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Andriy Luzhetskyy - One of the best experts on this subject based on the ideXlab platform.

  • cyclofaulknamycin with the rare amino acid d capreomycidine isolated from a well characterized Streptomyces Albus strain
    Microorganisms, 2021
    Co-Authors: Liliya Horbal, Josef Zapp, Marc Stierhof, Anja Palusczak, Nikolas Eckert, Andriy Luzhetskyy
    Abstract:

    Targeted genome mining is an efficient method of biosynthetic gene cluster prioritization within constantly growing genome databases. Using two capreomycidine biosynthesis genes, alpha-ketoglutarate-dependent arginine beta-hydroxylase and pyridoxal-phosphate-dependent aminotransferase, we identified two types of clusters: one type containing both genes involved in the biosynthesis of the abovementioned moiety, and other clusters including only arginine hydroxylase. Detailed analysis of one of the clusters, the flk cluster from Streptomyces Albus, led to the identification of a cyclic peptide that contains a rare D-capreomycidine moiety for the first time. The absence of the pyridoxal-phosphate-dependent aminotransferase gene in the flk cluster is compensated by the XNR_1347 gene in the S. Albus genome, whose product is responsible for biosynthesis of the abovementioned nonproteinogenic amino acid. Herein, we report the structure of cyclofaulknamycin and the characteristics of its biosynthetic gene cluster, biosynthesis and bioactivity profile.

  • dudomycins new secondary metabolites produced after heterologous expression of an nrps cluster from Streptomyces Albus ssp chlorinus nrrl b 24108
    Microorganisms, 2020
    Co-Authors: Constanze Lasch, Marta Rodriguez Estevez, Maksym Myronovskyi, Josef Zapp, Marc Stierhof, Andriy Luzhetskyy
    Abstract:

    Since the 1950s, natural products of bacterial origin were systematically developed to be used as drugs with a wide range of medical applications. The available treatment options for many diseases are still not satisfying, wherefore, the discovery of new structures has not lost any of its importance. Beyond the great variety of already isolated and characterized metabolites, Streptomycetes still harbor uninvestigated gene clusters whose products can be accessed using heterologous expression in host organisms. This works presents the discovery of a set of structurally novel secondary metabolites, dudomycins A to D, through the expression of a cryptic NRPS cluster from Streptomyces Albus ssp. Chlorinus NRRL B-24108 in the heterologous host strain Streptomyces Albus Del14. A minimal set of genes, required for the production of dudomycins, was defined through gene inactivation experiments. This paper also proposes a model for dudomycin biosynthesis.

  • novel fredericamycin variant overproduced by a streptomycin resistant Streptomyces Albus subsp chlorinus strain
    Marine Drugs, 2020
    Co-Authors: Marta Rodriguez Estevez, Maksym Myronovskyi, Birgit Rosenkranzer, Thomas Paululat, Lutz Petzke, Jeanette Ristau, Andriy Luzhetskyy
    Abstract:

    Streptomycetes are an important source of natural products potentially applicable in the pharmaceutical industry. Many of these drugs are secondary metabolites whose biosynthetic genes are very often poorly expressed under laboratory cultivation conditions. In many cases, antibiotic-resistant mutants exhibit increased production of natural drugs, which facilitates the identification and isolation of new substances. In this study, we report the induction of a type II polyketide synthase gene cluster in the marine strain Streptomyces Albus subsp. chlorinus through the selection of streptomycin-resistant mutants, resulting in overproduction of the novel compound fredericamycin C2 (1). Fredericamycin C2 (1) is structurally related to the potent antitumor drug lead fredericamycin A.

  • identification and heterologous expression of the albucidin gene cluster from the marine strain Streptomyces Albus subsp chlorinus nrrl b 24108
    Microorganisms, 2020
    Co-Authors: Maksym Myronovskyi, Marc Stierhof, Birgit Rosenkranzer, Lutz Petzke, Tobias Seiser, Andriy Luzhetskyy
    Abstract:

    Herbicides with new modes of action and safer toxicological and environmental profiles are needed to manage the evolution of weeds that are resistant to commercial herbicides. The unparalleled structural diversity of natural products makes these compounds a promising source for new herbicides. In 2009, a novel nucleoside phytotoxin, albucidin, with broad activity against grass and broadleaf weeds was isolated from a strain of Streptomyces Albus subsp. chlorinus NRRL B-24108. Here, we report the identification and heterologous expression of the previously uncharacterized albucidin gene cluster. Through a series of gene inactivation experiments, a minimal set of albucidin biosynthetic genes was determined. Based on gene annotation and sequence homology, a model for albucidin biosynthesis was suggested. The presented results enable the construction of producer strains for a sustainable supply of albucidin for biological activity studies.

  • benzanthric acid a novel metabolite from Streptomyces Albus del14 expressing the nybomycin gene cluster
    Frontiers in Chemistry, 2020
    Co-Authors: Marta Rodriguez Estevez, Nils Gummerlich, Maksym Myronovskyi, Josef Zapp, Andriy Luzhetskyy
    Abstract:

    Streptomycetes constitute a diverse bacterial group able to produce a wide variety of secondary metabolites with potential applications in the pharmacy industry. However, the genes responsible for the biosynthesis of these compounds are very frequently inactive or expressed at very low levels under standard laboratory cultivation conditions. Therefore, the activation or upregulation of secondary metabolite biosynthesis genes is a crucial step for the discovery of new bioactive natural products. We have recently reported the discovery of the biosynthetic genes for the antibiotic nybomycin (nyb genes) in Streptomyces Albus subsp. chlorinus. The nyb genes were expressed in the heterologous host Streptomyces Albus Del14, which produces not only nybomycin, but also a novel compound. In this study, we describe the isolation, purification, and structure elucidation of the new substance named benzanthric acid.

Philippe Mazodier - One of the best experts on this subject based on the ideXlab platform.

  • The RheA repressor is the thermosensor of the HSP18 heat shock response in Streptomyces Albus
    Proceedings of the National Academy of Sciences of the United States of America, 2000
    Co-Authors: Pascale Servant, Cosette Grandvalet, Philippe Mazodier
    Abstract:

    Microorganisms have mechanisms to sense their environment and rapidly adapt to survive changes in conditions. In Streptomyces Albus, various transcriptional repressors mediate the induction of heat shock genes. The RheA repressor regulates the synthesis of HSP18, a small heat shock protein, which plays a role in thermotolerance. The RheA protein was purified to determine how it responds rapidly to temperature. Gel retardation assays and footprinting experiments identified the specific target of RheA as an inverted repeat (TGTCATC 5N GATGACA) located in Phsp18, PrheA which is the common promoter region of the divergon. Gel retardation assays detected RheA-complexes formed with the hsp18-rheA promoters. The complexes did not form at higher temperature. In vitro transcription experiments showed that RheA is an autoregulatory protein and that its activity is inhibited by high temperature. The temperature-induced derepression by RheA is reversible. Dichroism circular spectroscopy revealed a reversible change of RheA conformation in relation with the temperature that could represent a transition between an active and an inactive form. Our experiments demonstrate that RheA acts as a cellular thermometer in hsp18 regulation.

  • RheA, the repressor of hsp18 in Streptomyces Albus G.
    Microbiology, 1999
    Co-Authors: Pascale Servant, Georges Rapoport, Philippe Mazodier
    Abstract:

    In Streptomyces Albus, Hsp18, a protein belonging to the family of small heat-shock proteins, can be detected only at high temperature. Disruption of orfY, located upstream and in the opposite orientation to hsp18, resulted in an elevated level of hsp18 mRNA at low temperature. Genetic and biochemical experiments indicated that the product of orfY, now called RheA (Repressor of hsp eighteen), directly represses hsp18. In Escherichia coli, an hsp18'-bgaB transcriptional fusion was repressed in a strain expressing S. Albus RheA. DNA-binding experiments with crude extracts of E. coli overproducing RheA indicated that RheA interacts specifically with the hsp18 promoter. Transcription analysis of rheA in the S. Albus wild-type and in rheA mutant strains suggested that RheA represses transcription not only of hsp18 but also of rheA itself.

  • The ClpB ATPase of Streptomyces Albus G belongs to the HspR heat shock regulon
    Molecular Microbiology, 1999
    Co-Authors: Cosette Grandvalet, Valerie De Crecy-lagard, Philippe Mazodier
    Abstract:

    The clpB gene of Streptomyces Albus was cloned by polymerase chain reaction (PCR) using degenerate oligonucleotides. Transcriptional analysis showed that the clpB gene was heat induced. Primer extension identified a transcription start site preceded by typical vegetative -10 and -35 hexamer sequences. The Streptomyces HspR repressor is known to bind to three inverted repeat motifs (IR1, IR2, IR3) upstream from the S. coelicolor dnaK operon. We identified an inverted repeat motif identical to IR3 upstream from the S. Albus clpB gene. DNA-binding experiments showed that HspR regulates clpB transcription by interacting directly with this motif. Streptomyces Albus is the first Gram-positive organism for which the co-regulation of DnaK and ClpB has been described. Such co-regulation suggests that there is a physiological relationship between these two proteins in this bacterium. Genes similar to hspR were also identified in Mycobacterium leprae, M. tuberculosis and in bacteria unrelated to the actinomycetales order, such as Helicobacter pylori and Aquifex aeolicus. HspR binding sites were found in these bacteria upstream from various heat shock genes, suggesting that these genes are regulated by HspR. The HspR binding site, here called HAIR (HspR associated inverted repeat), has the consensus sequence CTTGAGT N7 ACTCAAG.

  • hrca encoding the repressor of the groel genes in Streptomyces Albus g is associated with a second dnaj gene
    Journal of Bacteriology, 1998
    Co-Authors: Cosette Grandvalet, Georges Rapoport, Philippe Mazodier
    Abstract:

    Expression of the principal chaperones of the heat shock stimulon of Streptomyces Albus G are under the negative control of different repressors. The dnaK operon is regulated by hspR, the last gene of the operon (dnaK-grpE-dnaJ-hspR). hsp18, encoding a member of the small heat shock protein family, is regulated by orfY, which is in the opposite orientation upstream of hsp18. The groES-groEL1 operon and the groEL2 gene are regulated differently. They present tandem copies of the CIRCE element found in the 5′ region of many heat shock genes and shown to act in Bacillus subtilis as an operator for a repressor encoded by hrcA (hrc stands for heat regulation at CIRCE). We report the identification in S. Albus of a new heat shock operon containing hrcA and dnaJ homologs. Disruption of hrcA increased the transcription of the groES-groEL1 operon and of the groEL2 gene. These features were lost when the mutant was complemented in trans by an intact copy of hrcA. Despite considerable accumulation of the GroE chaperones in the hrcA mutant, there was no effect on formation of the aerial mycelium and sporulation, indicating that neither hrcA nor the level of groE gene expression is directly involved in the regulation of Streptomyces morphological differentiation.

  • disruption of hspr the repressor gene of the dnak operon in Streptomyces Albus g
    Molecular Microbiology, 1997
    Co-Authors: Cosette Grandvalet, Pascale Servant, Philippe Mazodier
    Abstract:

    hspR is the distal gene of the Streptomyces Albus dnaK operon. It encodes a protein similar to GlnR, the repressor of the Bacillus subtilis glutamine synthetase gene. Transcriptional analysis showed that disruption of hspR led to constitutive high-level expression of the dnaK operon, SDS-PAGE analysis revealed over-production and accumulation of the chaperone DnaK at low temperature HSP94, a heat-inducible protein cross-reacting with anti-CipB antibodies, was also shown to be constitutively overexpressed at low temperature in the hspR mutant. Those features were lost when the mutant was complemented in trans by an intact copy of hspR. The hspR mutant was impaired in its growth on solid rich medium: colonies grow slowly at 30 degrees C. However, formation of aerial mycelium and sporulation was not prevented. In liquid culture growth curves of the mutant and the wild type were similar. The kinetics of groEL gene induction were not modified by the hspR null mutation, indicating that HspR was not directly involved in the control of groEL transcription. Thus, in contrast with B. subtilis and other Gram-positive bacteria, transcription of Streptomyces dnaK and groEL operons is not controlled by the same regulator.

Maksym Myronovskyi - One of the best experts on this subject based on the ideXlab platform.

  • dudomycins new secondary metabolites produced after heterologous expression of an nrps cluster from Streptomyces Albus ssp chlorinus nrrl b 24108
    Microorganisms, 2020
    Co-Authors: Constanze Lasch, Marta Rodriguez Estevez, Maksym Myronovskyi, Josef Zapp, Marc Stierhof, Andriy Luzhetskyy
    Abstract:

    Since the 1950s, natural products of bacterial origin were systematically developed to be used as drugs with a wide range of medical applications. The available treatment options for many diseases are still not satisfying, wherefore, the discovery of new structures has not lost any of its importance. Beyond the great variety of already isolated and characterized metabolites, Streptomycetes still harbor uninvestigated gene clusters whose products can be accessed using heterologous expression in host organisms. This works presents the discovery of a set of structurally novel secondary metabolites, dudomycins A to D, through the expression of a cryptic NRPS cluster from Streptomyces Albus ssp. Chlorinus NRRL B-24108 in the heterologous host strain Streptomyces Albus Del14. A minimal set of genes, required for the production of dudomycins, was defined through gene inactivation experiments. This paper also proposes a model for dudomycin biosynthesis.

  • novel fredericamycin variant overproduced by a streptomycin resistant Streptomyces Albus subsp chlorinus strain
    Marine Drugs, 2020
    Co-Authors: Marta Rodriguez Estevez, Maksym Myronovskyi, Birgit Rosenkranzer, Thomas Paululat, Lutz Petzke, Jeanette Ristau, Andriy Luzhetskyy
    Abstract:

    Streptomycetes are an important source of natural products potentially applicable in the pharmaceutical industry. Many of these drugs are secondary metabolites whose biosynthetic genes are very often poorly expressed under laboratory cultivation conditions. In many cases, antibiotic-resistant mutants exhibit increased production of natural drugs, which facilitates the identification and isolation of new substances. In this study, we report the induction of a type II polyketide synthase gene cluster in the marine strain Streptomyces Albus subsp. chlorinus through the selection of streptomycin-resistant mutants, resulting in overproduction of the novel compound fredericamycin C2 (1). Fredericamycin C2 (1) is structurally related to the potent antitumor drug lead fredericamycin A.

  • identification and heterologous expression of the albucidin gene cluster from the marine strain Streptomyces Albus subsp chlorinus nrrl b 24108
    Microorganisms, 2020
    Co-Authors: Maksym Myronovskyi, Marc Stierhof, Birgit Rosenkranzer, Lutz Petzke, Tobias Seiser, Andriy Luzhetskyy
    Abstract:

    Herbicides with new modes of action and safer toxicological and environmental profiles are needed to manage the evolution of weeds that are resistant to commercial herbicides. The unparalleled structural diversity of natural products makes these compounds a promising source for new herbicides. In 2009, a novel nucleoside phytotoxin, albucidin, with broad activity against grass and broadleaf weeds was isolated from a strain of Streptomyces Albus subsp. chlorinus NRRL B-24108. Here, we report the identification and heterologous expression of the previously uncharacterized albucidin gene cluster. Through a series of gene inactivation experiments, a minimal set of albucidin biosynthetic genes was determined. Based on gene annotation and sequence homology, a model for albucidin biosynthesis was suggested. The presented results enable the construction of producer strains for a sustainable supply of albucidin for biological activity studies.

  • benzanthric acid a novel metabolite from Streptomyces Albus del14 expressing the nybomycin gene cluster
    Frontiers in Chemistry, 2020
    Co-Authors: Marta Rodriguez Estevez, Nils Gummerlich, Maksym Myronovskyi, Josef Zapp, Andriy Luzhetskyy
    Abstract:

    Streptomycetes constitute a diverse bacterial group able to produce a wide variety of secondary metabolites with potential applications in the pharmacy industry. However, the genes responsible for the biosynthesis of these compounds are very frequently inactive or expressed at very low levels under standard laboratory cultivation conditions. Therefore, the activation or upregulation of secondary metabolite biosynthesis genes is a crucial step for the discovery of new bioactive natural products. We have recently reported the discovery of the biosynthetic genes for the antibiotic nybomycin (nyb genes) in Streptomyces Albus subsp. chlorinus. The nyb genes were expressed in the heterologous host Streptomyces Albus Del14, which produces not only nybomycin, but also a novel compound. In this study, we describe the isolation, purification, and structure elucidation of the new substance named benzanthric acid.

  • heterologous expression of the nybomycin gene cluster from the marine strain Streptomyces Albus subsp chlorinus nrrl b 24108
    Marine Drugs, 2018
    Co-Authors: Marta Rodriguez Estevez, Nils Gummerlich, Maksym Myronovskyi, Suvd Nadmid, Andriy Luzhetskyy
    Abstract:

    Streptomycetes represent an important reservoir of active secondary metabolites with potential applications in the pharmaceutical industry. The gene clusters responsible for their production are often cryptic under laboratory growth conditions. Characterization of these clusters is therefore essential for the discovery of new microbial pharmaceutical drugs. Here, we report the identification of the previously uncharacterized nybomycin gene cluster from the marine actinomycete Streptomyces Albus subsp. chlorinus through its heterologous expression. Nybomycin has previously been reported to act against quinolone-resistant Staphylococcus aureus strains harboring a mutated gyrA gene but not against those with intact gyrA. The nybomycin-resistant mutants generated from quinolone-resistant mutants have been reported to be caused by a back-mutation in the gyrA gene that restores susceptibility to quinolones. On the basis of gene function assignment from bioinformatics analysis, we suggest a model for nybomycin biosynthesis.

Linquan Bai - One of the best experts on this subject based on the ideXlab platform.

  • reconstitution of kinamycin biosynthesis within the heterologous host Streptomyces Albus j1074
    Journal of Natural Products, 2018
    Co-Authors: Xiangyang Liu, Dongxu Liu, Meifeng Tao, Linquan Bai, Zixin Deng, Blaine A Pfeifer, Ming Jiang
    Abstract:

    Diazofluorene compounds such as kinamycin and lomaiviticin feature unique molecular structures and compelling medicinal bioactivities. However, a complete understanding of the biosynthetic details for this family of natural products has yet to be fully elucidated. In addition, a lack of genetically and technically amenable production hosts has limited access to the full medicinal potential of these compounds. Here, we report the capture of the complete kinamycin gene cluster from Streptomyces galtieri Sgt26 by bacterial artificial chromosome cloning, confirmed by successful production of kinamycin in the heterologous host Streptomyces Albus J1074. Sequence analysis and a series of gene deletion experiments revealed the boundary of the cluster, which spans 75 kb DNA. To probe the last step in biosynthesis, acetylation of kinamcyin F to kinamycin D, gene knockout, and complementation experiments identified a single gene product involved with final acetylation conversions. This study provides full genetic information for the kinamycin gene cluster from S. galtieri Sgt26 and establishes heterologous biosynthesis as a production platform for continued mechanistic assessment of compound formation and utilization.

  • conversion of the high yield salinomycin producer Streptomyces Albus bk3 25 into a surrogate host for polyketide production
    Science China-life Sciences, 2017
    Co-Authors: Xiaojie Zhang, Linquan Bai
    Abstract:

    An ideal surrogate host for heterologous production of various natural products is expected to have efficient nutrient utilization, fast growth, abundant precursors and energy supply, and a pronounced gene expression. Streptomyces Albus BK3-25 is a high-yield industrial strain producing type-I polyketide salinomycin, with a unique ability of bean oil utilization. Its potential of being a surrogate host for heterologous production of PKS was engineered and evaluated herein. Firstly, introduction of a three-gene cassette for the biosynthesis of ethylmalonyl-CoA resulted in accumulation of ethylmalonyl-CoA precursor and salinomycin, and subsequent deletion of the salinomycin biosynthetic gene cluster resulted in a host with rich supplies of common polyketide precursors, including malonyl-CoA, methylmalonyl-CoA, and ethylmalonyl-CoA. Secondly, the energy and reducing force were measured, and the improved accumulation of ATP and NADPH was observed in the mutant. Furthermore, the strength of a series of selected endogenous promoters based on microarray data was assessed at different growth phases, and a strong constitutive promoter was identified, providing a useful tool for further engineered gene expression. Finally, the potential of the BK3-25 derived host ZXJ-6 was evaluated with the introduction of the actinorhodin biosynthetic gene cluster from Streptomyces coelicolor, and the heterologous production of actinorhodin was obtained. This work clearly indicated the potential of the high-yield salinomycin producer as a surrogate host for heterologous production of polyketides, although more genetic manipulation should be conducted to streamline its performance.

  • mechanism of salinomycin overproduction in Streptomyces Albus as revealed by comparative functional genomics
    Applied Microbiology and Biotechnology, 2017
    Co-Authors: Xiaojie Zhang, Linquan Bai
    Abstract:

    The anticoccidial salinomycin is a polyketide produced by Streptomyces Albus, and the high-yield strain BK 3-25 produces 18.0 g/L salinomycin under lab condition. In order to elucidate the overproduction mechanism, the genome of BK 3-25 was fully sequenced and compared with the wild-type DSM 41398. Strain BK 3-25 has a 75-kb large deletion, containing type-I polyketide gene cluster PKS-9, and 60 additional InDels and SNVs affecting 55 CDSs, including a 1-bp deletion in type-I PKS gene cluster PKS-6. Subsequently, individual or combined deletions of the 75-kb region and PKS-6 in the wild-type resulted in improved salinomycin yields from 2.60 to 5.20, 6.90, and 9.50 g/L (53% of BK 3-25), respectively, suggesting a redirected flux of polyketide precursors to salinomycin biosynthesis. Moreover, due to the much higher transcription of salinomycin biosynthetic genes (sln) in the high-yield BK 3-25 than in the wild-type, 13 putative regulatory genes among the 55 CDSs were individually inactivated and 7 were proved to be negatively involved in the transcription of sln genes. Combined deletions of two major negative regulatory genes SLNWT_3357 and SLNWT_7015 caused further improved transcription of sln genes as well as the yield, from 2.60 to 7.30 g/L (40% of BK 3-25). Therefore, the comparative genomics approach combined with functional experiments identified that the multiple deletions and mutations of competing gene clusters and negative regulatory genes are crucial for salinomycin overproduction, setting an example for rational titer improvement of other polyketide natural products.

  • enhanced salinomycin production by adjusting the supply of polyketide extender units in Streptomyces Albus
    Metabolic Engineering, 2016
    Co-Authors: Xiaojie Zhang, Ming Jiang, Linquan Bai
    Abstract:

    The anticoccidial salinomycin is a polyketide produced by Streptomyces Albus and requires malonyl-CoAs, methylmalonyl-CoAs, and ethylmalonyl-CoAs for the backbone assembly. Genome sequencing of S. Albus DSM 41398 revealed a high percentage of genes involved in lipid metabolism, supporting the high salinomycin yield in oil-rich media. Seven PKS/PKS-NRPS gene clusters in the genome were found to be actively transcribed and had been individually deleted, which resulted in significantly improved salinomycin production. However, a combined deletion of PKS-NRPS-2 and PKS-6 showed no further improvement. Whereas the concentrations of malonyl-CoA and methylmalonyl-CoA were increased, the concentration of ethylmalonyl-CoA remained low in the mutants. An endogenous crotonyl-CoA reductase gene (ccr) was overexpressed in the ΔPKS-NRPS-2/ΔPKS-6 mutant, resulting in improved production. Combination of cluster deletions and over-expression of ccr gene led to an overall titer improvement of salinomycin from 0.60 to 6.60g/L. This engineering strategy can be implemented for various natural polyketides production.

  • cloning and characterization of the polyether salinomycin biosynthesis gene cluster of Streptomyces Albus xm211
    Applied and Environmental Microbiology, 2012
    Co-Authors: Chunyan Jiang, Hougen Wang, Qianjin Kang, Jing Liu, Linquan Bai
    Abstract:

    Salinomycin is widely used in animal husbandry as a food additive due to its antibacterial and anticoccidial activities. However, its biosynthesis had only been studied by feeding experiments with isotope-labeled precursors. A strategy with degenerate primers based on the polyether-specific epoxidase sequences was successfully developed to clone the salinomycin gene cluster. Using this strategy, a putative epoxidase gene, slnC, was cloned from the salinomycin producer Streptomyces Albus XM211. The targeted replacement of slnC and subsequent trans-complementation proved its involvement in salinomycin biosynthesis. A 127-kb DNA region containing slnC was sequenced, including genes for polyketide assembly and release, oxidative cyclization, modification, export, and regulation. In order to gain insight into the salinomycin biosynthesis mechanism, 13 gene replacements and deletions were conducted. Including slnC, 7 genes were identified as essential for salinomycin biosynthesis and putatively responsible for polyketide chain release, oxidative cyclization, modification, and regulation. Moreover, 6 genes were found to be relevant to salinomycin biosynthesis and possibly involved in precursor supply, removal of aberrant extender units, and regulation. Sequence analysis and a series of gene replacements suggest a proposed pathway for the biosynthesis of salinomycin. The information presented here expands the understanding of polyether biosynthesis mechanisms and paves the way for targeted engineering of salinomycin activity and productivity.

Ryan F Seipke - One of the best experts on this subject based on the ideXlab platform.

  • a chromatogram simplified Streptomyces Albus host for heterologous production of natural products
    Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2020
    Co-Authors: Asif Fazal, Divya Thankachan, Ellie Harris, Ryan F Seipke
    Abstract:

    : Cloning natural product biosynthetic gene clusters from cultured or uncultured sources and their subsequent expression by genetically tractable heterologous hosts is an essential strategy for the elucidation and characterisation of novel microbial natural products. The availability of suitable expression hosts is a critical aspect of this workflow. In this work, we mutagenised five endogenous biosynthetic gene clusters from Streptomyces Albus S4, which reduced the complexity of chemical extracts generated from the strain and eliminated antifungal and antibacterial bioactivity. We showed that the resulting quintuple mutant can express foreign biosynthetic gene clusters by heterologously producing actinorhodin, cinnamycin and prunustatin. We envisage that our strain will be a useful addition to the growing suite of heterologous expression hosts available for exploring microbial secondary metabolism.

  • a chromatogram simplified Streptomyces Albus host for heterologous production of natural products
    bioRxiv, 2019
    Co-Authors: Asif Fazal, Divya Thankachan, Ellie Harris, Ryan F Seipke
    Abstract:

    Cloning natural product biosynthetic gene clusters from cultured or uncultured sources and their subsequent expression by genetically tractable heterologous hosts is an essential strategy for the elucidation and characterisation of novel microbial natural products. The availability of suitable expression hosts is a critical aspect of this workflow. In this work, we mutagenised five endogenous biosynthetic gene clusters from Streptomyces Albus S4, which reduced the complexity of chemical extracts generated from the strain and eliminated antifungal and antibacterial bioactivity. We showed that the resulting quintuple mutant can express foreign BGCs by heterologously producing actinorhodin, cinnamycin and prunustatin. We envisage that our strain will be a useful addition to the growing suite of heterologous expression hosts available for exploring microbial secondary metabolism.

  • strain level diversity of secondary metabolism in Streptomyces Albus
    PLOS ONE, 2015
    Co-Authors: Ryan F Seipke
    Abstract:

    Streptomyces spp. are robust producers of medicinally-, industrially- and agriculturally-important small molecules. Increased resistance to antibacterial agents and the lack of new antibiotics in the pipeline have led to a renaissance in natural product discovery. This endeavor has benefited from inexpensive high quality DNA sequencing technology, which has generated more than 140 genome sequences for taxonomic type strains and environmental Streptomyces spp. isolates. Many of the sequenced streptomycetes belong to the same species. For instance, Streptomyces Albus has been isolated from diverse environmental niches and seven strains have been sequenced, consequently this species has been sequenced more than any other streptomycete, allowing valuable analyses of strain-level diversity in secondary metabolism. Bioinformatics analyses identified a total of 48 unique biosynthetic gene clusters harboured by Streptomyces Albus strains. Eighteen of these gene clusters specify the core secondary metabolome of the species. Fourteen of the gene clusters are contained by one or more strain and are considered auxiliary, while 16 of the gene clusters encode the production of putative strain-specific secondary metabolites. Analysis of Streptomyces Albus strains suggests that each strain of a Streptomyces species likely harbours at least one strain-specific biosynthetic gene cluster. Importantly, this implies that deep sequencing of a species will not exhaust gene cluster diversity and will continue to yield novelty.