatening diseases worldwide. Here we provide an in-depth functional characterization of LytB, the peptidoglycan hydrolase responsible for physical separation of daughter cells. Identified herein as an N-acetylglucosaminidase, LytB is involved also in colonization and invasion of the nasopharynx, biofilm formation and evasion of host immunity as previously demonstrated. We have shown that LytB cleaves the GlcNAc-β-(1,4)-MurNAc glycosidic bond of peptidoglycan building units. The hydrolysis occurs at sites with fully acetylated GlcNAc moieties, with preference for uncross-linked muropeptides. The necessity of GlcN acetylation and the presence of a single acidic moiety (Glu585) essential for catalysis strongly suggest a substrate-assisted mechanism with anchimeric assistance of the acetamido group of GlcNAc moieties. Additionally, modelling of the catalytic region bound to a hexasaccharide tripentapeptide provided insights into substrate-binding subsites and peptidoglycan recognition. Besides, cell-wall digestion products and solubilisation rates might indicate a tight control of LytB activity to prevent unrestrained breakdown of the cell wall. Choline-independent localization at the poles of the cell, mediated by the choline-binding domain, peptidoglycan modification, and choline-mediated (lipo)teichoic-acid attachment contribute to the high selectivity of LytB. Moreover, so far unknown chitin hydrolase and glycosyltransferase activities were detected using GlcNAc oligomers as substrate.
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15
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Alsohim AS, Taylor TB, Barrett GA, Gallie J, Zhang XX, Altamirano-Junqueira AE, Johnson LJ, Rainey PB, Jackson RW. The biosurfactant viscosin produced byPseudomonas fluorescens SBW25 aids spreading motility and plant growth promotion. Environ Microbiol 2014; 16:2267-81. [DOI: 10.1111/1462-2920.12469] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 11/28/2022]
Affiliation(s)
| | - Tiffany B. Taylor
- School of Biological Sciences; University of Reading; Reading RG6 6AJ UK
| | - Glyn A. Barrett
- School of Biological Sciences; University of Reading; Reading RG6 6AJ UK
| | - Jenna Gallie
- New Zealand Institute for Advanced Study; Massey University; Auckland New Zealand
- Department of Environmental Microbiology; Eawag; Dübendorf 8600 Switzerland
- Department of Environmental Systems Science; ETH Zürich; Zürich 8092 Switzerland
| | - Xue-Xian Zhang
- New Zealand Institute for Advanced Study; Massey University; Auckland New Zealand
| | | | - Louise J. Johnson
- School of Biological Sciences; University of Reading; Reading RG6 6AJ UK
| | - Paul B. Rainey
- New Zealand Institute for Advanced Study; Massey University; Auckland New Zealand
- Max Planck Institute for Evolutionary Biology; Plön Germany
| | - Robert W. Jackson
- School of Biological Sciences; University of Reading; Reading RG6 6AJ UK
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16
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Association of a D-alanyl-D-alanine carboxypeptidase gene with the formation of aberrantly shaped cells during the induction of viable but nonculturable Vibrio parahaemolyticus. Appl Environ Microbiol 2013; 79:7305-12. [PMID: 24056454 DOI: 10.1128/aem.01723-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio parahaemolyticus is a halophilic Gram-negative bacterium that causes human gastroenteritis. When the viable but nonculturable (VBNC) state of this bacterium was induced by incubation at 4°C in Morita minimal salt solution containing 0.5% NaCl, the rod-shaped cells became coccoid, and various aberrantly shaped intermediates were formed in the initial stage. This study examined the factors that influence the formation of these aberrantly shaped cells. The proportion of aberrantly shaped cells was not affected in a medium containing D-cycloserine (50 μg/ml) but was lower in a medium containing cephalosporin C (10 μg/ml) than in the control medium without antibiotics. The proportion of aberrantly shaped cells was higher in a culture medium that contained 0.5% NaCl than in culture media containing 1.0 or 1.5% NaCl. The expression of 15 of 17 selected genes associated with cell wall synthesis was enhanced, and the expression of VP2468 (dacB), which encodes D-alanyl-D-alanine carboxypeptidase, was enhanced the most. The proportion of aberrantly shaped cells was significantly lower in the dacB mutant strain than in the parent strain, but the proportion was restored in the presence of the complementary dacB gene. This study suggests that disturbance of the dynamics of cell wall synthesis by enhanced expression of the VP2468 gene is associated with the formation of aberrantly shaped cells in the initial stage of induction of VBNC V. parahaemolyticus cells under specific conditions.
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17
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Katavic PL, Yong KW, Herring JN, Deseo MA, Blanchfield JT, Ferro V, Garson MJ. Structure and stereochemistry of an anti-inflammatory anhydrosugar from the Australian marine sponge Plakinastrella clathrata and the synthesis of two analogues. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.06.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Zhang W, Lee M, Hesek D, Lastochkin E, Boggess B, Mobashery S. Reactions of the three AmpD enzymes of Pseudomonas aeruginosa. J Am Chem Soc 2013; 135:4950-3. [PMID: 23510438 DOI: 10.1021/ja400970n] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A group of Gram-negative bacteria, including the problematic pathogen Pseudomonas aeruginosa, has linked the steps in cell-wall recycling with the ability to manifest resistance to β-lactam antibiotics. A key step at the crossroads of the two events is performed by the protease AmpD, which hydrolyzes the peptide in the metabolite that influences these events. In contrast to other organisms that harbor this elaborate system, the genomic sequences of P. aeruginosa reveal it to have three paralogous genes for this protease, designated as ampD, ampDh2, and ampDh3. The recombinant gene products were purified to homogeneity, and their functions were assessed by the use of synthetic samples of three bacterial metabolites in cell-wall recycling and of three surrogates of cell-wall peptidoglycan. The results unequivocally identify AmpD as the bona fide recycling enzyme and AmpDh2 and AmpDh3 as enzymes involved in turnover of the bacterial cell wall itself. These findings define for the first time the events mediated by these three enzymes that lead to turnover of a key cell-wall recycling metabolite as well as the cell wall itself in its maturation.
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Affiliation(s)
- Weilie Zhang
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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19
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Lee M, Hesek D, Llarrull LI, Lastochkin E, Pi H, Boggess B, Mobashery S. Reactions of all Escherichia coli lytic transglycosylases with bacterial cell wall. J Am Chem Soc 2013; 135:3311-4. [PMID: 23421439 DOI: 10.1021/ja309036q] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactions of all seven Escherichia coli lytic transglycosylases with purified bacterial sacculus are characterized in a quantitative manner. These reactions, which initiate recycling of the bacterial cell wall, exhibit significant redundancy in the activities of these enzymes along with some complementarity. These discoveries underscore the importance of the functions of these enzymes for recycling of the cell wall.
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Affiliation(s)
- Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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20
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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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21
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Fibriansah G, Gliubich FI, Thunnissen AMWH. On the Mechanism of Peptidoglycan Binding and Cleavage by the endo-Specific Lytic Transglycosylase MltE from Escherichia coli. Biochemistry 2012; 51:9164-77. [DOI: 10.1021/bi300900t] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Guntur Fibriansah
- Laboratory
of Biophysical Chemistry, Groningen Biomolecular
Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Francesca I. Gliubich
- Laboratory
of Biophysical Chemistry, Groningen Biomolecular
Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Andy-Mark W. H. Thunnissen
- Laboratory
of Biophysical Chemistry, Groningen Biomolecular
Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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22
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Boudreau MA, Fisher JF, Mobashery S. Messenger functions of the bacterial cell wall-derived muropeptides. Biochemistry 2012; 51:2974-90. [PMID: 22409164 DOI: 10.1021/bi300174x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bacterial muropeptides are soluble peptidoglycan structures central to recycling of the bacterial cell wall and messengers in diverse cell signaling events. Bacteria sense muropeptides as signals that antibiotics targeting cell-wall biosynthesis are present, and eukaryotes detect muropeptides during the innate immune response to bacterial infection. This review summarizes the roles of bacterial muropeptides as messengers, with a special emphasis on bacterial muropeptide structures and the relationship of structure to the biochemical events that the muropeptides elicit. Muropeptide sensing and recycling in both Gram-positive and Gram-negative bacteria are discussed, followed by muropeptide sensing by eukaryotes as a crucial event in the innate immune response of insects (via peptidoglycan-recognition proteins) and mammals (through Nod-like receptors) to bacterial invasion.
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Affiliation(s)
- Marc A Boudreau
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
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23
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Chan YA, Hackett KT, Dillard JP. The lytic transglycosylases of Neisseria gonorrhoeae. Microb Drug Resist 2012; 18:271-9. [PMID: 22432703 DOI: 10.1089/mdr.2012.0001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Neisseria gonorrhoeae encodes five lytic transglycosylases (LTs) in the core genome, and most gonococcal strains also carry the gonococcal genetic island that encodes one or two additional LTs. These peptidoglycan (PG)-degrading enzymes are required for a number of processes that are either involved in the normal growth of the bacteria or affect the pathogenesis and gene transfer aspects of this species that make N. gonorrhoeae highly inflammatory and highly genetically variable. Systematic mutagenesis determined that two LTs are involved in producing the 1,6-anhydro PG monomers that cause the death of ciliated cells in Fallopian tubes. Here, we review the information available on these enzymes and discuss their roles in bacterial growth, cell separation, autolysis, type IV secretion, and pathogenesis.
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Affiliation(s)
- Yolande A Chan
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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24
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Yamaguchi T, Blázquez B, Hesek D, Lee M, Llarrull LI, Boggess B, Oliver AG, Fisher JF, Mobashery S. Inhibitors for Bacterial Cell-Wall Recycling. ACS Med Chem Lett 2012; 3:238-242. [PMID: 22844551 PMCID: PMC3404464 DOI: 10.1021/ml2002746] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 01/19/2012] [Indexed: 11/28/2022] Open
Abstract
Gram-negative bacteria have evolved an elaborate process for the recycling of their cell wall, which is initiated in the periplasmic space by the action of lytic transglycosylases. The product of this reaction, β-D-N-acetylglucosamine-(1→4)-1,6-anhydro-β-D-N-acetylmuramyl-L-Ala-γ-D-Glu-meso-DAP-D-Ala-D-Ala (compound 1), is internalized to begin the recycling events within the cytoplasm. The first step in the cytoplasmic recycling is catalyzed by the NagZ glycosylase, which cleaves in a hydrolytic reaction the N-acetylglucosamine glycosidic bond of metabolite 1. The reactions catalyzed by both the lytic glycosylases and NagZ are believed to involve oxocarbenium transition species. We describe herein the synthesis and evaluation of four iminosaccharides as possible mimetics of the oxocarbenium species, and disclose one as a potent (compound 3, K(i) = 300 ± 15 nM) competitive inhibitor of NagZ.
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Affiliation(s)
- Takao Yamaguchi
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Blas Blázquez
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Dusan Hesek
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Mijoon Lee
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Leticia I. Llarrull
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Bill Boggess
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Allen G. Oliver
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Jed F. Fisher
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
| | - Shahriar Mobashery
- Department
Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556,
United States
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25
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Fujimoto Y, Pradipta AR, Inohara N, Fukase K. Peptidoglycan as Nod1 ligand; fragment structures in the environment, chemical synthesis, and their innate immunostimulation. Nat Prod Rep 2012; 29:568-79. [PMID: 22370813 DOI: 10.1039/c2np00091a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Covering: up to 2011. This review focuses on the recent revealing of the immunostimulatory bacterial cell wall peptidoglycan (PGN) fragments as Nod1 ligands, especially a newly developed chemical synthesis of the partial structures, fragment structures in the environment and bacterial supernatant, and the immunostimulatory activities of the Nod1 ligands.
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Affiliation(s)
- Yukari Fujimoto
- Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
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26
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Hernández SB, Cota I, Ducret A, Aussel L, Casadesús J. Adaptation and preadaptation of Salmonella enterica to Bile. PLoS Genet 2012; 8:e1002459. [PMID: 22275872 PMCID: PMC3261920 DOI: 10.1371/journal.pgen.1002459] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 11/19/2011] [Indexed: 12/23/2022] Open
Abstract
Bile possesses antibacterial activity because bile salts disrupt membranes, denature proteins, and damage DNA. This study describes mechanisms employed by the bacterium Salmonella enterica to survive bile. Sublethal concentrations of the bile salt sodium deoxycholate (DOC) adapt Salmonella to survive lethal concentrations of bile. Adaptation seems to be associated to multiple changes in gene expression, which include upregulation of the RpoS-dependent general stress response and other stress responses. The crucial role of the general stress response in adaptation to bile is supported by the observation that RpoS− mutants are bile-sensitive. While adaptation to bile involves a response by the bacterial population, individual cells can become bile-resistant without adaptation: plating of a non-adapted S. enterica culture on medium containing a lethal concentration of bile yields bile-resistant colonies at frequencies between 10−6 and 10−7 per cell and generation. Fluctuation analysis indicates that such colonies derive from bile-resistant cells present in the previous culture. A fraction of such isolates are stable, indicating that bile resistance can be acquired by mutation. Full genome sequencing of bile-resistant mutants shows that alteration of the lipopolysaccharide transport machinery is a frequent cause of mutational bile resistance. However, selection on lethal concentrations of bile also provides bile-resistant isolates that are not mutants. We propose that such isolates derive from rare cells whose physiological state permitted survival upon encountering bile. This view is supported by single cell analysis of gene expression using a microscope fluidic system: batch cultures of Salmonella contain cells that activate stress response genes in the absence of DOC. This phenomenon underscores the existence of phenotypic heterogeneity in clonal populations of bacteria and may illustrate the adaptive value of gene expression fluctuations. This study describes mechanisms employed by the bacterium Salmonella enterica to survive bile: adaptation, mutation, and non-mutational preadaptation. Adaptation is easily observed in the laboratory: when a Salmonella culture is grown in the presence of a sublethal concentration of the bile salt sodium deoxycholate (DOC), the minimal inhibitory concentration of DOC increases. Adaptation appears to be associated to multiple changes in gene expression induced by DOC. Mutational bile resistance is also a common phenomenon: plating on agar containing a lethal concentration of bile yields bile-resistant colonies. Fluctuation analysis indicates that such colonies derive from bile-resistant cells present in the previous culture. However, selection on lethal concentrations of bile also provides bile-resistant isolates that are not mutants. Non-mutational preadaptation, a non-canonical phenomenon a priori, suggests that batch cultures contain rare Salmonella cells whose physiological state permits survival upon encountering bile. The view that non-mutational preadaptation may be a consequence of phenotypic heterogeneity is supported by the observation that Salmonella cultures contain cells that activate stress response genes in the absence of DOC.
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Affiliation(s)
| | - Ignacio Cota
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
| | - Adrien Ducret
- Laboratoire de Chimie Bactérienne, CNRS-UPR 9043, Aix-Marseille University, Marseille, France
| | - Laurent Aussel
- Laboratoire de Chimie Bactérienne, CNRS-UPR 9043, Aix-Marseille University, Marseille, France
| | - Josep Casadesús
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
- * E-mail:
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27
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Abstract
The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway.
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Affiliation(s)
- Jean van Heijenoort
- Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Bat 430, Université Paris-Sud, Orsay F-91405, France.
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28
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Fujimoto Y, Fukase K. Structures, synthesis, and human Nod1 stimulation of immunostimulatory bacterial peptidoglycan fragments in the environment. JOURNAL OF NATURAL PRODUCTS 2011; 74:518-525. [PMID: 21341753 DOI: 10.1021/np100795d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Bacteria release immunostimulatory compounds to the environment, and one of the stimulants is the ligand of nucleotide-binding oligomerization domain protein 1 (Nod1), an intracellular protein involved in the recognition of the bacterial component peptidoglycans having a diaminopimelic acid (DAP) structure. The polymorphisms of Nod1 have been linked to several inflammatory diseases and allergies that are strongly affected by environmental factors. The present paper summarizes recent results on the isolation and structural elucidation of natural human Nod1 (hNod1) ligands from the Escherichia coli (E. coli) K-12 culture supernatant, the first chemical synthesis of these natural ligands and related PGN fragments structures, and the hNod1 stimulatory activities of the chemically synthesized DAP-type PGN fragments. For structural characterization studies, the 7-(diethylamino)coumarin-3-carbonyl (DEAC) labeling method was also used to enhance the sensitivity in mass spectrometry studies, in order to observe PGN fragments in a comprehensive manner. The results suggest that DAP-containing bacteria release certain hNod1 ligands to the environment and that these ligands accumulate in the environment and regulate the immune system through Nod1.
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Affiliation(s)
- Yukari Fujimoto
- Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
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Artola-Recolons C, Llarrull LI, Lastochkin E, Mobashery S, Hermoso JA. Crystallization and preliminary X-ray diffraction analysis of the lytic transglycosylase MltE from Escherichia coli. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:161-3. [PMID: 21206052 PMCID: PMC3080000 DOI: 10.1107/s1744309110049171] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 11/24/2010] [Indexed: 11/10/2022]
Abstract
MltE from Escherichia coli (193 amino acids, 21,380 Da) is a lytic transglycosylase that initiates the first step of cell-wall recycling. This enzyme is responsible for the cleavage of the cell-wall peptidoglycan at the β-1,4-glycosidic bond between the N-acetylglucosamine and N-acetylmuramic acid units. At the end this reaction generates a disaccharide that is internalized and initiates the recycling process. To obtain insights into the biological functions of MltE, crystallization trials were performed and crystals of MltE protein that were suitable for X-ray diffraction analysis were obtained. The MltE protein of E. coli was crystallized using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture consisting of 28% polyethylene glycol 4000, 0.1 M Tris pH 8.4 and 0.2 M magnesium chloride. Further optimization was performed using the microbatch technique. Single crystals were obtained that belonged to the orthorhombic space group C222(1), with unit-cell parameters a=123.32, b=183.93, c=35.29 Å, and diffracted to a resolution of 2.1 Å.
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Affiliation(s)
- Cecilia Artola-Recolons
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, Madrid 28006, Spain
| | - Leticia I. Llarrull
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, Notre Dame, Indiana 46556, USA
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, Notre Dame, Indiana 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, Notre Dame, Indiana 46556, USA
| | - Juan A. Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, Madrid 28006, Spain
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Lee M, Hesek D, Shah IM, Oliver AG, Dworkin J, Mobashery S. Synthetic peptidoglycan motifs for germination of bacterial spores. Chembiochem 2010; 11:2525-9. [PMID: 21117117 PMCID: PMC3519099 DOI: 10.1002/cbic.201000626] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Indexed: 11/05/2022]
Affiliation(s)
- Mijoon Lee
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame, IN 46556, USA Fax: (+) 1-574-631-6652
| | - Dusan Hesek
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame, IN 46556, USA Fax: (+) 1-574-631-6652
| | - Ishita M. Shah
- Department of Microbiology and Immunology Columbia University New York, NY 10032, USA
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame, IN 46556, USA Fax: (+) 1-574-631-6652
| | - Jonathan Dworkin
- Department of Microbiology and Immunology Columbia University New York, NY 10032, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame, IN 46556, USA Fax: (+) 1-574-631-6652
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Ozyamak E, Black SS, Walker CA, Maclean MJ, Bartlett W, Miller S, Booth IR. The critical role of S-lactoylglutathione formation during methylglyoxal detoxification in Escherichia coli. Mol Microbiol 2010; 78:1577-90. [PMID: 21143325 PMCID: PMC3412212 DOI: 10.1111/j.1365-2958.2010.07426.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Survival of exposure to methylglyoxal (MG) in Gram-negative pathogens is largely dependent upon the operation of the glutathione-dependent glyoxalase system, consisting of two enzymes, GlxI (gloA) and GlxII (gloB). In addition, the activation of the KefGB potassium efflux system is maintained closed by glutathione (GSH) and is activated by S-lactoylGSH (SLG), the intermediate formed by GlxI and destroyed by GlxII. Escherichia coli mutants lacking GlxI are known to be extremely sensitive to MG. In this study we demonstrate that a ΔgloB mutant is as tolerant of MG as the parent, despite having the same degree of inhibition of MG detoxification as a ΔgloA strain. Increased expression of GlxII from a multicopy plasmid sensitizes E. coli to MG. Measurement of SLG pools, KefGB activity and cytoplasmic pH shows these parameters to be linked and to be very sensitive to changes in the activity of GlxI and GlxII. The SLG pool determines the activity of KefGB and the degree of acidification of the cytoplasm, which is a major determinant of the sensitivity to electrophiles. The data are discussed in terms of how cell fate is determined by the relative abundance of the enzymes and KefGB.
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Affiliation(s)
- Ertan Ozyamak
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, 423 Nieuwland Science Hall, Notre Dame, Indiana 46556-5670, USA
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Pradipta AR, Fujimoto Y, Hasegawa M, Inohara N, Fukase K. Characterization of natural human nucleotide-binding oligomerization domain protein 1 (Nod1) ligands from bacterial culture supernatant for elucidation of immune modulators in the environment. J Biol Chem 2010; 285:23607-13. [PMID: 20519512 DOI: 10.1074/jbc.m110.137893] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Nucleotide-binding oligomerization domain protein 1 (Nod1) is an intracellular protein involved in recognition of the bacterial component peptidoglycan. This recognition event induces a host defense response to eliminate invading pathogens. The genetic variation of Nod1 has been linked to several inflammatory diseases and allergies, which are strongly affected by environmental factors. We have found that many of the bacteria that contain DAP-type peptidoglycan release Nod1 ligands into the environment. However, the structures of natural Nod1 ligands in the environment are not well understood. Herein, we report the isolation and structural elucidation of natural human Nod1 (hNod1) ligands from the Escherichia coli K-12 culture supernatant. The supernatant was fractionated with reversed-phase high performance liquid chromatography (RP-HPLC), resulting in the isolation of several hNod1 stimulatory fractions. Structural characterization studies demonstrated that the molecular structure of the most active fraction was the native hNod1 ligand GlcNAc-(beta1-4)-(anhydro)MurNAc-l-Ala-gamma-d-Glu-meso-DAP. We also found other peptidoglycan fragments using the 7-(diethylamino)coumarin-3-carbonyl labeling method to enhance sensitivity in mass spectroscopy studies. These results suggested that DAP-containing bacteria release certain hNod1 ligands to the environment, and these ligands would accumulate in the environment and regulate the immune system through Nod1.
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Affiliation(s)
- Ambara R Pradipta
- Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan
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Lee M, Zhang W, Hesek D, Noll BC, Boggess B, Mobashery S. Bacterial AmpD at the crossroads of peptidoglycan recycling and manifestation of antibiotic resistance. J Am Chem Soc 2009; 131:8742-3. [PMID: 19496566 DOI: 10.1021/ja9025566] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The bacterial enzyme AmpD is an early catalyst in commitment of cell wall metabolites to the recycling events within the cytoplasm. The key internalized metabolite of cell wall recycling, beta-D-N-acetylglucosamine-(1-->4)-1,6-anhydro-beta-N-acetylmuramyl-L-Ala-gamma-D-Glu-meso-DAP-D-Ala-D-Ala (compound 1), is a poor substrate for AmpD. Two additional metabolites, 1,6-anhydro-N-acetylmuramyl-peptidyl derivatives 2a and 2c, served as substrates for AmpD with a k(cat)/K(m) of >10(4) M(-1) s(-1). The enzyme hydrolytically processes the lactyl amide bond of the 1,6-anhydro-N-acetylmuramyl moiety. The syntheses of these substrates and other ligands are reported herein, which made the characterization of the enzymic reaction possible. Furthermore, it is documented that the enzyme is specific for both the atypical peptide stem of the cell wall fragments and the presence of the sterically encumbered 1,6-anhydro-N-acetylmuramyl moiety; hence it is a peptidase with a unique function in bacterial physiology. The implications of the function of this catalyst for the entry into the cell wall recycling events and the reversal of induction of the production of beta-lactamase, an antibiotic resistance determinant, are discussed.
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Affiliation(s)
- Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Hesek D, Lee M, Zhang W, Noll BC, Mobashery S. Total synthesis of N-acetylglucosamine-1,6-anhydro-N-acetylmuramylpentapeptide and evaluation of its turnover by AmpD from Escherichia coli. J Am Chem Soc 2009; 131:5187-93. [PMID: 19309146 DOI: 10.1021/ja808498m] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bacterial cell wall is recycled extensively during the course of cell growth. The first recycling event involves the catalytic action of the lytic transglycosylase enzymes, which produce an uncommon 1,6-anhydropyranose moiety during separation of the muramyl residues from the peptidoglycan, the major constituent of the cell wall. This product, an N-acetyl-beta-D-glucosamine-(1-->4)-1,6-anhydro-N-acetyl-beta-D-muramylpeptide, is either internalized to initiate the recycling process or diffuses into the milieu to cause stimulation of the pro-inflammatory responses by the host. We report the total syntheses of N-acetyl-beta-D-glucosamine-(1-->4)-1,6-anhydro-N-acetyl-beta-D-muramyl-L-Ala-gamma-D-Glu-meso-DAP-D-Ala-D-Ala (compound 1, the product of lytic transglycosylase action on the cell wall of gram-negative bacteria) and N-acetyl-beta-D-glucosamine-(1-->4)-1,6-anhydro-N-acetyl-beta-D-muramyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala (compound 2, from lytic transglycosylase action on the cell wall of gram-positive bacteria). The syntheses were accomplished in 15 linear steps. Compound 1 is shown to be a substrate of the AmpD enzyme of the gram-negative bacterium Escherichia coli, an enzyme that removes the peptide from the disaccharide scaffold in the early cytoplasmic phase of cell wall turnover.
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Affiliation(s)
- Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Daptomycin: putative new mechanisms of action and resistance evolved from transcriptome data mining. ACTA ACUST UNITED AC 2009. [DOI: 10.1097/mrm.0b013e32832e82af] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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