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Christopher T. Walsh - One of the best experts on this subject based on the ideXlab platform.
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complexity generation in fungal peptidyl alkaloid biosynthesis a two enzyme pathway to the hexacyclic mdr export pump inhibitor ardeemin
ACS Chemical Biology, 2013Co-Authors: Stuart W Haynes, Xue Gao, Yi Tang, Christopher T. WalshAbstract:Ardeemins are hexacyclic peptidyl alkaloids isolated from Aspergillus fischeri as agents that block efflux of anticancer drugs by MultiDrug Resistance (MDR) export pumps. To evaluate the biosynthetic logic and enzymatic machinery for ardeemin framework assembly, we sequenced the A. fischeri genome and identified the ardABC gene cluster. Through both genetic deletions and biochemical characterizations of purified ArdA and ArdB we show this ArdAB enzyme pair is sufficient to convert anthranilate (Ant), l-Ala, and l-Trp to ardeemin. ArdA is a 430 kDa trimodular nonribosomal Peptide Synthase (NRPS) that converts the three building blocks into a fumiquinazoline (FQ) regioisomer termed ardeemin FQ. ArdB is a prenyltransferase that takes tricyclic ardeemin FQ and dimethylallyl diphosphate to the hexacyclic ardeemin scaffold via prenylation at C2 of the Trp-derived indole moiety with intramolecular capture by an amide NH of the fumiquinazoline ring. The two-enzyme ArdAB pathway reveals remarkable efficiency in co...
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Complexity Generation in Fungal Peptidyl Alkaloid Biosynthesis: A Two-Enzyme Pathway to the Hexacyclic MDR Export Pump Inhibitor Ardeemin
2013Co-Authors: Stuart W. Haynes, Xue Gao, Yi Tang, Christopher T. WalshAbstract:Ardeemins are hexacyclic peptidyl alkaloids isolated from Aspergillus fischeri as agents that block efflux of anticancer drugs by MultiDrug Resistance (MDR) export pumps. To evaluate the biosynthetic logic and enzymatic machinery for ardeemin framework assembly, we sequenced the A. fischeri genome and identified the ardABC gene cluster. Through both genetic deletions and biochemical characterizations of purified ArdA and ArdB we show this ArdAB enzyme pair is sufficient to convert anthranilate (Ant), l-Ala, and l-Trp to ardeemin. ArdA is a 430 kDa trimodular nonribosomal Peptide Synthase (NRPS) that converts the three building blocks into a fumiquinazoline (FQ) regioisomer termed ardeemin FQ. ArdB is a prenyltransferase that takes tricyclic ardeemin FQ and dimethylallyl diphosphate to the hexacyclic ardeemin scaffold via prenylation at C2 of the Trp-derived indole moiety with intramolecular capture by an amide NH of the fumiquinazoline ring. The two-enzyme ArdAB pathway reveals remarkable efficiency in construction of the hexacyclic peptidyl alkaloid scaffold
Rania Siam - One of the best experts on this subject based on the ideXlab platform.
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antibacterial and anticancer activities of orphan biosynthetic gene clusters from atlantis ii red sea brine pool
Microbial Cell Factories, 2019Co-Authors: Laila Ziko, Alhussein A Saqr, Amged Ouf, Matthias Gimpel, Ramy K Aziz, Peter Neubauer, Rania SiamAbstract:Cancer and infectious diseases are problematic because of continuous emergence of drug resistance. One way to address this enormous global health threat is bioprospecting the unlikeliest environments, such as extreme marine niches, which have tremendous biodiversity that is barely explored. One such environment is the Red Sea brine pool, Atlantis II Deep (ATII). Here, we functionally screened a fosmid library of metagenomic DNA isolated from the ATII lower convective layer (LCL) for antibacterial and anticancer activities. Selected clones, 14-7E and 10-2G, displayed antibacterial effects on the marine strain Bacillus sp. Cc6. Moreover, whole cell lysates from 14-7E and 10-2G exhibited decreased cell viability against MCF-7 (39.1% ± 6.6, 42% ± 8.1 at 50% v/v) and U2OS cells (35.7% ± 1.9, 79.9% ± 5.9 at 50% v/v), respectively. By sequencing the insert DNA from 14-7E and 10-2G, we identified two putative orphan biosynthetic gene clusters. Both clusters harbored putative ATP-binding cassette (ABC) transporter permeases and S-adenosylmethionine-related genes. Interestingly, the biosynthetic gene cluster identified on 14-7E is of archaeal origin and harbors a putative transcription factor. Several identified genes may be responsible for the observed antibacterial and anticancer activities. The 14-7E biosynthetic gene cluster may be encoding enzymes producing a specialized metabolite (effect of detected genes involved in C–C bond formation and glycosylation). The bioactivity may also be due to predicted subtilases encoded by this cluster. The 10-2G cluster harbored putative glycosyltransferase and non-ribosomal Peptide Synthase genes; thus the observed activity of this clone could be caused by a bioactive Peptide. The ATII LCL prokaryotic metagenome hosts putative orphan biosynthetic gene clusters that confer antibiotic and anticancer effects. Further biochemical studies should characterize the detected bioactive components, and the potential use of 14-7E metabolite for antibiosis and 10-2G metabolite as a selective anti-breast cancer drug.
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Antibacterial and anticancer activities of orphan biosynthetic gene clusters from Atlantis II Red Sea brine pool
BMC, 2019Co-Authors: Laila Ziko, Alhussein A Saqr, Amged Ouf, Matthias Gimpel, Ramy K Aziz, Peter Neubauer, Rania SiamAbstract:Abstract Background Cancer and infectious diseases are problematic because of continuous emergence of drug resistance. One way to address this enormous global health threat is bioprospecting the unlikeliest environments, such as extreme marine niches, which have tremendous biodiversity that is barely explored. One such environment is the Red Sea brine pool, Atlantis II Deep (ATII). Here, we functionally screened a fosmid library of metagenomic DNA isolated from the ATII lower convective layer (LCL) for antibacterial and anticancer activities. Results Selected clones, 14-7E and 10-2G, displayed antibacterial effects on the marine strain Bacillus sp. Cc6. Moreover, whole cell lysates from 14-7E and 10-2G exhibited decreased cell viability against MCF-7 (39.1% ± 6.6, 42% ± 8.1 at 50% v/v) and U2OS cells (35.7% ± 1.9, 79.9% ± 5.9 at 50% v/v), respectively. By sequencing the insert DNA from 14-7E and 10-2G, we identified two putative orphan biosynthetic gene clusters. Both clusters harbored putative ATP-binding cassette (ABC) transporter permeases and S-adenosylmethionine-related genes. Interestingly, the biosynthetic gene cluster identified on 14-7E is of archaeal origin and harbors a putative transcription factor. Several identified genes may be responsible for the observed antibacterial and anticancer activities. The 14-7E biosynthetic gene cluster may be encoding enzymes producing a specialized metabolite (effect of detected genes involved in C–C bond formation and glycosylation). The bioactivity may also be due to predicted subtilases encoded by this cluster. The 10-2G cluster harbored putative glycosyltransferase and non-ribosomal Peptide Synthase genes; thus the observed activity of this clone could be caused by a bioactive Peptide. Conclusions The ATII LCL prokaryotic metagenome hosts putative orphan biosynthetic gene clusters that confer antibiotic and anticancer effects. Further biochemical studies should characterize the detected bioactive components, and the potential use of 14-7E metabolite for antibiosis and 10-2G metabolite as a selective anti-breast cancer drug
Kwokyung Yuen - One of the best experts on this subject based on the ideXlab platform.
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First discovery of two polyketide Synthase genes for mitorubrinic acid and mitorubrinol yellow pigment biosynthesis and implications in virulence of Penicillium marneffei
2016Co-Authors: Patrick C Y Woo, Chingwan Lam, Emily W T Tam, Chris K F Leung, Samson S Y Wong, Susanna K P Lau, Kwokyung YuenAbstract:Background: The genome of P. marneffei, the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in China and Southeast Asia, possesses 23 polyketide Synthase (PKS) genes and 2 polyketide Synthase nonribosomal Peptide Synthase hybrid (PKS-NRPS) genes, which is of high diversity compared to other thermal dimorphic pathogenic fungi. We hypothesized that the yellow pigment in the mold form of P. marneffei could also be synthesized by one or more PKS genes. Methodology/Principal Findings: All 23 PKS and 2 PKS-NRPS genes of P. marneffei were systematically knocked down. A loss of the yellow pigment was observed in the mold form of the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants. Sequence analysis showed that PKS11 and PKS12 are fungal non-reducing PKSs. Ultra high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry (MS) and MS/MS analysis of the culture filtrates of wild type P. marneffei and the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants showed that the yellow pigment is composed of mitorubrinic acid and mitorubrinol. The survival of mice challenged with the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants was significantly better than those challenged with wild type P. marneffei (P,0.05). There was also statistically significant decrease in survival of pks11 knockdown, pks12 knockdown and pks11pks12 double knockdow
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first discovery of two polyketide Synthase genes for mitorubrinic acid and mitorubrinol yellow pigment biosynthesis and implications in virulence of penicillium marneffei
PLOS Neglected Tropical Diseases, 2012Co-Authors: Patrick C Y Woo, Chingwan Lam, Emily W T Tam, Chris K F Leung, Samson S Y Wong, Susanna K P Lau, Kwokyung YuenAbstract:Background The genome of P. marneffei, the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in China and Southeast Asia, possesses 23 polyketide Synthase (PKS) genes and 2 polyketide Synthase nonribosomal Peptide Synthase hybrid (PKS-NRPS) genes, which is of high diversity compared to other thermal dimorphic pathogenic fungi. We hypothesized that the yellow pigment in the mold form of P. marneffei could also be synthesized by one or more PKS genes. Methodology/Principal Findings All 23 PKS and 2 PKS-NRPS genes of P. marneffei were systematically knocked down. A loss of the yellow pigment was observed in the mold form of the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants. Sequence analysis showed that PKS11 and PKS12 are fungal non-reducing PKSs. Ultra high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry (MS) and MS/MS analysis of the culture filtrates of wild type P. marneffei and the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants showed that the yellow pigment is composed of mitorubrinic acid and mitorubrinol. The survival of mice challenged with the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants was significantly better than those challenged with wild type P. marneffei (P<0.05). There was also statistically significant decrease in survival of pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants compared to wild type P. marneffei in both J774 and THP1 macrophages (P<0.05). Conclusions/Significance The yellow pigment of the mold form of P. marneffei is composed of mitorubrinol and mitorubrinic acid. This represents the first discovery of PKS genes responsible for mitorubrinol and mitorubrinic acid biosynthesis. pks12 and pks11 are probably responsible for sequential use in the biosynthesis of mitorubrinol and mitorubrinic acid. Mitorubrinol and mitorubrinic acid are virulence factors of P. marneffei by improving its intracellular survival in macrophages.
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high diversity of polyketide Synthase genes and the melanin biosynthesis gene cluster in penicillium marneffei
FEBS Journal, 2010Co-Authors: Patrick C Y Woo, Emily W T Tam, Susanna K P Lau, Ken T K Chong, James J Cai, Edward T K Tung, Antonio H Y Ngan, Kwokyung YuenAbstract:Despite the unique phenotypic properties and clinical importance of Penicillium marneffei, the polyketide Synthase genes in its genome have never been characterized. Twenty-three putative polyketide Synthase genes and two putative polyketide Synthase nonribosomal Peptide-Synthase hybrid genes were identified in the P. marneffei genome, a diversity much higher than found in other pathogenic thermal dimorphic fungi, such as Histoplasma capsulatum (one polyketide Synthase gene) and Coccidioides immitis (10 polyketide Synthase genes). These genes were evenly distributed on the phylogenetic tree with polyketide Synthase genes of Aspergillus and other fungi, indicating that the high diversity was not a result of lineage-specific gene expansion through recent gene duplication. The melanin-biosynthesis gene cluster had gene order and orientations identical to those in the Talaromyces stipitatus (a teleomorph of Penicillium emmonsii) genome. Phylogenetically, all six genes of the melanin-biosynthesis gene cluster in P. marneffei were also most closely related to those in T. stipitatus, with high bootstrap supports. The polyketide Synthase gene of the melanin-biosynthesis gene cluster (alb1) in P. marneffei was knocked down, which was accompanied by loss of melanin pigment production and reduced ornamentation in conidia. The survival of mice challenged with the alb1 knockdown mutant was significantly better than those challenged with wild-type P. marneffei (P < 0.005). The sterilizing doses of hydrogen peroxide, leading to a 50% reduction in survival of conidia, were 11 min for wild-type P. marneffei and 6 min for the alb1 knockdown mutant of P. marneffei, implying that the melanin-biosynthesis gene cluster contributed to virulence through decreased susceptibility to killing by hydrogen peroxide.
Shawn R. Starkenburg - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae)
2016Co-Authors: Blake T. Hovde, Heather M Hunsperger, Chloe R. Deodato, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, B. Barlow, Shawn R. StarkenburgAbstract:Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (*40 % of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photo-period. The C. tobin genome harbors the first hybrid polyketide Synthase/non-ribosomal Peptide Synthase gene complex reported for an algal species, and encodes potential anti-microbial Peptides and proteins involved in multidrug and toxic compound extrusion. A ne
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Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae)
PLoS genetics, 2015Co-Authors: Blake T. Hovde, Heather M Hunsperger, Chloe R. Deodato, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide Synthase/non-ribosomal Peptide Synthase gene complex reported for an algal species, and encodes potential anti-microbial Peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two “red” RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes.
Stuart W Haynes - One of the best experts on this subject based on the ideXlab platform.
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complexity generation in fungal peptidyl alkaloid biosynthesis a two enzyme pathway to the hexacyclic mdr export pump inhibitor ardeemin
ACS Chemical Biology, 2013Co-Authors: Stuart W Haynes, Xue Gao, Yi Tang, Christopher T. WalshAbstract:Ardeemins are hexacyclic peptidyl alkaloids isolated from Aspergillus fischeri as agents that block efflux of anticancer drugs by MultiDrug Resistance (MDR) export pumps. To evaluate the biosynthetic logic and enzymatic machinery for ardeemin framework assembly, we sequenced the A. fischeri genome and identified the ardABC gene cluster. Through both genetic deletions and biochemical characterizations of purified ArdA and ArdB we show this ArdAB enzyme pair is sufficient to convert anthranilate (Ant), l-Ala, and l-Trp to ardeemin. ArdA is a 430 kDa trimodular nonribosomal Peptide Synthase (NRPS) that converts the three building blocks into a fumiquinazoline (FQ) regioisomer termed ardeemin FQ. ArdB is a prenyltransferase that takes tricyclic ardeemin FQ and dimethylallyl diphosphate to the hexacyclic ardeemin scaffold via prenylation at C2 of the Trp-derived indole moiety with intramolecular capture by an amide NH of the fumiquinazoline ring. The two-enzyme ArdAB pathway reveals remarkable efficiency in co...