A5057040957- Radioactive element chemistry and processing
- Mass Spectrometry Techniques and Applications
- Bacterial Genetics and Biotechnology
- Enzyme Structure and Function
- Antibiotic Resistance in Bacteria
- Microtubule and mitosis dynamics
- Vibrio bacteria research studies
- Photosynthetic Processes and Mechanisms
- Redox biology and oxidative stress
- RNA and protein synthesis mechanisms
- Microfluidic and Capillary Electrophoresis Applications
- Metalloenzymes and iron-sulfur proteins
- Pneumonia and Respiratory Infections
- Analytical Chemistry and Chromatography
- Bacterial biofilms and quorum sensing
- Protein Structure and Dynamics
- Ion-surface interactions and analysis
- Metal complexes synthesis and properties
- Trace Elements in Health
- Metal-Catalyzed Oxygenation Mechanisms
- Electrochemical Analysis and Applications
- Heavy Metal Exposure and Toxicity
- Education, sociology, and vocational training
- DNA Repair Mechanisms
- bioluminescence and chemiluminescence research
Centre National de la Recherche Scientifique
2005-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014-2023
Institut de Biosciences et Biotechnologies
2016-2023
Aix-Marseille Université
2009-2023
Bioénergétique et Ingénierie des Protéines
2010-2022
CEA Cadarache
2007-2021
Université de Bourgogne
2016
College of the Holy Cross
2016
CEA Grenoble
2003-2012
Direction de la Recherche Fondamentale
2012
Metal acquisition is a vital microbial process in metal-scarce environments, such as inside host. Using metabolomic exploration, targeted mutagenesis, and biochemical analysis, we discovered an operon Staphylococcus aureus that encodes the different functions required for biosynthesis trafficking of broad-spectrum metallophore related to plant nicotianamine (here called staphylopine). The staphylopine reveals association three enzyme activities: histidine racemase, distantly synthase,...
Summary D einococcus bacteria are famous for their extreme radiation tolerance. The IrrE protein was shown to be essential tolerance and, in an unelucidated manner, induction of a number genes response radiation, including recA and other DNA repair genes. Earlier studies indicated that could zinc peptidase, but proteolytic activity not demonstrated. Here, using several vivo vitro experiments, from deserti found interact with DdrO , predicted regulator encoded by radiation‐induced gene is,...
Human Eg5, a mitotic motor of the kinesin superfamily, is involved in formation and maintenance spindle. The recent discovery small molecules that inhibit HsEg5 by binding to its catalytic domain leading arrest has attracted more interest Eg5 as potential anticancer drug target. We have used hydrogen−deuterium exchange mass spectrometry directed mutagenesis identify secondary structure elements form sites new inhibitors, particular for S-trityl-l-cysteine, potent inhibitor activity vitro...
The type III secretion system (T3SS) is a complex macromolecular machinery employed by number of Gram-negative pathogens to inject effectors directly into the cytoplasm eukaryotic cells. ExoU from opportunistic pathogen Pseudomonas aeruginosa one most aggressive toxins injected T3SS, leading rapid cell necrosis. Here we report crystal structure in with its chaperone, SpcU. folds membrane-binding, bridging, and phospholipase domains. SpcU maintains N-terminus an unfolded state, required for...
To improve our understanding of uranium toxicity, the determinants uranyl affinity in proteins must be better characterized. In this work, we analyzed contribution a phosphoryl group on binding protein site, using site 1 EF-hand motif calmodulin. The recombinant domain calmodulin from A. thaliana was engineered to impair metal at 2 and used as structured template. Threonine position 9 loop phosphorylated vitro, catalytic subunit kinase CK2. Hence, T(9)TKE(12) sequence substituted by CK2...
Type III secretion (T3S) systems play key roles in pathogenicity of many Gram-negative bacteria and are employed to inject toxins directly into the cytoplasm target cells. They composed over 20 different proteins that associate a basal structure traverses both inner outer bacterial membranes hollow, needle-like through which travel. The PscF protein is main component Pseudomonas aeruginosa T3S needle. Here we demonstrate PscF, when purified on its own, able form fibers 8 nm width >1 microm...
Because nickel is both essential and toxic to a great variety of organisms, its detection transport highly regulated. In Escherichia coli other related Gram-negative bacteria, high affinity depends on proteins expressed by the nik operon. A central actor this process periplasmic NikA protein. previous structural report has proposed that binds as pentahydrate species. However, stereochemical considerations X-ray absorption spectroscopic results are incompatible with interpretation. Here, we...
Escherichia coli and related bacteria require nickel for the synthesis of hydrogenases, enzymes involved in hydrogen oxidation proton reduction. Nickel transport to cytoplasm depends on five proteins, NikA−E. We have previously reported three-dimensional structure soluble periplasmic transporter NikA a complex with FeEDTA(H2O)−. now determined EDTA-free found that it binds small organic molecule contributes three ligands coordination transition metal ion. Unexpectedly, His416, which was far...
The type III secretion system (T3SS) is a complex nanomachine employed by many Gram-negative pathogens, including the nosocomial agent Pseudomonas aeruginosa, to inject toxins directly into cytoplasm of eukaryotic cells. A key component all T3SS translocon, proteinaceous channel that inserted target membrane, which allows passage In most bacterial species, two distinct membrane proteins (the "translocators") are involved in translocon formation, whereas cytoplasm, however, they remain...
The use of triethylammonium bicarbonate (TEAB) solution in electrospray mass spectrometry proved to be a very efficient way for studying proteins or noncovalent protein complexes under "nondenaturing" conditions. low charge states observed the spectra improve separation ions arising from macromolecular species close masses. Moreover, multiply charged generated TEAB are significantly more stable than those formed conventional conditions (for example, with ammonium acetate solution)....
Streptococcus pneumoniae is the worldwide leading cause of deaths from invasive infections such as pneumoniae, sepsis, and meningitidis in children elderly. Nasopharyngeal colonization, which plays a key role development pneumococcal disease, highly dependent on family surface-exposed proteins, choline-binding proteins (CBPs). Here we report crystal structure phosphorylcholine esterase (Pce), catalytic domain protein E (CBPE), has been shown to be crucial for host/pathogen interaction...
Methionine (Met) is prone to oxidation and can be converted Met sulfoxide (MetO), which exists as R- S-diastereomers. MetO reduced back by the ubiquitous methionine reductase (Msr) enzymes. Canonical MsrA MsrB were shown absolutely stereospecific for reduction of S-diastereomer R-diastereomer, respectively. Recently, a new enzymatic system, MsrQ/MsrP conserved in all gram-negative bacteria, was identified key actor oxidized periplasmic proteins. The haem-binding membrane protein MsrQ...
Abstract Exposure to harmful conditions such as radiation and desiccation induce oxidative stress DNA damage. In radiation-resistant Deinococcus bacteria, the radiation/desiccation response is controlled by two proteins: XRE family transcriptional repressor DdrO COG2856 metalloprotease IrrE. The latter cleaves inactivates DdrO. Here, we report biochemical characterization crystal structure of DdrO, which first a protein targeted protein. composed domains that fold independently are separated...
Pseudomonas aeruginosa, an increasingly prevalent opportunistic pathogen, utilizes a type III secretion system for injection of toxins into host cells in order to initiate infection. A crucial component this is PcrV, which essential cytotoxicity and found both within the bacterial cytoplasm localized extracellularly, suggesting that it may play more than one role infectivity. LcrV, homolog PcrV Yersinia, has been proposed participate effector regulation by interacting with LcrG, act as...
In MerT, the mercury transporter, a first cysteine pair, located in trans-membrane helix, receives from periplasm. Then, second housed cytoplasmic loop connecting and third helices, is thought to transfer metal another pair N-terminal extension of mercuric reductase. We found that 23-amino acid synthetic peptide corresponding can bind one atom per molecule this be transferred specifically MerAa. The solution structure Hg-bound ppMerT has been solved by 1H NMR spectroscopy.
Abstract An experimental procedure associating both hydrogen/deuterium exchange mass spectrometry (H/D‐MS) and mutagenesis was developed to identify the protein‐binding region of small inhibitors targeting motor domain human mitotic kinesin Eg5. All tested decrease deuterium incorporation rate same peptides corresponding following secondary structure elements: loop L5/helix α 2 (region Tyr125‐Glu145) strand β 5/helix 3 Ile202‐Leu227). Replacement these two regions by equivalent ones from N....
Abstract Better understanding of uranyl–protein interactions is a prerequisite to predict uranium chemical toxicity in cells. The EF‐hand motif the calmodulin site I about thousand times more affine for uranyl than calcium, and threonine phosphorylation increases affinity by two orders magnitude at pH 7. In this study, we confront X‐ray absorption spectroscopy with Fourier transform infrared (FTIR) spectroscopy, time‐resolved laser‐induced fluorescence (TRLFS), structural models obtained...