1
|
Kim B, Han SR, Lee H, Oh TJ. Insights into group-specific pattern of secondary metabolite gene cluster in Burkholderia genus. Front Microbiol 2024; 14:1302236. [PMID: 38293557 PMCID: PMC10826400 DOI: 10.3389/fmicb.2023.1302236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/21/2023] [Indexed: 02/01/2024] Open
Abstract
Burkholderia is a versatile strain that has expanded into several genera. It has been steadily reported that the genome features of Burkholderia exhibit activities ranging from plant growth promotion to pathogenicity across various isolation areas. The objective of this study was to investigate the secondary metabolite patterns of 366 Burkholderia species through comparative genomics. Samples were selected based on assembly quality assessment and similarity below 80% in average nucleotide identity. Duplicate samples were excluded. Samples were divided into two groups using FastANI analysis. Group A included B. pseudomallei complex. Group B included B. cepacia complex. The limitations of MLST were proposed. The detection of genes was performed, including environmental and virulence-related genes. In the pan-genome analysis, each complex possessed a similar pattern of cluster for orthologous groups. Group A (n = 185) had 14,066 cloud genes, 2,465 shell genes, 682 soft-core genes, and 2,553 strict-core genes. Group B (n = 181) had 39,867 cloud genes, 4,986 shell genes, 324 soft-core genes, 222 core genes, and 2,949 strict-core genes. AntiSMASH was employed to analyze the biosynthetic gene cluster (BGC). The results were then utilized for network analysis using BiG-SCAPE and CORASON. Principal component analysis was conducted and a table was constructed using the results obtained from antiSMASH. The results were divided into Group A and Group B. We expected the various species to show similar patterns of secondary metabolite gene clusters. For in-depth analysis, a network analysis of secondary metabolite gene clusters was conducted, exemplified by BiG-SCAPE analysis. Depending on the species and complex, Burkholderia possessed several kinds of siderophore. Among them, ornibactin was possessed in most Burkholderia and was clustered into 4,062 clans. There was a similar pattern of gene clusters depending on the species. NRPS_04014 belonged to siderophore BGCs including ornibactin and indigoidine. However, it was observed that each family included a similar species. This suggests that, besides siderophores being species-specific, the ornibactin gene cluster itself might also be species-specific. The results suggest that siderophores are associated with environmental adaptation, possessing a similar pattern of siderophore gene clusters among species, which could provide another perspective on species-specific environmental adaptation mechanisms.
Collapse
Affiliation(s)
- Byeollee Kim
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan, Republic of Korea
| | - So-Ra Han
- Genome-Based BioIT Convergence Institute, Asan, Republic of Korea
| | - Hyun Lee
- Genome-Based BioIT Convergence Institute, Asan, Republic of Korea
- Division of Computer Science and Engineering, SunMoon University, Asan, Republic of Korea
| | - Tae-Jin Oh
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan, Republic of Korea
- Genome-Based BioIT Convergence Institute, Asan, Republic of Korea
- Department of Pharmaceutical Engineering and Biotechnology, SunMoon University, Asan, Republic of Korea
| |
Collapse
|
2
|
Compilation of the Antimicrobial Compounds Produced by Burkholderia Sensu Stricto. Molecules 2023; 28:molecules28041646. [PMID: 36838633 PMCID: PMC9958762 DOI: 10.3390/molecules28041646] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/26/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
Due to the increase in multidrug-resistant microorganisms, the investigation of novel or more efficient antimicrobial compounds is essential. The World Health Organization issued a list of priority multidrug-resistant bacteria whose eradication will require new antibiotics. Among them, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae are in the "critical" (most urgent) category. As a result, major investigations are ongoing worldwide to discover new antimicrobial compounds. Burkholderia, specifically Burkholderia sensu stricto, is recognized as an antimicrobial-producing group of species. Highly dissimilar compounds are among the molecules produced by this genus, such as those that are unique to a particular strain (like compound CF66I produced by Burkholderia cepacia CF-66) or antimicrobials found in a number of species, e.g., phenazines or ornibactins. The compounds produced by Burkholderia include N-containing heterocycles, volatile organic compounds, polyenes, polyynes, siderophores, macrolides, bacteriocins, quinolones, and other not classified antimicrobials. Some of them might be candidates not only for antimicrobials for both bacteria and fungi, but also as anticancer or antitumor agents. Therefore, in this review, the wide range of antimicrobial compounds produced by Burkholderia is explored, focusing especially on those compounds that were tested in vitro for antimicrobial activity. In addition, information was gathered regarding novel compounds discovered by genome-guided approaches.
Collapse
|
3
|
Adaikpoh BI, Fernandez HN, Eustáquio AS. Biotechnology approaches for natural product discovery, engineering, and production based on Burkholderia bacteria. Curr Opin Biotechnol 2022; 77:102782. [PMID: 36049254 DOI: 10.1016/j.copbio.2022.102782] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/13/2022] [Accepted: 07/26/2022] [Indexed: 11/15/2022]
Abstract
Bacterial natural products (NPs) retain high value in discovery efforts for applications in medicine and agriculture. Burkholderia β-Proteobacteria are a promising source of NPs. In this review, we summarize the recently developed genetic manipulation techniques used to access silent/cryptic biosynthetic gene clusters from Burkholderia native producers. We also discuss the development of Burkholderia bacteria as heterologous hosts and the application of Burkholderia in industrial-scale production of NPs. Genetic engineering and fermentation media optimization have enabled the industrial-scale production of at least two Burkholderia NPs. The biotechnology approaches discussed here will continue to facilitate the discovery and development of NPs from Burkholderia.
Collapse
Affiliation(s)
- Barbara I Adaikpoh
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Hannah N Fernandez
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alessandra S Eustáquio
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA.
| |
Collapse
|
4
|
Guidelines for metabolomics-guided transposon mutagenesis for microbial natural product discovery. Methods Enzymol 2022; 665:305-323. [PMID: 35379440 DOI: 10.1016/bs.mie.2021.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is a great discrepancy between the natural product output of cultured microorganisms and their bioinformatically predicted biosynthetic potential, such that most of the molecular diversity contained within microbial reservoirs has yet to be discovered. One of the primary reasons is insufficient expression of natural product biosynthetic gene clusters (BGCs) under standard laboratory conditions. Several methods have been developed to increase production from such "cryptic" BGCs. Among these, we recently implemented mass spectrometry-guided transposon mutagenesis, a forward genetic screen in which mutants that exhibit stimulated biosynthesis of cryptic metabolites, as read out by mass spectrometry, are selected from a transposon mutant library. Herein, we use Burkholderia gladioli as an example and provide guidelines for generating transposon mutant libraries, measuring metabolomic inventories through mass spectrometry, performing comparative metabolomics to prioritize cryptic natural products from the mutant library, and isolating and characterizing novel natural products elicited through mutagenesis. Application of this approach will be useful in both accessing novel natural products from cryptic BGCs and identifying genes involved in their global regulation.
Collapse
|
5
|
Hemmerling F, Piel J. Strategies to access biosynthetic novelty in bacterial genomes for drug discovery. Nat Rev Drug Discov 2022; 21:359-378. [PMID: 35296832 DOI: 10.1038/s41573-022-00414-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2022] [Indexed: 12/17/2022]
Abstract
Bacteria provide a rich source of natural products with potential therapeutic applications, such as novel antibiotic classes or anticancer drugs. Bioactivity-guided screening of bacterial extracts and characterization of biosynthetic pathways for drug discovery is now complemented by the availability of large (meta)genomic collections, placing researchers into the postgenomic, big-data era. The progress in next-generation sequencing and the rise of powerful computational tools provide unprecedented insights into unexplored taxa, ecological niches and 'biosynthetic dark matter', revealing diverse and chemically distinct natural products in previously unstudied bacteria. In this Review, we discuss such sources of new chemical entities and the implications for drug discovery with a particular focus on the strategies that have emerged in recent years to identify and access novelty.
Collapse
Affiliation(s)
- Franziska Hemmerling
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Jörn Piel
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland.
| |
Collapse
|
6
|
Aursnes M, Primdahl KG, Kaupang Å, Park JD, Seyedsayamdost MR, Nolsøe JMJ. On the Structure of Thailandene A: Synthetic Examination of the Cryptic Natural Product Aided by a Theoretical Approach. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/s-0041-1737242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractPhenotype-guided transposon mutagenesis has emerged as a valuable tool to access cryptic metabolites encoded in bacterial genomes. Recently, the method was demonstrated by inducing silent biosynthetic gene clusters in Burkholderia thailandensis. Amongst the isolated metabolic products, thailandene A exhibited promising antibiotic activity. By assignment, the linear polyenic aldehyde contained a labile motif, where an ostensible chiral secondary alcohol was interlaced in an allylic and a homoallylic constellation. Our attention was drawn to the pseudo-symmetric relationship between the heterofunctionalities, indicating the transformation of a dodecapentaenedial scaffold. Centering on an iterative cross-coupling protocol, the assigned all-E-(12R)-hydroxydodecapentaenal moiety was assembled by combining Zincke chemistry with the MIDA-attenuated Suzuki reaction developed in the Burke laboratory. Thus, according to the devised strategy, the mixed 1,2-bisborylated vinyl linchpin was consecutively functionalized with 5-bromodienal derivatives in a doubly orthogonal fashion. However, when the synthetic material was matched against the bacterial isolate, inconsistencies were observed. A re-examination of the cryptic natural product was conducted by juxtaposing analytical data from experiment and density functional theory calculations, in which hydroperoxide was evaluated as a candidate metabolite present in the bacterial isolate.
Collapse
Affiliation(s)
- Marius Aursnes
- Department of Pharmaceutical Chemistry, University of Oslo
| | | | - Åsmund Kaupang
- Department of Pharmaceutical Chemistry, University of Oslo
| | | | | | - Jens M. J. Nolsøe
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
| |
Collapse
|
7
|
Bach E, Passaglia LMP, Jiao J, Gross H. Burkholderia in the genomic era: from taxonomy to the discovery of new antimicrobial secondary metabolites. Crit Rev Microbiol 2021; 48:121-160. [PMID: 34346791 DOI: 10.1080/1040841x.2021.1946009] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Species of Burkholderia are highly versatile being found not only abundantly in soil, but also as plants and animals' commensals or pathogens. Their complex multireplicon genomes harbour an impressive number of polyketide synthase (PKS) and nonribosomal peptide-synthetase (NRPS) genes coding for the production of antimicrobial secondary metabolites (SMs), which have been successfully deciphered by genome-guided tools. Moreover, genome metrics supported the split of this genus into Burkholderia sensu stricto (s.s.) and five new other genera. Here, we show that the successful antimicrobial SMs producers belong to Burkholderia s.s. Additionally, we reviewed the occurrence, bioactivities, modes of action, structural, and biosynthetic information of thirty-eight Burkholderia antimicrobial SMs shedding light on their diversity, complexity, and uniqueness as well as the importance of genome-guided strategies to facilitate their discovery. Several Burkholderia NRPS and PKS display unusual features, which are reflected in their structural diversity, important bioactivities, and varied modes of action. Up to now, it is possible to observe a general tendency of Burkholderia SMs being more active against fungi. Although the modes of action and biosynthetic gene clusters of many SMs remain unknown, we highlight the potential of Burkholderia SMs as alternatives to fight against new diseases and antibiotic resistance.
Collapse
Affiliation(s)
- Evelise Bach
- Departamento de Genética and Programa de Pós-graduação em Genética e Biologia Molecular, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Luciane Maria Pereira Passaglia
- Departamento de Genética and Programa de Pós-graduação em Genética e Biologia Molecular, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Junjing Jiao
- Department for Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Tübingen, Germany
| | - Harald Gross
- Department for Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Tübingen, Germany
| |
Collapse
|
8
|
Li A, Okada BK, Rosen PC, Seyedsayamdost MR. Piperacillin triggers virulence factor biosynthesis via the oxidative stress response in Burkholderia thailandensis. Proc Natl Acad Sci U S A 2021; 118:e2021483118. [PMID: 34172579 PMCID: PMC8256049 DOI: 10.1073/pnas.2021483118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Natural products have been an important source of therapeutic agents and chemical tools. The recent realization that many natural product biosynthetic genes are silent or sparingly expressed during standard laboratory growth has prompted efforts to investigate their regulation and develop methods to induce their expression. Because it is difficult to intuit signals that induce a given biosynthetic locus, we recently implemented a forward chemical-genetic approach to identify such inducers. In the current work, we applied this approach to nine silent biosynthetic loci in the model bacterium Burkholderia thailandensis to systematically screen for elicitors from a library of Food and Drug Administration-approved drugs. We find that β-lactams, fluoroquinolones, antifungals, and, surprisingly, calcimimetics, phenothiazine antipsychotics, and polyaromatic antidepressants are the most effective global inducers of biosynthetic genes. Investigations into the mechanism of stimulation of the silent virulence factor malleicyprol by the β-lactam piperacillin allowed us to elucidate the underlying regulatory circuits. Low-dose piperacillin causes oxidative stress, thereby inducing redox-sensing transcriptional regulators, which activate malR, a pathway-specific positive regulator of the malleicyprol gene cluster. Malleicyprol is thus part of the OxyR and SoxR regulons in B. thailandensis, allowing the bacterium to initiate virulence in response to oxidative stress. Our work catalogs a diverse array of elicitors and a previously unknown regulatory input for secondary metabolism in B. thailandensis.
Collapse
Affiliation(s)
- Anran Li
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Bethany K Okada
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| | - Paul C Rosen
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| | - Mohammad R Seyedsayamdost
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544;
- Department of Chemistry, Princeton University, Princeton, NJ 08544
| |
Collapse
|
9
|
Covington BC, Xu F, Seyedsayamdost MR. A Natural Product Chemist's Guide to Unlocking Silent Biosynthetic Gene Clusters. Annu Rev Biochem 2021; 90:763-788. [PMID: 33848426 PMCID: PMC9148385 DOI: 10.1146/annurev-biochem-081420-102432] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microbial natural products have provided an important source of therapeutic leads and motivated research and innovation in diverse scientific disciplines. In recent years, it has become evident that bacteria harbor a large, hidden reservoir of potential natural products in the form of silent or cryptic biosynthetic gene clusters (BGCs). These can be readily identified in microbial genome sequences but do not give rise to detectable levels of a natural product. Herein, we provide a useful organizational framework for the various methods that have been implemented for interrogating silent BGCs. We divide all available approaches into four categories. The first three are endogenous strategies that utilize the native host in conjunction with classical genetics, chemical genetics, or different culture modalities. The last category comprises expression of the entire BGC in a heterologous host. For each category, we describe the rationale, recent applications, and associated advantages and limitations.
Collapse
Affiliation(s)
- Brett C Covington
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA; ,
| | - Fei Xu
- Institute of Pharmaceutical Biotechnology and Department of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China;
| | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA; ,
- Department of Molecular Biology, Princeton University, New Jersey 08544, USA
| |
Collapse
|
10
|
Burkholderia thailandensis Methylated Hydroxyalkylquinolines: Biosynthesis and Antimicrobial Activity in Cocultures. Appl Environ Microbiol 2020; 86:AEM.01452-20. [PMID: 33008823 DOI: 10.1128/aem.01452-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/15/2020] [Indexed: 02/04/2023] Open
Abstract
The bacterium Burkholderia thailandensis produces an arsenal of secondary metabolites that have diverse structures and roles in the ecology of this soil-dwelling bacterium. In coculture experiments, B. thailandensis strain E264 secretes an antimicrobial that nearly eliminates another soil bacterium, Bacillus subtilis strain 168. To identify the antimicrobial, we used a transposon mutagenesis approach. This screen identified antimicrobial-defective mutants with insertions in the hmqA, hmqC, and hmqF genes involved in biosynthesis of a family of 2-alkyl-4(1H)-quinolones called 4-hydroxy-3-methyl-2-alkenylquinolines (HMAQs), which are closely related to the Pseudomonas aeruginosa 4-hydroxy-2-alkylquinolines (HAQs). Insertions also occurred in the previously uncharacterized gene BTH_II1576 ("hmqL"). The results confirm that BTH_II1576 is involved in generating N-oxide derivatives of HMAQs (HMAQ-NOs). Synthetic HMAQ-NO is active against B. subtilis 168, showing ∼50-fold more activity than HMAQ. Both the methyl group and the length of the carbon side chain account for the high activity of HMAQ-NO. The results provide new information on the biosynthesis and activities of HMAQs and reveal new insight into how these molecules might be important for the ecology of B. thailandensis IMPORTANCE The soil bacterium Burkholderia thailandensis produces 2-alkyl-4(1H)-quinolones that are mostly methylated 4-hydroxyalkenylquinolines, a family of relatively unstudied metabolites similar to molecules also synthesized by Pseudomonas aeruginosa Several of the methylated 4-hydroxyalkenylquinolines have antimicrobial activity against other species. We show that Bacillus subtilis strain 168 is particularly susceptible to N-oxidated methylalkenylquinolines (HMAQ-NOs). We confirmed that HMAQ-NO biosynthesis requires the previously unstudied protein HmqL. These results provide new information about the biology of 2-alkyl-4(1H)-quinolones, particularly the methylated 4-hydroxyalkenylquinolines, which are unique to B. thailandensis This study also has importance for understanding B. thailandensis secondary metabolites and has implications for potential therapeutic development.
Collapse
|
11
|
Yoshimura A, Covington BC, Gallant É, Zhang C, Li A, Seyedsayamdost MR. Unlocking Cryptic Metabolites with Mass Spectrometry-Guided Transposon Mutant Selection. ACS Chem Biol 2020; 15:2766-2774. [PMID: 32808751 DOI: 10.1021/acschembio.0c00558] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The products of most secondary metabolite biosynthetic gene clusters (BGCs) have yet to be discovered, in part due to low expression levels in laboratory cultures. Reporter-guided mutant selection (RGMS) has recently been developed for this purpose: a mutant library is generated and screened, using genetic reporters to a chosen BGC, to select transcriptionally active mutants that then enable the characterization of the "cryptic" metabolite. The requirement for genetic reporters limits the approach to a single pathway within genetically tractable microorganisms. Herein, we utilize untargeted metabolomics in conjunction with transposon mutagenesis to provide a global read-out of secondary metabolism across large numbers of mutants. We employ self-organizing map analytics and imaging mass spectrometry to identify and characterize seven cryptic metabolites from mutant libraries of two different Burkholderia species. Applications of the methodologies reported can expand our understanding of the products and regulation of cryptic BGCs across phylogenetically diverse bacteria.
Collapse
Affiliation(s)
- Aya Yoshimura
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Brett C. Covington
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Étienne Gallant
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Chen Zhang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Anran Li
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Mohammad R. Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
12
|
Secondary metabolites from the Burkholderia pseudomallei complex: structure, ecology, and evolution. J Ind Microbiol Biotechnol 2020; 47:877-887. [PMID: 33052546 DOI: 10.1007/s10295-020-02317-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/22/2020] [Indexed: 12/15/2022]
Abstract
Bacterial secondary metabolites play important roles in promoting survival, though few have been carefully studied in their natural context. Numerous gene clusters code for secondary metabolites in the genomes of members of the Bptm group, made up of three closely related species with distinctly different lifestyles: the opportunistic pathogen Burkholderia pseudomallei, the non-pathogenic saprophyte Burkholderia thailandensis, and the host-adapted pathogen Burkholderia mallei. Several biosynthetic gene clusters are conserved across two or all three species, and this provides an opportunity to understand how the corresponding secondary metabolites contribute to survival in different contexts in nature. In this review, we discuss three secondary metabolites from the Bptm group: bactobolin, malleilactone (and malleicyprol), and the 4-hydroxy-3-methyl-2-alkylquinolines, providing an overview of each of their biosynthetic pathways and insight into their potential ecological roles. Results of studies on these secondary metabolites provide a window into how secondary metabolites contribute to bacterial survival in different environments, from host infections to polymicrobial soil communities.
Collapse
|
13
|
Mao D, Yoshimura A, Wang R, Seyedsayamdost MR. Reporter-Guided Transposon Mutant Selection for Activation of Silent Gene Clusters in Burkholderia thailandensis. Chembiochem 2020; 21:1826-1831. [PMID: 31984619 DOI: 10.1002/cbic.201900748] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Indexed: 01/01/2023]
Abstract
Most natural product biosynthetic gene clusters that can be observed bioinformatically are silent. This insight has prompted the development of several methodologies for inducing their expression. One of the more recent methods, termed reporter-guided mutant selection (RGMS), entails creation of a library of mutants that is then screened for the desired phenotype via reporter gene expression. Herein, we apply a similar approach to Burkholderia thailandensis and, using transposon mutagenesis, mutagenize three strains, each carrying a fluorescent reporter in the malleilactone (mal), capistruin (cap), or an unidentified ribosomal peptide (tomm) gene cluster. We show that even a small library of <500 mutants can be used to induce expression of each cluster. We also explore the mechanism of activation and find that inhibition of pyrimidine biosynthesis is linked to the induction of the mal cluster. Both a transposon insertion into pyrF as well as small-molecule-mediated inhibition of PyrF trigger malleilactone biosynthesis. Our results pave the way toward the broad application of RGMS and related approaches to Burkholderia spp.
Collapse
Affiliation(s)
- Dainan Mao
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Aya Yoshimura
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Rurun Wang
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| |
Collapse
|