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Shyam M, Shilkar D, Rakshit G, Jayaprakash V. Approaches for Targeting the Mycobactin Biosynthesis Pathway for Novel Anti-tubercular Drug Discovery: Where We Stand. Expert Opin Drug Discov 2022; 17:699-715. [PMID: 35575503 DOI: 10.1080/17460441.2022.2077328] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Several decades of antitubercular drug discovery efforts have focused on novel antitubercular chemotherapies. However, recent efforts have greatly shifted towards countering extremely/multi/total drug-resistant species. Targeting the conditionally essential elements inside Mycobacterium is a relatively new approach against tuberculosis and has received lackluster attention. The siderophore, Mycobactin, is a conditionally essential molecule expressed by mycobacteria in iron-stress conditions. It helps capture the micronutrient iron, essential for the smooth functioning of cellular processes. AREAS COVERED The authors discuss opportunities to target the conditionally essential pathways to help develop newer drugs and prolong the shelf life of existing therapeutics, emphasizing the bottlenecks in fast-tracking antitubercular drug discovery. EXPERT OPINION While the lack of iron supply can cripple bacterial growth and multiplication, excess iron can cause oxidative overload. Constant up-regulation can strain the bacterial synthetic machinery, further slowing its growth. Mycobactin synthesis is tightly controlled by a genetically conserved mega enzyme family via up-regulation (HupB) or down-regulation (IdeR) based on iron availability in its microenvironment. Furthermore, the recycling of siderophores by the MmpL-MmpS4/5 orchestra provides endogenous drug targets to beat the bugs with iron-toxicity contrivance. These processes can be exploited as chinks in the armor of Mycobacterium and be used for new drug development.
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Affiliation(s)
- Mousumi Shyam
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Deepak Shilkar
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Gourav Rakshit
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Venkatesan Jayaprakash
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
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Dimopoulou A, Theologidis I, Varympopi A, Papafotis D, Mermigka G, Tzima A, Panopoulos NJ, Skandalis N. Shifting Perspectives of Translational Research in Bio-Bactericides: Reviewing the Bacillus amyloliquefaciens Paradigm. BIOLOGY 2021; 10:biology10111202. [PMID: 34827195 PMCID: PMC8614995 DOI: 10.3390/biology10111202] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/11/2021] [Accepted: 11/15/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary The continuous reduction of approved conventional microbicides, due to health concerns and the development of plant-pathogen resistance, has been urged for the use of safe alternatives in crop protection. Several beneficial bacterial species, termed biological control agents, are currently used in lieu of chemical pesticides. The approach to select such bacterial species and manufacture commercial products has been based on their biocontrol effect under optimal growth conditions, which is far from the real nutrient-limited field conditions of plant niches. It’s important to determine the complex interactions that occur among BCAs, plant host and niche microbiome to fully understand and exploit the potential of biological control agents. Furthermore, it’s crucial to acknowledge the environmental impact of their long-term use. Abstract Bacterial biological control agents (BCAs) have been increasingly used against plant diseases. The traditional approach to manufacturing such commercial products was based on the selection of bacterial species able to produce secondary metabolites that inhibit mainly fungal growth in optimal media. Such species are required to be massively produced and sustain long-term self-storage. The endpoint of this pipeline is large-scale field tests in which BCAs are handled as any other pesticide. Despite recent knowledge of the importance of BCA-host-microbiome interactions to trigger plant defenses and allow colonization, holistic approaches to maximize their potential are still in their infancy. There is a gap in scientific knowledge between experiments in controlled conditions for optimal BCA and pathogen growth and the nutrient-limited field conditions in which they face niche microbiota competition. Moreover, BCAs are considered to be safe by competent authorities and the public, with no side effects to the environment; the OneHealth impact of their application is understudied. This review summarizes the state of the art in BCA research and how current knowledge and new biotechnological tools have impacted BCA development and application. Future challenges, such as their combinational use and ability to ameliorate plant stress are also discussed. Addressing such challenges would establish their long-term use as centerfold agricultural pesticides and plant growth promoters.
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Affiliation(s)
- Anastasia Dimopoulou
- Institute of Molecular Biology and Biotechnology, FORTH, 70013 Heraklion, Greece; (A.D.); (G.M.)
| | - Ioannis Theologidis
- Laboratory of Pesticides’ Toxicology, Benaki Phytopathological Institute, 14561 Athens, Greece;
| | - Adamantia Varympopi
- Enzyme and Microbial Biotechnology Unit, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece; (A.V.); (D.P.)
| | - Dimitris Papafotis
- Enzyme and Microbial Biotechnology Unit, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece; (A.V.); (D.P.)
| | - Glykeria Mermigka
- Institute of Molecular Biology and Biotechnology, FORTH, 70013 Heraklion, Greece; (A.D.); (G.M.)
| | - Aliki Tzima
- Laboratory of Plant Pathology, Department of Crop Production, School of Agricultural Production Infrastructure and Environment, Faculty of Crop Science, Agricultural University of Athens, 11855 Athens, Greece;
| | - Nick J. Panopoulos
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA;
| | - Nicholas Skandalis
- Health Sciences Campus, Keck School of Medicine, University of Southern California, 1441 Eastlake Ave, Los Angeles, CA 90033, USA
- Correspondence:
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Līpiņš DD, Jeminejs A, Novosjolova I, Bizdēna Ē, Turks M. Synthesis of Azido and Triazolyl Purine Ribonucleosides. Curr Protoc 2021; 1:e241. [PMID: 34491626 DOI: 10.1002/cpz1.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Here, we describe detailed synthetic protocols for preparation of 6-amino/thio-2-triazolylpurine ribonucleosides. First, 9-(2',3',5'-tri-O-acetyl-β-D-ribofuranosyl)-2,6-diazido-9H-purine, to be used as a key starting material, is synthesized in an SN Ar reaction with NaN3 starting from commercially available 9-(2',3',5'-tri-O-acetyl-β-D-ribofuranosyl)-2,6-dichloro-9H-purine. Next, 2,6-bis-triazolylpurine ribonucleoside is obtained in a CuAAC reaction between diazidopurine derivative and phenyl acetylene, and used in SN Ar reactions with N- and S-nucleophiles. In these reactions, the triazolyl ring at the purine C6 position acts as a good leaving group. Cleavage of acetyl protecting groups from the ribosyl moiety is achieved in presence of piperidine. In the SN Ar reaction with amino acid derivatives, the acetyl groups remain intact. Moreover, 9-(2',3',5'-tri-O-acetyl-β-D-ribofuranosyl)-2,6-diazido-9H-purine is selectively reduced at the C6 position using a CuSO4 ·5H2 O/sodium ascorbate system. This provides a straightforward approach for synthesis of 9-(2',3',5'-tri-O-acetyl-β-D-ribofuranosyl)-6-amino-2-azido-9H-purine. © 2021 Wiley Periodicals LLC Basic Protocol 1: Synthesis of 6-amino-2-triazolylpurine ribonucleosides Basic Protocol 2: Synthesis of 6-thio-2-triazolylpurine ribonucleosides Basic Protocol 3: Synthesis of 6-amino-2-azidopurine ribonucleoside.
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Affiliation(s)
- Dāgs Dāvis Līpiņš
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Andris Jeminejs
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Irina Novosjolova
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Ērika Bizdēna
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
| | - Māris Turks
- Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, Latvia
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Direct Antibiotic Activity of Bacillibactin Broadens the Biocontrol Range of Bacillus amyloliquefaciens MBI600. mSphere 2021; 6:e0037621. [PMID: 34378986 PMCID: PMC8386435 DOI: 10.1128/msphere.00376-21] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus amyloliquefaciens is considered the most successful biological control agent due to its ability to colonize the plant rhizosphere and phyllosphere where it outgrows plant pathogens by competition, antibiosis, and inducing plant defense. Its antimicrobial function is thought to depend on a diverse spectrum of secondary metabolites, including peptides, cyclic lipopeptides, and polyketides, which have been shown to target mostly fungal pathogens. In this study, we isolated and characterized the catecholate siderophore bacillibactin by B. amyloliquefaciens MBI600 under iron-limiting conditions and we further identified its potential antibiotic activity against plant pathogens. Our data show that bacillibactin production restrained in vitro and in planta growth of the nonsusceptible (to MBI600) pathogen Pseudomonas syringae pv. tomato. Notably, it was also related to increased antifungal activity of MBI600. In addition to bacillibactin biosynthesis, iron starvation led to upregulation of specific genes involved in microbial fitness and competition. IMPORTANCE Siderophores have mostly been studied concerning their contribution to the fitness and virulence of bacterial pathogens. In the present work, we isolated and characterized for the first time the siderophore bacillibactin from a commercial bacterial biocontrol agent. We proved that its presence in the culture broth has significant biocontrol activity against nonsusceptible bacterial and fungal phytopathogens. In addition, we suggest that its activity is due to a new mechanism of action, that of direct antibiosis, rather than by competition through iron scavenging. Furthermore, we showed that bacillibactin biosynthesis is coregulated with the transcription of antimicrobial metabolite synthases and fitness regulatory genes that maximize competition capability. Finally, this work highlights that the efficiency and range of existing bacterial biocontrol agents can be improved and broadened via the rational modification of the growth conditions of biocontrol organisms.
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Wiegand S, Rast P, Kallscheuer N, Jogler M, Heuer A, Boedeker C, Jeske O, Kohn T, Vollmers J, Kaster AK, Quast C, Glöckner FO, Rohde M, Jogler C. Analysis of Bacterial Communities on North Sea Macroalgae and Characterization of the Isolated Planctomycetes Adhaeretor mobilis gen. nov., sp. nov., Roseimaritima multifibrata sp. nov., Rosistilla ulvae sp. nov. and Rubripirellula lacrimiformis sp. nov. Microorganisms 2021; 9:microorganisms9071494. [PMID: 34361930 PMCID: PMC8303584 DOI: 10.3390/microorganisms9071494] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 12/31/2022] Open
Abstract
Planctomycetes are bacteria that were long thought to be unculturable, of low abundance, and therefore neglectable in the environment. This view changed in recent years, after it was shown that members of the phylum Planctomycetes can be abundant in many aquatic environments, e.g., in the epiphytic communities on macroalgae surfaces. Here, we analyzed three different macroalgae from the North Sea and show that Planctomycetes is the most abundant bacterial phylum on the alga Fucus sp., while it represents a minor fraction of the surface-associated bacterial community of Ulva sp. and Laminaria sp. Especially dominant within the phylum Planctomycetes were Blastopirellula sp., followed by Rhodopirellula sp., Rubripirellula sp., as well as other Pirellulaceae and Lacipirellulaceae, but also members of the OM190 lineage. Motivated by the observed abundance, we isolated four novel planctomycetal strains to expand the collection of species available as axenic cultures since access to different strains is a prerequisite to investigate the success of planctomycetes in marine environments. The isolated strains constitute four novel species belonging to one novel and three previously described genera in the order Pirellulales, class Planctomycetia, phylum Planctomycetes.
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Affiliation(s)
- Sandra Wiegand
- Department of Microbiology, Radboud University, 6525 AJ Nijmegen, The Netherlands; (S.W.); (N.K.); (T.K.)
- Institute for Biological Interfaces 5 (IBG-5), Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; (J.V.); (A.-K.K.)
| | - Patrick Rast
- Leibniz Institute DSMZ, 38124 Braunschweig, Germany; (P.R.); (A.H.); (C.B.); (O.J.)
| | - Nicolai Kallscheuer
- Department of Microbiology, Radboud University, 6525 AJ Nijmegen, The Netherlands; (S.W.); (N.K.); (T.K.)
- Institute of Bio- and Geosciences, Biotechnology (IBG-1), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
| | - Mareike Jogler
- Department of Microbial Interactions, Institute of Microbiology, Friedrich-Schiller University, 07743 Jena, Germany;
| | - Anja Heuer
- Leibniz Institute DSMZ, 38124 Braunschweig, Germany; (P.R.); (A.H.); (C.B.); (O.J.)
| | - Christian Boedeker
- Leibniz Institute DSMZ, 38124 Braunschweig, Germany; (P.R.); (A.H.); (C.B.); (O.J.)
| | - Olga Jeske
- Leibniz Institute DSMZ, 38124 Braunschweig, Germany; (P.R.); (A.H.); (C.B.); (O.J.)
| | - Timo Kohn
- Department of Microbiology, Radboud University, 6525 AJ Nijmegen, The Netherlands; (S.W.); (N.K.); (T.K.)
| | - John Vollmers
- Institute for Biological Interfaces 5 (IBG-5), Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; (J.V.); (A.-K.K.)
| | - Anne-Kristin Kaster
- Institute for Biological Interfaces 5 (IBG-5), Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; (J.V.); (A.-K.K.)
| | - Christian Quast
- Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany;
| | - Frank Oliver Glöckner
- Alfred Wegener Institute Bremerhaven, MARUM, University of Bremen, 28359 Bremen, Germany;
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
| | - Christian Jogler
- Department of Microbiology, Radboud University, 6525 AJ Nijmegen, The Netherlands; (S.W.); (N.K.); (T.K.)
- Department of Microbial Interactions, Institute of Microbiology, Friedrich-Schiller University, 07743 Jena, Germany;
- Correspondence: ; Tel.: +49-364-194-9301
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Shyam M, Shilkar D, Verma H, Dev A, Sinha BN, Brucoli F, Bhakta S, Jayaprakash V. The Mycobactin Biosynthesis Pathway: A Prospective Therapeutic Target in the Battle against Tuberculosis. J Med Chem 2020; 64:71-100. [PMID: 33372516 DOI: 10.1021/acs.jmedchem.0c01176] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The alarming rise in drug-resistant clinical cases of tuberculosis (TB) has necessitated the rapid development of newer chemotherapeutic agents with novel mechanisms of action. The mycobactin biosynthesis pathway, conserved only among the mycolata family of actinobacteria, a group of intracellularly surviving bacterial pathogens that includes Mycobacterium tuberculosis, generates a salicyl-capped peptide mycobactin under iron-stress conditions in host macrophages to support the iron demands of the pathogen. This in vivo essentiality makes this less explored mycobactin biosynthesis pathway a promising endogenous target for novel lead-compounds discovery. In this Perspective, we have provided an up-to-date account of drug discovery efforts targeting selected enzymes (MbtI, MbtA, MbtM, and PPTase) from the mbt gene cluster (mbtA-mbtN). Furthermore, a succinct discussion on non-specific mycobactin biosynthesis inhibitors and the Trojan horse approach adopted to impair iron metabolism in mycobacteria has also been included in this Perspective.
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Affiliation(s)
- Mousumi Shyam
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215 Jharkhand, India.,Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Deepak Shilkar
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215 Jharkhand, India
| | - Harshita Verma
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Abhimanyu Dev
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215 Jharkhand, India
| | - Barij Nayan Sinha
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215 Jharkhand, India
| | - Federico Brucoli
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, U.K
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Venkatesan Jayaprakash
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215 Jharkhand, India
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Chakraborty K, Kizhakkekalam VK, Joy M. Macrocyclic polyketides with siderophore mode of action from marine heterotrophic Shewanella algae: Prospective anti-infective leads attenuate drug-resistant pathogens. J Appl Microbiol 2020; 130:1552-1570. [PMID: 33006801 DOI: 10.1111/jam.14875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/19/2020] [Accepted: 09/24/2020] [Indexed: 02/01/2023]
Abstract
AIMS Biotechnological and chemical characterization of previously undescribed homologous siderophore-type macrocyclic polyketides from heterotrophic Shewanella algae Microbial Type Culture Collection (MTCC) 12715 affiliated with Rhodophycean macroalga Hypnea valentiae of marine origin, with significant anti-infective potential against drug-resistant pathogens. METHODS AND RESULTS The heterotrophic bacterial strain in symbiotic association with intertidal macroalga H. valentiae was isolated to homogeneity in a culture-dependent method and screened for bioactivities by spot-over-lawn assay. The bacterial organic extract was purified and characterized by extensive chromatographic and spectroscopic methods, respectively, and was assessed for antibacterial activities with disc diffusion and microtube dilution methods. The macrocyclic polyketide compounds exhibited wide-spectrum of anti-infective potential against clinically significant vancomycin-resistant Enterococcus faecalis (VREfs), methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Klebsiella pneumonia with minimum inhibitory concentration of about 1-3 µg ml-1 , insomuch as the antibiotics chloramphenicol and ampicillin were active at ≥6·25 µg ml-1 . The studied compounds unveiled Fe3+ chelating activity, which designated that their prospective anti-infective activities against the pathogens could be due to their siderophore mechanism of action. In support of that, the bacterium exhibited siderophore production on bioassay involving the cast upon culture agar plate, and the presence of siderophore biosynthetic gene (≈1000 bp) (MF 981936) further corroborated the inference. In silico molecular modelling with penicillin-binding protein (PBP2a) coded by mecA genes of MRSA (docking score -11·68 to -12·69 kcal mol-1 ) verified their in vitro antibacterial activities. Putative biosynthetic pathway of macrocyclic polyketides through stepwise decarboxylative condensation initiated by malonate-acyl carrier protein further validated their structural and molecular attributes. CONCLUSIONS The studied siderophore-type macrocyclic polyketides from S. algae MTCC 12715 with significant anti-infective potential could be considered as promising candidates for pharmaceutical and biotechnological applications, especially against emerging multidrug-resistant pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY This study exhibited the heterotrophic bacteria in association with intertidal macroalga as propitious biological resources to biosynthesize novel antibacterial agents.
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Affiliation(s)
- K Chakraborty
- Marine Bioprospecting Section of Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.,Faculty of Marine Sciences, Cochin University of Science and Technology, Kerala State, Lakeside Campus, Cochin, India
| | - V K Kizhakkekalam
- Marine Bioprospecting Section of Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.,Faculty of Marine Sciences, Cochin University of Science and Technology, Kerala State, Lakeside Campus, Cochin, India
| | - M Joy
- Marine Bioprospecting Section of Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.,Faculty of Marine Sciences, Cochin University of Science and Technology, Kerala State, Lakeside Campus, Cochin, India
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Das R, Gayakvad B, Shinde SD, Rani J, Jain A, Sahu B. Ultrashort Peptides—A Glimpse into the Structural Modifications and Their Applications as Biomaterials. ACS APPLIED BIO MATERIALS 2020; 3:5474-5499. [DOI: 10.1021/acsabm.0c00544] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Rudradip Das
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
| | - Bhavinkumar Gayakvad
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
| | - Suchita Dattatray Shinde
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
| | - Jyoti Rani
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
| | - Alok Jain
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
| | - Bichismita Sahu
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India
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Ganesh PS, Vishnupriya S, Vadivelu J, Mariappan V, Vellasamy KM, Shankar EM. Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing-controlled virulence factors, biofilm, and inhibitors. Microbiol Immunol 2020; 64:87-98. [PMID: 31769530 DOI: 10.1111/1348-0421.12762] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/25/2022]
Abstract
Burkholderia cepacia complex (Bcc) are opportunistic pathogens implicated with nosocomial infections, and high rates of morbidity and mortality, especially in individuals with cystic fibrosis (CF). B. cepacia are naturally resistant to different classes of antibiotics, and can subvert the host innate immune responses by producing quorum sensing (QS) controlled virulence factors and biofilms. It still remains a conundrum as to how exactly the bacterium survives the intracellular environment within the host cells of CF patients and immunocompromised individuals although the bacterium can invade human lung epithelial cells, neutrophils, and murine macrophages. The mechanisms associated with intracellular survival in the airway epithelial cells and the role of QS and virulence factors in B. cepacia infections in cystic fibrosis remain largely unclear. The current review focuses on understanding the role of QS-controlled virulence factors and biofilms, and provides additional impetus to understanding the potentials of QS-inhibitory strategies against B. cepacia.
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Affiliation(s)
- Pitchaipillai Sankar Ganesh
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Sivakumar Vishnupriya
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kumutha M Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Esaki M Shankar
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
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Gulick AM, Aldrich CC. Trapping interactions between catalytic domains and carrier proteins of modular biosynthetic enzymes with chemical probes. Nat Prod Rep 2019; 35:1156-1184. [PMID: 30046790 DOI: 10.1039/c8np00044a] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to early 2018 The Nonribosomal Peptide Synthetases (NRPSs) and Polyketide Synthases (PKSs) are families of modular enzymes that produce a tremendous diversity of natural products, with antibacterial, antifungal, immunosuppressive, and anticancer activities. Both enzymes utilize a fascinating modular architecture in which the synthetic intermediates are covalently attached to a peptidyl- or acyl-carrier protein that is delivered to catalytic domains for natural product elongation, modification, and termination. An investigation of the structural mechanism therefore requires trapping the often transient interactions between the carrier and catalytic domains. Many novel chemical probes have been produced to enable the structural and functional investigation of multidomain NRPS and PKS structures. This review will describe the design and implementation of the chemical tools that have proven to be useful in biochemical and biophysical studies of these natural product biosynthetic enzymes.
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Affiliation(s)
- Andrew M Gulick
- University at Buffalo, Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, 955 Main St, Buffalo, NY 14203, USA.
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Lux MC, Standke LC, Tan DS. Targeting adenylate-forming enzymes with designed sulfonyladenosine inhibitors. J Antibiot (Tokyo) 2019; 72:325-349. [PMID: 30982830 PMCID: PMC6594144 DOI: 10.1038/s41429-019-0171-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/19/2019] [Accepted: 02/26/2019] [Indexed: 02/07/2023]
Abstract
Adenylate-forming enzymes are a mechanistic superfamily that are involved in diverse biochemical pathways. They catalyze ATP-dependent activation of carboxylic acid substrates as reactive acyl adenylate (acyl-AMP) intermediates and subsequent coupling to various nucleophiles to generate ester, thioester, and amide products. Inspired by natural products, acyl sulfonyladenosines (acyl-AMS) that mimic the tightly bound acyl-AMP reaction intermediates have been developed as potent inhibitors of adenylate-forming enzymes. This simple yet powerful inhibitor design platform has provided a wide range of biological probes as well as several therapeutic lead compounds. Herein, we provide an overview of the nine structural classes of adenylate-forming enzymes and examples of acyl-AMS inhibitors that have been developed for each.
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Affiliation(s)
- Michaelyn C Lux
- Tri-Institutional PhD Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA
| | - Lisa C Standke
- Pharmacology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA
| | - Derek S Tan
- Tri-Institutional PhD Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA. .,Pharmacology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA. .,Chemical Biology Program, Sloan Kettering Institute, and Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
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12
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Bythrow GV, Mohandas P, Guney T, Standke LC, Germain GA, Lu X, Ji C, Levendosky K, Chavadi SS, Tan DS, Quadri LEN. Kinetic Analyses of the Siderophore Biosynthesis Inhibitor Salicyl-AMS and Analogues as MbtA Inhibitors and Antimycobacterial Agents. Biochemistry 2019; 58:833-847. [PMID: 30582694 DOI: 10.1021/acs.biochem.8b01153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
There is a paramount need for expanding the drug armamentarium to counter the growing problem of drug-resistant tuberculosis. Salicyl-AMS, an inhibitor of salicylic acid adenylation enzymes, is a first-in-class antibacterial lead compound for the development of tuberculosis drugs targeting the biosynthesis of salicylic-acid-derived siderophores. In this study, we determined the Ki of salicyl-AMS for inhibition of the salicylic acid adenylation enzyme MbtA from Mycobacterium tuberculosis (MbtAtb), designed and synthesized two new salicyl-AMS analogues to probe structure-activity relationships (SAR), and characterized these two analogues alongside salicyl-AMS and six previously reported analogues in biochemical and cell-based studies. The biochemical studies included determination of kinetic parameters ( Kiapp, konapp, koff, and tR) and analysis of the mechanism of inhibition. For these studies, we optimized production and purification of recombinant MbtAtb, for which Km and kcat values were determined, and used the enzyme in conjunction with an MbtAtb-optimized, continuous, spectrophotometric assay for MbtA activity and inhibition. The cell-based studies provided an assessment of the antimycobacterial activity and postantibiotic effect of the nine MbtAtb inhibitors. The antimycobacterial properties were evaluated using a strain of nonpathogenic, fast-growing Mycobacterium smegmatis that was genetically engineered for MbtAtb-dependent susceptibility to MbtA inhibitors. This convenient model system greatly facilitated the cell-based studies by bypassing the methodological complexities associated with the use of pathogenic, slow-growing M. tuberculosis. Collectively, these studies provide new information on the mechanism of inhibition of MbtAtb by salicyl-AMS and eight analogues, afford new SAR insights for these inhibitors, and highlight several suitable candidates for future preclinical evaluation.
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Affiliation(s)
- Glennon V Bythrow
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Biology Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Poornima Mohandas
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Biology Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Tezcan Guney
- Chemical Biology Program, Sloan Kettering Institute , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States
| | - Lisa C Standke
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States
| | - Gabrielle A Germain
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Biology Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Xuequan Lu
- Chemical Biology Program, Sloan Kettering Institute , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States
| | - Cheng Ji
- Chemical Biology Program, Sloan Kettering Institute , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States
| | - Keith Levendosky
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Biology Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Sivagami Sundaram Chavadi
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States
| | - Derek S Tan
- Chemical Biology Program, Sloan Kettering Institute , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States.,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States.,Tri-Institutional Research Program , Memorial Sloan Kettering Cancer Center , 1275 York Avenue , New York , New York 10065 , United States
| | - Luis E N Quadri
- Department of Biology, Brooklyn College , City University of New York , 2900 Bedford Avenue , Brooklyn , New York 11210 , United States.,Biology Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States.,Biochemistry Program, Graduate Center , City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
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13
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Patel K, Butala S, Khan T, Suvarna V, Sherje A, Dravyakar B. Mycobacterial siderophore: A review on chemistry and biology of siderophore and its potential as a target for tuberculosis. Eur J Med Chem 2018; 157:783-790. [PMID: 30142615 DOI: 10.1016/j.ejmech.2018.08.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 10/28/2022]
Abstract
Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis is known to secrete low molecular mass compounds called siderophores especially under low iron conditions to chelate iron from host environment. Iron is essential for growth and other essential processes to sustain life of the bacterium in the host. Hence targeting siderophore is considered to be an alternative approach to prevent further virulence of bacterium into the host. This review article presents classification of siderophores, their role in transporting iron into the tubercular cell, biosynthesis of mycobactins, viability of siderophore as a therapeutic target and also focuses on overview on various approaches to target siderophore. The approaches encompass mutation effect on genes involved in siderophore recycling, synthetic as well as natural compounds that can inhibit further spread of bacterium by targeting siderophore.
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Affiliation(s)
- Kavitkumar Patel
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India.
| | - Sahil Butala
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India
| | - Tabassum Khan
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India
| | - Vasanti Suvarna
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India
| | - Atul Sherje
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India
| | - Bhushan Dravyakar
- Department of Pharmaceutical Chemistry, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, 400 056, India
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14
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Chakraborty K, Thilakan B, Kizhakkekalam V. Antibacterial aryl-crowned polyketide from Bacillus subtilis
associated with seaweed Anthophycus longifolius. J Appl Microbiol 2017; 124:108-125. [DOI: 10.1111/jam.13627] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 09/25/2017] [Accepted: 10/26/2017] [Indexed: 11/30/2022]
Affiliation(s)
- K. Chakraborty
- Marine Biotechnology Division; Central Marine Fisheries Research Institute; Cochin Kerala India
| | - B. Thilakan
- Marine Biotechnology Division; Central Marine Fisheries Research Institute; Cochin Kerala India
| | - V.K. Kizhakkekalam
- Marine Biotechnology Division; Central Marine Fisheries Research Institute; Cochin Kerala India
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15
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Bilitewski U, Blodgett JAV, Duhme-Klair AK, Dallavalle S, Laschat S, Routledge A, Schobert R. Chemical and Biological Aspects of Nutritional Immunity-Perspectives for New Anti-Infectives that Target Iron Uptake Systems. Angew Chem Int Ed Engl 2017; 56:14360-14382. [PMID: 28439959 DOI: 10.1002/anie.201701586] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Indexed: 12/22/2022]
Abstract
Upon bacterial infection, one of the defense mechanisms of the host is the withdrawal of essential metal ions, in particular iron, which leads to "nutritional immunity". However, bacteria have evolved strategies to overcome iron starvation, for example, by stealing iron from the host or other bacteria through specific iron chelators with high binding affinity. Fortunately, these complex interactions between the host and pathogen that lead to metal homeostasis provide several opportunities for interception and, thus, allow the development of novel antibacterial compounds. This Review focuses on iron, discusses recent highlights, and gives some future perspectives which are relevant in the fight against antibiotic resistance.
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Affiliation(s)
- Ursula Bilitewski
- AG Compound Profiling and Screening, Helmholtz Zentrum für Infektionsforschung, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Joshua A V Blodgett
- Department of Biology, Washington University, St. Louis, MO, 63130-4899, USA
| | | | - Sabrina Dallavalle
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, I-20133, Milano, Italy
| | - Sabine Laschat
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 7, 0569, Stuttgart, Germany
| | - Anne Routledge
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Rainer Schobert
- Organische Chemie I, Universität Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
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16
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Bilitewski U, Blodgett JAV, Duhme-Klair AK, Dallavalle S, Laschat S, Routledge A, Schobert R. Chemische und biologische Aspekte von “Nutritional Immunity” - Perspektiven für neue Antiinfektiva mit Fokus auf bakterielle Eisenaufnahmesysteme. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701586] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ursula Bilitewski
- AG Compound Profiling and Screening; Helmholtz-Zentrum für Infektionsforschung; Inhoffenstraße 7 38124 Braunschweig Deutschland
| | | | | | - Sabrina Dallavalle
- Department of Food, Environmental and Nutritional Sciences; Università degli Studi di Milano; I-20133 Milano Italien
| | - Sabine Laschat
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55, 7 0569 Stuttgart Deutschland
| | - Anne Routledge
- Department of Chemistry; University of York, Heslington; York YO10 5DD Großbritannien
| | - Rainer Schobert
- Organische Chemie I; Universität Bayreuth; Universitätsstraße 30 95447 Bayreuth Deutschland
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17
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Abstract
Covering: up to 2017.Natural products are important secondary metabolites produced by bacterial and fungal species that play important roles in cellular growth and signaling, nutrient acquisition, intra- and interspecies communication, and virulence. A subset of natural products is produced by nonribosomal peptide synthetases (NRPSs), a family of large, modular enzymes that function in an assembly line fashion. Because of the pharmaceutical activity of many NRPS products, much effort has gone into the exploration of their biosynthetic pathways and the diverse products they make. Many interesting NRPS pathways have been identified and characterized from both terrestrial and marine bacterial sources. Recently, several NRPS pathways in human commensal bacterial species have been identified that produce molecules with antibiotic activity, suggesting another source of interesting NRPS pathways may be the commensal and pathogenic bacteria that live on the human body. The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) have been identified as a significant cause of human bacterial infections that are frequently multidrug resistant. The emerging resistance profile of these organisms has prompted calls from multiple international agencies to identify novel antibacterial targets and develop new approaches to treat infections from ESKAPE pathogens. Each of these species contains several NRPS biosynthetic gene clusters. While some have been well characterized and produce known natural products with important biological roles in microbial physiology, others have yet to be investigated. This review catalogs the NRPS pathways of ESKAPE pathogens. The exploration of novel NRPS products may lead to a better understanding of the chemical communication used by human pathogens and potentially to the discovery of novel therapeutic approaches.
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Affiliation(s)
- Andrew M Gulick
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA.
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18
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Dashti Y, Grkovic T, Abdelmohsen UR, Hentschel U, Quinn RJ. Actinomycete Metabolome Induction/Suppression with N-Acetylglucosamine. JOURNAL OF NATURAL PRODUCTS 2017; 80:828-836. [PMID: 28355070 DOI: 10.1021/acs.jnatprod.6b00673] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The metabolite profiles of three sponge-derived actinomycetes, namely, Micromonospora sp. RV43, Rhodococcus sp. RV157, and Actinokineospora sp. EG49 were investigated after elicitation with N-acetyl-d-glucosamine. 1H NMR fingerprint methodology was utilized to study the differences in the metabolic profiles of the bacterial extracts before and after elicitation. Our study found that the addition of N-acetyl-d-glucosamine modified the secondary metabolite profiles of the three investigated actinomycete isolates. N-Acetyl-d-glucosamine induced the production of 3-formylindole (11) and guaymasol (12) in Micromonospora sp. RV43, the siderophore bacillibactin 16, and surfactin antibiotic 17 in Rhodococcus sp. RV157 and increased the production of minor metabolites actinosporins E-H (21-24) in Actinokineospora sp. EG49. These results highlight the use of NMR fingerprinting to detect changes in metabolism following addition of N-acetyl-d-glucosamine. N-Acetyl-d-glucosamine was shown to have multiple effects including suppression of metabolites, induction of new metabolites, and increased production of minor compounds.
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Affiliation(s)
- Yousef Dashti
- Eskitis Institute for Drug Discovery, Griffith University , Brisbane, QLD 4111 Australia
| | - Tanja Grkovic
- Eskitis Institute for Drug Discovery, Griffith University , Brisbane, QLD 4111 Australia
| | - Usama Ramadan Abdelmohsen
- Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg , Julius-von-Sachs-Platz 3, D-97082 Würzburg, Germany
| | - Ute Hentschel
- Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg , Julius-von-Sachs-Platz 3, D-97082 Würzburg, Germany
| | - Ronald J Quinn
- Eskitis Institute for Drug Discovery, Griffith University , Brisbane, QLD 4111 Australia
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Abstract
The nonribosomal peptide synthetases are modular enzymes that catalyze synthesis of important peptide products from a variety of standard and non-proteinogenic amino acid substrates. Within a single module are multiple catalytic domains that are responsible for incorporation of a single residue. After the amino acid is activated and covalently attached to an integrated carrier protein domain, the substrates and intermediates are delivered to neighboring catalytic domains for peptide bond formation or, in some modules, chemical modification. In the final module, the peptide is delivered to a terminal thioesterase domain that catalyzes release of the peptide product. This multi-domain modular architecture raises questions about the structural features that enable this assembly line synthesis in an efficient manner. The structures of the core component domains have been determined and demonstrate insights into the catalytic activity. More recently, multi-domain structures have been determined and are providing clues to the features of these enzyme systems that govern the functional interaction between multiple domains. This chapter describes the structures of NRPS proteins and the strategies that are being used to assist structural studies of these dynamic proteins, including careful consideration of domain boundaries for generation of truncated proteins and the use of mechanism-based inhibitors that trap interactions between the catalytic and carrier protein domains.
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20
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Novosjolova I, Bizdēna Ē, Turks M. Synthesis and Applications of Azolylpurine and Azolylpurine Nucleoside Derivatives. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403527] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Quadri LEN. Biosynthesis of mycobacterial lipids by polyketide synthases and beyond. Crit Rev Biochem Mol Biol 2014; 49:179-211. [DOI: 10.3109/10409238.2014.896859] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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22
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Viti C, Marchi E, Decorosi F, Giovannetti L. Molecular mechanisms of Cr(VI) resistance in bacteria and fungi. FEMS Microbiol Rev 2013; 38:633-59. [PMID: 24188101 DOI: 10.1111/1574-6976.12051] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/13/2013] [Accepted: 10/28/2013] [Indexed: 11/28/2022] Open
Abstract
Hexavalent chromium [Cr(VI)] contamination is one of the main problems of environmental protection because the Cr(VI) is a hazard to human health. The Cr(VI) form is highly toxic, mutagenic, and carcinogenic, and it spreads widely beyond the site of initial contamination because of its mobility. Cr(VI), crossing the cellular membrane via the sulfate uptake pathway, generates active intermediates Cr(V) and/or Cr(IV), free radicals, and Cr(III) as the final product. Cr(III) affects DNA replication, causes mutagenesis, and alters the structure and activity of enzymes, reacting with their carboxyl and thiol groups. To persist in Cr(VI)-contaminated environments, microorganisms must have efficient systems to neutralize the negative effects of this form of chromium. The systems involve detoxification or repair strategies such as Cr(VI) efflux pumps, Cr(VI) reduction to Cr(III), and activation of enzymes involved in the ROS detoxifying processes, repair of DNA lesions, sulfur metabolism, and iron homeostasis. This review provides an overview of the processes involved in bacterial and fungal Cr(VI) resistance that have been identified through 'omics' studies. A comparative analysis of the described molecular mechanisms is offered and compared with the cellular evidences obtained using classical microbiological approaches.
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Affiliation(s)
- Carlo Viti
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente - sezione di Microbiologia, Università degli Studi di Firenze, Florence, Italy
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Duckworth BP, Nelson KM, Aldrich CC. Adenylating enzymes in Mycobacterium tuberculosis as drug targets. Curr Top Med Chem 2012; 12:766-96. [PMID: 22283817 DOI: 10.2174/156802612799984571] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 11/08/2011] [Indexed: 11/22/2022]
Abstract
Adenylation or adenylate-forming enzymes (AEs) are widely found in nature and are responsible for the activation of carboxylic acids to intermediate acyladenylates, which are mixed anhydrides of AMP. In a second reaction, AEs catalyze the transfer of the acyl group of the acyladenylate onto a nucleophilic amino, alcohol, or thiol group of an acceptor molecule leading to amide, ester, and thioester products, respectively. Mycobacterium tuberculosis encodes for more than 60 adenylating enzymes, many of which represent potential drug targets due to their confirmed essentiality or requirement for virulence. Several strategies have been used to develop potent and selective AE inhibitors including highthroughput screening, fragment-based screening, and the rationale design of bisubstrate inhibitors that mimic the acyladenylate. In this review, a comprehensive analysis of the mycobacterial adenylating enzymes will be presented with a focus on the identification of small molecule inhibitors. Specifically, this review will cover the aminoacyl tRNAsynthetases (aaRSs), MenE required for menaquinone synthesis, the FadD family of enzymes including the fatty acyl- AMP ligases (FAAL) and the fatty acyl-CoA ligases (FACLs) involved in lipid metabolism, and the nonribosomal peptide synthetase adenylation enzyme MbtA that is necessary for mycobactin synthesis. Additionally, the enzymes NadE, GuaA, PanC, and MshC involved in the respective synthesis of NAD, guanine, pantothenate, and mycothiol will be discussed as well as BirA that is responsible for biotinylation of the acyl CoA-carboxylases.
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Hur GH, Vickery CR, Burkart MD. Explorations of catalytic domains in non-ribosomal peptide synthetase enzymology. Nat Prod Rep 2012; 29:1074-98. [PMID: 22802156 DOI: 10.1039/c2np20025b] [Citation(s) in RCA: 214] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many pharmaceuticals on the market today belong to a large class of natural products called nonribosomal peptides (NRPs). Originating from bacteria and fungi, these peptide-based natural products consist not only of the 20 canonical L-amino acids, but also non-proteinogenic amino acids, heterocyclic rings, sugars, and fatty acids, generating tremendous chemical diversity. As a result, these secondary metabolites exhibit a broad array of bioactivity, ranging from antimicrobial to anticancer. The biosynthesis of these complex compounds is carried out by large multimodular megaenzymes called nonribosomal peptide synthetases (NRPSs). Each module is responsible for incorporation of a monomeric unit into the natural product peptide and is composed of individual domains that perform different catalytic reactions. Biochemical and bioinformatic investigations of these enzymes have uncovered the key principles of NRP synthesis, expanding the pharmaceutical potential of their enzymatic processes. Progress has been made in the manipulation of this biosynthetic machinery to develop new chemoenzymatic approaches for synthesizing novel pharmaceutical agents with increased potency. This review focuses on the recent discoveries and breakthroughs in the structural elucidation, molecular mechanism, and chemical biology underlying the discrete domains within NRPSs.
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Tatham E, Sundaram Chavadi S, Mohandas P, Edupuganti UR, Angala SK, Chatterjee D, Quadri LEN. Production of mycobacterial cell wall glycopeptidolipids requires a member of the MbtH-like protein family. BMC Microbiol 2012; 12:118. [PMID: 22726990 PMCID: PMC3537567 DOI: 10.1186/1471-2180-12-118] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 05/07/2012] [Indexed: 12/22/2022] Open
Abstract
Background Glycopeptidolipids (GPLs) are among the major free glycolipid components of the outer membrane of several saprophytic and clinically-relevant Mycobacterium species. The architecture of GPLs is based on a constant tripeptide-amino alcohol core of nonribosomal peptide synthetase origin that is N-acylated with a 3-hydroxy/methoxy acyl chain synthesized by a polyketide synthase and further decorated with variable glycosylation patterns built from methylated and acetylated sugars. GPLs have been implicated in many aspects of mycobacterial biology, thus highlighting the significance of gaining an understanding of their biosynthesis. Our bioinformatics analysis revealed that every GPL biosynthetic gene cluster known to date contains a gene (referred herein to as gplH) encoding a member of the MbtH-like protein family. Herein, we sought to conclusively establish whether gplH was required for GPL production. Results Deletion of gplH, a gene clustered with nonribosomal peptide synthetase-encoding genes in the GPL biosynthetic gene cluster of Mycobacterium smegmatis, produced a GPL deficient mutant. Transformation of this mutant with a plasmid expressing gplH restored GPL production. Complementation was also achieved by plasmid-based constitutive expression of mbtH, a paralog of gplH found in the biosynthetic gene cluster for production of the siderophore mycobactin of M. smegmatis. Further characterization of the gplH mutant indicated that it also displayed atypical colony morphology, lack of sliding motility, altered capacity for biofilm formation, and increased drug susceptibility. Conclusions Herein, we provide evidence formally establishing that gplH is essential for GPL production in M. smegmatis. Inactivation of gplH also leads to a pleiotropic phenotype likely to arise from alterations in the cell envelope due to the lack of GPLs. While genes encoding MbtH-like proteins have been shown to be needed for production of siderophores and antibiotics, our study presents the first case of one such gene proven to be required for production of a cell wall component. Furthermore, our results provide the first example of a mbtH-like gene with confirmed functional role in a member of the Mycobacterium genus. Altogether, our findings demonstrate a critical role of gplH in mycobacterial biology and advance our understanding of the genetic requirements for the biosynthesis of an important group of constituents of the mycobacterial outer membrane.
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Affiliation(s)
- Elizabeth Tatham
- Department of Biology, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
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Wen Y, Wu X, Teng Y, Qian C, Zhan Z, Zhao Y, Li O. Identification and analysis of the gene cluster involved in biosynthesis of paenibactin, a catecholate siderophore produced by Paenibacillus elgii B69. Environ Microbiol 2011; 13:2726-37. [DOI: 10.1111/j.1462-2920.2011.02542.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The mycobactin siderophore system is present in many Mycobacterium species, including M. tuberculosis and other clinically relevant mycobacteria. This siderophore system is believed to be utilized by both pathogenic and nonpathogenic mycobacteria for iron acquisition in both in vivo and ex vivo iron-limiting environments, respectively. Several M. tuberculosis genes located in a so-called mbt gene cluster have been predicted to be required for the biosynthesis of the core scaffold of mycobactin based on sequence analysis. A systematic and controlled mutational analysis probing the hypothesized essential nature of each of these genes for mycobactin production has been lacking. The degree of conservation of mbt gene cluster orthologs remains to be investigated as well. In this study, we sought to conclusively establish whether each of nine mbt genes was required for mycobactin production and to examine the conservation of gene clusters orthologous to the M. tuberculosis mbt gene cluster in other bacteria. We report a systematic mutational analysis of the mbt gene cluster ortholog found in Mycobacterium smegmatis. This mutational analysis demonstrates that eight of the nine mbt genes investigated are essential for mycobactin production. Our genome mining and phylogenetic analyses reveal the presence of orthologous mbt gene clusters in several bacterial species. These gene clusters display significant organizational differences originating from an intricate evolutionary path that might have included horizontal gene transfers. Altogether, the findings reported herein advance our understanding of the genetic requirements for the biosynthesis of an important mycobacterial secondary metabolite with relevance to virulence.
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Ferreras JA, Gupta A, Amin ND, Basu A, Sinha BN, Worgall S, Jayaprakash V, Quadri LEN. Chemical scaffolds with structural similarities to siderophores of nonribosomal peptide-polyketide origin as novel antimicrobials against Mycobacterium tuberculosis and Yersinia pestis. Bioorg Med Chem Lett 2011; 21:6533-7. [PMID: 21940166 DOI: 10.1016/j.bmcl.2011.08.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/09/2011] [Accepted: 08/11/2011] [Indexed: 11/26/2022]
Abstract
Mycobacterium tuberculosis (Mtb) and Yersinia pestis (Yp) produce siderophores with scaffolds of nonribosomal peptide-polyketide origin. Compounds with structural similarities to these siderophores were synthesized and evaluated as antimicrobials against Mtb and Yp under iron-limiting conditions mimicking the iron scarcity these pathogens encounter in the host and under standard iron-rich conditions. Several new antimicrobials were identified, including some with increased potency in the iron-limiting condition. Our study illustrates the possibility of screening compound libraries in both iron-rich and iron-limiting conditions to identify antimicrobials that may selectively target iron scarcity-adapted bacteria and highlights the usefulness of building combinatorial libraries of compounds having scaffolds with structural similarities to siderophores to feed into antimicrobial screening programs.
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Affiliation(s)
- Julian A Ferreras
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
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Asghar AH, Shastri S, Dave E, Wowk I, Agnoli K, Cook AM, Thomas MS. The pobA gene of Burkholderia cenocepacia encodes a Group I Sfp-type phosphopantetheinyltransferase required for biosynthesis of the siderophores ornibactin and pyochelin. Microbiology (Reading) 2011; 157:349-361. [DOI: 10.1099/mic.0.045559-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The opportunistic pathogen Burkholderia cenocepacia produces the siderophores ornibactin and pyochelin under iron-restricted conditions. Biosynthesis of both siderophores requires the involvement of non-ribosomal peptide synthetases (NRPSs). Using a transposon containing the lacZ reporter gene, two B. cenocepacia mutants were isolated which were deficient in siderophore production. Mutant IW10 was shown to produce normal amounts of ornibactin but only trace amounts of pyochelin, whereas synthesis of both siderophores was abolished in AHA27. Growth of AHA27, but not IW10, was inhibited under iron-restricted conditions. In both mutants, the transposon had integrated into the pobA gene, which encodes a polypeptide exhibiting similarity to the Sfp-type phosphopantetheinyltransferases (PPTases). These enzymes are responsible for activation of NRPSs by the covalent attachment of the 4′-phosphopantetheine (P-pant) moiety of coenzyme A. Previously characterized PPTase genes from other bacteria were shown to efficiently complement both mutants for siderophore production when provided in trans. The B. cenocepacia pobA gene was also able to efficiently complement an Escherichia coli entD mutant for production of the siderophore enterobactin. Using mutant IW10, in which the lacZ gene carried by the transposon is inserted in the same orientation as pobA, it was shown that pobA is not appreciably iron-regulated. Finally, we confirmed that Sfp-type bacterial PPTases can be subdivided into two distinct groups, and we present the amino acid signature sequences which characterize each of these groups.
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Affiliation(s)
- Atif H. Asghar
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Sravanthi Shastri
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Emma Dave
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Irena Wowk
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Kirsty Agnoli
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Anne M. Cook
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Mark S. Thomas
- Department of Infection and Immunity, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
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Drake EJ, Duckworth BP, Neres J, Aldrich CC, Gulick AM. Biochemical and structural characterization of bisubstrate inhibitors of BasE, the self-standing nonribosomal peptide synthetase adenylate-forming enzyme of acinetobactin synthesis. Biochemistry 2010; 49:9292-305. [PMID: 20853905 DOI: 10.1021/bi101226n] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The human pathogen Acinetobacter baumannii produces a siderophore called acinetobactin that is derived from one molecule each of threonine, histidine, and 2,3-dihydroxybenzoic acid (DHB). The activity of several nonribosomal peptide synthetase (NRPS) enzymes is used to combine the building blocks into the final molecule. The acinetobactin synthesis pathway initiates with a self-standing adenylation enzyme, BasE, that activates the DHB molecule and covalently transfers it to the pantetheine cofactor of an aryl-carrier protein of BasF, a strategy that is shared with many siderophore-producing NRPS clusters. In this reaction, DHB reacts with ATP to form the aryl adenylate and pyrophosphate. In a second partial reaction, the DHB is transferred to the carrier protein. Inhibitors of BasE and related enzymes have been identified that prevent growth of bacteria on iron-limiting media. Recently, a new inhibitor of BasE has been identified via high-throughput screening using a fluorescence polarization displacement assay. We present here biochemical and structural studies to examine the binding mode of this inhibitor. The kinetics of the wild-type BasE enzyme is shown, and inhibition studies demonstrate that the new compound exhibits competitive inhibition against both ATP and 2,3-dihydroxybenzoate. Structural examination of BasE bound to this inhibitor illustrates a novel binding mode in which the phenyl moiety partially fills the enzyme pantetheine binding tunnel. Structures of rationally designed bisubstrate inhibitors are also presented.
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Affiliation(s)
- Eric J Drake
- Hauptman-Woodward Institute and Department of Structural Biology, University at Buffalo, Buffalo, NY 14203-1102, USA
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31
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Thompson DK, Chourey K, Wickham GS, Thieman SB, VerBerkmoes NC, Zhang B, McCarthy AT, Rudisill MA, Shah M, Hettich RL. Proteomics reveals a core molecular response of Pseudomonas putida F1 to acute chromate challenge. BMC Genomics 2010; 11:311. [PMID: 20482812 PMCID: PMC2996968 DOI: 10.1186/1471-2164-11-311] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Accepted: 05/19/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pseudomonas putida is a model organism for bioremediation because of its remarkable metabolic versatility, extensive biodegradative functions, and ubiquity in contaminated soil environments. To further the understanding of molecular pathways responding to the heavy metal chromium(VI) [Cr(VI)], the proteome of aerobically grown, Cr(VI)-stressed P. putida strain F1 was characterized within the context of two disparate nutritional environments: rich (LB) media and minimal (M9L) media containing lactate as the sole carbon source. RESULTS Growth studies demonstrated that F1 sensitivity to Cr(VI) was impacted substantially by nutrient conditions, with a carbon-source-dependent hierarchy (lactate > glucose >> acetate) observed in minimal media. Two-dimensional HPLC-MS/MS was employed to identify differential proteome profiles generated in response to 1 mM chromate under LB and M9L growth conditions. The immediate response to Cr(VI) in LB-grown cells was up-regulation of proteins involved in inorganic ion transport, secondary metabolite biosynthesis and catabolism, and amino acid metabolism. By contrast, the chromate-responsive proteome derived under defined minimal growth conditions was characterized predominantly by up-regulated proteins related to cell envelope biogenesis, inorganic ion transport, and motility. TonB-dependent siderophore receptors involved in ferric iron acquisition and amino acid adenylation domains characterized up-regulated systems under LB-Cr(VI) conditions, while DNA repair proteins and systems scavenging sulfur from alternative sources (e.g., aliphatic sulfonates) tended to predominate the up-regulated proteome profile obtained under M9L-Cr(VI) conditions. CONCLUSIONS Comparative analysis indicated that the core molecular response to chromate, irrespective of the nutritional conditions tested, comprised seven up-regulated proteins belonging to six different functional categories including transcription, inorganic ion transport/metabolism, and amino acid transport/metabolism. These proteins might potentially serve as indicators of chromate stress in natural microbial communities.
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Affiliation(s)
- Dorothea K Thompson
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
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Sikora AL, Cahill SM, Blanchard JS. Enterobactin synthetase-catalyzed formation of P(1),P(3)-diadenosine-5'-tetraphosphate. Biochemistry 2009; 48:10827-9. [PMID: 19852513 DOI: 10.1021/bi901680m] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The EntE enzyme, involved in the synthesis of the iron siderophore enterobactin, catalyzes the adenylation of 2,3-dihydroxybenzoic acid, followed by its transfer to the phosphopantetheine arm of holo-EntB, an aryl carrier protein. In the absence of EntB, EntE catalyzes the formation of Ap(4)A, a molecule that is implicated in regulating cell division during oxidative stress. We propose that the expression of EntE during iron starvation produces Ap(4)A to slow growth until intracellular iron stores can be restored.
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Affiliation(s)
- Alison L Sikora
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Gulick AM. Conformational dynamics in the Acyl-CoA synthetases, adenylation domains of non-ribosomal peptide synthetases, and firefly luciferase. ACS Chem Biol 2009; 4:811-27. [PMID: 19610673 DOI: 10.1021/cb900156h] [Citation(s) in RCA: 317] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ANL superfamily of adenylating enzymes contains acyl- and aryl-CoA synthetases, firefly luciferase, and the adenylation domains of the modular non-ribosomal peptide synthetases (NRPSs). Members of this family catalyze two partial reactions: the initial adenylation of a carboxylate to form an acyl-AMP intermediate, followed by a second partial reaction, most commonly the formation of a thioester. Recent biochemical and structural evidence has been presented that supports the use by this enzyme family of a remarkable catalytic strategy for the two catalytic steps. The enzymes use a 140 degrees domain rotation to present opposing faces of the dynamic C-terminal domain to the active site for the different partial reactions. Support for this domain alternation strategy is presented along with an explanation of the advantage of this catalytic strategy for the reaction catalyzed by the ANL enzymes. Finally, the ramifications of this domain rotation in the catalytic cycle of the modular NRPS enzymes are discussed.
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Affiliation(s)
- Andrew M. Gulick
- Hauptman-Woodward Medical Research Institute and Department of Structural Biology, State University of New York at Buffalo, 700 Ellicott St., Buffalo, New York 14203-1102
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Fang X, Wallqvist A, Reifman J. A systems biology framework for modeling metabolic enzyme inhibition of Mycobacterium tuberculosis. BMC SYSTEMS BIOLOGY 2009; 3:92. [PMID: 19754970 PMCID: PMC2759933 DOI: 10.1186/1752-0509-3-92] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2009] [Accepted: 09/15/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND Because metabolism is fundamental in sustaining microbial life, drugs that target pathogen-specific metabolic enzymes and pathways can be very effective. In particular, the metabolic challenges faced by intracellular pathogens, such as Mycobacterium tuberculosis, residing in the infected host provide novel opportunities for therapeutic intervention. RESULTS We developed a mathematical framework to simulate the effects on the growth of a pathogen when enzymes in its metabolic pathways are inhibited. Combining detailed models of enzyme kinetics, a complete metabolic network description as modeled by flux balance analysis, and a dynamic cell population growth model, we quantitatively modeled and predicted the dose-response of the 3-nitropropionate inhibitor on the growth of M. tuberculosis in a medium whose carbon source was restricted to fatty acids, and that of the 5'-O-(N-salicylsulfamoyl) adenosine inhibitor in a medium with low-iron concentration. CONCLUSION The predicted results quantitatively reproduced the experimentally measured dose-response curves, ranging over three orders of magnitude in inhibitor concentration. Thus, by allowing for detailed specifications of the underlying enzymatic kinetics, metabolic reactions/constraints, and growth media, our model captured the essential chemical and biological factors that determine the effects of drug inhibition on in vitro growth of M. tuberculosis cells.
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Affiliation(s)
- Xin Fang
- Biotechnology HPC Software Applications Institute, Telemedicine and Advanced Technology Research Center, U,S, Army Medical Research and Materiel Command, Ft, Detrick, MD 21702, USA.
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Frederick RE, Mayfield JA, DuBois JL. Iron trafficking as an antimicrobial target. Biometals 2009; 22:583-93. [PMID: 19350396 PMCID: PMC3742301 DOI: 10.1007/s10534-009-9236-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
Abstract
Iron is essential for the survival of most organisms. Microbial iron acquisition depends on multiple, sometimes complex steps, many of which are not shared by higher eukaryotes. Depriving pathogenic microbes of iron is therefore a potential antimicrobial strategy. The following minireview briefly describes general elements in microbial iron uptake pathways and summarizes some of the current work aiming at their medicinal inhibition.
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Affiliation(s)
- Rosanne E Frederick
- Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556, USA
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Villiers BRM, Hollfelder F. Mapping the limits of substrate specificity of the adenylation domain of TycA. Chembiochem 2009; 10:671-82. [PMID: 19189362 DOI: 10.1002/cbic.200800553] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The catalytic potential of tyrocidine synthetase 1 (TycA) was probed by the kinetic characterization of its adenylation activity. We observed reactions with 30 substrates, thus suggesting some substrate promiscuity. However, although the TycA adenylation (A) domain was able to accommodate alternative substrates, their k(cat)/K(M) values ranged over six orders of magnitude. A comparison of the activities allowed the systematic mapping of the substrate specificity determinants of the TycA A-domain. Hydrophobicity plays a major role in the recognition of substrate analogues but can be combined with shape complementarity, conferring higher activity, and/or steric exclusion, leading to substantial discrimination against larger substrates. A comparison of the k(cat)/K(M) values of the TycA A-domain and phenylalanyl-tRNA synthetase showed that the level of discrimination was comparable in the two enzymes for the adenylation reaction and suggested that TycA was also subjected to high selective pressure. The specificity patterns observed and the quantification of alternative activities provide a basis for exploring possible paths for the future directed evolution of A-domain specificity.
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Affiliation(s)
- Benoit R M Villiers
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, UK
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Gupte A, Boshoff HI, Wilson DJ, Neres J, Labello NP, Somu RV, Xing C, Barry CE, Aldrich CC. Inhibition of siderophore biosynthesis by 2-triazole substituted analogues of 5'-O-[N-(salicyl)sulfamoyl]adenosine: antibacterial nucleosides effective against Mycobacterium tuberculosis. J Med Chem 2009; 51:7495-507. [PMID: 19053762 DOI: 10.1021/jm8008037] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis, biochemical, and biological evaluation of a systematic series of 2-triazole derivatives of 5'-O-[N-(salicyl)sulfamoyl]adenosine (Sal-AMS) are described as inhibitors of aryl acid adenylating enzymes (AAAE) involved in siderophore biosynthesis by Mycobacterium tuberculosis. Structure-activity relationships revealed a remarkable ability to tolerate a wide range of substituents at the 4-position of the triazole moiety, and a majority of the compounds possessed subnanomolar apparent inhibition constants. However, the in vitro potency did not always translate into whole cell biological activity against M. tuberculosis, suggesting that intrinsic resistance plays an important role in the observed activities. Additionally, the well-known valence tautomerism between 2-azidopurines and their fused tetrazole counterparts led to an unexpected facile acylation of the purine N-6 amino group.
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Affiliation(s)
- Amol Gupte
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Neres J, Wilson DJ, Celia L, Beck BJ, Aldrich CC. Aryl acid adenylating enzymes involved in siderophore biosynthesis: fluorescence polarization assay, ligand specificity, and discovery of non-nucleoside inhibitors via high-throughput screening. Biochemistry 2008; 47:11735-49. [PMID: 18928302 DOI: 10.1021/bi801625b] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The design and synthesis of a fluorescent probe Fl-Sal-AMS 6 based on the tight-binding inhibitor 5'- O-[ N-(salicyl)sulfamoyl]adenosine (Sal-AMS) is described for the aryl acid adenylating enzymes (AAAEs) known as MbtA, YbtE, EntE, VibE, DhbE, and BasE involved in siderophore biosynthesis from Mycobacterium tuberculosis, Yersinia pestis, Escherichia coli, Vibrio cholerae, Bacillus subtilis, and Acinetobacter baumannii, respectively. The probe was successfully used to develop a fluorescence polarization assay for these six AAAEs, and equilibrium dissociation constants were determined in direct binding experiments. Fl-Sal-AMS was effective for AAAEs that utilize salicylic acid or 2,3-dihydroxybenzoic acid as native substrates, with dissociation constants ranging from 9-369 nM, but was ineffective for AsbC, the AAAE from Bacillus anthracis, which activates 3,4-dihydroxybenzoic acid. Competitive binding experiments using a series of ligands including substrates, reaction products, and inhibitors provided the first comparative structure-activity relationships for AAAEs. The fluorescence polarization assay was then miniaturized to a 384-well plate format, and high-throughput screening was performed at the National Screening Laboratory for the Regional Centers of Excellence in Biodefense and Emerging Infectious Diseases (NSRB) against BasE, an AAAE from Acinetobacter baumannii involved in production of the siderophore acinetobactin. Several small molecule inhibitors with new chemotypes were identified, and compound 23 containing a pyrazolo[5,4- a]pyridine scaffold emerged as the most promising ligand with a K D of 78 nM, which was independently confirmed by isothermal calorimetry, and inhibition was also verified in an ATP-[ (32)P]-pyrophosphate exchange steady-state kinetic assay.
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Affiliation(s)
- João Neres
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Raza W, Wu H, Shah MAA, Shen Q. Retracted: A catechol type siderophore, bacillibactin: biosynthesis, regulation and transport in Bacillus subtilis. J Basic Microbiol 2008; 48. [PMID: 18785660 DOI: 10.1002/jobm.200800097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Retraction: The following article from the Journal of Basic Microbiology, "A catechol type siderophore, bacillibactin: biosynthesis, regulation and transport in Bacillus subtilis" by Waseem Raza, Hongsheng Wu, Muhammad Ali Abdullah Shah and Qirong Shen, published online on 11 September 2008 in Wiley InterScience (www.interscience.wiley.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Erika Kothe, and the publisher Wiley-VCH. The retraction has been agreed due to substantial overlap of the content of this article with previously published articles in other journals.The Journal of Basic Microbiology apologises to our readership.
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Affiliation(s)
- Waseem Raza
- College of Resource and Environmental Sciences, Nanjing Agriculture University, Nanjing, China
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40
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Cisar JS, Tan DS. Small molecule inhibition of microbial natural product biosynthesis-an emerging antibiotic strategy. Chem Soc Rev 2008; 37:1320-9. [PMID: 18568158 DOI: 10.1039/b702780j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A variety of natural products modulate critical biological processes in the microorganisms that produce them. Thus, inhibition of the corresponding natural product biosynthesis pathways represents a promising avenue to develop novel antibiotics. In this tutorial review, we describe several recent examples of designed small molecule inhibitors of microbial natural product biosynthesis and their use in evaluating this emerging antibiotic strategy.
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Affiliation(s)
- Justin S Cisar
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 422, New York, NY 10065, USA
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The genome of Clostridium kluyveri, a strict anaerobe with unique metabolic features. Proc Natl Acad Sci U S A 2008; 105:2128-33. [PMID: 18218779 DOI: 10.1073/pnas.0711093105] [Citation(s) in RCA: 296] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clostridium kluyveri is unique among the clostridia; it grows anaerobically on ethanol and acetate as sole energy sources. Fermentation products are butyrate, caproate, and H2. We report here the genome sequence of C. kluyveri, which revealed new insights into the metabolic capabilities of this well studied organism. A membrane-bound energy-converting NADH:ferredoxin oxidoreductase (RnfCDGEAB) and a cytoplasmic butyryl-CoA dehydrogenase complex (Bcd/EtfAB) coupling the reduction of crotonyl-CoA to butyryl-CoA with the reduction of ferredoxin represent a new energy-conserving module in anaerobes. The genes for NAD-dependent ethanol dehydrogenase and NAD(P)-dependent acetaldehyde dehydrogenase are located next to genes for microcompartment proteins, suggesting that the two enzymes, which are isolated together in a macromolecular complex, form a carboxysome-like structure. Unique for a strict anaerobe, C. kluyveri harbors three sets of genes predicted to encode for polyketide/nonribosomal peptide synthetase hybrides and one set for a nonribosomal peptide synthetase. The latter is predicted to catalyze the synthesis of a new siderophore, which is formed under iron-deficient growth conditions.
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Abstract
High-affinity iron acquisition is mediated by siderophore-dependent pathways in the majority of pathogenic and nonpathogenic bacteria and fungi. Considerable progress has been made in characterizing and understanding mechanisms of siderophore synthesis, secretion, iron scavenging, and siderophore-delivered iron uptake and its release. The regulation of siderophore pathways reveals multilayer networks at the transcriptional and posttranscriptional levels. Due to the key role of many siderophores during virulence, coevolution led to sophisticated strategies of siderophore neutralization by mammals and (re)utilization by bacterial pathogens. Surprisingly, hosts also developed essential siderophore-based iron delivery and cell conversion pathways, which are of interest for diagnostic and therapeutic studies. In the last decades, natural and synthetic compounds have gained attention as potential therapeutics for iron-dependent treatment of infections and further diseases. Promising results for pathogen inhibition were obtained with various siderophore-antibiotic conjugates acting as "Trojan horse" toxins and siderophore pathway inhibitors. In this article, general aspects of siderophore-mediated iron acquisition, recent findings regarding iron-related pathogen-host interactions, and current strategies for iron-dependent pathogen control will be reviewed. Further concepts including the inhibition of novel siderophore pathway targets are discussed.
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Affiliation(s)
- Marcus Miethke
- Philipps Universität Marburg, FB Chemie Biochemie, Hans Meerwein Strasse, D-35032 Marburg, Germany
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Otten LG, Schaffer ML, Villiers BRM, Stachelhaus T, Hollfelder F. An optimized ATP/PP(i)-exchange assay in 96-well format for screening of adenylation domains for applications in combinatorial biosynthesis. Biotechnol J 2007; 2:232-40. [PMID: 17294409 DOI: 10.1002/biot.200600220] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We report a new format for measuring ATP/[(32)P]pyrophosphate exchange in a higher throughput assay of adenylation domains (A-domains) of non-ribosomal peptide synthetases. These enzymes are key specificity determinants in the assembly line biosynthesis of non-ribosomal peptides, an important class of natural products with an activity spectrum ranging from antibiotic to antitumor activities. Our assay in 96-well format allows the rapid measurement of approximately 1000 data points per week as a basis for precise assessment of the kinetics of A-domains. The assay also allows quantitative high-throughput screening of the substrate specificity of A-domains identifying alternative, promiscuous substrates. We show that our assay is able to give high quality data for the T278A mutant of the A-domain of the tyrocidine synthetase module TycA with a 330-fold lower k(cat)/K(M). The large dynamic range of this assay will be useful for the screening of libraries of mutant A-domains. Finally we describe and evaluate a procedure for the high-throughput purification of A-domains in 96-well format for the latter purpose. Our approach will be of utility for mechanistic analysis, substrate profiling and directed evolution of the A-domains, to ultimately enable the combinatorial biosynthesis of non-natural analogues of non-ribosomal peptides that may have potential as alternative drug candidates.
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Affiliation(s)
- Linda G Otten
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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Martens T, Gram L, Grossart HP, Kessler D, Müller R, Simon M, Wenzel SC, Brinkhoff T. Bacteria of the Roseobacter clade show potential for secondary metabolite production. MICROBIAL ECOLOGY 2007; 54:31-42. [PMID: 17351813 DOI: 10.1007/s00248-006-9165-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 08/04/2006] [Accepted: 09/06/2006] [Indexed: 05/14/2023]
Abstract
Members of the Roseobacter clade are abundant and widespread in marine habitats and have very diverse metabolisms. Production of acylated homoserine lactones (AHL) and secondary metabolites, e.g., antibiotics has been described sporadically. This prompted us to screen 22 strains of this group for production of signaling molecules, antagonistic activity against bacteria of different phylogenetic groups, and the presence of genes encoding for nonribosomal peptide synthetases (NRPS) and polyketide synthases (PKS), representing enzymes involved in the synthesis of various pharmaceutically important natural products. The screening approach for NRPS and PKS genes was based on polymerase chain reaction (PCR) with degenerate primers specific for conserved sequence motifs. Additionally, sequences from whole genome sequencing projects of organisms of the Roseobacter clade were considered. Obtained PCR products were cloned, sequenced, and compared with genes of known function. With the PCR approach genes showing similarity to known NRPS and PKS genes were found in seven and five strains, respectively, and three PKS and NRPS sequences from genome sequencing projects were obtained. Three strains exhibited antagonistic activity and also showed production of AHL. Overall production of AHL was found in 10 isolates. Phylogenetic analysis of the 16S rRNA gene sequences of the tested organisms showed that several of the AHL-positive strains clustered together. Three strains were positive for three or four categories tested, and were found to be closely related within the genus Phaeobacter. The presence of a highly similar hybrid PKS/NRPS gene locus of unknown function in sequenced genomes of the Roseobacter clade plus the significant similarity of gene fragments from the strains studied to these genes argues for the functional requirement of the encoded hybrid PKS/NRPS complex. Our screening results therefore suggest that the Roseobacter clade is indeed employing PKS/NRPS biochemistry and should thus be further studied as a potential and largely untapped source of secondary metabolites.
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Affiliation(s)
- Torben Martens
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, PO Box 2503, D-26111 Oldenburg, Germany
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45
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Thomas MS. Iron acquisition mechanisms of the Burkholderia cepacia complex. Biometals 2007; 20:431-52. [PMID: 17295049 DOI: 10.1007/s10534-006-9065-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2006] [Accepted: 11/28/2006] [Indexed: 01/21/2023]
Abstract
The Burkholderia cepacia complex (Bcc) is comprised of at least 10 closely related species of Gram-negative proteobacteria that are associated with infections in certain groups of immunocompromised individuals, particularly those with cystic fibrosis. Infections in humans tend to occur in the lungs, which present an iron-restricted environment to a prospective pathogen, and accordingly members of the Bcc appear to possess efficient mechanisms for iron capture. These bacteria specify up to four different types of siderophore (ornibactin, pyochelin, cepabactin and cepaciachelin) that employ the full repertoire of iron-binding groups present in most naturally occurring siderophores. Members of the Bcc are also capable of utilising some exogenous siderophores that they are not able to synthesise. In addition to siderophore-mediated mechanisms of iron uptake, the Bcc possess mechanisms for acquiring iron from haem and from ferritin. The Bcc therefore appear to be well-equipped for life in an iron-poor environment.
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Affiliation(s)
- Mark S Thomas
- Unit of Infection and Immunity, School of Medicine and Biomedical Sciences, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, UK.
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Somu RV, Wilson DJ, Bennett EM, Boshoff HI, Celia L, Beck BJ, Barry CE, Aldrich CC. Antitubercular nucleosides that inhibit siderophore biosynthesis: SAR of the glycosyl domain. J Med Chem 2006; 49:7623-35. [PMID: 17181146 PMCID: PMC2526467 DOI: 10.1021/jm061068d] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tuberculosis is the leading cause of infectious disease mortality in the world by a bacterial pathogen. We previously demonstrated that a bisubstrate inhibitor of the adenylation enzyme MbtA, which is responsible for the second step of mycobactin biosynthesis, exhibited potent antitubercular activity. Here we systematically investigate the structure-activity relationships of the bisubstrate inhibitor glycosyl domain resulting in the identification of a carbocyclic analogue that possesses a KIapp value of 2.3 nM and MIC99 values of 1.56 microM against M. tuberculosis H37Rv. The SAR data suggest the intriguing possibility that the bisubstrate inhibitors utilize a transporter for entry across the mycobacterial cell envelope. Additionally, we report improved conditions for the expression of MbtA and biochemical analysis, demonstrating that MbtA follows a random sequential enzyme mechanism for the adenylation half-reaction.
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Affiliation(s)
- Ravindranadh V Somu
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
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Bay L, Larsen JL, Leisner JJ. Distribution of three genes involved in the PJM1 iron-sequestering system in various Vibrio anguillarum serogroups. Syst Appl Microbiol 2006; 30:85-92. [PMID: 16644168 DOI: 10.1016/j.syapm.2006.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Gene sequences with high homologies to the two genes fatA and fatD, associated with the pJM1 virulence plasmid-encoded iron-sequestering system (anguibactin) in Vibrio anguillarum serogroup O1 strains, were found in a range of serogroup O2a strains and one NT 4 strain that either contained no plasmids or only small-sized plasmids. None of these strains contained the angR gene responsible for regulation of the anguibactin synthesis. DNA sequences of presumed fatA and fatD fragments from one O2a strain and one NT4 strain were identical to each other. The fatA sequence of these strains included 35 nucleotide substitutions and 7 amino acid substitutions out of 555 nucleotides when compared with the fatA sequence of the O1 strain 76775. The fatD sequence included 10 nucleotide substitutions and 1 amino acid substitution out of 543 nucleotides when compared with 76775. The fact that the majority of nucleotide substitutes in the fatA and fatD fragments did not result in amino acid substitutes suggest that these sequences may to some degree be preserved by selective pressure. The functional role of these genes in the O2a serogroup is most likely different from their role in the pJM1 system.
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Affiliation(s)
- Lene Bay
- Department of Veterinary Pathobiology, Royal Veterinary and Agricultural University, Grønnegårdsvej 15, DK-1870 Frederiksberg C., Denmark
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Lamas-Maceiras M, Vaca I, Rodríguez E, Casqueiro J, Martín J. Amplification and disruption of the phenylacetyl-CoA ligase gene of Penicillium chrysogenum encoding an aryl-capping enzyme that supplies phenylacetic acid to the isopenicillin N-acyltransferase. Biochem J 2006; 395:147-55. [PMID: 16321143 PMCID: PMC1409706 DOI: 10.1042/bj20051599] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A gene, phl, encoding a phenylacetyl-CoA ligase was cloned from a phage library of Penicillium chrysogenum AS-P-78. The presence of five introns in the phl gene was confirmed by reverse transcriptase-PCR. The phl gene encoded an aryl-CoA ligase closely related to Arabidopsis thaliana 4-coumaroyl-CoA ligase. The Phl protein contained most of the amino acids defining the aryl-CoA (4-coumaroyl-CoA) ligase substrate-specificity code and differed from acetyl-CoA ligase and other acyl-CoA ligases. The phl gene was not linked to the penicillin gene cluster. Amplification of phl in an autonomous replicating plasmid led to an 8-fold increase in phenylacetyl-CoA ligase activity and a 35% increase in penicillin production. Transformants containing the amplified phl gene were resistant to high concentrations of phenylacetic acid (more than 2.5 g/l). Disruption of the phl gene resulted in a 40% decrease in penicillin production and a similar reduction of phenylacetyl-CoA ligase activity. The disrupted mutants were highly susceptible to phenylacetic acid. Complementation of the disrupted mutants with the phl gene restored normal levels of penicillin production and resistance to phenylacetic acid. The phenylacetyl-CoA ligase encoded by the phl gene is therefore involved in penicillin production, although a second aryl-CoA ligase appears to contribute partially to phenylacetic acid activation. The Phl protein lacks a peptide-carrier-protein domain and behaves as an aryl-capping enzyme that activates phenylacetic acid and transfers it to the isopenicillin N acyltransferase. The Phl protein contains the peroxisome-targeting sequence that is also present in the isopenicillin N acyltransferase. The peroxisomal co-localization of these two proteins indicates that the last two enzymes of the penicillin pathway form a peroxisomal functional complex.
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Affiliation(s)
- Mónica Lamas-Maceiras
- *Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, 24071 León, Spain
| | - Inmaculada Vaca
- †Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, 1 Av. Real, 24006 León, Spain
| | - Esther Rodríguez
- *Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, 24071 León, Spain
| | - Javier Casqueiro
- *Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, 24071 León, Spain
| | - Juan F. Martín
- *Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, 24071 León, Spain
- †Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, 1 Av. Real, 24006 León, Spain
- To whom correspondence should be addressed (email )
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Miethke M, Bisseret P, Beckering CL, Vignard D, Eustache J, Marahiel MA. Inhibition of aryl acid adenylation domains involved in bacterial siderophore synthesis. FEBS J 2006; 273:409-19. [PMID: 16403027 DOI: 10.1111/j.1742-4658.2005.05077.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aryl acid adenylation domains are the initial enzymes for aryl-capping of catecholic siderophores in a plethora of microorganisms. In order to overcome the problem of iron acquisition in host organisms, siderophore biosynthesis is decisive for virulence development in numerous important human and animal pathogens. Recently, it was shown that growth of Mycobacterium tuberculosis and Yersinia pestis can be inhibited in an iron-dependent manner using the arylic acyl adenylate analogue 5'-O-[N-(salicyl)-sulfamoyl] adenosine that acts on the salicylate activating domains, MbtA and YbtE [Ferreras JA, Ryu JS, Di Lello F, Tan DS, Quadri LEN (2005) Nat Chem Biol1, 29-32]. The present study explores the behaviour of the 2,3-dihydroxybenzoate activating domain DhbE (bacillibactin synthesis) and compares it to that of YbtE (yersiniabactin synthesis) upon enzymatic inhibition using a set of newly synthesized aryl sulfamoyl adenosine derivatives. The obtained results underline the highly specific mode of inhibition for both aryl acid activating domains in accordance with their natively accepted aryl moiety. These findings are discussed regarding the structure-function based aspect of aryl substrate binding to the DhbE and YbtE active sites.
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Affiliation(s)
- Marcus Miethke
- Philipps-Universität Marburg, Fachbereich Chemie/Biochemie, Marburg, Germany
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Schwartz D, Grammel N, Heinzelmann E, Keller U, Wohlleben W. Phosphinothricin tripeptide synthetases in Streptomyces viridochromogenes Tü494. Antimicrob Agents Chemother 2006; 49:4598-607. [PMID: 16251301 PMCID: PMC1280124 DOI: 10.1128/aac.49.11.4598-4607.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The tripeptide backbone of phosphinothricin (PT) tripeptide (PTT), a compound with herbicidal activity from Streptomyces viridochromogenes, is assembled by three stand-alone peptide synthetase modules. The enzyme PhsA (66 kDa) recruits the PT-precursor N-acetyl-demethylphosphinothricin (N-Ac-DMPT), whereas the two alanine residues of PTT are assembled by the enzymes PhsB and PhsC (129 and 119 kDa, respectively). During or after assembly, the N-Ac-DMPT residue in the peptide is converted to PT by methylation and deacetylation. Both phsB and phsC appear to be cotranscribed together with two other genes from a single promoter and they are located at a distance of 20 kb from the gene phsA, encoding PhsA, in the PTT biosynthesis gene cluster of S. viridochromogenes. PhsB and PhsC represent single nonribosomal peptide synthetase elongation modules lacking a thioesterase domain. Gene inactivations, genetic complementations, determinations of substrate specificity of the heterologously produced proteins, and comparison of PhsC sequence with the amino terminus of the alanine-activating nonribosomal peptide synthetase PTTSII from S. viridochromogenes confirmed the role of the two genes in the bialanylation of Ac-DMPT. The lack of an integral thioesterase domain in the PTT assembly system points to product release possibly involving two type II thioesterase genes (the1 and the2) located in the PTT gene cluster alone or in conjunction with an as yet unknown mechanism of product release.
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Affiliation(s)
- Dirk Schwartz
- Mikrobiologie/Biotechnologie, Eberhard-Karls-Universität Tübingen, Germany
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