Engineering the Erythromycin-Producing Strain Saccharopolyspora erythraea HOE107 for the Heterologous Production of Polyketide Antibiotics

Bacteria of the genus Saccharopolyspora produce important polyketide antibiotics, including erythromycin A (Sac. erythraea) and spinosad (Sac. spinosa). We herein report the development of an industrial erythromycin-producing strain, Sac. erythraea HOE107, into a host for the heterologous expression of polyketide biosynthetic gene clusters (BGCs) from other Saccharopolyspora species and related actinomycetes. To facilitate the integration of natural product BGCs and auxiliary genes beneficial for the production of natural products, the erythromycin polyketide synthase (ery) genes were replaced with two bacterial attB genomic integration sites associated with bacteriophages ϕC31 and ϕBT1. We also established a highly efficient conjugation protocol for the introduction of large bacterial artificial chromosome (BAC) clones into Sac. erythraea strains. Based on this optimized protocol, an arrayed BAC library was effectively transferred into Sac. erythraea. The large spinosad gene cluster from Sac. spinosa and the actinorhodin gene cluster from Streptomyces coelicolor were successfully expressed in the ery deletion mutant. Deletion of the endogenous giant polyketide synthase genes pkeA1-pkeA4, the product of which is not known, and the flaviolin gene cluster (rpp) from the bacterium increased the heterologous production of spinosad and actinorhodin. Furthermore, integration of pJTU6728 carrying additional beneficial genes dramatically improved the yield of actinorhodin in the engineered Sac. erythraea strains. Our study demonstrated that the engineered Sac. erythraea strains SLQ185, LJ161, and LJ162 are good hosts for the expression of heterologous antibiotics and should aid in expression-based genome-mining approaches for the discovery of new and cryptic antibiotics from Streptomyces and rare actinomycetes.

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Validation of the Intact Zwittermicin A Biosynthetic Gene Cluster and Discovery of a Complementary Resistance Mechanism in Bacillus thuringiensis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00111-11 ◽

2011 ◽

Vol 55 (9) ◽

pp. 4161-4169 ◽

Cited By ~ 26

Author(s):

Yi Luo ◽

Li-Fang Ruan ◽

Chang-Ming Zhao ◽

Cheng-Xian Wang ◽

Dong-Hai Peng ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Gene Cluster ◽

Polyketide Synthase ◽

Resistance Mechanism ◽

Bac Library ◽

Gene Clusters ◽

Artificial Chromosome ◽

Nonribosomal Peptide ◽

Content Type ◽

Zwittermicin A

ABSTRACTZwittermicin A (ZmA) is a hybrid polyketide-nonribosomal peptide produced by certainBacillus cereusgroup strains. It displays broad-spectrum antimicrobial activity. Its biosynthetic pathway inB. cereushas been proposed through analysis of the nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) modules involved in ZmA biosynthesis. In this study, we constructed a bacterial artificial chromosome (BAC) library fromBacillus thuringiensissubsp.kurstakistrain YBT-1520 genomic DNA. The presence of known genes involved in the biosynthesis of ZmA in this BAC library was investigated by PCR techniques. Nine positive clones were identified, two of which (covering an approximately 60-kb region) could confer ZmA biosynthesis ability uponB. thuringiensisBMB171 after simultaneous transfer into this host by two compatible shuttle BAC vectors. Another previously unidentified gene cluster, namedzmaWXY, was found to improve the yield of ZmA and was experimentally defined to function as a ZmA resistance transporter which expels ZmA from the cells. Putative transposase genes were detected on the flanking regions of the two gene clusters (the ZmA synthetic cluster andzmaWXY), which suggests a mobile nature of these two gene clusters. The intact ZmA gene cluster was validated, and a resistance mechanism complementary to that forzmaR(the previously identified ZmA self-resistance gene) was revealed. This study also provided a straightforward strategy to isolate and identify a huge gene cluster fromBacillus.

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Identification of polyketide synthase gene clusters in a phage P1-derived artificial chromosome library of a Philippine strain of Streptomyces sp. PCS3-D2

Asia Pacific Journal of Molecular Biology and Biotechnology ◽

10.35118/apjmbb.2019.027.2.08 ◽

2019 ◽

pp. 56-63

Author(s):

Aileen Bayot Custodio ◽

Edwin Plata Alcantara

Keyword(s):

Gene Cluster ◽

Polyketide Synthase ◽

Genetic Manipulation ◽

Gene Clusters ◽

Artificial Chromosome ◽

Restriction Enzyme Digestion ◽

Type I ◽

Putative Gene ◽

Streptomyces Sp ◽

Type Iii

A phage P1-derived artificial chromosome (PAC) library was constructed from genomic DNA of Streptomyces sp. PCS3-D2. Polymerase chain reaction (PCR) screening of the PAC library revealed two clones, PAC16D and P222O, which were positively identified to harbor polyketide synthase (PKS) Type I and PKS Type III gene clusters, respectively. Restriction enzyme digestion showed that PAC16D and PAC222O contained a 130 kb and a 140 kb insert, respectively. Results of sequencing and bioinformatics analyses revealed that PAC16D comprised of a full-length PKS type I bafilomycin gene cluster while PAC222O harbored truncated siderophore and putative gene clusters as well as a complete PKS III biosynthetic gene cluster. The PKS III gene cluster had three genes similar to alkyl resorcinol biosynthetic genes, however majority of the novel gene cluster had little similarity to known PKS Type III gene clusters. The successful cloning and identification of these gene clusters from Streptomyces sp. PCS3-D2 serve as the jump off point to further genetic manipulation in order to produce the insecticidal natural product in a heterologous host.

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Cloning, sequencing and heterologous expression of the medermycin biosynthetic gene cluster of Streptomyces sp. AM-7161: towards comparative analysis of the benzoisochromanequinone gene clusters

Microbiology ◽

10.1099/mic.0.26310-0 ◽

2003 ◽

Vol 149 (7) ◽

pp. 1633-1645 ◽

Cited By ~ 84

Author(s):

Koji Ichinose ◽

Makoto Ozawa ◽

Keiko Itou ◽

Kanako Kunieda ◽

Yutaka Ebizuka

Keyword(s):

Heterologous Expression ◽

Gene Cluster ◽

Polyketide Synthase ◽

Acyl Carrier Protein ◽

Streptomyces Coelicolor ◽

Gene Clusters ◽

Biosynthetic Gene Cluster ◽

Carrier Protein ◽

Biosynthetic Gene ◽

Six Genes

Medermycin is a Streptomyces aromatic C-glycoside antibiotic classified in the benzoisochromanequinones (BIQs), which presents several interesting biosynthetic problems concerning polyketide synthase (PKS), post-PKS tailoring and deoxysugar pathways. The biosynthetic gene cluster for medermycin (the med cluster) was cloned from Streptomyces sp. AM-7161. Completeness of the clone was proved by the heterologous expression of a cosmid carrying the entire med cluster in Streptomyces coelicolor CH999 to produce medermycin. The DNA sequence of the cosmid (36 202 bp) revealed 34 complete ORFs, with an incomplete ORF at either end. Functional assignment of the deduced products was made for PKS and biosynthetically related enzymes, tailoring steps including strereochemical control, oxidation, angolosamine pathway, C-glycosylation, and regulation. The med cluster was estimated to be about 30 kb long, covering 29 ORFs. An unusual characteristic of the cluster is the disconnected organization of the minimal PKS genes: med-ORF23 encoding the acyl carrier protein is 20 kb apart from med-ORF1 and med-ORF2 for the two ketosynthase components. Secondly, the six genes (med-ORF14, 15, 16, 17, 18 and 20) for the biosynthesis of the deoxysugar, angolosamine, are all contiguous. Finally, the finding of a glycosyltransferase gene, med-ORF8, suggests a possible involvement of conventional C-glycosylation in medermycin biosynthesis. Comparison among the three complete BIQ gene clusters – med and those for actinorhodin (act) and granaticin (gra) – revealed some common genes whose deduced functions are unavailable from database searches (the ‘unknowns’). An example is med-ORF5, a homologue of actVI-ORF3 and gra-ORF18, which was highlighted by a recent proteomic analysis of S. coelicolor A3(2).

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Identification of the kinanthraquinone biosynthetic gene cluster by expression of an atypical response regulator

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbaa082 ◽

2021 ◽

Vol 85 (3) ◽

pp. 714-721

Author(s):

Risa Takao ◽

Katsuyuki Sakai ◽

Hiroyuki Koshino ◽

Hiroyuki Osada ◽

Shunji Takahashi

Keyword(s):

Heterologous Expression ◽

Gene Cluster ◽

Secondary Metabolite ◽

Response Regulator ◽

Bac Library ◽

Gene Clusters ◽

Biosynthetic Gene Cluster ◽

Gene Organization ◽

Biosynthetic Gene ◽

Streptomyces Sp

ABSTRACT Recent advances in genome sequencing have revealed a variety of secondary metabolite biosynthetic gene clusters in actinomycetes. Understanding the biosynthetic mechanism controlling secondary metabolite production is important for utilizing these gene clusters. In this study, we focused on the kinanthraquinone biosynthetic gene cluster, which has not been identified yet in Streptomyces sp. SN-593. Based on chemical structure, 5 type II polyketide synthase gene clusters were listed from the genome sequence of Streptomyces sp. SN-593. Among them, a candidate gene cluster was selected by comparing the gene organization with grincamycin, which is synthesized through an intermediate similar to kinanthraquinone. We initially utilized a BAC library for subcloning the kiq gene cluster, performed heterologous expression in Streptomyces lividans TK23, and identified the production of kinanthraquinone and kinanthraquinone B. We also found that heterologous expression of kiqA, which belongs to the DNA-binding response regulator OmpR family, dramatically enhanced the production of kinanthraquinones.

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Overproduction of Ristomycin A by Activation of a Silent Gene Cluster in Amycolatopsis japonicum MG417-CF17

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03512-14 ◽

2014 ◽

Vol 58 (10) ◽

pp. 6185-6196 ◽

Cited By ~ 51

Author(s):

Marius Spohn ◽

Norbert Kirchner ◽

Andreas Kulik ◽

Angelika Jochim ◽

Felix Wolf ◽

...

Keyword(s):

Mass Spectrometry ◽

Gene Cluster ◽

High Performance ◽

Pathogenic Bacteria ◽

Genome Mining ◽

Gene Clusters ◽

Von Willebrand Disease ◽

Biosynthesis Gene Cluster ◽

Content Type ◽

Bioinformatic Tools

ABSTRACTThe emergence of antibiotic-resistant pathogenic bacteria within the last decades is one reason for the urgent need for new antibacterial agents. A strategy to discover new anti-infective compounds is the evaluation of the genetic capacity of secondary metabolite producers and the activation of cryptic gene clusters (genome mining). One genus known for its potential to synthesize medically important products isAmycolatopsis. However,Amycolatopsis japonicumdoes not produce an antibiotic under standard laboratory conditions. In contrast to mostAmycolatopsisstrains,A. japonicumis genetically tractable with different methods. In order to activate a possible silent glycopeptide cluster, we introduced a gene encoding the transcriptional activator of balhimycin biosynthesis, thebbrgene fromAmycolatopsis balhimycina(bbrAba), intoA. japonicum. This resulted in the production of an antibiotically active compound. Following whole-genome sequencing ofA. japonicum, 29 cryptic gene clusters were identified by genome mining. One of these gene clusters is a putative glycopeptide biosynthesis gene cluster. Using bioinformatic tools, ristomycin (syn. ristocetin), a type III glycopeptide, which has antibacterial activity and which is used for the diagnosis of von Willebrand disease and Bernard-Soulier syndrome, was deduced as a possible product of the gene cluster. Chemical analyses by high-performance liquid chromatography and mass spectrometry (HPLC-MS), tandem mass spectrometry (MS/MS), and nuclear magnetic resonance (NMR) spectroscopy confirmed thein silicoprediction that the recombinantA. japonicum/pRM4-bbrAbasynthesizes ristomycin A.

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Enzyme-constrained models and omics analysis of Streptomyces coelicolor reveal metabolic changes that enhance heterologous production

10.1101/796722 ◽

2019 ◽

Author(s):

Snorre Sulheim ◽

Tjaša Kumelj ◽

Dino van Dissel ◽

Ali Salehzadeh-Yazdi ◽

Chao Du ◽

...

Keyword(s):

Heterologous Expression ◽

Streptomyces Coelicolor ◽

Gene Clusters ◽

Metabolic Model ◽

Heterologous Production ◽

Comprehensive Picture ◽

Constrained Models ◽

Systemic Understanding ◽

Genome Scale ◽

Further Development

AbstractMany biosynthetic gene clusters (BGCs) require heterologous expression to realize their genetic potential, including silent and metagenomic BGCs. Although the engineered Streptomyces coelicolor M1152 is a widely used host for heterologous expression of BGCs, a systemic understanding of how its genetic modifications affect the metabolism is lacking and limiting further development. We performed a comparative analysis of M1152 and its ancestor M145, connecting information from proteomics, transcriptomics, and cultivation data into a comprehensive picture of the metabolic differences between these strains. Instrumental to this comparison was the application of an improved consensus genome-scale metabolic model (GEM) of S. coelicolor. Although many metabolic patterns are retained in M1152, we find that this strain suffers from oxidative stress, possibly caused by increased oxidative metabolism. Furthermore, precursor availability is likely not limiting polyketide production, implying that other strategies could be beneficial for further development of S. coelicolor for heterologous production of novel compounds.

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The Fusarium verticillioides FUM Gene Cluster Encodes a Zn(II)2Cys6 Protein That Affects FUM Gene Expression and Fumonisin Production

Eukaryotic Cell ◽

10.1128/ec.00400-06 ◽

2007 ◽

Vol 6 (7) ◽

pp. 1210-1218 ◽

Cited By ~ 137

Author(s):

Daren W. Brown ◽

Robert A. E. Butchko ◽

Mark Busman ◽

Robert H. Proctor

Keyword(s):

Gene Cluster ◽

Polyketide Synthase ◽

Fusarium Verticillioides ◽

Gene Clusters ◽

Biosynthetic Gene Cluster ◽

Regulatory Proteins ◽

Wild Type ◽

Polyketide Synthase Gene ◽

Splice Forms ◽

Self Protection

ABSTRACT Fumonisins are mycotoxins produced by some Fusarium species and can contaminate maize or maize products. Ingestion of fumonisins is associated with diseases, including cancer and neural tube defects, in humans and animals. In fungi, genes involved in the synthesis of mycotoxins and other secondary metabolites are often located adjacent to each other in gene clusters. Such genes can encode structural enzymes, regulatory proteins, and/or proteins that provide self-protection. The fumonisin biosynthetic gene cluster includes 16 genes, none of which appear to play a role in regulation. In this study, we identified a previously undescribed gene (FUM21) located adjacent to the fumonisin polyketide synthase gene, FUM1. The presence of a Zn(II)2Cys6 DNA-binding domain in the predicted protein suggested that FUM21 was involved in transcriptional regulation. FUM21 deletion (Δfum21) mutants produce little to no fumonisin in cracked maize cultures but some FUM1 and FUM8 transcripts in a liquid GYAM medium. Complementation of a Δfum21 mutant with a wild-type copy of the gene restored fumonisin production. Analysis of FUM21 cDNAs identified four alternative splice forms (ASFs), and microarray analysis indicated the ASFs were differentially expressed. Based on these data, we present a model for how FUM21 ASFs may regulate fumonisin biosynthesis.

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Functional Genome Mining for Metabolites Encoded by Large Gene Clusters through Heterologous Expression of a Whole-Genome Bacterial Artificial Chromosome Library in Streptomyces spp.

Applied and Environmental Microbiology ◽

10.1128/aem.01383-16 ◽

2016 ◽

Vol 82 (19) ◽

pp. 5795-5805 ◽

Cited By ~ 31

Author(s):

Min Xu ◽

Yemin Wang ◽

Zhilong Zhao ◽

Guixi Gao ◽

Sheng-Xiong Huang ◽

...

Keyword(s):

Heterologous Expression ◽

Genome Mining ◽

Gene Clusters ◽

Artificial Chromosome ◽

Functional Screening ◽

Biosynthetic Pathways ◽

Biosynthetic Gene ◽

Biosynthetic Gene Clusters ◽

Content Type ◽

Bac Libraries

ABSTRACTGenome sequencing projects in the last decade revealed numerous cryptic biosynthetic pathways for unknown secondary metabolites in microbes, revitalizing drug discovery from microbial metabolites by approaches called genome mining. In this work, we developed a heterologous expression and functional screening approach for genome mining from genomic bacterial artificial chromosome (BAC) libraries inStreptomycesspp. We demonstrate mining from a strain ofStreptomyces rochei, which is known to produce streptothricins and borrelidin, by expressing its BAC library in the surrogate hostStreptomyces lividansSBT5, and screening for antimicrobial activity. In addition to the successful capture of the streptothricin and borrelidin biosynthetic gene clusters, we discovered two novel linear lipopeptides and their corresponding biosynthetic gene cluster, as well as a novel cryptic gene cluster for an unknown antibiotic fromS. rochei. This high-throughput functional genome mining approach can be easily applied to other streptomycetes, and it is very suitable for the large-scale screening of genomic BAC libraries for bioactive natural products and the corresponding biosynthetic pathways.IMPORTANCEMicrobial genomes encode numerous cryptic biosynthetic gene clusters for unknown small metabolites with potential biological activities. Several genome mining approaches have been developed to activate and bring these cryptic metabolites to biological tests for future drug discovery. Previous sequence-guided procedures relied on bioinformatic analysis to predict potentially interesting biosynthetic gene clusters. In this study, we describe an efficient approach based on heterologous expression and functional screening of a whole-genome library for the mining of bioactive metabolites fromStreptomyces. The usefulness of this function-driven approach was demonstrated by the capture of four large biosynthetic gene clusters for metabolites of various chemical types, including streptothricins, borrelidin, two novel lipopeptides, and one unknown antibiotic fromStreptomyces rocheiSal35. The transfer, expression, and screening of the library were all performed in a high-throughput way, so that this approach is scalable and adaptable to industrial automation for next-generation antibiotic discovery.

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Characterization of the Nodularin Synthetase Gene Cluster and Proposed Theory of the Evolution of Cyanobacterial Hepatotoxins

Applied and Environmental Microbiology ◽

10.1128/aem.70.11.6353-6362.2004 ◽

2004 ◽

Vol 70 (11) ◽

pp. 6353-6362 ◽

Cited By ~ 169

Author(s):

Michelle C. Moffitt ◽

Brett A. Neilan

Keyword(s):

Gene Cluster ◽

Rational Design ◽

Polyketide Synthase ◽

Alternative Hypothesis ◽

Phylogenetic Analyses ◽

Cyanobacterial Bloom ◽

Gene Clusters ◽

Biosynthetic Gene Cluster ◽

Biosynthetic Gene ◽

Microcystin Synthetase

ABSTRACT Nodularia spumigena is a bloom-forming cyanobacterium which produces the hepatotoxin nodularin. The complete gene cluster encoding the enzymatic machinery required for the biosynthesis of nodularin in N. spumigena strain NSOR10 was sequenced and characterized. The 48-kb gene cluster consists of nine open reading frames (ORFs), ndaA to ndaI, which are transcribed from a bidirectional regulatory promoter region and encode nonribosomal peptide synthetase modules, polyketide synthase modules, and tailoring enzymes. The ORFs flanking the nda gene cluster in the genome of N. spumigena strain NSOR10 were identified, and one of them was found to encode a protein with homology to previously characterized transposases. Putative transposases are also associated with the structurally related microcystin synthetase (mcy) gene clusters derived from three cyanobacterial strains, indicating a possible mechanism for the distribution of these biosynthetic gene clusters between various cyanobacterial genera. We propose an alternative hypothesis for hepatotoxin evolution in cyanobacteria based on the results of comparative and phylogenetic analyses of the nda and mcy gene clusters. These analyses suggested that nodularin synthetase evolved from a microcystin synthetase progenitor. The identification of the nodularin biosynthetic gene cluster and evolution of hepatotoxicity in cyanobacteria reported in this study may be valuable for future studies on toxic cyanobacterial bloom formation. In addition, an appreciation of the natural evolution of nonribosomal biosynthetic pathways will be vital for future combinatorial engineering and rational design of novel metabolites and pharmaceuticals.

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Biosynthesis of a Complex Yersiniabactin-Like Natural Product via themicLocus in Phytopathogen Ralstonia solanacearum

Applied and Environmental Microbiology ◽

10.1128/aem.05198-11 ◽

2011 ◽

Vol 77 (17) ◽

pp. 6117-6124 ◽

Cited By ~ 36

Author(s):

Martin F. Kreutzer ◽

Hirokazu Kage ◽

Peter Gebhardt ◽

Barbara Wackler ◽

Hans P. Saluz ◽

...

Keyword(s):

Natural Product ◽

Gene Cluster ◽

Ralstonia Solanacearum ◽

Insertional Mutagenesis ◽

Polyketide Synthase ◽

Genome Mining ◽

Content Type ◽

A Genome ◽

Iron Deficient ◽

Peptide Synthetase

ABSTRACTA genome mining study in the plant pathogenic bacteriumRalstonia solanacearumGMI1000 unveiled a polyketide synthase/nonribosomal peptide synthetase gene cluster putatively involved in siderophore biosynthesis. Insertional mutagenesis confirmed the respective locus to be operational under iron-deficient conditions and spurred the isolation of the associated natural product. Bioinformatic analyses of the gene cluster facilitated the structural characterization of this compound, which was subsequently identified as the antimycoplasma agent micacocidin. The metal-chelating properties of micacocidin were evaluated in competition experiments, and the cellular uptake of gallium-micacocidin complexes was demonstrated inR. solanacearumGMI1000, indicating a possible siderophore role. Comparative genomics revealed a conservation of the micacocidin gene cluster in defined, but globally dispersed phylotypes ofR. solanacearum.

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