A5029338783- Enzyme Structure and Function
- Metalloenzymes and iron-sulfur proteins
- Protein Structure and Dynamics
- Metal-Catalyzed Oxygenation Mechanisms
- Hemoglobin structure and function
- Photosynthetic Processes and Mechanisms
- Hydrogen Storage and Materials
- Electrocatalysts for Energy Conversion
- Solid-state spectroscopy and crystallography
- Mass Spectrometry Techniques and Applications
- Photoreceptor and optogenetics research
- Radioactive element chemistry and processing
- Ammonia Synthesis and Nitrogen Reduction
- Biochemical and Molecular Research
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy Techniques in Biomedical and Chemical Research
- Amino Acid Enzymes and Metabolism
- Advanced Fluorescence Microscopy Techniques
- Breast Cancer Treatment Studies
- Redox biology and oxidative stress
- Enzyme Production and Characterization
- Catalysis for Biomass Conversion
- Medical Imaging Techniques and Applications
- Porphyrin Metabolism and Disorders
- RNA modifications and cancer
European Synchrotron Radiation Facility
2015-2024
Laboratoire de Chimie et Biologie des Métaux
2007-2024
Université Grenoble Alpes
2007-2024
CEA Grenoble
2009-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009-2024
Centre National de la Recherche Scientifique
2009-2024
Centre Oscar Lambret
2003-2023
Université Laval
2022
Bipar
2021
Institut de Recherche Interdisciplinaire de Grenoble
2020
Iron-peroxide intermediates are central in the reaction cycle of many iron-containing biomolecules. We trapped iron(III)-(hydro)peroxo species crystals superoxide reductase (SOR), a nonheme mononuclear iron enzyme that scavenges radicals. X-ray diffraction data at 1.95 angstrom resolution and Raman spectra recorded crystallo revealed iron-(hydro)peroxo with (hydro)peroxo group bound end-on. The dynamic SOR active site promotes formation transient hydrogen bond networks, which presumably...
Abstract The light-driven sodium-pumping rhodopsin KR2 from Krokinobacter eikastus is the only non-proton cation active transporter with demonstrated potential for optogenetics. However, existing structural data on correspond exclusively to its ground state, and show no sodium inside protein, which hampers understanding of mechanism. Here we present crystal structure O-intermediate physiologically relevant pentameric form at resolution 2.1 Å, revealing a ion near retinal Schiff base,...
The red fluorescent protein KillerRed, engineered from the hydrozoan chromoprotein anm2CP, has been reported to induce strong cytotoxicity through chromophore assisted light inactivation (CALI) effect. Here, we present X‐ray structures of KillerRed in its native and bleached states. A long water‐filled channel is revealed, connecting methylene bridge solvent. This facilitates transit oxygen reactive species (ROS) formed by reaction with excited chromophore. functional roles key mutations...
The recently developed red fluorescent protein Keima exhibits the largest Stokes shift (180 nm) observed to date. Combining X-ray crystallography with (in crystallo) UV−visible absorption, fluorescence, and Raman spectroscopy, we have investigated molecular determinants of this peculiar property. results demonstrate a pH-dependent "reverse chromophore protonation" triggered by key residue Asp157 which couples cis/trans isomerization chromophore. These data provided guidelines rationally...
The analysis of structural data obtained by X-ray crystallography benefits from information complementary techniques, especially as applied to the crystals themselves. As a consequence, optical spectroscopies in biology have become instrumental assessing relevance and context many crystallographic results. Since year 2000, it has been possible record such adjacent to, or directly on, Structural Biology Group beamlines ESRF. A core laboratory featuring various spectrometers, named Cryobench,...
Photoactivatable fluorescent proteins are essential players in nanoscopy approaches based on the super-localization of single molecules. The subclass reversibly photoswitchable typically activate through isomerization chromophore coupled with a change its protonation state. However, interplay between these two events, details photoswitching pathways, and role protein dynamics remain incompletely understood. Here, by using combination structural spectroscopic approaches, we discovered...
ID30A-3 (or MASSIF-3) is a mini-focus (beam size 18 µm × 14 µm) highly intense (2.0 1013 photons s-1), fixed-energy (12.81 keV) beamline for macromolecular crystallography (MX) experiments at the European Synchrotron Radiation Facility (ESRF). MASSIF-3 one of two beamlines sited on first branch canted undulator setup ESRF ID30 port and equipped with MD2 micro-diffractometer, Flex HCD sample changer, an Eiger X 4M fast hybrid photon-counting detector. recommended collecting diffraction data...
Anaerobic methanotrophic archaea (ANME) are crucial to planetary carbon cycling. They oxidise methane in anoxic niches by transferring electrons directly nitrate or metal oxides and alternatively sulfate-reducing bacteria. Due their physiological complexity, none of the ANME species have been isolated, hampering biochemical investigation enzymatic processes involved anaerobic oxidation. Here, we deciphered methane-capturing enzyme through native purification from microbial enrichments....
Cristallisation a 294 K dans Pca2 1 avec a=12,924, b=14,034, c=15,364 A, Z=4; affinement jusqu'a R=0,032. A T=349 K, cristallisation Pcab a=13,003, b=14,038, c=15,450 R=0,044. Dans la phase haute temperature, les anions sont des bioctaedres centrosymetriques et trois cinq cations desordonnes. ferroelectrique deux desordonnes
We have observed the photoactivatable fluorescent protein IrisFP in a transient dark state with near-atomic resolution. This is assigned to radical species that either relaxes ground or evolves into permanently bleached chromophore. took advantage of X-rays populate radical, which presumably forms under illumination visible light by an electron-transfer reaction triplet state. The combined X-ray diffraction and crystallo UV−vis absorption, fluorescence, Raman data reveal formation involves...
Abstract [NiFe] hydrogenases are metalloenzymes catalyzing the reversible heterolytic cleavage of hydrogen into protons and electrons. Gas tunnels make deeply buried active site accessible to substrates inhibitors. Understanding architecture function is pivotal modulating feature O 2 tolerance in a subgroup these hydrogenases, as they interesting for developments renewable energy technologies. Here we describe crystal structure ‐tolerant membrane‐bound hydrogenase Ralstonia eutropha (ReMBH),...
Significance Tracking the route of substrates, intermediates, and inhibitors in proteins is fundamental understanding their specific function. However, following gases like molecular oxygen within enzymes has always been challenging. In protein X-ray crystallography, can be mimicked using krypton or xenon (with a higher electron count); however, these have different physical behavior compared to true substrates/inhibitors. our crystal structure O 2 -tolerant membrane-bound [NiFe] hydrogenase...
Iron-sulfur (Fe-S) clusters are inorganic prosthetic groups in proteins composed exclusively of iron and sulfide. These cofactors required a wide range critical cellular pathways. do not form spontaneously vivo; several to mobilize sulfur iron, assemble traffic-nascent clusters. Bacteria have developed Fe-S assembly systems, such as the ISC, NIF, SUF systems. Interestingly, Mycobacterium tuberculosis (Mtb), causative agent (TB), machinery is primary biogenesis system. This operon essential...
Multi-wavelength anomalous dispersion (MAD) using brominated derivatives is considered a common and convenient technique for solving chemically synthesized nucleic acid structures. Here, it shown that relatively moderate X-ray dose (of the order of 5 × 1015 photons mm−2) can induce sufficient debromination to prevent structure determination. The decrease in bromine occupancy with radiation be accounted by simple exponential, an estimated rate constant at absorption-peak wavelength, 7.4 (0.8)...
Pentakis(methylammonium) undecachlorodibismuthate(III), [NH 3 (CH )] 5 Bi 2 Cl 11 , PMACB, at 130 K has the monoclinic structure (MLT). In low-temperature phase, all methylammonium cations are ordered (the C-N axes fixed) and hydrogen bonded by weak N-H...Cl interactions, with distances between 3.04 3.42 A. comparison to orthorhombic room-temperature phase (ORT), in MLT one can observe only a change torsion angle of bioctahedra units without any essential distortion BiCl 6 octahedra. The...
Synchrotrons are now producing thousands of macromolecular structures each year. The need for complementary techniques available on site has progressively emerged, either to assess the relevance structure a protein or monitor changes that may occur during X-ray diffraction data collection. Microspectrophotometers in UV–visible absorbance fluorescence mode have evolved over past few decades become instruments choice perform such tests. Described here recent improvements microspectrophotometer...