Correction: A sequential model of the contribution of preschool fluid and crystallized cognitive abilities to later school achievement.

[This corrects the article DOI: 10.1371/journal.pone.

Light-Activated Artificial CO-Reductase: Structure and Activity.

Light-dependent reduction of carbon dioxide (CO) into value-added products can be catalyzed by a variety of molecular complexes. Here we report a rare example of a structurally characterized artificial enzyme, resulting from the combination of a heme binding protein, heme oxygenase, with cobalt-protoporphyrin IX, with good activity for the photoreduction of CO to carbon monoxide (CO). Using a copper-based photosensitizer, thus making the photosystem free of noble metals, a large turnover frequency value of ∼616 h, a turnover value of ∼589, after 3 h reaction, and a CO vs H selectivity of 72% were obtained, establishing a record among previously reported artificial CO reductases.

Substrate-dependent oxidative inactivation of a W-dependent formate dehydrogenase involving selenocysteine displacement.

Metal-dependent formate dehydrogenases are very promising targets for enzyme optimization and design of bio-inspired catalysts for CO reduction, towards innovative strategies for climate change mitigation. For effective application of these enzymes, the catalytic mechanism must be better understood, and the molecular determinants clarified. Despite numerous studies, several doubts persist, namely regarding the role played by the possible dissociation of the SeCys ligand from the Mo/W active site.

The High-Pressure Freezing Laboratory for Macromolecular Crystallography (HPMX), an ancillary tool for the macromolecular crystallography beamlines at the ESRF.

This article describes the High-Pressure Freezing Laboratory for Macromolecular Crystallography (HPMX) at the ESRF, and highlights new and complementary research opportunities that can be explored using this facility. The laboratory is dedicated to investigating interactions between macromolecules and gases in crystallo, and finds applications in many fields of research, including fundamental biology, biochemistry, and environmental and medical science. At present, the HPMX laboratory offers the use of different high-pressure cells adapted for helium, argon, krypton, xenon, nitrogen, oxygen, carbon dioxide and methane.

Evolutionary adaptation from hydrolytic to oxygenolytic catalysis at the α/β-hydrolase fold.

Protein fold adaptation to novel enzymatic reactions is a fundamental evolutionary process. Cofactor-independent oxygenases degrading -heteroaromatic substrates belong to the α/β-hydrolase (ABH) fold superfamily that typically does not catalyze oxygenation reactions. Here, we have integrated crystallographic analyses under normoxic and hyperoxic conditions with molecular dynamics and quantum mechanical calculations to investigate its prototypic 1--3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (HOD) member.

Mechanistic and functional aspects of the Ruminococcin C sactipeptide isoforms.

In a scenario where the discovery of new molecules to fight antibiotic resistance is a public health concern, ribosomally synthesized and post-translationally modified peptides constitute a promising alternative. In this context, the Gram-positive human gut symbiont E1 produces five sactipeptides, Ruminococcins C1 to C5 (RumC1-C5), co-expressed with two radical SAM maturases. RumC1 has been shown to be effective against various multidrug resistant Gram-positives clinical isolates.

Light-Driven Hydrogen Evolution Reaction Catalyzed by a Molybdenum-Copper Artificial Hydrogenase.

Orange protein (Orp) is a small bacterial metalloprotein of unknown function that harbors a unique molybdenum/copper (Mo/Cu) heterometallic cluster, [SMoSCuSMoS]. In this paper, the performance of Orp as a catalyst for the photocatalytic reduction of protons into H has been investigated under visible light irradiation. We report the complete biochemical and spectroscopic characterization of -Orp containing the [SMoSCuSMoS] cluster, with docking and molecular dynamics simulations suggesting a positively charged Arg, Lys-containing pocket as the binding site.

Structural and Biochemical Characterization of Zinc SufU-SufS Complex.

Iron-sulfur (Fe-S) clusters are inorganic prosthetic groups in proteins composed exclusively of iron and inorganic sulfide. These cofactors are required in a wide range of critical cellular pathways. Iron-sulfur clusters do not form spontaneously in vivo; several proteins are required to mobilize sulfur and iron, assemble and traffic-nascent clusters.

A sequential model of the contribution of preschool fluid and crystallized cognitive abilities to later school achievement.

The present study documented in two distinct population-based samples the contribution of preschool fluid and crystallized cognitive abilities to school achievement in primary school and examined the mediating role of crystallized abilities in this sequence of predictive associations. In both samples, participants were assessed on the same cognitive abilities at 63 months (sample 1, n = 1072), and at 41 and 73 months (sample 2, n = 1583), and then with respect to their school achievement from grade 1 (7 years) to grade 6 (12 years). Preschool crystallized abilities were found to play a key role in predicting school achievement.

High-pressure crystallography shows noble gas intervention into protein-lipid interaction and suggests a model for anaesthetic action.

In this work we examine how small hydrophobic molecules such as inert gases interact with membrane proteins (MPs) at a molecular level. High pressure atmospheres of argon and krypton were used to produce noble gas derivatives of crystals of three well studied MPs (two different proton pumps and a sodium light-driven ion pump). The structures obtained using X-ray crystallography showed that the vast majority of argon and krypton binding sites were located on the outer hydrophobic surface of the MPs - a surface usually accommodating hydrophobic chains of annular lipids (which are known structural and functional determinants for MPs).

Comparative study of the effects of high hydrostatic pressure per se and high argon pressure on urate oxidase ligand stabilization.

The stability of the tetrameric enzyme urate oxidase in complex with excess of 8-azaxanthine was investigated either under high hydrostatic pressure per se or under a high pressure of argon. The active site is located at the interface of two subunits, and the catalytic activity is directly related to the integrity of the tetramer. This study demonstrates that applying pressure to a protein-ligand complex drives the thermodynamic equilibrium towards ligand saturation of the complex, revealing a new binding site.

Decoding the intricate network of molecular interactions of a hyperstable engineered biocatalyst.

Computational design of protein catalysts with enhanced stabilities for use in research and enzyme technologies is a challenging task. Using force-field calculations and phylogenetic analysis, we previously designed the haloalkane dehalogenase DhaA115 which contains 11 mutations that confer upon it outstanding thermostability ( = 73.5 °C; Δ > 23 °C).

LEAFY protein crystals with a honeycomb structure as a platform for selective preparation of outstanding stable bio-hybrid materials.

Well-organized protein assemblies offer many properties that justify their use for the design of innovative bionanomaterials. Herein, crystals of the oligomerization domain of the LEAFY protein from Ginkgo biloba, organized in a honeycomb architecture, were used as a modular platform for the selective grafting of a ruthenium-based complex. The resulting bio-hybrid crystalline material was fully characterized by UV-visible and Raman spectroscopy and by mass spectrometry and LC-MS analysis after selective enzymatic digestion.

Krypton-derivatization highlights O-channeling in a four-electron reducing oxidase.

F420H2-oxidase (FprA) catalyses the four-electron reduction of O2 to 2H2O using the reduced form of F420 as electron donor. The hydrophobic O2-channel detected by Kr-derivatization and the concerted movement of a gating loop could contribute to prevent unwanted side-reaction between the catalytic intermediates and solvents, therefore preventing reactive oxygen species formation.

Exploring the gas access routes in a [NiFeSe] hydrogenase using crystals pressurized with krypton and oxygen.

Hydrogenases are metalloenzymes that catalyse both H evolution and uptake. They are gas-processing enzymes with deeply buried active sites, so the gases diffuse through channels that connect the active site to the protein surface. The [NiFeSe] hydrogenases are a special class of hydrogenases containing a selenocysteine as a nickel ligand; they are more catalytically active and less O-sensitive than standard [NiFe] hydrogenases.

Structural, biochemical and functional analyses of tRNA-monooxygenase enzyme MiaE from Pseudomonas putida provide insights into tRNA/MiaE interaction.

MiaE (2-methylthio-N6-isopentenyl-adenosine37-tRNA monooxygenase) is a unique non-heme diiron enzyme that catalyzes the O2-dependent post-transcriptional allylic hydroxylation of a hypermodified nucleotide 2-methylthio-N6-isopentenyl-adenosine (ms2i6A37) at position 37 of selected tRNA molecules to produce 2-methylthio-N6-4-hydroxyisopentenyl-adenosine (ms2io6A37). Here, we report the in vivo activity, biochemical, spectroscopic characterization and X-ray crystal structure of MiaE from Pseudomonas putida. The investigation demonstrates that the putative pp-2188 gene encodes a MiaE enzyme.

ID30A-3 (MASSIF-3) - a beamline for macromolecular crystallography at the ESRF with a small intense beam.

ID30A-3 (or MASSIF-3) is a mini-focus (beam size 18 µm × 14 µm) highly intense (2.0 × 10 photons s), fixed-energy (12.81 keV) beamline for macromolecular crystallography (MX) experiments at the European Synchrotron Radiation Facility (ESRF).

Molecular mechanism of light-driven sodium pumping.

The light-driven sodium-pumping rhodopsin KR2 from Krokinobacter eikastus is the only non-proton cation active transporter with demonstrated potential for optogenetics. However, the existing structural data on KR2 correspond exclusively to its ground state, and show no sodium inside the protein, which hampers the understanding of sodium-pumping mechanism. Here we present crystal structure of the O-intermediate of the physiologically relevant pentameric form of KR2 at the resolution of 2.

Ligand pathways in neuroglobin revealed by low-temperature photodissociation and docking experiments.

A combined biophysical approach was applied to map gas-docking sites within murine neuroglobin (Ngb), revealing snapshots of events that might govern activity and dynamics in this unique hexacoordinate globin, which is most likely to be involved in gas-sensing in the central nervous system and for which a precise mechanism of action remains to be elucidated. The application of UV-visible microspectroscopy , solution X-ray absorption near-edge spectroscopy and X-ray diffraction experiments at 15-40 K provided the structural characterization of an Ngb photolytic intermediate by cryo-trapping and allowed direct observation of the relocation of carbon monoxide within the distal heme pocket after photodissociation. Moreover, X-ray diffraction at 100 K under a high pressure of dioxygen, a physiological ligand of Ngb, unravelled the existence of a storage site for O in Ngb which coincides with Xe-III, a previously described docking site for xenon or krypton.

The carbon monoxide dehydrogenase accessory protein CooJ is a histidine-rich multidomain dimer containing an unexpected Ni(II)-binding site.

Activation of nickel enzymes requires specific accessory proteins organized in multiprotein complexes controlling metal transfer to the active site. Histidine-rich clusters are generally present in at least one of the metallochaperones involved in nickel delivery. The maturation of carbon monoxide dehydrogenase in the proteobacterium requires three accessory proteins, CooC, CooT, and CooJ, dedicated to nickel insertion into the active site, a distorted [NiFeS] cluster coordinated to an iron site.

Tracking the route of molecular oxygen in O-tolerant membrane-bound [NiFe] hydrogenase.

[NiFe] hydrogenases catalyze the reversible splitting of H into protons and electrons at a deeply buried active site. The catalytic center can be accessed by gas molecules through a hydrophobic tunnel network. While most [NiFe] hydrogenases are inactivated by O, a small subgroup, including the membrane-bound [NiFe] hydrogenase (MBH) of , is able to overcome aerobic inactivation by catalytic reduction of O to water.

Mapping Hydrophobic Tunnels and Cavities in Neuroglobin with Noble Gas under Pressure.

Internal cavities are crucial for conformational flexibility of proteins and can be mapped through noble gas diffusion and docking. Here we investigate the hydrophobic cavities and tunnel network in neuroglobin (Ngb), a hexacoordinated heme protein likely to be involved in neuroprotection, using crystallography under noble gas pressure, mostly at room temperature. In murine Ngb, a large internal cavity is involved in the heme sliding mechanism to achieve binding of gaseous ligands through coordination to the heme iron.

HIGH-DOSE 131I-MIBG THERAPIES IN CHILDREN: FEASIBILITY, PATIENT DOSIMETRY AND RADIATION EXPOSURE TO WORKERS AND FAMILY CAREGIVERS.

The objective of the present multicentric phase II study (MIITOP) was to determine the response rate, survival and toxicity of tandem infusions of 131I-meta-iodobenzylguanidine (mIBG) and topotecan in children with relapsed/refractory neuroblastoma. High-dose 131I-mIBG therapy programme requires a deal of planning, availability of hospital resources and the commitment of individuals with training and expertise in multiple disciplines. Here in the present study, procedures and the results of patient's dosimetry, as well as family and worker's exposures, were reported for the patients treated in Lille.

Krypton Derivatization of an O2 -Tolerant Membrane-Bound [NiFe] Hydrogenase Reveals a Hydrophobic Tunnel Network for Gas Transport.

[NiFe] hydrogenases are metalloenzymes catalyzing the reversible heterolytic cleavage of hydrogen into protons and electrons. Gas tunnels make the deeply buried active site accessible to substrates and inhibitors. Understanding the architecture and function of the tunnels is pivotal to modulating the feature of O2 tolerance in a subgroup of these [NiFe] hydrogenases, as they are interesting for developments in renewable energy technologies.

Superoxide reductase from Giardia intestinalis: structural characterization of the first SOR from a eukaryotic organism shows an iron centre that is highly sensitive to photoreduction.

Superoxide reductase (SOR), which is commonly found in prokaryotic organisms, affords protection from oxidative stress by reducing the superoxide anion to hydrogen peroxide. The reaction is catalyzed at the iron centre, which is highly conserved among the prokaryotic SORs structurally characterized to date. Reported here is the first structure of an SOR from a eukaryotic organism, the protozoan parasite Giardia intestinalis (GiSOR), which was solved at 2.