1
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Zivkovic I, Gruic-Sovulj I. Exploring mechanisms of mupirocin resistance and hyper-resistance. Biochem Soc Trans 2024; 52:1109-1120. [PMID: 38884776 DOI: 10.1042/bst20230581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/18/2024]
Abstract
Mupirocin is a broad-spectrum antibiotic that acts predominantly against Gram-positive bacteria. It is produced by Pseudomonas fluorescens NCIMB 10586 and has been clinically used to treat primary and secondary skin infections and to eradicate nasal colonisation of methicillin-resistant Staphylococcus aureus strains. Mupirocin inhibits protein synthesis by blocking the active site of isoleucyl-tRNA synthetase (IleRS), which prevents the enzyme from binding isoleucine and ATP for Ile-tRNAIle synthesis. Two types of IleRS are found in bacteria - while IleRS1 is susceptible to mupirocin inhibition, IleRS2 provides resistance to cells. These two types belong to distinct evolutionary clades which likely emerged from an early gene duplication in bacteria. Resistance in IleRS2 is based on the loss of interactions that govern mupirocin binding to IleRS1, such as hydrogen bonding to the carboxylate moiety of mupirocin. IleRS2 enzymes with Ki in the millimolar range have recently been discovered. These hyper-resistant IleRS2 variants surprisingly have a non-canonical version of the catalytic motif, which serves as a signature motif of class I aminoacyl-tRNA synthetases to which IleRS belongs. The non-canonical motif, in which the 1st and 3rd positions are swapped, is key for hyper-resistance and can be accommodated without abolishing enzyme activity in IleRS2 but not in IleRS1. Clinical use of mupirocin led to the emergence of resistance in S. aureus. Low-level resistance arises by mutations of the housekeeping IleRS1, while high-level resistance develops by the acquisition of the resistant IleRS2 on a plasmid. There is no evidence that hyper-resistant variants have been found in clinical isolates.
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Affiliation(s)
- Igor Zivkovic
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Ita Gruic-Sovulj
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
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2
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Schwanemann T, Otto M, Wynands B, Marienhagen J, Wierckx N. A Pseudomonas taiwanensis malonyl-CoA platform strain for polyketide synthesis. Metab Eng 2023; 77:219-230. [PMID: 37031949 DOI: 10.1016/j.ymben.2023.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/31/2023] [Accepted: 04/02/2023] [Indexed: 04/11/2023]
Abstract
Malonyl-CoA is a central precursor for biosynthesis of a wide range of complex secondary metabolites. The development of platform strains with increased malonyl-CoA supply can contribute to the efficient production of secondary metabolites, especially if such strains exhibit high tolerance towards these chemicals. In this study, Pseudomonas taiwanensis VLB120 was engineered for increased malonyl-CoA availability to produce bacterial and plant-derived polyketides. A multi-target metabolic engineering strategy focusing on decreasing the malonyl-CoA drain and increasing malonyl-CoA precursor availability, led to an increased production of various malonyl-CoA-derived products, including pinosylvin, resveratrol and flaviolin. The production of flaviolin, a molecule deriving from five malonyl-CoA molecules, was doubled compared to the parental strain by this malonyl-CoA increasing strategy. Additionally, the engineered platform strain enabled production of up to 84 mg L-1 resveratrol from supplemented p-coumarate. One key finding of this study was that acetyl-CoA carboxylase overexpression majorly contributed to an increased malonyl-CoA availability for polyketide production in dependence on the used strain-background and whether downstream fatty acid synthesis was impaired, reflecting its complexity in metabolism. Hence, malonyl-CoA availability is primarily determined by competition of the production pathway with downstream fatty acid synthesis, while supply reactions are of secondary importance for compounds that derive directly from malonyl-CoA in Pseudomonas.
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Affiliation(s)
- Tobias Schwanemann
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Maike Otto
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Benedikt Wynands
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Jan Marienhagen
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany; Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
| | - Nick Wierckx
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
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3
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Chen G, Zhou Y, Dai J, Yan S, Miao W, Ren L. Calcium alginate/PNIPAAm hydrogel with body temperature response and great biocompatibility: Application as burn wound dressing. Int J Biol Macromol 2022; 216:686-697. [PMID: 35817237 DOI: 10.1016/j.ijbiomac.2022.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/16/2022] [Accepted: 07/03/2022] [Indexed: 11/05/2022]
Abstract
Deep burns often do not heal easily, because the dermis of the skin is severely damaged, leading to severe inflammation and bacterial infection. Therefore, it is of great clinical significance to develop a dressing that promotes the healing process of deep burn wound. In this study, we used N-isopropyl acrylamide, sodium alginate and calcium chloride as the main materials, a series of calcium alginate/ poly (N-isopropyl acrylamide)(NIPAAm) hydrogel (CAPH) with different component ratios were synthesized. Its swelling properties, temperature response properties, rheological properties, biocompatibility properties, and in vitro drug release properties were investigated. Based on the above conditions, the CAPH(sodium alginate:NIPAAm = 2:15) with the best comprehensive performance was selected, which has a good biocompatibility. In addition, 0.02 % (w/v) mupirocin was loaded in CAPH. The temperature-responsive property of PNIPAAm in CAPH at 34 °C not only allowed the CAPH to rapidly release the drug under to prevent infection, but also to assist in wound contraction. Application of CAPH to localized wounds of deep second-degree burns in mice showed a faster healing rate and tissue regeneration. At the same time, collagen recovery was enhanced, collagen bundles were arranged in an orderly manner, and the scarring was not obvious after 16 days. Therefore, this research prepared a new safe and effective biomaterial.
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Affiliation(s)
- Guoguang Chen
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China
| | - Yaxin Zhou
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China
| | - Jie Dai
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China
| | - Shiyu Yan
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China
| | - Wenjun Miao
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China
| | - Lili Ren
- School of pharmacy, Nanjing Tech University, 30th South Puzhu Road, Nanjing 211816, China.
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Zhang N, Wu J, Zhang S, Yuan M, Xu H, Li J, Zhang P, Wang M, Kempher ML, Tao X, Zhang LQ, Ge H, He YX. Molecular basis for coordinating secondary metabolite production by bacterial and plant signaling molecules. J Biol Chem 2022; 298:102027. [PMID: 35568198 PMCID: PMC9163588 DOI: 10.1016/j.jbc.2022.102027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022] Open
Abstract
The production of secondary metabolites is a major mechanism used by beneficial rhizobacteria to antagonize plant pathogens. These bacteria have evolved to coordinate the production of different secondary metabolites due to the heavy metabolic burden imposed by secondary metabolism. However, for most secondary metabolites produced by bacteria, it is not known how their biosynthesis is coordinated. Here, we showed that PhlH from the rhizobacterium Pseudomonas fluorescens is a TetR-family regulator coordinating the expression of enzymes related to the biosynthesis of several secondary metabolites, including 2,4-diacetylphloroglucinol (2,4-DAPG), mupirocin, and pyoverdine. We present structures of PhlH in both its apo form and 2,4-DAPG-bound form and elucidate its ligand-recognizing and allosteric switching mechanisms. Moreover, we found that dissociation of 2,4-DAPG from the ligand-binding domain of PhlH was sufficient to allosterically trigger a pendulum-like movement of the DNA-binding domains within the PhlH dimer, leading to a closed-to-open conformational transition. Finally, molecular dynamics simulations confirmed that two distinct conformational states were stabilized by specific hydrogen bonding interactions and that disruption of these hydrogen bonds had profound effects on the conformational transition. Our findings not only reveal a well-conserved route of allosteric signal transduction in TetR-family regulators but also provide novel mechanistic insights into bacterial metabolic coregulation.
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Affiliation(s)
- Nannan Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.
| | - Jin Wu
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Siping Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Maoran Yuan
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Hang Xu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Jie Li
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Pingping Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China
| | - Mingzhu Wang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Megan L Kempher
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Xuanyu Tao
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Li-Qun Zhang
- College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Honghua Ge
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China.
| | - Yong-Xing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China.
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Santos-Aberturas J, Vior NM. Beyond Soil-Dwelling Actinobacteria: Fantastic Antibiotics and Where to Find Them. Antibiotics (Basel) 2022; 11:195. [PMID: 35203798 PMCID: PMC8868522 DOI: 10.3390/antibiotics11020195] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 12/10/2022] Open
Abstract
Bacterial secondary metabolites represent an invaluable source of bioactive molecules for the pharmaceutical and agrochemical industries. Although screening campaigns for the discovery of new compounds have traditionally been strongly biased towards the study of soil-dwelling Actinobacteria, the current antibiotic resistance and discovery crisis has brought a considerable amount of attention to the study of previously neglected bacterial sources of secondary metabolites. The development and application of new screening, sequencing, genetic manipulation, cultivation and bioinformatic techniques have revealed several other groups of bacteria as producers of striking chemical novelty. Biosynthetic machineries evolved from independent taxonomic origins and under completely different ecological requirements and selective pressures are responsible for these structural innovations. In this review, we summarize the most important discoveries related to secondary metabolites from alternative bacterial sources, trying to provide the reader with a broad perspective on how technical novelties have facilitated the access to the bacterial metabolic dark matter.
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Affiliation(s)
| | - Natalia M. Vior
- Department of Molecular Microbiology, John Innes Centre, Norwich NR7 4UH, UK
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Pseudomonas protegens FJKB0103 Isolated from Rhizosphere Exhibits Anti-Methicillin-Resistant Staphylococcus aureus Activity. Microorganisms 2022; 10:microorganisms10020315. [PMID: 35208770 PMCID: PMC8877278 DOI: 10.3390/microorganisms10020315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus is amongst the most virulent pathogens, causing chronic and life-threatening human infections. Methicillin-resistant S. aureus (MRSA) are multidrug-resistant strains, and the ability of forming a biofilm reduces their sensitivity to antibiotics. Thus, the alternative compounds inhibiting both resistant strains and biofilm formation are in high demand. In our study, the strain FJKB0103 was isolated from the rhizosphere of Garcinia mangostana, showing strong anti-MRSA activity. We performed molecular phylogenic analysis, analyzed average nucleotide identity (ANI), in silico DNA-DNA hybridization (isDDH), and biochemical characteristics to identify strain FJKB0103 as Pseudomonas protegens. Herein, the genome of strain FJKB0103 was sequenced and subjected to antiSMASH platform, mutational, and functional analyses. The FJKB0103 draft genome was 6,776,967 bp with a 63.4% G + C content, and 16 potential secondary compound biosynthetic clusters in P. protegens FJKB0103 were predicted. The deletion mutant and complementary analysis suggested that DAPG was the anti-MRSA compound. Further tests showed that MRSA strains were sensitive to DAPG, and the lysis of bacterial cells was observed at a high concentration of DAPG. Additionally, DAPG inhibited the biofilm formation of MRSA at subinhibitory concentration. These results suggested that DAPG might be a good alternative treatment to control infections caused by MRSA.
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Naureen Z, Gilani SA, Benny BK, Sadia H, Hafeez FY, Khanum A. Metabolomic Profiling of Plant Growth-Promoting Rhizobacteria for Biological Control of Phytopathogens. Fungal Biol 2022. [DOI: 10.1007/978-3-031-04805-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Apura P, Gonçalves LG, Viegas SC, Arraiano CM. The world of ribonucleases from pseudomonads: a short trip through the main features and singularities. Microb Biotechnol 2021; 14:2316-2333. [PMID: 34427985 PMCID: PMC8601179 DOI: 10.1111/1751-7915.13890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/30/2021] [Indexed: 11/27/2022] Open
Abstract
The development of synthetic biology has brought an unprecedented increase in the number molecular tools applicable into a microbial chassis. The exploration of such tools into different bacteria revealed not only the challenges of context dependency of biological functions but also the complexity and diversity of regulatory layers in bacterial cells. Most of the standardized genetic tools and principles/functions have been mostly based on model microorganisms, namely Escherichia coli. In contrast, the non-model pseudomonads lack a deeper understanding of their regulatory layers and have limited molecular tools. They are resistant pathogens and promising alternative bacterial chassis, making them attractive targets for further studies. Ribonucleases (RNases) are key players in the post-transcriptional control of gene expression by degrading or processing the RNA molecules in the cell. These enzymes act according to the cellular requirements and can also be seen as the recyclers of ribonucleotides, allowing a continuous input of these cellular resources. This makes these post-transcriptional regulators perfect candidates to regulate microbial physiology. This review summarizes the current knowledge and unique properties of ribonucleases in the world of pseudomonads, taking into account genomic context analysis, biological function and strategies to use ribonucleases to improve biotechnological processes.
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Affiliation(s)
- Patrícia Apura
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Luis G. Gonçalves
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Sandra C. Viegas
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
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9
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Williams EP, Bachvaroff TR, Place AR. A Global Approach to Estimating the Abundance and Duplication of Polyketide Synthase Domains in Dinoflagellates. Evol Bioinform Online 2021; 17:11769343211031871. [PMID: 34345159 PMCID: PMC8283056 DOI: 10.1177/11769343211031871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 06/23/2021] [Indexed: 11/17/2022] Open
Abstract
Many dinoflagellate species make toxins in a myriad of different molecular configurations but the underlying chemistry in all cases is presumably via modular synthases, primarily polyketide synthases. In many organisms modular synthases occur as discrete synthetic genes or domains within a gene that act in coordination thus forming a module that produces a particular fragment of a natural product. The modules usually occur in tandem as gene clusters with a syntenic arrangement that is often predictive of the resultant structure. Dinoflagellate genomes however are notoriously complex with individual genes present in many tandem repeats and very few synthetic modules occurring as gene clusters, unlike what has been seen in bacteria and fungi. However, modular synthesis in all organisms requires a free thiol group that acts as a carrier for sequential synthesis called a thiolation domain. We scanned 47 dinoflagellate transcriptomes for 23 modular synthase domain models and compared their abundance among 10 orders of dinoflagellates as well as their co-occurrence with thiolation domains. The total count of domain types was quite large with over thirty-thousand identified, 29 000 of which were in the core dinoflagellates. Although there were no specific trends in domain abundance associated with types of toxins, there were readily observable lineage specific differences. The Gymnodiniales, makers of long polyketide toxins such as brevetoxin and karlotoxin had a high relative abundance of thiolation domains as well as multiple thiolation domains within a single transcript. Orders such as the Gonyaulacales, makers of small polyketides such as spirolides, had fewer thiolation domains but a relative increase in the number of acyl transferases. Unique to the core dinoflagellates, however, were thiolation domains occurring alongside tetratricopeptide repeats that facilitate protein-protein interactions, especially hexa and hepta-repeats, that may explain the scaffolding required for synthetic complexes capable of making large toxins. Clustering analysis for each type of domain was also used to discern possible origins of duplication for the multitude of single domain transcripts. Single domain transcripts frequently clustered with synonymous domains from multi-domain transcripts such as the BurA and ZmaK like genes as well as the multi-ketosynthase genes, sometimes with a large degree of apparent gene duplication, while fatty acid synthesis genes formed distinct clusters. Surprisingly the acyl-transferases and ketoreductases involved in fatty acid synthesis (FabD and FabG, respectively) were found in very large clusters indicating an unprecedented degree of gene duplication for these genes. These results demonstrate a complex evolutionary history of core dinoflagellate modular synthases with domain specific duplications throughout the lineage as well as clues to how large protein complexes can be assembled to synthesize the largest natural products known.
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Affiliation(s)
- Ernest P Williams
- Institute of Marine and Environmental Technologies, University of Maryland Center for Environmental Science, Baltimore, MD, USA
| | - Tsvetan R Bachvaroff
- Institute of Marine and Environmental Technologies, University of Maryland Center for Environmental Science, Baltimore, MD, USA
| | - Allen R Place
- Institute of Marine and Environmental Technologies, University of Maryland Center for Environmental Science, Baltimore, MD, USA
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Walker PD, Weir ANM, Willis CL, Crump MP. Polyketide β-branching: diversity, mechanism and selectivity. Nat Prod Rep 2021; 38:723-756. [PMID: 33057534 DOI: 10.1039/d0np00045k] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: 2008 to August 2020 Polyketides are a family of natural products constructed from simple building blocks to generate a diverse range of often complex chemical structures with biological activities of both pharmaceutical and agrochemical importance. Their biosynthesis is controlled by polyketide synthases (PKSs) which catalyse the condensation of thioesters to assemble a functionalised linear carbon chain. Alkyl-branches may be installed at the nucleophilic α- or electrophilic β-carbon of the growing chain. Polyketide β-branching is a fascinating biosynthetic modification that allows for the conversion of a β-ketone into a β-alkyl group or functionalised side-chain. The overall transformation is catalysed by a multi-protein 3-hydroxy-3-methylglutaryl synthase (HMGS) cassette and is reminiscent of the mevalonate pathway in terpene biosynthesis. The first step most commonly involves the aldol addition of acetate to the electrophilic carbon of the β-ketothioester catalysed by a 3-hydroxy-3-methylglutaryl synthase (HMGS). Subsequent dehydration and decarboxylation selectively generates either α,β- or β,γ-unsaturated β-alkyl branches which may be further modified. This review covers 2008 to August 2020 and summarises the diversity of β-branch incorporation and the mechanistic details of each catalytic step. This is extended to discussion of polyketides containing multiple β-branches and the selectivity exerted by the PKS to ensure β-branching fidelity. Finally, the application of HMGS in data mining, additional β-branching mechanisms and current knowledge of the role of β-branches in this important class of biologically active natural products is discussed.
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Affiliation(s)
- P D Walker
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - A N M Weir
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - C L Willis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - M P Crump
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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Mujwar S, Deshmukh R, Harwansh RK, Gupta JK, Gour A. Drug Repurposing Approach for Developing Novel Therapy Against Mupirocin-Resistant Staphylococcus aureus. Assay Drug Dev Technol 2020; 17:298-309. [PMID: 31634019 DOI: 10.1089/adt.2019.944] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Multidrug resistance (MDR) is a major health issue for the treatment of infectious diseases throughout the world. Staphylococcus aureus (S. aureus) is a Gram-positive bacteria, responsible for various local and systemic infections in humans. The continuous and abrupt use of antibiotics against bacteria such as S. aureus results in the development of resistant strains. Presently, mupirocin (MUP) is the drug of choice against S. aureus and MDR (methicillin-resistant). However, S. aureus has acquired resistance against MUP as well due to isoleucyl-tRNA synthetase (IleS) mutation at sites 588 and 631. Thus, the aim of the present study was to discover novel bioactives against MUP-resistant S. aureus using in silico drug repurposing approaches. In silico drug repurposing techniques were used to obtain suitable bioactive lead molecules such as buclizine, tasosartan, emetine, medrysone, and so on. These lead molecules might be able to resolve this issue. These leads were obtained through molecular docking simulation based virtual screening, which could be promising for the treatment of MUP-resistant S. aureus. The findings of the present work need to be validated further through in vitro and in vivo studies for their clinical application.
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Affiliation(s)
- Somdutt Mujwar
- Institute of Pharmaceutical Research, GLA University, Mathura, India
| | - Rohitas Deshmukh
- Institute of Pharmaceutical Research, GLA University, Mathura, India
| | - Ranjit K Harwansh
- Institute of Pharmaceutical Research, GLA University, Mathura, India
| | | | - Alekh Gour
- Department of Biological Management, Goa Institute of Management, Sanquelim, India
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12
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Wan X, Yao G, Liu Y, Chen J, Jiang H. Research Progress in the Biosynthetic Mechanisms of Marine Polyether Toxins. Mar Drugs 2019; 17:E594. [PMID: 31652489 PMCID: PMC6835853 DOI: 10.3390/md17100594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022] Open
Abstract
Marine polyether toxins, mainly produced by marine dinoflagellates, are novel, complex, and diverse natural products with extensive toxicological and pharmacological effects. Owing to their harmful effects during outbreaks of marine red tides, as well as their potential value for the development of new drugs, marine polyether toxins have been extensively studied, in terms of toxicology, pharmacology, detection, and analysis, structural identification, as well as their biosynthetic mechanisms. Although the biosynthetic mechanisms of marine polyether toxins are still unclear, certain progress has been made. In this review, research progress and current knowledge on the biosynthetic mechanisms of polyether toxins are summarized, including the mechanisms of carbon skeleton deletion, pendant alkylation, and polyether ring formation, along with providing a summary of mined biosynthesis-related genes. Finally, future research directions and applications of marine polyether toxins are discussed.
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Affiliation(s)
- Xiukun Wan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Yanli Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
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Sakr A, Brégeon F, Rolain JM, Blin O. Staphylococcus aureus nasal decolonization strategies: a review. Expert Rev Anti Infect Ther 2019; 17:327-340. [PMID: 31012332 DOI: 10.1080/14787210.2019.1604220] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Introduction: Staphylococcus aureus (S. aureus) infections are associated with increased morbidity, mortality and health-care costs. Persistent nasal carriage of S. aureus found in 10-30% of the general population, constitutes a risk factor for these infections. Nasal decolonization is one of the used strategies to prevent this risk in some situations. Areas covered: Mupirocin nasal ointment has been used for the nasal decolonization and prevention of staphylococcal infections in various settings like surgeries. However, rising rates of resistance to mupirocin require the development of new decolonization agents. In this review, we will discuss mupirocin, its origins, studies that proved its efficacy and the associated resistance, as well as other decolonization agents under investigation. Expert opinion: As some limitations exist to mupirocin use, further research for alternatives is encouraged. Some old approved antiseptics (chlorhexidine, povidone-iodine) or antibiotics (rifampicin, bacitracin) have been investigated for their efficacy in this indication. Other new agents (tea tree oil, retapamulin, LTX-109, XF-73, phages, lysostaphin, squalamine analogues, etc.) are being studied. Some of them are still in preclinical phases, and others have reached clinical trials, but further research is needed. Special interest should be given to single dose decolonization strategies and to molecules that do not select resistant strains.
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Affiliation(s)
- Adèle Sakr
- a R&D department , Biosqual SAS , Marseille , France
| | - Fabienne Brégeon
- b IRD, APHM, MEPHI, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie , Aix Marseille Univ , Marseille , France
| | - Jean-Marc Rolain
- b IRD, APHM, MEPHI, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie , Aix Marseille Univ , Marseille , France
| | - Olivier Blin
- c Service de Pharmacologie Clinique et Pharmacovigilance, AP-HM, Pharmacologie intégrée et interface clinique et industriel , Institut de Neurosciences des Systèmes, UMR AMU-INSERM 1106 , Marseille , France
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14
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Tucaliuc A, Blaga AC, Galaction AI, Cascaval D. Mupirocin: applications and production. Biotechnol Lett 2019; 41:495-502. [PMID: 30927135 DOI: 10.1007/s10529-019-02670-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 03/27/2019] [Indexed: 12/30/2022]
Abstract
Mupirocin is an antibiotic from monocarboxylic acid class used as antibacterial agent against methicillin-resistant Staphylococcus aureus (MRSA) and can be obtained as a mixture of four pseudomonic acids by Pseudomonas fluorescens biosynthesis. Nowadays improving antibiotics occupies an important place in the pharmaceutical industry as more and more resistant microorganisms are developing. Mupirocin is used to control the MRSA outbreaks, for infections of soft tissue or skin and for nasal decolonization. Due to its wide use without prescription, the microorganism's resistance to Mupirocin increased from up to 81%, thus becoming imperative its control or improvement. As the biotechnological production of Mupirocin has not been previously reviewed, in the present paper we summarize some consideration on the biochemical process for the production of pseudomonic acids (submerged fermentation and product recovery). Different strains of Pseudomonas, different culture medium and different conditions for the fermentation were analysed related to the antibiotics yield and the product recovery step is analysed in relation to the final purity. However, many challenges have to be overcome in order to obtain pseudomonic acid new versions with better properties related to antibacterial activity.
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Affiliation(s)
- Alexandra Tucaliuc
- Faculty of Chemical Engineering and Environmental Protection "Cristofor Simionescu", "Gheorghe Asachi" Technical University of Iasi, Iasi, Romania
| | - Alexandra Cristina Blaga
- Faculty of Chemical Engineering and Environmental Protection "Cristofor Simionescu", "Gheorghe Asachi" Technical University of Iasi, Iasi, Romania.
| | - Anca Irina Galaction
- Faculty of Medical Bioengineering, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania
| | - Dan Cascaval
- Faculty of Chemical Engineering and Environmental Protection "Cristofor Simionescu", "Gheorghe Asachi" Technical University of Iasi, Iasi, Romania
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15
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Connolly JA, Wilson A, Macioszek M, Song Z, Wang L, Mohammad HH, Yadav M, di Martino M, Miller CE, Hothersall J, Haines AS, Stephens ER, Crump MP, Willis CL, Simpson TJ, Winn PJ, Thomas CM. Defining the genes for the final steps in biosynthesis of the complex polyketide antibiotic mupirocin by Pseudomonas fluorescens NCIMB10586. Sci Rep 2019; 9:1542. [PMID: 30733464 PMCID: PMC6367315 DOI: 10.1038/s41598-018-38038-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 12/17/2018] [Indexed: 11/09/2022] Open
Abstract
The mupirocin trans-AT polyketide synthase pathway, provides a model system for manipulation of antibiotic biosynthesis. Its final phase involves removal of the tertiary hydroxyl group from pseudomonic acid B, PA-B, producing the fully active PA-A in a complex series of steps. To further clarify requirements for this conversion, we fed extracts containing PA-B to mutants of the producer strain singly deficient in each mup gene. This additionally identified mupM and mupN as required plus the sequence but not enzymic activity of mupL and ruled out need for other mup genes. A plasmid expressing mupLMNOPVCFU + macpE together with a derivative of the producer P. fluorescens strain NCIMB10586 lacking the mup cluster allowed conversion of PA-B to PA-A. MupN converts apo-mAcpE to holo-form while MupM is a mupirocin-resistant isoleucyl tRNA synthase, preventing self-poisoning. Surprisingly, the expression plasmid failed to allow the closely related P. fluorescens strain SBW25 to convert PA-B to PA-A.
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Affiliation(s)
- Jack A Connolly
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,School of Chemistry, University of St Andrews, BMS Building, North Haugh, St Andrews, KY16 9ST, UK
| | - Amber Wilson
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Malgorzata Macioszek
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Dr M. Macioszek, DOCS International Poland, ul. Grojecka 5, 02-019, Warszawa, Poland
| | - Zhongshu Song
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Luoyi Wang
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Hadi H Mohammad
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,College of Medicine, Kirkuk University, Kirkuk, Iraq
| | - Mukul Yadav
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Maura di Martino
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Ms M. di Martino, Dept Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Claire E Miller
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Dr C. E. Miller, The BioHub Birmingham, Birmingham Research Park, 97 Vincent Drive, Edgbaston, Birmingham, B15 2SQ, UK
| | - Joanne Hothersall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Anthony S Haines
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Elton R Stephens
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Matthew P Crump
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Christine L Willis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Thomas J Simpson
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Peter J Winn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Christopher M Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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16
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Francklyn CS, Mullen P. Progress and challenges in aminoacyl-tRNA synthetase-based therapeutics. J Biol Chem 2019; 294:5365-5385. [PMID: 30670594 DOI: 10.1074/jbc.rev118.002956] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are universal enzymes that catalyze the attachment of amino acids to the 3' ends of their cognate tRNAs. The resulting aminoacylated tRNAs are escorted to the ribosome where they enter protein synthesis. By specifically matching amino acids to defined anticodon sequences in tRNAs, ARSs are essential to the physical interpretation of the genetic code. In addition to their canonical role in protein synthesis, ARSs are also involved in RNA splicing, transcriptional regulation, translation, and other aspects of cellular homeostasis. Likewise, aminoacylated tRNAs serve as amino acid donors for biosynthetic processes distinct from protein synthesis, including lipid modification and antibiotic biosynthesis. Thanks to the wealth of details on ARS structures and functions and the growing appreciation of their additional roles regulating cellular homeostasis, opportunities for the development of clinically useful ARS inhibitors are emerging to manage microbial and parasite infections. Exploitation of these opportunities has been stimulated by the discovery of new inhibitor frameworks, the use of semi-synthetic approaches combining chemistry and genome engineering, and more powerful techniques for identifying leads from the screening of large chemical libraries. Here, we review the inhibition of ARSs by small molecules, including the various families of natural products, as well as inhibitors developed by either rational design or high-throughput screening as antibiotics and anti-parasitic therapeutics.
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Affiliation(s)
- Christopher S Francklyn
- From the Department of Biochemistry, College of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Patrick Mullen
- From the Department of Biochemistry, College of Medicine, University of Vermont, Burlington, Vermont 05405
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17
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Matilla MA, Krell T. Plant Growth Promotion and Biocontrol Mediated by Plant-Associated Bacteria. PLANT MICROBIOME: STRESS RESPONSE 2018. [DOI: 10.1007/978-981-10-5514-0_3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Validation of Putative Apicoplast-Targeting Drugs Using a Chemical Supplementation Assay in Cultured Human Malaria Parasites. Antimicrob Agents Chemother 2017; 62:AAC.01161-17. [PMID: 29109165 DOI: 10.1128/aac.01161-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/18/2017] [Indexed: 11/20/2022] Open
Abstract
Malaria parasites contain a relict plastid, the apicoplast, which is considered an excellent drug target due to its bacterial-like ancestry. Numerous parasiticidals have been proposed to target the apicoplast, but few have had their actual targets substantiated. Isopentenyl pyrophosphate (IPP) production is the sole required function of the apicoplast in the blood stage of the parasite life cycle, and IPP supplementation rescues parasites from apicoplast-perturbing drugs. Hence, any drug that kills parasites when IPP is supplied in culture must have a nonapicoplast target. Here, we use IPP supplementation to discriminate whether 23 purported apicoplast-targeting drugs are on- or off-target. We demonstrate that a prokaryotic DNA replication inhibitor (ciprofloxacin), several prokaryotic translation inhibitors (chloramphenicol, doxycycline, tetracycline, clindamycin, azithromycin, erythromycin, and clarithromycin), a tRNA synthase inhibitor (mupirocin), and two IPP synthesis pathway inhibitors (fosmidomycin and FR900098) have apicoplast targets. Intriguingly, fosmidomycin and FR900098 leave the apicoplast intact, whereas the others eventually result in apicoplast loss. Actinonin, an inhibitor of bacterial posttranslational modification, does not produce a typical delayed-death response but is rescued with IPP, thereby confirming its apicoplast target. Parasites treated with putative apicoplast fatty acid pathway inhibitors could not be rescued, demonstrating that these drugs have their primary targets outside the apicoplast, which agrees with the dispensability of the apicoplast fatty acid synthesis pathways in the blood stage of malaria parasites. IPP supplementation provides a simple test of whether a compound has a target in the apicoplast and can be used to screen novel compounds for mode of action.
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19
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Timmermans ML, Paudel YP, Ross AC. Investigating the Biosynthesis of Natural Products from Marine Proteobacteria: A Survey of Molecules and Strategies. Mar Drugs 2017; 15:E235. [PMID: 28762997 PMCID: PMC5577590 DOI: 10.3390/md15080235] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/21/2017] [Accepted: 07/24/2017] [Indexed: 02/07/2023] Open
Abstract
The phylum proteobacteria contains a wide array of Gram-negative marine bacteria. With recent advances in genomic sequencing, genome analysis, and analytical chemistry techniques, a whole host of information is being revealed about the primary and secondary metabolism of marine proteobacteria. This has led to the discovery of a growing number of medically relevant natural products, including novel leads for the treatment of multidrug-resistant Staphylococcus aureus (MRSA) and cancer. Of equal interest, marine proteobacteria produce natural products whose structure and biosynthetic mechanisms differ from those of their terrestrial and actinobacterial counterparts. Notable features of secondary metabolites produced by marine proteobacteria include halogenation, sulfur-containing heterocycles, non-ribosomal peptides, and polyketides with unusual biosynthetic logic. As advances are made in the technology associated with functional genomics, such as computational sequence analysis, targeted DNA manipulation, and heterologous expression, it has become easier to probe the mechanisms for natural product biosynthesis. This review will focus on genomics driven approaches to understanding the biosynthetic mechanisms for natural products produced by marine proteobacteria.
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Affiliation(s)
| | - Yagya P Paudel
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
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20
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Masschelein J, Jenner M, Challis GL. Antibiotics from Gram-negative bacteria: a comprehensive overview and selected biosynthetic highlights. Nat Prod Rep 2017. [PMID: 28650032 DOI: 10.1039/c7np00010c] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: up to 2017The overwhelming majority of antibiotics in clinical use originate from Gram-positive Actinobacteria. In recent years, however, Gram-negative bacteria have become increasingly recognised as a rich yet underexplored source of novel antimicrobials, with the potential to combat the looming health threat posed by antibiotic resistance. In this article, we have compiled a comprehensive list of natural products with antimicrobial activity from Gram-negative bacteria, including information on their biosynthetic origin(s) and molecular target(s), where known. We also provide a detailed discussion of several unusual pathways for antibiotic biosynthesis in Gram-negative bacteria, serving to highlight the exceptional biocatalytic repertoire of this group of microorganisms.
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Affiliation(s)
- J Masschelein
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - M Jenner
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - G L Challis
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
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21
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Matilla MA, Nogellova V, Morel B, Krell T, Salmond GPC. Biosynthesis of the acetyl-CoA carboxylase-inhibiting antibiotic, andrimid in Serratia is regulated by Hfq and the LysR-type transcriptional regulator, AdmX. Environ Microbiol 2016; 18:3635-3650. [PMID: 26914969 PMCID: PMC5216899 DOI: 10.1111/1462-2920.13241] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/20/2016] [Indexed: 12/30/2022]
Abstract
Infections due to multidrug-resistant bacteria represent a major global health challenge. To combat this problem, new antibiotics are urgently needed and some plant-associated bacteria are a promising source. The rhizobacterium Serratia plymuthica A153 produces several bioactive secondary metabolites, including the anti-oomycete and antifungal haterumalide, oocydin A and the broad spectrum polyamine antibiotic, zeamine. In this study, we show that A153 produces a second broad spectrum antibiotic, andrimid. Using genome sequencing, comparative genomics and mutagenesis, we defined new genes involved in andrimid (adm) biosynthesis. Both the expression of the adm gene cluster and regulation of andrimid synthesis were investigated. The biosynthetic cluster is operonic and its expression is modulated by various environmental cues, including temperature and carbon source. Analysis of the genome context of the adm operon revealed a gene encoding a predicted LysR-type regulator, AdmX, apparently unique to Serratia strains. Mutagenesis and gene expression assays demonstrated that AdmX is a transcriptional activator of the adm gene cluster. At the post-transcriptional level, the expression of the adm cluster is positively regulated by the RNA chaperone, Hfq, in an RpoS-independent manner. Our results highlight the complexity of andrimid biosynthesis - an antibiotic with potential clinical and agricultural utility.
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Affiliation(s)
- Miguel A. Matilla
- Department of BiochemistryUniversity of CambridgeTennis Court RoadCambridgeCB2 1QWUK
- Department of Environmental ProtectionEstación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasProf. Albareda 1Granada18008Spain
| | - Veronika Nogellova
- Department of BiochemistryUniversity of CambridgeTennis Court RoadCambridgeCB2 1QWUK
| | - Bertrand Morel
- Department of Environmental ProtectionEstación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasProf. Albareda 1Granada18008Spain
| | - Tino Krell
- Department of Environmental ProtectionEstación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasProf. Albareda 1Granada18008Spain
| | - George P. C. Salmond
- Department of BiochemistryUniversity of CambridgeTennis Court RoadCambridgeCB2 1QWUK
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22
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Shehata HR, Ettinger CL, Eisen JA, Raizada MN. Genes Required for the Anti-fungal Activity of a Bacterial Endophyte Isolated from a Corn Landrace Grown Continuously by Subsistence Farmers Since 1000 BC. Front Microbiol 2016; 7:1548. [PMID: 27757101 PMCID: PMC5047915 DOI: 10.3389/fmicb.2016.01548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022] Open
Abstract
Endophytes are microbes that inhabit internal plant tissues without causing disease. Some endophytes are known to combat pathogens. The corn (maize) landrace Chapalote has been grown continuously by subsistence farmers in the Americas since 1000 BC, without the use of fungicides, and the crop remains highly valued by farmers, in part for its natural tolerance to pests. We hypothesized that the pathogen tolerance of Chapalote may, in part, be due to assistance from its endophytes. We previously identified a bacterial endophyte from Chapalote seeds, Burkholderia gladioli strain 3A12, for its ability to combat a diversity of crop pathogens, including Sclerotinia homoeocarpa, the most important fungal disease of creeping bentgrass, a relative of maize used here as a model system. Strain 3A12 represents a unique opportunity to understand the anti-fungal activities of an endophyte associated with a crop variety grown by subsistence farmers since ancient times. Here, microscopy combined with Tn5-mutagenesis demonstrates that the anti-fungal mode of action of 3A12 involves flagella-dependent swarming toward its pathogen target, attachment and biofilm-mediated microcolony formation. The mutant screen revealed that YajQ, a receptor for the secondary messenger c-di-GMP, is a critical signaling system that mediates this endophytic mobility-based defense for its host. Microbes from the traditional seeds of farmers may represent a new frontier in elucidating host-microbe mutualistic interactions.
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Affiliation(s)
- Hanan R. Shehata
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
- Department of Microbiology, School of Pharmacy, Mansoura UniversityMansoura, Egypt
| | - Cassandra L. Ettinger
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
| | - Jonathan A. Eisen
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
- Department of Medical Microbiology and Immunology, University of California Davis, DavisCA, USA
| | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
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23
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Antimalarial Benzoxaboroles Target Plasmodium falciparum Leucyl-tRNA Synthetase. Antimicrob Agents Chemother 2016; 60:4886-95. [PMID: 27270277 DOI: 10.1128/aac.00820-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 05/26/2016] [Indexed: 01/18/2023] Open
Abstract
There is a need for new antimalarials, ideally with novel mechanisms of action. Benzoxaboroles have been shown to be active against bacteria, fungi, and trypanosomes. Therefore, we investigated the antimalarial activity and mechanism of action of 3-aminomethyl benzoxaboroles against Plasmodium falciparum Two 3-aminomethyl compounds, AN6426 and AN8432, demonstrated good potency against cultured multidrug-resistant (W2 strain) P. falciparum (50% inhibitory concentration [IC50] of 310 nM and 490 nM, respectively) and efficacy against murine Plasmodium berghei infection when administered orally once daily for 4 days (90% effective dose [ED90], 7.4 and 16.2 mg/kg of body weight, respectively). To characterize mechanisms of action, we selected parasites with decreased drug sensitivity by culturing with stepwise increases in concentration of AN6426. Resistant clones were characterized by whole-genome sequencing. Three generations of resistant parasites had polymorphisms in the predicted editing domain of the gene encoding a P. falciparum leucyl-tRNA synthetase (LeuRS; PF3D7_0622800) and in another gene (PF3D7_1218100), which encodes a protein of unknown function. Solution of the structure of the P. falciparum LeuRS editing domain suggested key roles for mutated residues in LeuRS editing. Short incubations with AN6426 and AN8432, unlike artemisinin, caused dose-dependent inhibition of [(14)C]leucine incorporation by cultured wild-type, but not resistant, parasites. The growth of resistant, but not wild-type, parasites was impaired in the presence of the unnatural amino acid norvaline, consistent with a loss of LeuRS editing activity in resistant parasites. In summary, the benzoxaboroles AN6426 and AN8432 offer effective antimalarial activity and act, at least in part, against a novel target, the editing domain of P. falciparum LeuRS.
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24
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Methyltransferases excised from trans-AT polyketide synthases operate on N-acetylcysteamine-bound substrates. J Antibiot (Tokyo) 2016; 69:567-570. [PMID: 27301661 PMCID: PMC4963292 DOI: 10.1038/ja.2016.66] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/02/2016] [Accepted: 05/08/2016] [Indexed: 12/20/2022]
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25
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Klochko VV, Zelena LB, Kim JY, Avdeeva LV, Reva ON. Prospects of a new antistaphylococcal drug batumin revealed by molecular docking and analysis of the complete genome sequence of the batumin-producer Pseudomonas batumici UCM B-321. Int J Antimicrob Agents 2016; 47:56-61. [DOI: 10.1016/j.ijantimicag.2015.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/25/2015] [Accepted: 10/02/2015] [Indexed: 11/16/2022]
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26
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Helfrich EJN, Piel J. Biosynthesis of polyketides by trans-AT polyketide synthases. Nat Prod Rep 2016; 33:231-316. [DOI: 10.1039/c5np00125k] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This review discusses the biosynthesis of natural products that are generated bytrans-AT polyketide synthases, a family of catalytically versatile enzymes that represents one of the major group of proteins involved in the production of bioactive polyketides.
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Affiliation(s)
- Eric J. N. Helfrich
- Institute of Microbiology
- Eidgenössische Technische Hochschule (ETH) Zurich
- 8093 Zurich
- Switzerland
| | - Jörn Piel
- Institute of Microbiology
- Eidgenössische Technische Hochschule (ETH) Zurich
- 8093 Zurich
- Switzerland
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27
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Jungmann K, Jansen R, Gerth K, Huch V, Krug D, Fenical W, Müller R. Two of a Kind--The Biosynthetic Pathways of Chlorotonil and Anthracimycin. ACS Chem Biol 2015; 10:2480-90. [PMID: 26348978 DOI: 10.1021/acschembio.5b00523] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chlorotonil A is a novel polyketide isolated from the myxobacterium Sorangium cellulosum So ce1525 that features a unique gem-dichloro-1,3-dione moiety. It exhibits potent bioactivity, most notably against the problematic malaria pathogen Plasmodium falciparum in the nanomolar range. In addition, strong antibacterial and moderate antifungal activity were determined. The outstanding biological activity of chlorotonil A as well as its unusual chemical structure triggered our interest in elucidating its biosynthesis, a prerequisite for alteration of the scaffold by synthetic biology approaches. This endeavor was facilitated by a recent report describing the strikingly similar structure of anthracimycin from a marine streptomycete, a compound of considerable interest due to its potent antibacterial activity. In this study, we report the identification and characterization of the chlorotonil A biosynthetic gene cluster from So ce1525 and compare it with that for anthracimycin biosynthesis. Access to both gene clusters allowed us to highlight commonalities between the two pathways and revealed striking differences, some of which can plausibly explain the structural differences observed between these intriguing natural products.
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Affiliation(s)
- Katrin Jungmann
- Department of Microbial
Natural Products, Helmholtz Institute for Pharmaceutical Research
Saarland, Helmholtz Centre for Infection Research and Pharmaceutical
Biotechnology, Saarland University, Saarbrücken, Germany
| | - Rolf Jansen
- Helmholtz Centre for Infection Research, Department of Microbial Drugs, Braunschweig, Germany
| | - Klaus Gerth
- Helmholtz Centre for Infection Research, Department of Microbial Drugs, Braunschweig, Germany
| | - Volker Huch
- Department of Microbial
Natural Products, Helmholtz Institute for Pharmaceutical Research
Saarland, Helmholtz Centre for Infection Research and Pharmaceutical
Biotechnology, Saarland University, Saarbrücken, Germany
| | - Daniel Krug
- Department of Microbial
Natural Products, Helmholtz Institute for Pharmaceutical Research
Saarland, Helmholtz Centre for Infection Research and Pharmaceutical
Biotechnology, Saarland University, Saarbrücken, Germany
| | - William Fenical
- Center for Marine
Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, United States
| | - Rolf Müller
- Department of Microbial
Natural Products, Helmholtz Institute for Pharmaceutical Research
Saarland, Helmholtz Centre for Infection Research and Pharmaceutical
Biotechnology, Saarland University, Saarbrücken, Germany
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Matilla MA, Leeper FJ, Salmond GPC. Biosynthesis of the antifungal haterumalide, oocydin A, in Serratia, and its regulation by quorum sensing, RpoS and Hfq. Environ Microbiol 2015; 17:2993-3008. [PMID: 25753587 PMCID: PMC4552970 DOI: 10.1111/1462-2920.12839] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/27/2015] [Accepted: 03/02/2015] [Indexed: 02/02/2023]
Abstract
Polyketides represent an important class of bioactive natural products with a broad range of biological activities. We identified recently a large trans-acyltransferase (AT) polyketide synthase gene cluster responsible for the biosynthesis of the antifungal, anti-oomycete and antitumor haterumalide, oocydin A (ooc). Using genome sequencing and comparative genomics, we show that the ooc gene cluster is widespread within biocontrol and phytopathogenic strains of the enterobacteria, Serratia and Dickeya. The analysis of in frame deletion mutants confirmed the role of a hydroxymethylglutaryl-coenzyme A synthase cassette, three flavin-dependent tailoring enzymes, a free-standing acyl carrier protein and two hypothetical proteins in oocydin A biosynthesis. The requirement of the three trans-acting AT domains for the biosynthesis of the macrolide was also demonstrated. Expression of the ooc gene cluster was shown to be positively regulated by an N-acyl-L-homoserine lactone-based quorum sensing system, but operating in a strain-dependent manner. At a post-transcriptional level, the RNA chaperone, Hfq, plays a key role in oocydin A biosynthesis. The Hfq-dependent regulation is partially mediated by the stationary phase sigma factor, RpoS, which was also shown to positively regulate the synthesis of the macrolide. Our results reveal differential regulation of the divergently transcribed ooc transcriptional units, highlighting the complexity of oocydin A production.
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Affiliation(s)
- Miguel A Matilla
- Department of Biochemistry, University of CambridgeTennis Court Road, Cambridge, CB2 1QW, UK
| | - Finian J Leeper
- Department of Chemistry, University of CambridgeLensfield Road, Cambridge, CB2 1EW, UK
| | - George P C Salmond
- Department of Biochemistry, University of CambridgeTennis Court Road, Cambridge, CB2 1QW, UK,*For correspondence. E-mail ; Tel. +44 (0)1223 333650; Fax +44 (0)1223 766108
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Mousa WK, Raizada MN. Biodiversity of genes encoding anti-microbial traits within plant associated microbes. FRONTIERS IN PLANT SCIENCE 2015; 6:231. [PMID: 25914708 PMCID: PMC4392301 DOI: 10.3389/fpls.2015.00231] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/23/2015] [Indexed: 05/10/2023]
Abstract
The plant is an attractive versatile home for diverse associated microbes. A subset of these microbes produces a diversity of anti-microbial natural products including polyketides, non-ribosomal peptides, terpenoids, heterocylic nitrogenous compounds, volatile compounds, bacteriocins, and lytic enzymes. In recent years, detailed molecular analysis has led to a better understanding of the underlying genetic mechanisms. New genomic and bioinformatic tools have permitted comparisons of orthologous genes between species, leading to predictions of the associated evolutionary mechanisms responsible for diversification at the genetic and corresponding biochemical levels. The purpose of this review is to describe the biodiversity of biosynthetic genes of plant-associated bacteria and fungi that encode selected examples of antimicrobial natural products. For each compound, the target pathogen and biochemical mode of action are described, in order to draw attention to the complexity of these phenomena. We review recent information of the underlying molecular diversity and draw lessons through comparative genomic analysis of the orthologous coding sequences (CDS). We conclude by discussing emerging themes and gaps, discuss the metabolic pathways in the context of the phylogeny and ecology of their microbial hosts, and discuss potential evolutionary mechanisms that led to the diversification of biosynthetic gene clusters.
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Affiliation(s)
- Walaa K. Mousa
- Department of Plant Agriculture, University of GuelphGuelph, ON, Canada
- Department of Pharmacognosy, Faculty of Pharmacy, Mansoura UniversityMansoura, Egypt
| | - Manish N. Raizada
- Department of Plant Agriculture, University of GuelphGuelph, ON, Canada
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Bojarska J, Maniukiewicz W, Fruziński A, Jędrzejczyk M, Wojciechowski J, Krawczyk H. Structural and spectroscopic characterization and Hirshfeld surface analysis of major component of antibiotic mupirocin – pseudomonic acid A. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.07.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Matthijs S, Vander Wauven C, Cornu B, Ye L, Cornelis P, Thomas CM, Ongena M. Antimicrobial properties of Pseudomonas strains producing the antibiotic mupirocin. Res Microbiol 2014; 165:695-704. [PMID: 25303834 DOI: 10.1016/j.resmic.2014.09.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 09/17/2014] [Accepted: 09/29/2014] [Indexed: 11/19/2022]
Abstract
Mupirocin is a polyketide antibiotic with broad antibacterial activity. It was isolated and characterized about 40 years ago from Pseudomonas fluorescens NCIMB 10586. To study the phylogenetic distribution of mupirocin producing strains in the genus Pseudomonas a large collection of Pseudomonas strains of worldwide origin, consisting of 117 Pseudomonas type strains and 461 strains isolated from different biological origins, was screened by PCR for the mmpD gene of the mupirocin gene cluster. Five mmpD(+) strains from different geographic and biological origin were identified. They all produced mupirocin and were strongly antagonistic against Staphylococcus aureus. Phylogenetic analysis showed that mupirocin production is limited to a single species. Inactivation of mupirocin production leads to complete loss of in vitro antagonism against S. aureus, except on certain iron-reduced media where the siderophore pyoverdine is responsible for the in vitro antagonism of a mupirocin-negative mutant. In addition to mupirocin some of the strains produced lipopeptides of the massetolide group. These lipopeptides do not play a role in the observed in vitro antagonism of the mupirocin producing strains against S. aureus.
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Affiliation(s)
- Sandra Matthijs
- Institut de Recherches Microbiologiques - Wiame, Campus du CERIA, 1 avenue Emile Gryson, bât 4B, B-1070 Bruxelles, Belgium.
| | - Corinne Vander Wauven
- Institut de Recherches Microbiologiques - Wiame, Campus du CERIA, 1 avenue Emile Gryson, bât 4B, B-1070 Bruxelles, Belgium.
| | - Bertrand Cornu
- Institut de Recherches Microbiologiques - Wiame, Campus du CERIA, 1 avenue Emile Gryson, bât 4B, B-1070 Bruxelles, Belgium.
| | - Lumeng Ye
- Department of Bioengineering Sciences, Research Group of Microbiology and Vlaams Instituut voor Biotechnologie, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Pierre Cornelis
- Department of Bioengineering Sciences, Research Group of Microbiology and Vlaams Instituut voor Biotechnologie, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Christopher M Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Marc Ongena
- Walloon Center for Industrial Biology, University of Liège, Gembloux Agro-Bio Tech, Gembloux, Belgium.
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Enzymatic glycosylation of the topical antibiotic mupirocin. Glycoconj J 2014; 31:563-72. [DOI: 10.1007/s10719-014-9538-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 11/26/2022]
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Van Wagoner RM, Satake M, Wright JLC. Polyketide biosynthesis in dinoflagellates: what makes it different? Nat Prod Rep 2014; 31:1101-37. [DOI: 10.1039/c4np00016a] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Musiol EM, Greule A, Härtner T, Kulik A, Wohlleben W, Weber T. The AT₂ domain of KirCI loads malonyl extender units to the ACPs of the kirromycin PKS. Chembiochem 2013; 14:1343-52. [PMID: 23828654 DOI: 10.1002/cbic.201300211] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Indexed: 11/06/2022]
Abstract
The antibiotic kirromycin is assembled by a hybrid modular polyketide synthases (PKSs)/nonribosomal peptide synthetases (NRPSs). Five of six PKSs of this complex assembly line do not have acyltransferase (AT) and have to recruit this activity from discrete AT enzymes. Here, we show that KirCI is a discrete AT which is involved in kirromycin production and displays a rarely found three-domain architecture (AT₁-AT₂-ER). We demonstrate that the second AT domain, KirCI-AT₂, but not KirCI-AT₁, is the malonyl-CoA-specific AT which utilizes this precursor for loading the acyl carrier proteins (ACPs) of the trans-AT PKS in vitro. In the kirromycin biosynthetic pathway, ACP5 is exclusively loaded with ethylmalonate by the enzyme KirCII and is not recognized as a substrate by KirCI. Interestingly, the excised KirCI-AT₂ can also transfer malonate to ACP5 and thus has a relaxed ACP-specificity compared to the entire KirCI protein. The ability of KirCI-AT₂ to load different ACPs provides opportunities for AT engineering as a potential strategy for polyketide diversification.
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Affiliation(s)
- Ewa Maria Musiol
- Mikrobiologie/Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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Orelle C, Szal T, Klepacki D, Shaw KJ, Vázquez-Laslop N, Mankin AS. Identifying the targets of aminoacyl-tRNA synthetase inhibitors by primer extension inhibition. Nucleic Acids Res 2013; 41:e144. [PMID: 23761439 PMCID: PMC3737564 DOI: 10.1093/nar/gkt526] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Aminoacyl-transfer RNA (tRNA) synthetases (RS) are essential components of the cellular translation machinery and can be exploited for antibiotic discovery. Because cells have many different RS, usually one for each amino acid, identification of the specific enzyme targeted by a new natural or synthetic inhibitor can be cumbersome. We describe the use of the primer extension technique in conjunction with specifically designed synthetic genes to identify the RS targeted by an inhibitor. Suppression of a synthetase activity reduces the amount of the cognate aminoacyl-tRNA in a cell-free translation system resulting in arrest of translation when the corresponding codon enters the decoding center of the ribosome. The utility of the technique is demonstrated by identifying a switch in target specificity of some synthetic inhibitors of threonyl-tRNA synthetase.
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Affiliation(s)
- Cédric Orelle
- Center for Pharmaceutical Biotechnology, University of Illinois, Chicago, IL 60607, USA and Trius Therapeutics, Inc., San Diego, CA 92121, USA
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Borgos SEF, Bordel S, Sletta H, Ertesvåg H, Jakobsen Ø, Bruheim P, Ellingsen TE, Nielsen J, Valla S. Mapping global effects of the anti-sigma factor MucA in Pseudomonas fluorescens SBW25 through genome-scale metabolic modeling. BMC SYSTEMS BIOLOGY 2013; 7:19. [PMID: 23497367 PMCID: PMC3641028 DOI: 10.1186/1752-0509-7-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 02/06/2013] [Indexed: 11/26/2022]
Abstract
Background Alginate is an industrially important polysaccharide, currently produced commercially by harvesting of marine brown sea-weeds. The polymer is also synthesized as an exo-polysaccharide by bacteria belonging to the genera Pseudomonas and Azotobacter, and these organisms may represent an alternative alginate source in the future. The current work describes an attempt to rationally develop a biological system tuned for very high levels of alginate production, based on a fundamental understanding of the system through metabolic modeling supported by transcriptomics studies and carefully controlled fermentations. Results Alginate biosynthesis in Pseudomonas fluorescens was studied in a genomics perspective, using an alginate over-producing strain carrying a mutation in the anti-sigma factor gene mucA. Cells were cultivated in chemostats under nitrogen limitation on fructose or glycerol as carbon sources, and cell mass, growth rate, sugar uptake, alginate and CO2 production were monitored. In addition a genome scale metabolic model was constructed and samples were collected for transcriptome analyses. The analyses show that polymer production operates in a close to optimal way with respect to stoichiometric utilization of the carbon source and that the cells increase the uptake of carbon source to compensate for the additional needs following from alginate synthesis. The transcriptome studies show that in the presence of the mucA mutation, the alg operon is upregulated together with genes involved in energy generation, genes on both sides of the succinate node of the TCA cycle and genes encoding ribosomal and other translation-related proteins. Strains expressing a functional MucA protein (no alginate production) synthesize cellular biomass in an inefficient way, apparently due to a cycle that involves oxidation of NADPH without ATP production. The results of this study indicate that the most efficient way of using a mucA mutant as a cell factory for alginate production would be to use non-growing conditions and nitrogen deprivation. Conclusions The insights gained in this study should be very useful for a future efficient production of microbial alginates.
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Affiliation(s)
- Sven E F Borgos
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, N 7491, Norway
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Matilla MA, Stöckmann H, Leeper FJ, Salmond GPC. Bacterial biosynthetic gene clusters encoding the anti-cancer haterumalide class of molecules: biogenesis of the broad spectrum antifungal and anti-oomycete compound, oocydin A. J Biol Chem 2012; 287:39125-38. [PMID: 23012376 PMCID: PMC3493953 DOI: 10.1074/jbc.m112.401026] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/05/2012] [Indexed: 01/16/2023] Open
Abstract
Haterumalides are halogenated macrolides with strong antitumor properties, making them attractive targets for chemical synthesis. Unfortunately, current synthetic routes to these molecules are inefficient. The potent haterumalide, oocydin A, was previously identified from two plant-associated bacteria through its high bioactivity against plant pathogenic fungi and oomycetes. In this study, we describe oocydin A (ooc) biosynthetic gene clusters identified by genome sequencing, comparative genomics, and chemical analysis in four plant-associated enterobacteria of the Serratia and Dickeya genera. Disruption of the ooc gene cluster abolished oocydin A production and bioactivity against fungi and oomycetes. The ooc gene clusters span between 77 and 80 kb and encode five multimodular polyketide synthase (PKS) proteins, a hydroxymethylglutaryl-CoA synthase cassette and three flavin-dependent tailoring enzymes. The presence of two free-standing acyltransferase proteins classifies the oocydin A gene cluster within the growing family of trans-AT PKSs. The amino acid sequences and organization of the PKS domains are consistent with the chemical predictions and functional peculiarities associated with trans-acyltransferase PKS. Based on extensive in silico analysis of the gene cluster, we propose a biosynthetic model for the production of oocydin A and, by extension, for other members of the haterumalide family of halogenated macrolides exhibiting anti-cancer, anti-fungal, and other interesting biological properties.
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Affiliation(s)
- Miguel A. Matilla
- From the Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW and
| | - Henning Stöckmann
- the Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Finian J. Leeper
- the Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - George P. C. Salmond
- From the Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW and
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Lipko IA, Kalyuzhnaya OV, Kravchenko OS, Parfenova VV. Identification of polyketide synthase genes in genome of Pseudomonas fluorescens strain 28Bb-06 from freshwater sponge Baikalospongia bacillifera. Mol Biol 2012. [DOI: 10.1134/s0026893312040073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Jackson KE, Pham JS, Kwek M, De Silva NS, Allen SM, Goodman CD, McFadden GI, Ribas de Pouplana L, Ralph SA. Dual targeting of aminoacyl-tRNA synthetases to the apicoplast and cytosol in Plasmodium falciparum. Int J Parasitol 2012; 42:177-86. [DOI: 10.1016/j.ijpara.2011.11.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 11/22/2011] [Accepted: 11/23/2011] [Indexed: 11/16/2022]
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MupB, a new high-level mupirocin resistance mechanism in Staphylococcus aureus. Antimicrob Agents Chemother 2012; 56:1916-20. [PMID: 22252810 DOI: 10.1128/aac.05325-11] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mupirocin is a topical antibiotic used for the treatment of skin infections and the eradication of methicillin-resistant Staphylococcus aureus carriage. It inhibits bacterial protein synthesis by interfering with isoleucyl-tRNA synthetase activity. High-level mupirocin resistance (MIC of ≥ 512 μg/ml) is mediated by the expression of mupA (ileS2), which encodes an alternate isoleucyl-tRNA synthetase. In this study, we describe high-level mupirocin resistance mediated by a novel locus, mupB. The mupB gene (3,102 bp) shares 65.5% sequence identity with mupA but only 45.5% identity with ileS. The deduced MupB protein shares 58.1% identity (72.3% similarity) and 25.4% identity (41.8% similarity) with MupA and IleS, respectively. Despite this limited homology, MupB contains conserved motifs found in class I tRNA synthetases. Attempts to transfer high-level mupirocin resistance via conjugation or transformation (using plasmid extracts from an mupB-containing strain) were unsuccessful. However, by cloning the mupB gene into a shuttle vector, it was possible to transfer the resistance phenotype to susceptible S. aureus by electroporation, proving that mupB was responsible for the high-level mupirocin resistance. Further studies need to be done to determine the prevalence of mupB and to understand risk factors and outcomes associated with resistance mediated by this gene.
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42
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Musiol EM, Weber T. Discrete acyltransferases involved in polyketide biosynthesis. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md20048a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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