scholarly journals Inductive Production of the Iron-Chelating 2-Pyridones Benefits the Producing Fungus To Compete for Diverse Niches

mBio ◽  
2021 ◽  
Author(s):  
Bo Chen ◽  
Yanlei Sun ◽  
Shiqin Li ◽  
Ying Yin ◽  
Chengshu Wang
Keyword(s):  
Gene Cluster ◽  
Beauveria Bassiana ◽  
Chemical Ecology ◽  
Biological Activities ◽  
Insect Pathogen ◽  
Metarhizium Robertsii ◽  
Content Type

Different 2-pyridones have been identified, with multiple biological activities but unclear chemical ecology. We found that the silent tenS gene cluster was activated in the insect pathogen Beauveria bassiana when the fungus was cocultured with its natural competitor Metarhizium robertsii .

scholarly journals Expanded Natural Product Diversity Revealed by Analysis of Lanthipeptide-Like Gene Clusters in Actinobacteria

2015 ◽  
Vol 81 (13) ◽  
pp. 4339-4350 ◽  
Author(s):  
Qi Zhang ◽  
James R. Doroghazi ◽  
Xiling Zhao ◽  
Mark C. Walker ◽  
Wilfred A. van der Donk
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Gene Cluster ◽  
Posttranslational Modifications ◽  
Large Scale ◽  
Biological Activities ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Content Type ◽  
Modified Peptides

ABSTRACTLanthionine-containing peptides (lanthipeptides) are a rapidly growing family of polycyclic peptide natural products belonging to the large class of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Lanthipeptides are widely distributed in taxonomically distant species, and their currently known biosynthetic systems and biological activities are diverse. Building on the recent natural product gene cluster family (GCF) project, we report here large-scale analysis of lanthipeptide-like biosynthetic gene clusters fromActinobacteria. Our analysis suggests that lanthipeptide biosynthetic pathways, and by extrapolation the natural products themselves, are much more diverse than currently appreciated and contain many different posttranslational modifications. Furthermore, lanthionine synthetases are much more diverse in sequence and domain topology than currently characterized systems, and they are used by the biosynthetic machineries for natural products other than lanthipeptides. The gene cluster families described here significantly expand the chemical diversity and biosynthetic repertoire of lanthionine-related natural products. Biosynthesis of these novel natural products likely involves unusual and unprecedented biochemistries, as illustrated by several examples discussed in this study. In addition, class IV lanthipeptide gene clusters are shown not to be silent, setting the stage to investigate their biological activities.

scholarly journals Genome Sequence of Beauveria bassiana Strain ATCC 74040, a Widely Employed Insect Pathogen

2020 ◽  
Vol 9 (23) ◽  
Author(s):  
Rossano Atzeni ◽  
Gabriele Moro ◽  
Maria Giovanna Marche ◽  
Paolo Uva ◽  
Luca Ruiu
Keyword(s):  
Beauveria Bassiana ◽  
Genome Sequence ◽  
Mechanism Of Action ◽  
Broad Spectrum ◽  
Insecticidal Activity ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Strain Atcc ◽  
Insect Pathogen ◽  
Content Type

ABSTRACT The broad-spectrum insecticidal activity of Beauveria bassiana strain ATCC 74040 is well documented. The whole-genome sequence of this strain is reported here, revealing a plethora of genes related to its insecticidal potential and providing new insights on the mechanism of action.

scholarly journals A Novel CO-Responsive Transcriptional Regulator and Enhanced H2Production by an Engineered Thermococcus onnurineus NA1 Strain

2014 ◽  
Vol 81 (5) ◽  
pp. 1708-1714 ◽  
Author(s):  
Min-Sik Kim ◽  
Ae Ran Choi ◽  
Seong Hyuk Lee ◽  
Hae-Chang Jung ◽  
Seung Seob Bae ◽  
...  
Keyword(s):  
Production Rate ◽  
Gene Cluster ◽  
Type Strain ◽  
Wild Type Strain ◽  
Regulatory System ◽  
Transcriptional Regulator ◽  
Bioreactor Culture ◽  
Wild Type ◽  
Content Type ◽  
Transcriptional Regulatory

ABSTRACTGenome analysis revealed the existence of a putative transcriptional regulatory system governing CO metabolism inThermococcus onnurineusNA1, a carboxydotrophic hydrogenogenic archaeon. The regulatory system is composed of CorQ with a 4-vinyl reductase domain and CorR with a DNA-binding domain of the LysR-type transcriptional regulator family in close proximity to the CO dehydrogenase (CODH) gene cluster. Homologous genes of the CorQR pair were also found in the genomes ofThermococcusspecies and “CandidatusKorarchaeum cryptofilum” OPF8. In-frame deletion of eithercorQorcorRcaused a severe impairment in CO-dependent growth and H2production. WhencorQandcorRdeletion mutants were complemented by introducing thecorQRgenes under the control of a strong promoter, the mRNA and protein levels of the CODH gene were significantly increased in a ΔCorR strain complemented with integratedcorQR(ΔCorR/corQR↑) compared with those in the wild-type strain. In addition, the ΔCorR/corQR↑strain exhibited a much higher H2production rate (5.8-fold) than the wild-type strain in a bioreactor culture. The H2production rate (191.9 mmol liter−1h−1) and the specific H2production rate (249.6 mmol g−1h−1) of this strain were extremely high compared with those of CO-dependent H2-producing prokaryotes reported so far. These results suggest that thecorQRgenes encode a positive regulatory protein pair for the expression of a CODH gene cluster. The study also illustrates that manipulation of the transcriptional regulatory system can improve biological H2production.

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

2014 ◽  
Vol 58 (10) ◽  
pp. 6185-6196 ◽  
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.

scholarly journals Characterization of a Signaling System inStreptococcus mitisThat Mediates Interspecies Communication withStreptococcus pneumoniae

2018 ◽  
Vol 85 (2) ◽  
Author(s):  
R. Junges ◽  
K. Sturød ◽  
G. Salvadori ◽  
H. A. Åmdal ◽  
T. Chen ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Gene Cluster ◽  
Communication System ◽  
Target Genes ◽  
Genetic Mutation ◽  
Signal Molecules ◽  
Streptococcus Mitis ◽  
Futile Cycle ◽  
Content Type ◽  
Surface Polysaccharide

ABSTRACTStreptococcus mitisis found in the oral cavity and nasopharynx and forms a significant portion of the human microbiome. In this study,in silicoanalyses indicated the presence of an Rgg regulator and short hydrophobic peptide (Rgg/SHP) cell-to-cell communication system inS. mitis. Although Rgg presented greater similarity to a repressor inStreptococcus pyogenes, autoinducing assays and genetic mutation analysis revealed that inS. mitisRgg acts as an activator. Transcriptome analysis showed that in addition toshp, the system regulates two other downstream genes, comprising a segment of a putative lantibiotic gene cluster that is in a conjugative element locus in different members of the mitis group. Close comparison to a similar lantibiotic gene cluster inStreptococcus pneumoniaeindicated thatS. mitislacked the full set of genes. Despite the potential of SHP to trigger a futile cycle of autoinduction, growth was not significantly affected for therggmutant under normal or antibiotic stress conditions. TheS. mitisSHP was, however, fully functional in promoting cross-species communication and increasingS. pneumoniaesurface polysaccharide production, which in this species is regulated by Rgg/SHP. The activity of SHPs produced by both species was detected in cocultures using aS. mitisreporter strain. In competitive assays, a slight advantage was observed for therggmutants. We conclude that the Rgg/SHP system inS. mitisregulates the expression of its ownshpand activates an Rgg/SHP system inS. pneumoniaethat regulates surface polysaccharide synthesis. Fundamentally, cross-communication of such systems may have a role during multispecies interactions.IMPORTANCEBacteria secrete signal molecules into the environment which are sensed by other cells when the density reaches a certain threshold. In this study, we describe a communication system inStreptococcus mitis, a commensal species from the oral cavity, which we also found in several species and strains of streptococci from the mitis group. Further, we show that this system can promote cross-communication withS. pneumoniae, a closely related major human pathogen. Importantly, we show that this cross-communication can take place during coculture. While the genes regulated inS. mitisare likely part of a futile cycle of activation, the target genes inS. pneumoniaeare potentially involved in virulence. The understanding of such complex communication networks can provide important insights into the dynamics of bacterial communities.

scholarly journals Transcriptional Regulator PhlH Modulates 2,4-Diacetylphloroglucinol Biosynthesis in Response to the Biosynthetic Intermediate and End Product

2017 ◽  
Vol 83 (21) ◽  
Author(s):  
Xu Yan ◽  
Rui Yang ◽  
Rui-Xue Zhao ◽  
Jian-Ting Han ◽  
Wen-Juan Jia ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Gene Cluster ◽  
Plant Pathogens ◽  
Feedback Regulation ◽  
Biosynthetic Gene Cluster ◽  
Sequence Motif ◽  
Target Sequence ◽  
Gene Encoding ◽  
Negative Feedback Regulation ◽  
Content Type

ABSTRACT Certain strains of biocontrol bacterium Pseudomonas fluorescens produce the secondary metabolite 2,4-diacetylphloroglucinol (2,4-DAPG) to antagonize soilborne phytopathogens in the rhizosphere. The gene cluster responsible for the biosynthesis of 2,4-DAPG is named phlACBDEFGH and it is still unclear how the pathway-specific regulator phlH within this gene cluster regulates the metabolism of 2,4-DAPG. Here, we found that PhlH in Pseudomonas fluorescens strain 2P24 represses the expression of the phlG gene encoding the 2,4-DAPG hydrolase by binding to a sequence motif overlapping with the −35 site recognized by σ70 factors. Through biochemical screening of PhlH ligands we identified the end product 2,4-DAPG and its biosynthetic intermediate monoacetylphloroglucinol (MAPG), which can act as signaling molecules to modulate the binding of PhlH to the target sequence and activate the expression of phlG. Comparison of 2,4-DAPG production between the ΔphlH, ΔphlG, and ΔphlHG mutants confirmed that phlH and phlG impose negative feedback regulation over 2,4-DAPG biosynthesis. It was further demonstrated that the 2,4-DAPG degradation catalyzed by PhlG plays an insignificant role in 2,4-DAPG tolerance but contributes to bacterial growth advantages under carbon/nitrogen starvation conditions. Taken together, our data suggest that by monitoring and down-tuning in situ levels of 2,4-DAPG, the phlHG genes could dynamically modulate the metabolic loads attributed to 2,4-DAPG production and potentially contribute to rhizosphere adaptation. IMPORTANCE 2,4-DAPG, which is synthesized by biocontrol pseudomonad bacteria, is a broad-spectrum antibiotic against bacteria, fungi, oomycetes, and nematodes and plays an important role in suppressing soilborne plant pathogens. Although most of the genes in the 2,4-DAPG biosynthetic gene cluster (phl) have been characterized, it is still not clear how the pathway-specific regulator phlH is involved in 2,4-DAPG metabolism. This work revealed the role of PhlH in modulating 2,4-DAPG levels by controlling the expression of 2,4-DAPG hydrolase PhlG in response to 2,4-DAPG and MAPG. Since 2,4-DAPG biosynthesis imposes a metabolic burden on biocontrol pseudomonads, it is expected that the fine regulation of phlG by PhlH offers a way to dynamically modulate the metabolic loads attributed to 2,4-DAPG production.

scholarly journals A Bacterial Microcompartment Is Used for Choline Fermentation byEscherichia coli536

2018 ◽  
Vol 200 (10) ◽  
Author(s):  
Taylor I. Herring ◽  
Tiffany N. Harris ◽  
Chiranjit Chowdhury ◽  
Sujit Kumar Mohanty ◽  
Thomas A. Bobik
Keyword(s):  
Electron Microscopy ◽  
Heart Disease ◽  
Gene Cluster ◽  
Transcriptional Regulator ◽  
Human Gut ◽  
Content Type ◽  
E Coli ◽  
Bacterial Microcompartment ◽  
New Type ◽  
Insight Into

ABSTRACTBacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization byProteusandDesulfovibriospecies. However, many aspects of this process have not been fully defined. Here, we investigate choline degradation by the uropathogenEscherichia coli536. Growth studies indicatedE. coli536 degrades choline primarily by fermentation. Electron microscopy indicated that a bacterial microcompartment was used for this process. Bioinformatic analyses suggested that the choline utilization (cut) gene cluster ofE. coli536 includes two operons, one containing three genes and a main operon of 13 genes. Regulatory studies indicate that thecutXgene encodes a positive transcriptional regulator required for induction of the maincutoperon in response to choline supplementation. Each of the 16 genes in thecutcluster was individually deleted, and phenotypes were examined. ThecutX,cutY,cutF,cutO,cutC,cutD,cutU, andcutVgenes were required for choline degradation, but the remaining genes of thecutcluster were not essential under the conditions used. The reasons for these varied phenotypes are discussed.IMPORTANCEHere, we investigate choline degradation inE. coli536. These studies provide a basis for understanding a new type of bacterial microcompartment and may provide deeper insight into the link between choline degradation in the human gut and cancer and heart disease. These are also the first studies of choline degradation inE. coli536, an organism for which sophisticated genetic analysis methods are available. In addition, thecutgene cluster ofE. coli536 is located in pathogenicity island II (PAI-II536) and hence might contribute to pathogenesis.

scholarly journals Establishment of anIn Vitrod-Cycloserine-Synthesizing System by UsingO-Ureido-l-Serine Synthase and d-Cycloserine Synthetase Found in the Biosynthetic Pathway

2013 ◽  
Vol 57 (6) ◽  
pp. 2603-2612 ◽  
Author(s):  
Narutoshi Uda ◽  
Yasuyuki Matoba ◽  
Takanori Kumagai ◽  
Kosuke Oda ◽  
Masafumi Noda ◽  
...  
Keyword(s):  
Gene Cluster ◽  
High Performance ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
Homocysteine Thiolactone ◽  
Putative Gene ◽  
Content Type ◽  
Dna Fragment ◽  
Layer Chromatography

ABSTRACTWe have recently cloned a DNA fragment containing a gene cluster that is responsible for the biosynthesis of an antituberculosis antibiotic,d-cycloserine. The gene cluster is composed of 10 open reading frames, designateddcsAtodcsJ. Judging from the sequence similarity between each putative gene product and known proteins, DcsC, which displays high homology to diaminopimelate epimerase, may catalyze the racemization ofO-ureidoserine. DcsD is similar toO-acetylserine sulfhydrylase, which generatesl-cysteine usingO-acetyl-l-serine with sulfide, and therefore, DcsD may be a synthase to generateO-ureido-l-serine usingO-acetyl-l-serine and hydroxyurea. DcsG, which exhibits similarity to a family of enzymes with an ATP-grasp fold, may be an ATP-dependent synthetase convertingO-ureido-d-serine intod-cycloserine. In the present study, to characterize the enzymatic functions of DcsC, DcsD, and DcsG, each protein was overexpressed inEscherichia coliand purified to near homogeneity. The biochemical function of each of the reactions catalyzed by these three proteins was verified by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and, in some cases, mass spectrometry. The results from this study demonstrate that by using a mixture of the three purified enzymes and the two commercially available substratesO-acetyl-l-serine and hydroxyurea, synthesis ofd-cycloserine was successfully attained. Thesein vitrostudies yield the conclusion that DcsD and DcsG are necessary for the syntheses ofO-ureido-l-serine andd-cycloserine, respectively. DcsD was also able to catalyze the synthesis ofl-cysteine when sulfide was added instead of hydroxyurea. Furthermore, the present study shows that DcsG can also form other cyclicd-amino acid analogs, such asd-homocysteine thiolactone.

scholarly journals Draft Genome Sequence of Comamonas testosteroni TA441, a Bacterium That Has a Cryptic Phenol Degradation Gene Cluster

2019 ◽  
Vol 8 (39) ◽  
Author(s):  
Hiroyuki Arai ◽  
Masaharu Ishii
Keyword(s):  
Gene Cluster ◽  
Genome Sequence ◽  
Phenol Degradation ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Comamonas Testosteroni ◽  
Spontaneous Mutations ◽  
Content Type ◽  
Repressor Gene ◽  
Mutant Strains

Comamonas testosteroni TA441 has a complete phenol degradation gene cluster but does not degrade phenol because the cluster is tightly repressed. However, mutant strains that can degrade phenol arise by spontaneous mutations of a repressor gene during incubation with phenol. Here, we report the draft genome sequence of strain TA441.

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