A5017737292- Photosynthetic Processes and Mechanisms
- Metalloenzymes and iron-sulfur proteins
- Plant biochemistry and biosynthesis
- Pharmacogenetics and Drug Metabolism
- Electrocatalysts for Energy Conversion
- Advanced battery technologies research
- Drug Transport and Resistance Mechanisms
- Microbial Metabolic Engineering and Bioproduction
- Computational Drug Discovery Methods
- Legume Nitrogen Fixing Symbiosis
- Antioxidant Activity and Oxidative Stress
- Hydrogen Storage and Materials
- Plant Pathogenic Bacteria Studies
- Transgenic Plants and Applications
- Bacteriophages and microbial interactions
- Algal biology and biofuel production
- Plant-Microbe Interactions and Immunity
- Light effects on plants
- Photoreceptor and optogenetics research
- Enzyme Catalysis and Immobilization
- Receptor Mechanisms and Signaling
- PI3K/AKT/mTOR signaling in cancer
- Catalysis and Hydrodesulfurization Studies
- Bacterial Genetics and Biotechnology
- Organophosphorus compounds synthesis
Université de Toulouse
2009-2024
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2024
Centre National de la Recherche Scientifique
2011-2024
Agency for Science, Technology and Research
2020-2024
Institut National des Sciences Appliquées de Toulouse
2020-2024
CREATe Centre
2022
Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés
2009-2019
Université Toulouse III - Paul Sabatier
2007-2016
Laboratoire de Microbiologie, Adaptation et Pathogénie
2007-2012
Laboratoire de Microbiologie et Génétique Moléculaires
2007-2012
Dickeya dadantii is a pathogen infecting wide range of plant species. Soft rot, the visible symptom, mainly due to production pectate lyases (Pels) that can destroy cell walls. Previously we found pel gene expression modulated by H-NS and FIS, two nucleoid-associated proteins (NAPs) modulating DNA topology. Here, show relaxation in growing D. cells decreases genes. Deletion fis aggravates, whereas hns alleviates negative impact on expression. We further FIS directly bind pelE promoter...
Direct electron transfer between enzymes and electrodes is now commonly achieved, but obtaining protein films that are very stable may be challenging. This particularly crucial in the case of hydrogenases, catalyze biological conversion dihydrogen protons, because instability hydrogenase prevent use these as electrocatalysts H(2) oxidation production biofuel cells photoelectrochemical cells. Here we show two different FeFe hydrogenases (from Chamydomonas reinhardtii Clostridium...
We investigated di-hydrogen transport between the solvent and active site of FeFe hydrogenases. Substrate channels supposedly exist serve various functions in certain redox enzymes which use or produce O2, H2, NO, CO, N2, but preferred paths have not always been unambiguously identified, whether a continuous, permanent channel is an absolute requirement for transporting diatomic molecules unknown. Here, we review literature on gas proteins report site-directed mutagenesis kinetic methods,...
Carbon monoxide is often described as a competitive inhibitor of FeFe hydrogenases, and it used for probing H2 binding to synthetic or in silico models the active site H-cluster. Yet does not always behave simple inhibitor. Using an original approach which combines accurate electrochemical measurements theoretical calculations, we elucidate mechanism by which, under certain conditions, CO can cause permanent damage Like case oxygen inhibition, reaction with engages entire H-cluster, rather...
Using direct electrochemistry to learn about the mechanism of electrocatalysts and redox enzymes requires that kinetic models be developed. Here we thoroughly discuss interpretation electrochemical signals obtained with adsorbed molecular catalysts can reversibly convert their substrate product. We derive analytical relations between observables (overpotentials for catalysis in each direction, positions, magnitudes features catalytic wave) characteristics cycle (redox properties...
Spatial clustering of enzymes has proven an elegant approach to optimize metabolite transfer between in synthetic metabolic pathways. Among the multiple methods used promote colocalisation, enzyme fusion is probably simplest. Inspired by natural systems, we have explored consequences spatial reorganizations catalytic domains Xanthophyllomyces dendrorhous carotenoid produced Saccharomyces cerevisiae. Synthetic genes encoding bidomain composed CrtI and CrtB from CrtYB were connected two...
Homologous recombination between circular sister chromosomes during DNA replication in bacteria can generate chromosome dimers that must be resolved into monomers prior to cell division. In Escherichia coli, dimer resolution is achieved by site-specific recombination, Xer involving two paralogous tyrosine recombinases, XerC and XerD, a 28-bp site (dif) located at the junction of arms. tightly controlled septal protein FtsK. XerCD recombinases FtsK are found on most sequenced eubacterial...
Chronoamperometric experiments with adsorbed electrocatalysts are commonly performed either for analytical purposes or studying the catalytic mechanism of a redox enzyme. In context amperometric sensors, current may be recorded as function time while analyte concentration is being increased to determine linearity range. mechanistic studies enzymes, chronoamperometry proved powerful untangling effects electrode potential and time, which convoluted in cyclic voltammetric measurements,...
Summary Erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. Pectinolytic enzymes and, in particular, pectate lyases (Pels) play key role soft rot symptoms but the efficient colonization of plants by E. requires additional factors. These factors include harpin HrpN, cellulase Cel5, proteases (Prts), flagellar proteins and Sap system, involved detoxification antimicrobial peptides. HrpN flagellum are mostly early steps infection whereas degradative (Pels, Prts) mainly...
NADPH cytochrome P450 oxidoreductase (CPR) is the obligatory electron supplier in sustaining activity of microsomal (CYP). The variant nature isoform specific proximal interface CYPs implies that CPR capable multiple degenerated interactions with for transfer, through different binding mechanisms, which are still not well understood. Recently, we showed dynamics allows formation open conformers can be sampled by its structurally diverse redox partners a CYP-isoform dependent manner. To...
Abstract Because of wide applications in food, feed, pharmaceutical and cosmetic industries, the carotenoid market is growing rapidly. Most carotenoids are hydrophobic, which limits their bioavailability. Glycosylation a natural route that substantially increases water solubility, as well bioavailability, photostability biological activities carotenoids. Here, we report metabolic engineering efforts (e.g., promoter RBS engineering, optimization carbon sources supplementation bottleneck...
Optogenetics arises as a valuable tool to precisely control genetic circuits in microbial cell factories. Light holds the promise of optimizing bioproduction methods and maximizing yields, but its implementation at different steps strain development process culture scales remains challenging. In this study, we aim beta-carotene using optogenetics Saccharomyces cerevisiae investigate how performance translates across scales. We built four lab-scale illumination devices, each handling volumes,...
NADPH-cytochrome P450 reductase (CPR) is a redox partner of microsomal cytochrome P450s and prototype the diflavin family. CPR contains 3 distinct functional domains: FMN-binding domain (acceptor reduction), linker (hinge), connecting/FAD (NADPH oxidation). It has been demonstrated that mechanism exhibits an important step in which it switches from compact, closed conformation (locked state) to ensemble open conformations (unlocked state), latter enabling electron transfer partners. The...
Summary Production of the essential virulence factors, called pectate lyases (Pels), in phytopathogenic bacterium Erwinia chrysanthemi is controlled by a complex regulation system and responds to various stimuli, such as presence pectin or plant extracts, growth phase, temperature iron concentration. The phase are most important signals identified. Eight regulators modulating expression pel genes (encoding Pels) have been characterized. These organized network allowing sequential functioning...
NADPH-cytochrome P450 reductase (CPR) is the unique redox partner of microsomal cytochrome P450s (CYPs). CPR exists in a conformational equilibrium between open and closed conformations throughout its electron transfer (ET) function. Previously, we have shown that electrostatic flexibility properties hinge segment are critical for ET. Three mutants human were studied (S243P, I245P R246A) combined with representative drug-metabolizing CYPs (isoforms 1A2, 2A6 3A4). To probe effect these...
Cytochromes P450, forming a superfamily of monooxygenases containing heme as cofactor, show great versatility in substrate specificity. Metabolic engineering can take advantage this feature to unlock novel metabolic pathways. However, the cytochromes P450 often difficulty being expressed heterologous chassis. As case study prokaryotic host Escherichia coli, synthesis β-cryptoxanthin was addressed. This carotenoid intermediate is difficult produce, its requires monoterminal hydroxylation...
Molecular biodiversity results from branched metabolic pathways driven by enzymatic regioselectivities. An additional complexity occurs in metabolites with an internal structural symmetry, offering identical extremities to the enzymes. For example, terpene family, β-carotene presents two terminal closed-ring structures. Theses cycles can be hydroxylated cytochrome P450s CYP97 family. Two sequential hydroxylations lead first formation of monohydroxylated β-cryptoxanthin and subsequently that...
Fusion of catalytic domains can accelerate cascade reactions by bringing enzymes in close proximity. However, the design a protein fusion and choice linker are often challenging lack guidance. To determine impact parameters on proteins, library linkers featuring various lengths, secondary structures, extensions hydrophobicities was designed. Linkers were used to fuse lycopene cyclase (crtY) β-carotene hydroxylase (crtZ) from
Overexpression of a single enzyme in multigene heterologous pathway may be out balance with the other enzymes pathway, leading to accumulated toxic intermediates, imbalanced carbon flux, reduced productivity or an inhibited growth phenotype. Therefore, optimal, balanced, and synchronized expression levels particular metabolic is critical maximize production desired compounds while maintaining cell fitness growing culture. Furthermore, optimal intracellular concentration determined by...