443 results match your criteria: "LOEWE Center for Synthetic Microbiology & Department of Chemistry[Affiliation]"

Specialized or secondary metabolites are small molecules of biological origin, often showing potent biological activities with applications in agriculture, engineering and medicine. Usually, the biosynthesis of these natural products is governed by sets of co-regulated and physically clustered genes known as biosynthetic gene clusters (BGCs). To share information about BGCs in a standardized and machine-readable way, the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard and repository was initiated in 2015.

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  • Pyrrolizidine alkaloids (PAs) are a diverse group of compounds found in plants and bacteria, characterized by a specific chemical structure and produced through two main pathways (one in plants and another in bacteria).
  • The study identified a gene cluster in the bacterium Xenorhabdus hominickii responsible for the production of a specific PA called pyrrolizwilline, shedding light on its biosynthesis.
  • Researchers also characterized an important enzyme in the pathway, XhpG, utilizing advanced techniques like X-ray crystallography to understand its role in converting a precursor compound into pyrrolizwilline.
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Promiscuous enzymes often serve as the starting point for the evolution of novel functions. Yet, the extent to which the promiscuity of an individual enzyme can be harnessed several times independently for different purposes during evolution is poorly reported. Here, we present a case study illustrating how NAD(P)-dependent succinate semialdehyde dehydrogenase of Escherichia coli (Sad) is independently recruited through various evolutionary mechanisms for distinct metabolic demands, in particular vitamin biosynthesis and central carbon metabolism.

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  • * The regulation of glycolate metabolism in certain alphaproteobacteria is complex, involving multiple regulators: BhcR activates the BHAC, while GlcR represses glycolate oxidase production, and CceR influences the shift between glycolysis and gluconeogenesis.
  • * This study highlights the metabolic flexibility of Alphaproteobacteria, showing their ability to simultaneously utilize glycolate along with other carbon sources depending on environmental availability.
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  • - NOSO-95A, an antibiotic from entomopathogenic Xenorhabdus bacteria, is the first of the odilorhabdin class, showing broad-spectrum activity and paving the way for the synthetic derivative NOSO-502, which may combat antibiotic resistance.
  • - Although the action of odilorhabdins has been studied, their biosynthesis was not well understood until researchers produced NOSO-95A in E. coli by refactoring its biosynthetic gene cluster (BGC).
  • - By applying NRPS engineering techniques, the team explored biosynthetic pathways and discovered mechanisms for creating unusual amino acids, which could help develop new odilorhabdin analogues with better therapeutic properties.
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Lipid A in outer membrane vesicles shields bacteria from polymyxins.

J Extracell Vesicles

May 2024

Institute for Lung Research, Universities of Giessen and Marburg Lung Center, German Center for Lung Research (DZL), Philipps-University Marburg, Marburg, Germany.

The continuous emergence of multidrug-resistant bacterial pathogens poses a major global healthcare challenge, with Klebsiella pneumoniae being a prominent threat. We conducted a comprehensive study on K. pneumoniae's antibiotic resistance mechanisms, focusing on outer membrane vesicles (OMVs) and polymyxin, a last-resort antibiotic.

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  • Researchers are exploring biopesticides from Xenorhabdus and Photorhabdus bacteria to control Aedes albopictus mosquitoes, as these bacteria show significant insecticidal properties.
  • Testing revealed that various strains of Xenorhabdus and Photorhabdus could kill mosquito larvae with mortality rates between 52-100%, and they also inhibited mosquito egg hatching.
  • Key compounds, fabclavine and xenocoumacin, were identified as effective larvicides, indicating potential for developing them into new biolarvicides or enhancing existing products for mosquito control.
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  • Many drugs used in medicine come from bacterial natural products created by complex enzymes called nonribosomal peptide synthetases (NRPSs) that link amino acids together.
  • This research identifies new recombination sites within a specific part of NRPSs, the thiolation (T) domain, paving the way for innovative engineering of these enzymes.
  • The study introduces a method called "eXchange Unit between T domains" (XUT), which enables scientists to combine NRPS fragments with different characteristics to create specific drugs, such as a proteasome inhibitor constructed from five distinct NRPS pieces.
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In this work, we have developed an expansion microscopy (ExM) protocol that combines ExM with photoactivated localization microscopy (ExPALM) for yeast cell imaging, and report a robust protocol for single-molecule and expansion microscopy of fission yeast, abbreviated as SExY. Our optimized SExY protocol retains about 50% of the fluorescent protein signal, doubling the amount obtained compared to the original protein retention ExM (proExM) protocol. It allows for a fivefold, highly isotropic expansion of fission yeast cells, which we carefully controlled while optimizing protein yield.

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A Synthetic Pathway for the Production of Benzylsuccinate in .

Molecules

January 2024

Fachbereich Biologe, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany.

()-Benzylsuccinate is generated in anaerobic toluene degradation by the radical addition of toluene to fumarate and further degraded to benzoyl-CoA by a β-oxidation pathway. Using metabolic modules for benzoate transport and activation to benzoyl-CoA and the enzymes of benzylsuccinate β-oxidation, we established an artificial pathway for benzylsuccinate production in , which is based on its degradation pathway running in reverse. Benzoate is supplied to the medium but needs to be converted to benzoyl-CoA by an uptake transporter and a benzoate-CoA ligase or CoA-transferase.

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Conformational Dynamics of the Most Efficient Carboxylase Contributes to Efficient CO Fixation.

J Chem Inf Model

December 2023

Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepión 4030000, Chile.

Crotonyl-CoA carboxylase/reductase (Ccr) is one of the fastest CO fixing enzymes and has become part of efficient artificial CO-fixation pathways in vitro, paving the way for future applications. The underlying mechanism of its efficiency, however, is not yet completely understood. X-ray structures of different intermediates in the catalytic cycle reveal tetramers in a dimer of dimers configuration with two open and two closed active sites.

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Bacterial chromosomes are dynamically and spatially organised within cells. In slow-growing Escherichia coli, the chromosomal terminus is initially located at the new pole and must therefore migrate to midcell during replication to reproduce the same pattern in the daughter cells. Here, we use high-throughput time-lapse microscopy to quantify this transition, its timing and its relationship to chromosome segregation.

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Cation-exchange stationary phases were characterized in different chromatographic modes (HILIC, RPLC, IC) and applied to the separation of non-charged hydrophobic and hydrophilic analytes. The set of columns under investigation included both commercially available cation-exchangers and self-prepared PS/DVB-based columns, the latter consisting of adjustable amounts of carboxylic and sulfonic acid functional groups. The influence of cation-exchange site and polymer substrate on the multimodal properties of cation-exchangers was identified using selectivity parameters, polymer imaging and excess adsorption isotherms.

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Fluorescent microscopy is the primary method to study DNA organization within cells. However, the variability and low signal/noise commonly associated with live-cell time-lapse imaging challenges quantitative measurements. In particular, obtaining quantitative or mechanistic insight often depends on the accurate tracking of fluorescent particles.

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Surface proteome of plasma extracellular vesicles as mechanistic and clinical biomarkers for malaria.

Infection

October 2023

Institute for Lung Research, Universities of Giessen and Marburg Lung Center, Philipps-University Marburg, German Center for Lung Research (DZL), Marburg, Germany.

Article Synopsis
  • Malaria, primarily caused by the Plasmodium falciparum parasite, is a severe disease affecting many in tropical regions, and there's a pressing need for biomarkers to assess disease severity and outcomes.
  • Researchers analyzed blood samples from healthy individuals and malaria patients, using an EV Array to identify proteins on small extracellular vesicles (sEVs) that varied between these two groups.
  • They found that specific proteins, especially CD106, could effectively differentiate between healthy and malaria-affected individuals, suggesting that these sEV-associated proteins could serve as future diagnostic or predictive biomarkers for malaria.
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Implementation of the β-hydroxyaspartate cycle increases growth performance of Pseudomonas putida on the PET monomer ethylene glycol.

Metab Eng

March 2023

Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany; LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany. Electronic address:

Ethylene glycol (EG) is a promising next generation feedstock for bioprocesses. It is a key component of the ubiquitous plastic polyethylene terephthalate (PET) and other polyester fibers and plastics, used in antifreeze formulations, and can also be generated by electrochemical conversion of syngas, which makes EG a key compound in a circular bioeconomy. The majority of biotechnologically relevant bacteria assimilate EG via the glycerate pathway, a wasteful metabolic route that releases CO and requires reducing equivalents as well as ATP.

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The key to ensuring proper chromosome segregation during mitosis is the kinetochore (KT), a tightly regulated multiprotein complex that links the centromeric chromatin to the spindle microtubules and as such leads the segregation process. Understanding its architecture, function, and regulation is therefore essential. However, due to its complexity and dynamics, only its individual subcomplexes could be studied in structural detail so far.

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Identification of Ensifer meliloti genes required for survival during peat-based bioinoculant maturation by STM-seq.

J Biotechnol

January 2023

Instituto de Biotecnología y Biología Molecular - CONICET CCT-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina.

Rhizobial inoculants are sold either as rhizobia within a liquid matrix; or as rhizobia adhered to granules composed of peat prill or finely ground peat moss. During the production of peat-based inoculants, a series of physiological changes occur that result in an increased capability of the rhizobia to survive on the seeds. The number of viable rhizobia on preinoculated seeds at the point of sale, however, is often a limiting factor, as is the inefficiency of the inoculant bacteria to compete with the local rhizobia for the host colonization.

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Intranasal administration of Acinetobacter lwoffii in a murine model of asthma induces IL-6-mediated protection associated with cecal microbiota changes.

Allergy

May 2023

Institute of Laboratory Medicine, member of the German Center for Lung Research (DZL) and the Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany.

Background: Early-life exposure to certain environmental bacteria including Acinetobacter lwoffii (AL) has been implicated in protection from chronic inflammatory diseases including asthma later in life. However, the underlying mechanisms at the immune-microbe interface remain largely unknown.

Methods: The effects of repeated intranasal AL exposure on local and systemic innate immune responses were investigated in wild-type and Il6 , Il10 , and Il17 mice exposed to ovalbumin-induced allergic airway inflammation.

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With an ever-increasing amount of (meta)genomic data being deposited in sequence databases, (meta)genome mining for natural product biosynthetic pathways occupies a critical role in the discovery of novel pharmaceutical drugs, crop protection agents and biomaterials. The genes that encode these pathways are often organised into biosynthetic gene clusters (BGCs). In 2015, we defined the Minimum Information about a Biosynthetic Gene cluster (MIBiG): a standardised data format that describes the minimally required information to uniquely characterise a BGC.

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The faithful segregation and inheritance of bacterial chromosomes and low-copy number plasmids requires dedicated partitioning systems. The most common of these, ParABS, consists of ParA, a DNA-binding ATPase and ParB, a protein that binds to centromeric-like sequences on the DNA cargo. The resulting nucleoprotein complexes are believed to move up a self-generated gradient of nucleoid-associated ParA.

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Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease that exhibits constitutive activation of phosphoinositide 3-kinase (PI3K) driven by chronic B-cell receptor signaling or PTEN deficiency. Since pan-PI3K inhibitors cause severe side effects, we investigated the anti-lymphoma efficacy of the specific PI3Kβ/δ inhibitor AZD8186. We identified a subset of DLBCL models within activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL that were sensitive to AZD8186 treatment.

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Single-molecule localization microscopy (SMLM) is an advanced microscopy method that uses the blinking of fluorescent molecules to determine the position of these molecules with a resolution below the diffraction limit (∼5-40 nm). While SMLM imaging itself is becoming more popular, the computational analysis surrounding the technique is still a specialized area and often remains a "black box" for experimental researchers. Here, we provide an introduction to the required computational analysis of SMLM imaging, post-processing and typical data analysis.

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Bacterial gene expression depends on the efficient functioning of global transcriptional networks, however their interconnectivity and orchestration rely mainly on the action of individual DNA binding proteins called transcription factors (TFs). TFs interact not only with their specific target sites, but also with secondary (off-target) sites, and vary in their promiscuity. It is not clear yet what mechanisms govern the interactions with secondary sites, and how such rewiring affects the overall regulatory network, but this could clearly constrain horizontal gene transfer.

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Bacterial Type IV CRISPR-Cas systems are thought to rely on multi-subunit ribonucleoprotein complexes to interfere with mobile genetic elements, but the substrate requirements and potential DNA nuclease activities for many systems within this type are uncharacterized. Here we show that the native Pseudomonas oleovorans Type IV-A CRISPR-Cas system targets DNA in a PAM-dependent manner and elicits interference without showing DNA nuclease activity. We found that the first crRNA of P.

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