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Gupta VK, Bakshi U, Chang D, Lee AR, Davis JM, Chandrasekaran S, Jin YS, Freeman MF, Sung J. TaxiBGC: a Taxonomy-Guided Approach for Profiling Experimentally Characterized Microbial Biosynthetic Gene Clusters and Secondary Metabolite Production Potential in Metagenomes. mSystems 2022; 7:e0092522. [PMID: 36378489 PMCID: PMC9765181 DOI: 10.1128/msystems.00925-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Biosynthetic gene clusters (BGCs) in microbial genomes encode bioactive secondary metabolites (SMs), which can play important roles in microbe-microbe and host-microbe interactions. Given the biological significance of SMs and the current profound interest in the metabolic functions of microbiomes, the unbiased identification of BGCs from high-throughput metagenomic data could offer novel insights into the complex chemical ecology of microbial communities. Currently available tools for predicting BGCs from shotgun metagenomes have several limitations, including the need for computationally demanding read assembly, predicting a narrow breadth of BGC classes, and not providing the SM product. To overcome these limitations, we developed taxonomy-guided identification of biosynthetic gene clusters (TaxiBGC), a command-line tool for predicting experimentally characterized BGCs (and inferring their known SMs) in metagenomes by first pinpointing the microbial species likely to harbor them. We benchmarked TaxiBGC on various simulated metagenomes, showing that our taxonomy-guided approach could predict BGCs with much-improved performance (mean F1 score, 0.56; mean PPV score, 0.80) compared with directly identifying BGCs by mapping sequencing reads onto the BGC genes (mean F1 score, 0.49; mean PPV score, 0.41). Next, by applying TaxiBGC on 2,650 metagenomes from the Human Microbiome Project and various case-control gut microbiome studies, we were able to associate BGCs (and their SMs) with different human body sites and with multiple diseases, including Crohn's disease and liver cirrhosis. In all, TaxiBGC provides an in silico platform to predict experimentally characterized BGCs and their SM production potential in metagenomic data while demonstrating important advantages over existing techniques. IMPORTANCE Currently available bioinformatics tools to identify BGCs from metagenomic sequencing data are limited in their predictive capability or ease of use to even computationally oriented researchers. We present an automated computational pipeline called TaxiBGC, which predicts experimentally characterized BGCs (and infers their known SMs) in shotgun metagenomes by first considering the microbial species source. Through rigorous benchmarking techniques on simulated metagenomes, we show that TaxiBGC provides a significant advantage over existing methods. When demonstrating TaxiBGC on thousands of human microbiome samples, we associate BGCs encoding bacteriocins with different human body sites and diseases, thereby elucidating a possible novel role of this antibiotic class in maintaining the stability of microbial ecosystems throughout the human body. Furthermore, we report for the first time gut microbial BGC associations shared among multiple pathologies. Ultimately, we expect our tool to facilitate future investigations into the chemical ecology of microbial communities across diverse niches and pathologies.
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Affiliation(s)
- Vinod K. Gupta
- Microbiome Program, Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Utpal Bakshi
- Institute of Health Sciences, Presidency University, Kolkata, West Bengal, India
| | - Daniel Chang
- Department of Computer Science and Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Aileen R. Lee
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota—Twin Cities, St. Paul, Minnesota, USA
- BioTechnology Institute, University of Minnesota—Twin Cities, St. Paul, Minnesota, USA
| | - John M. Davis
- Division of Rheumatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Sriram Chandrasekaran
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
- Center for Bioinformatics and Computational Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Michael F. Freeman
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota—Twin Cities, St. Paul, Minnesota, USA
- BioTechnology Institute, University of Minnesota—Twin Cities, St. Paul, Minnesota, USA
| | - Jaeyun Sung
- Microbiome Program, Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Division of Surgery Research, Department of Surgery, Mayo Clinic, Rochester, Minnesota, USA
- Division of Rheumatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
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2
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Nair AV, Robson A, Ackrill TD, Till M, Byrne MJ, Back CR, Tiwari K, Davies JA, Willis CL, Race PR. Structure and mechanism of a dehydratase/decarboxylase enzyme couple involved in polyketide β-methyl branch incorporation. Sci Rep 2020; 10:15323. [PMID: 32948786 PMCID: PMC7501309 DOI: 10.1038/s41598-020-71850-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 07/30/2020] [Indexed: 01/16/2023] Open
Abstract
Complex polyketides of bacterial origin are biosynthesised by giant assembly-line like megaenzymes of the type 1 modular polyketide synthase (PKS) class. The trans-AT family of modular PKSs, whose biosynthetic frameworks diverge significantly from those of the archetypal cis-AT type systems represent a new paradigm in natural product enzymology. One of the most distinctive enzymatic features common to trans-AT PKSs is their ability to introduce methyl groups at positions β to the thiol ester in the growing polyketide chain. This activity is achieved through the action of a five protein HCS cassette, comprising a ketosynthase, a 3-hydroxy-3-methylglutaryl-CoA synthase, a dehydratase, a decarboxylase and a dedicated acyl carrier protein. Here we report a molecular level description, achieved using a combination of X-ray crystallography, in vitro enzyme assays and site-directed mutagenesis, of the bacillaene synthase dehydratase/decarboxylase enzyme couple PksH/PksI, responsible for the final two steps in β-methyl branch installation in this trans-AT PKS. Our work provides detailed mechanistic insight into this biosynthetic peculiarity and establishes a molecular framework for HCS cassette enzyme exploitation and manipulation, which has future potential value in guiding efforts in the targeted synthesis of functionally optimised 'non-natural' natural products.
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Affiliation(s)
- Asha V Nair
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Alice Robson
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Thomas D Ackrill
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Marisa Till
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Matthew J Byrne
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Catherine R Back
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Kavita Tiwari
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Jonathan A Davies
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Christine L Willis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Paul R Race
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK. .,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK.
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Cheng YS, Sun W, Xu M, Shen M, Khraiwesh M, Sciotti RJ, Zheng W. Repurposing Screen Identifies Unconventional Drugs With Activity Against Multidrug Resistant Acinetobacter baumannii. Front Cell Infect Microbiol 2019; 8:438. [PMID: 30662875 PMCID: PMC6328479 DOI: 10.3389/fcimb.2018.00438] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/10/2018] [Indexed: 12/28/2022] Open
Abstract
Antibiotic-resistant nosocomial infections are an emerging public health issue; carbapenem-resistant gram-negative bacteria such as Acinetobacter baumannii are among the pathogens against which new therapeutic agents are desperately needed. Drug repurposing has recently emerged as an alternative approach to rapidly identifying effective drugs and drug combinations to combat drug resistant bacteria. We performed a drug repurposing screen against a highly virulent, multidrug resistant, Acinetobacter baumannii strain AB5075. This strain, isolated from a patient, is resistant to 25 first-line antibiotics for gram-negative bacteria. A compound screen using a bacterial growth assay led to identification and confirmation of 43 active compounds. Among these confirmed compounds, seven are approved drugs or pharmacologically active compounds for non-antimicrobial indications. Three of these drugs, 5-fluorouracil, fluspirilene, and Bay 11-7082 resensitized strain AB5075 to azithromycin and colistin in a two-drug combination format. The approach using a drug repurposing screen with a pathogen sample isolated from a patient and a high throughput bacterial growth assay led to the successful identification of new drug combinations to overcome a multidrug resistant bacterial infection.
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Affiliation(s)
- Yu-Shan Cheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Wei Sun
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Miao Xu
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Min Shen
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
| | - Mozna Khraiwesh
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Richard J Sciotti
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, United States
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5
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Liyanage HM, Arachchi DNM, Abeysekara T, Guneratne L. Toxicology of freshwater cyanobacteria. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2016; 34:137-168. [PMID: 27229761 DOI: 10.1080/10590501.2016.1193923] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Many chemical contaminants in drinking water have been shown to cause adverse health effects in humans after prolonged exposure. Cyanobacteria are one of the most potent and diverse groups of photosynthetic prokaryotes. One key component of cyanobacterial success in the environment is the production of potent toxins as secondary metabolites, which have been responsible for numerous adverse health impacts in humans. Anthropogenic activities have led to the increase of eutrophication in freshwater bodies' worldwide, causing cyanobacterial blooms to become more frequent. The present article will discuss about harmful cyanobacteria and their toxicology with special references to microcystin, nodularin, and cylindrospermopsin.
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Affiliation(s)
- H M Liyanage
- a National Institute of Fundamental Studies , Kandy , Sri Lanka
| | | | - T Abeysekara
- b Nephrology and Transplantation Unit, Teaching Hospital , Kandy , Sri Lanka
| | - L Guneratne
- c Renal Care & Research Centre, District Hospital , Girandurukotte , Sri Lanka
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Elshahawi SI, Shaaban KA, Kharel MK, Thorson JS. A comprehensive review of glycosylated bacterial natural products. Chem Soc Rev 2015; 44:7591-697. [PMID: 25735878 PMCID: PMC4560691 DOI: 10.1039/c4cs00426d] [Citation(s) in RCA: 299] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A systematic analysis of all naturally-occurring glycosylated bacterial secondary metabolites reported in the scientific literature up through early 2013 is presented. This comprehensive analysis of 15 940 bacterial natural products revealed 3426 glycosides containing 344 distinct appended carbohydrates and highlights a range of unique opportunities for future biosynthetic study and glycodiversification efforts.
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Affiliation(s)
- Sherif I Elshahawi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA. and Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - Khaled A Shaaban
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA. and Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, USA
| | - Madan K Kharel
- School of Pharmacy, University of Maryland Eastern Shore, Princess Anne, Maryland, USA
| | - Jon S Thorson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA. and Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, USA
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7
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A Novel Microbisporicin Producer Identified by Early Dereplication during Lantibiotic Screening. BIOMED RESEARCH INTERNATIONAL 2015; 2015:419383. [PMID: 26346738 PMCID: PMC4539421 DOI: 10.1155/2015/419383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/29/2015] [Accepted: 05/31/2015] [Indexed: 11/20/2022]
Abstract
With the increasing need of effective antibiotics against multi-drug resistant pathogens, lantibiotics are an attractive option of a new class of molecules. They are ribosomally synthetized and posttranslationally modified peptides possessing potent antimicrobial activity against aerobic and anaerobic Gram-positive pathogens, including those increasingly resistant to β-lactams and glycopeptides. Some of them (actagardine, mersacidin, planosporicin, and microbisporicin) inhibit cell wall biosynthesis in pathogens and their effect is not antagonized by vancomycin. Hereby, we apply an efficient strategy for lantibiotic screening to 240 members of a newly described genus of filamentous actinomycetes, named Actinoallomurus, that is considered a yet-poorly-exploited promising source for novel bioactive metabolites. By combining antimicrobial differential assay against Staphylococcus aureus and its L-form (also in the presence of a β-lactamase cocktail or Ac-Lys-D-alanyl-D-alanine tripeptide), with LC-UV-MS dereplication coupled with bioautography, a novel producer of the potent microbisporicin complex was rapidly identified. Under the commercial name of NAI-107, it is currently in late preclinical phase for the treatment of multi-drug resistant Gram-positive pathogens. To our knowledge, this is the first report on a lantibiotic produced by an Actinoallomurus sp. and on a microbisporicin producer not belonging to the Microbispora genus.
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8
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Fedorenko V, Genilloud O, Horbal L, Marcone GL, Marinelli F, Paitan Y, Ron EZ. Antibacterial Discovery and Development: From Gene to Product and Back. BIOMED RESEARCH INTERNATIONAL 2015; 2015:591349. [PMID: 26339625 PMCID: PMC4538407 DOI: 10.1155/2015/591349] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/30/2014] [Accepted: 01/13/2015] [Indexed: 12/23/2022]
Abstract
Concern over the reports of antibiotic-resistant bacterial infections in hospitals and in the community has been publicized in the media, accompanied by comments on the risk that we may soon run out of antibiotics as a way to control infectious disease. Infections caused by Enterococcus faecium, Staphylococcus aureus, Klebsiella species, Clostridium difficile, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, and other Enterobacteriaceae species represent a major public health burden. Despite the pharmaceutical sector's lack of interest in the topic in the last decade, microbial natural products continue to represent one of the most interesting sources for discovering and developing novel antibacterials. Research in microbial natural product screening and development is currently benefiting from progress that has been made in other related fields (microbial ecology, analytical chemistry, genomics, molecular biology, and synthetic biology). In this paper, we review how novel and classical approaches can be integrated in the current processes for microbial product screening, fermentation, and strain improvement.
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Affiliation(s)
- Victor Fedorenko
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, Lviv 79005, Ukraine
| | - Olga Genilloud
- Fundación MEDINA, Health Sciences Technology Park, 18016 Granada, Spain
| | - Liliya Horbal
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, Lviv 79005, Ukraine
| | - Giorgia Letizia Marcone
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
- The Protein Factory, Interuniversity Centre Politecnico di Milano, ICRM CNR Milano, and University of Insubria, 21100 Varese, Italy
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
- The Protein Factory, Interuniversity Centre Politecnico di Milano, ICRM CNR Milano, and University of Insubria, 21100 Varese, Italy
| | - Yossi Paitan
- Clinical Microbiology Laboratory, Meir Medical Center, 44281 Kfar Saba, Israel
| | - Eliora Z. Ron
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 6997801 Tel Aviv, Israel
- Galilee Research Institute (MIGAL), 11016 Kiryat Shmona, Israel
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9
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Binda E, Marinelli F, Marcone GL. Old and New Glycopeptide Antibiotics: Action and Resistance. Antibiotics (Basel) 2014; 3:572-94. [PMID: 27025757 PMCID: PMC4790382 DOI: 10.3390/antibiotics3040572] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/20/2014] [Accepted: 10/23/2014] [Indexed: 12/05/2022] Open
Abstract
Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycopeptides are glycosylated non-ribosomal peptides produced by a diverse group of soil actinomycetes. They target Gram-positive bacteria by binding to the acyl-d-alanyl-d-alanine (d-Ala-d-Ala) terminus of the growing peptidoglycan on the outer surface of the cytoplasmatic membrane. Glycopeptide-resistant organisms avoid such a fate by replacing the d-Ala-d-Ala terminus with d-alanyl-d-lactate (d-Ala-d-Lac) or d-alanyl-d-serine (d-Ala-d-Ser), thus markedly reducing antibiotic affinity for the cellular target. Resistance has manifested itself in enterococci and staphylococci largely through the expression of genes (named van) encoding proteins that reprogram cell wall biosynthesis and, thus, evade the action of the antibiotic. These resistance mechanisms were most likely co-opted from the glycopeptide producing actinomycetes, which use them to avoid suicide during antibiotic production, rather than being orchestrated by pathogen bacteria upon continued treatment. van-like gene clusters, similar to those described in enterococci, were in fact identified in many glycopeptide-producing actinomycetes, such as Actinoplanes teichomyceticus, which produces teicoplanin, and Streptomyces toyocaensis, which produces the A47934 glycopeptide. In this paper, we describe the natural and semi-synthetic glycopeptide antibiotics currently used as last resort drugs for Gram-positive infections and compare the van gene-based strategies of glycopeptide resistance among the pathogens and the producing actinomycetes. Particular attention is given to the strategy of immunity recently described in Nonomuraea sp. ATCC 39727. Nonomuraea sp. ATCC 39727 is the producer of A40926, which is the natural precursor of the second generation semi-synthetic glycopeptide dalbavancin, very recently approved for acute bacterial skin and skin structure infections. A thorough understanding of glycopeptide immunity in this producing microorganism may be particularly relevant to predict and eventually control the evolution of resistance that might arise following introduction of dalbavancin and other second generation glycopeptides into clinics.
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Affiliation(s)
- Elisa Binda
- Department of Biotechnology and Life Sciences, University of Insubria, Varese 20100, Italy.
- The Protein Factory, Interuniversity Centre Politecnico di Milano, ICRM CNR Milano and University of Insubria, Milan 21100, Italy.
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese 20100, Italy.
- The Protein Factory, Interuniversity Centre Politecnico di Milano, ICRM CNR Milano and University of Insubria, Milan 21100, Italy.
| | - Giorgia Letizia Marcone
- Department of Biotechnology and Life Sciences, University of Insubria, Varese 20100, Italy.
- The Protein Factory, Interuniversity Centre Politecnico di Milano, ICRM CNR Milano and University of Insubria, Milan 21100, Italy.
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Pep2Path: automated mass spectrometry-guided genome mining of peptidic natural products. PLoS Comput Biol 2014; 10:e1003822. [PMID: 25188327 PMCID: PMC4154637 DOI: 10.1371/journal.pcbi.1003822] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/22/2014] [Indexed: 01/10/2023] Open
Abstract
Nonribosomally and ribosomally synthesized bioactive peptides constitute a source of molecules of great biomedical importance, including antibiotics such as penicillin, immunosuppressants such as cyclosporine, and cytostatics such as bleomycin. Recently, an innovative mass-spectrometry-based strategy, peptidogenomics, has been pioneered to effectively mine microbial strains for novel peptidic metabolites. Even though mass-spectrometric peptide detection can be performed quite fast, true high-throughput natural product discovery approaches have still been limited by the inability to rapidly match the identified tandem mass spectra to the gene clusters responsible for the biosynthesis of the corresponding compounds. With Pep2Path, we introduce a software package to fully automate the peptidogenomics approach through the rapid Bayesian probabilistic matching of mass spectra to their corresponding biosynthetic gene clusters. Detailed benchmarking of the method shows that the approach is powerful enough to correctly identify gene clusters even in data sets that consist of hundreds of genomes, which also makes it possible to match compounds from unsequenced organisms to closely related biosynthetic gene clusters in other genomes. Applying Pep2Path to a data set of compounds without known biosynthesis routes, we were able to identify candidate gene clusters for the biosynthesis of five important compounds. Notably, one of these clusters was detected in a genome from a different subphylum of Proteobacteria than that in which the molecule had first been identified. All in all, our approach paves the way towards high-throughput discovery of novel peptidic natural products. Pep2Path is freely available from http://pep2path.sourceforge.net/, implemented in Python, licensed under the GNU General Public License v3 and supported on MS Windows, Linux and Mac OS X.
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Zabala A, Chooi YH, Choi MS, Lin HC, Tang Y. Fungal polyketide synthase product chain-length control by partnering thiohydrolase. ACS Chem Biol 2014; 9:1576-86. [PMID: 24845309 PMCID: PMC4215887 DOI: 10.1021/cb500284t] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 05/20/2014] [Indexed: 12/18/2022]
Abstract
Fungal highly reducing polyketide synthases (HRPKSs) are an enigmatic group of multidomain enzymes that catalyze the biosynthesis of structurally diverse compounds. This variety stems from their intrinsic programming rules, which permutate the use of tailoring domains and determine the overall number of iterative cycles. From genome sequencing and mining of the producing strain Eupenicillium brefeldianum ATCC 58665, we identified an HRPKS involved in the biosynthesis of an important protein transport-inhibitor Brefeldin A (BFA), followed by reconstitution of its activity in Saccharomyces cerevisiae and in vitro. Bref-PKS demonstrated an NADPH-dependent reductive tailoring specificity that led to the synthesis of four different octaketide products with varying degrees of reduction. Furthermore, contrary to what is expected from the structure of BFA, Bref-PKS is found to be a nonaketide synthase in the absence of an associated thiohydrolase Bref-TH. Such chain-length control by the partner thiohydrolase was found to be present in other HRPKS systems and highlights the importance of including tailoring enzyme activities in predicting fungal HRPKS functions and their products.
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Affiliation(s)
- Angelica
O. Zabala
- Department of Chemical
and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Yit-Heng Chooi
- Research
School of Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Moon Seok Choi
- Department of Chemical
and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Hsiao-Ching Lin
- Department of Chemical
and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Yi Tang
- Department of Chemical
and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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12
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Till M, Race PR. Progress challenges and opportunities for the re-engineering of trans-AT polyketide synthases. Biotechnol Lett 2014; 36:877-88. [PMID: 24557077 DOI: 10.1007/s10529-013-1449-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 12/23/2013] [Indexed: 12/13/2022]
Abstract
Polyketides are a structurally and functionally diverse family of bioactive natural products that are used extensively as pharmaceuticals and agrochemicals. In bacteria these molecules are biosynthesized by giant, multi-functional enzymatic complexes, termed modular polyketide synthases (PKSs), that function in assembly-line like fashion to fuse and tailor simple carboxylic acid monomers into a vast array of elaborate chemical scaffolds. Modifying PKSs through targeted synthase re-engineering is a promising approach for accessing functionally-optimized polyketides. Due to their highly mosaic architectures the recently identified trans-AT family of modular synthases appear inherently more amenable to re-engineering than their well studied cis-AT counterparts. Here, we review recent progress in the re-engineering of trans-AT PKSs, summarize opportunities for harnessing the biosynthetic potential of these systems, and highlight challenges that such re-engineering approaches present.
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Affiliation(s)
- M Till
- School of Biochemistry, Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK
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13
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Binda E, Marcone GL, Berini F, Pollegioni L, Marinelli F. Streptomyces spp. as efficient expression system for a D,D-peptidase/D,D-carboxypeptidase involved in glycopeptide antibiotic resistance. BMC Biotechnol 2013; 13:24. [PMID: 23497129 PMCID: PMC3610138 DOI: 10.1186/1472-6750-13-24] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 03/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND VanYn, encoded by the dbv7 gene (also known as vanYn) of the biosynthetic cluster devoted to A40926 production, is a novel protein involved in the mechanism of self-resistance in Nonomuraea sp. ATCC 39727. This filamentous actinomycete is an uncommon microorganism, difficult-to-handle but biotechnologically valuable since it produces the glycopeptide antibiotic A40926, which is the precursor of the second-generation dalbavancin in phase III of clinical development. In order to investigate VanYn role in glycopeptide resistance in the producer actinomycete an appropriate host-vector expression system is required. RESULTS The cloning strategy of vanYn gene (G-C ratio 73.3%) in the expression vector pIJ86 yielded a recombinant protein with a tag encoding for a histidine hexamer added at the C-terminus (C-His6-vanYn) or at the N-terminus (N-His6-vanYn). These plasmids were used to transform three Streptomyces spp., which are genetically-treatable high G-C content Gram-positive bacteria taxonomically related to the homologous producer Nonomuraea sp.. Highest yield of protein expression and purification (12 mg of protein per liter of culture at 3 L bioreactor-scale) was achieved in Streptomyces venezuelae ATCC 10595, that is a fast growing streptomyces susceptible to glycopeptides. VanYn is a transmembrane protein which was easily detached and recovered from the cell wall fraction. Purified C-His6-VanYn showed d,d-carboxypeptidase and d,d-dipeptidase activities on synthetic analogs of bacterial peptidoglycan (PG) precursors. C-His6-VanYn over-expression conferred glycopeptide resistance to S. venezuelae. On the contrary, the addition of His6-tag at the N-terminus of the protein abolished its biological activity either in vitro or in vivo assays. CONCLUSIONS Heterologous expression of vanYn from Nonomuraea sp. ATCC 39727 in S. venezuelae was successfully achieved and conferred the host an increased level of glycopeptide resistance. Cellular localization of recombinant VanYn together with its enzymatic activity as a d,d-peptidase/d,d-carboxypeptidase agree with its role in removing the last d-Ala from the pentapeptide PG precursors and reprogramming cell wall biosynthesis, as previously reported in glycopeptide resistant pathogens.
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Affiliation(s)
- Elisa Binda
- Department of Biotechnology and Life Sciences, University of Insubria, via J, H, Dunant 3, Varese, Italy.
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Bacterial Responses and Genome Instability Induced by Subinhibitory Concentrations of Antibiotics. Antibiotics (Basel) 2013; 2:100-14. [PMID: 27029295 PMCID: PMC4790301 DOI: 10.3390/antibiotics2010100] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 11/17/2022] Open
Abstract
Nowadays, the emergence and spread of antibiotic resistance have become an utmost medical and economical problem. It has also become evident that subinhibitory concentrations of antibiotics, which pollute all kind of terrestrial and aquatic environments, have a non-negligible effect on the evolution of antibiotic resistance in bacterial populations. Subinhibitory concentrations of antibiotics have a strong effect on mutation rates, horizontal gene transfer and biofilm formation, which may all contribute to the emergence and spread of antibiotic resistance. Therefore, the molecular mechanisms and the evolutionary pressures shaping the bacterial responses to subinhibitory concentrations of antibiotics merit to be extensively studied. Such knowledge is valuable for the development of strategies to increase the efficacy of antibiotic treatments and to extend the lifetime of antibiotics used in therapy by slowing down the emergence of antibiotic resistance.
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Myxobacterial metabolites enhance cell proliferation and reduce intracellular stress in cells from a Parkinson's disease mouse model. Gene 2013; 514:36-40. [DOI: 10.1016/j.gene.2012.10.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 10/22/2012] [Accepted: 10/26/2012] [Indexed: 11/21/2022]
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