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Publications de l’I2BC


  • N. Abdollahi, A. Albani, E. Anthony, A. Baud, M. Cardon, R. Clerc, D. Czernecki, R. Conte, L. David, A. Delaune, S. Djerroud, P. Fourgoux, N. Guiglielmoni, J. Laurentie, N. Lehmann, C. Lochard, R. Montagne, V. Myrodia, V. Opuu, E. Parey, L. Polit, S. Privé, C. Quignot, M. Ruiz-Cuevas, M. Sissoko, N. Sompairac, A. Vallerix, V. Verrecchia, M. Delarue, R. Guérois, Y. Ponty, S. Sacquin-Mora, A. Carbone, C. Froidevaux, S. Le Crom, O. Lespinet, M. Weigt, S. Abboud, J. Bernardes, G. Bouvier, C. Dequeker, A. Ferré, P. Fuchs, G. Lelandais, P. Poulain, H. Richard, H. Schweke, E. Laine, et A. Lopes, « Meet-U: Educating through research immersion », PLoS computational biology, vol. 14, nᵒ 3, p. e1005992, mars 2018.
    Résumé : We present a new educational initiative called Meet-U that aims to train students for collaborative work in computational biology and to bridge the gap between education and research. Meet-U mimics the setup of collaborative research projects and takes advantage of the most popular tools for collaborative work and of cloud computing. Students are grouped in teams of 4-5 people and have to realize a project from A to Z that answers a challenging question in biology. Meet-U promotes "coopetition," as the students collaborate within and across the teams and are also in competition with each other to develop the best final product. Meet-U fosters interactions between different actors of education and research through the organization of a meeting day, open to everyone, where the students present their work to a jury of researchers and jury members give research seminars. This very unique combination of education and research is strongly motivating for the students and provides a formidable opportunity for a scientific community to unite and increase its visibility. We report on our experience with Meet-U in two French universities with master's students in bioinformatics and modeling, with protein-protein docking as the subject of the course. Meet-U is easy to implement and can be straightforwardly transferred to other fields and/or universities. All the information and data are available at
    Mots-clés : AMIG, BDG, BIM.

  • C. Adam, R. Guérois, A. Citarella, L. Verardi, F. Adolphe, C. Béneut, V. Sommermeyer, C. Ramus, J. Govin, Y. Couté, et V. Borde, « The PHD finger protein Spp1 has distinct functions in the Set1 and the meiotic DSB formation complexes », PLOS Genetics, vol. 14, nᵒ 2, p. e1007223, févr. 2018.

  • M. Ansaldi, L. Debarbieux, S. Gandon, M. - A. Petit, P. Tavares, et P. Boulanger, « "French Phage Network"-Third Meeting Report », Viruses, vol. 10, nᵒ 3, mars 2018.
    Résumé : In its third year of existence, the French Phage Network ( is pursuing its expansion. With more than 25 groups, mostly based in France, working on the various aspects of phage research, the network has increased its visibility, interactivity, and activity. The third meeting of the network, held on November 2017 at the Gif-sur-Yvette Centre National de la Recherche Scientifique (CNRS) campus, was a great opportunity for many young scientists to present their work and interact with more senior scientists, amongst which several were invited from abroad. Here we provide a summary of the work presented at this occasion during the oral presentations and poster sessions.
    Mots-clés : bacteria, bacteriophage, co-evolution, France, genomics, infection, PHAG+, phage therapy, resistance, structural biology, T5PHAG, VIRO, virulence.

  • T. Avin-Wittenberg, F. Baluška, P. V. Bozhkov, P. H. Elander, A. R. Fernie, G. Galili, A. Hassan, D. Hofius, E. Isono, R. Le Bars, C. Masclaux-Daubresse, E. A. Minina, H. Peled-Zehavi, N. S. Coll, L. M. Sandalio, B. Satiat-Jeunemaitre, A. Sirko, P. S. Testillano, et H. Batoko, « Autophagy-related approaches for improving nutrient use efficiency and crop yield protection », Journal of Experimental Botany, vol. 69, nᵒ 6, p. 1335-1353, mars 2018.
    Mots-clés : BIOCELL, CYTO, DYNBSJ, PF, PHOT.

  • A. Barwinska-Sendra, A. Baslé, K. J. Waldron, et S. Un, « A charge polarization model for the metal-specific activity of superoxide dismutases », Physical chemistry chemical physics: PCCP, janv. 2018.
    Résumé : The pathogenicity of Staphylococcus aureus is enhanced by having two superoxide dismutases (SODs): a Mn-specific SOD and another that can use either Mn or Fe. Using 94 GHz electron-nuclear double resonance (ENDOR) and electron double resonance detected (ELDOR)-NMR we show that, despite their different metal-specificities, their structural and electronic similarities extend down to their active-site 1H- and 14N-Mn(ii) hyperfine interactions. However these interactions, and hence the positions of these nuclei, are different in the inactive Mn-reconstituted Escherichia coli Fe-specific SOD. Density functional theory modelling attributes this to a different angular position of the E. coli H171 ligand. This likely disrupts the Mn-H171-E170' triad causing a shift in charge and in metal redox potential, leading to the loss of activity. This is supported by the correlated differences in the Mn(ii) zero-field interactions of the three SOD types and suggests that the triad is important for determining metal specific activity.
    Mots-clés : B3S, BHFMR.

  • S. Blanchet, D. Cornu, I. Hatin, H. Grosjean, P. Bertin, et O. Namy, « Deciphering the reading of the genetic code by near-cognate tRNA », Proceedings of the National Academy of Sciences, vol. 115, nᵒ 12, p. 3018-3023, mars 2018.

  • S. Bouffard, E. Dambroise, A. Brombin, S. Lempereur, I. Hatin, M. Simion, R. Corre, F. Bourrat, J. - S. Joly, et F. Jamen, « Fibrillarin is essential for S-phase progression and neuronal differentiation in zebrafish dorsal midbrain and retina », Developmental Biology, févr. 2018.
    Résumé : Fibrillarin (Fbl) is a highly conserved protein that plays an essential role in ribosome biogenesis and more particularly in the methylation of ribosomal RNAs and rDNA histones. In cellular models, FBL was shown to play an important role in tumorigenesis and stem cell differentiation. We used the zebrafish as an in vivo model to study Fbl function during embryonic development. We show here that the optic tectum and the eye are severely affected by Fbl depletion whereas ventral regions of the brain are less impacted. The morphogenesis defects are associated with impaired neural differentiation and massive apoptosis. Polysome gradient experiments show that fbl mutant larvae display defects in ribosome biogenesis and activity. Strikingly, flow cytometry analyses revealed different S-phase profiles between wild-type and mutant cells, suggesting a defect in S-phase progression.
    Mots-clés : BDG, Cell cycle regulation, Danio rerio, Differentiation, GST, Neural progenitors, Optic tectum, Ribosome biogenesis.

  • G. Bourgeois, J. Seguin, M. Babin, P. Belin, M. Moutiez, Y. Mechulam, M. Gondry, et E. Schmitt, « Structural basis for partition of the cyclodipeptide synthases into two subfamilies », Journal of Structural Biology, 2018.

  • A. Boussac, I. Ugur, A. Marion, M. Sugiura, V. R. I. Kaila, et A. W. Rutherford, « The low spin - high spin equilibrium in the S2-state of the water oxidizing enzyme », Biochimica Et Biophysica Acta, vol. 1859, nᵒ 5, p. 342-356, févr. 2018.
    Résumé : In Photosystem II (PSII), the Mn4CaO5-cluster of the active site advances through five sequential oxidation states (S0to S4) before water is oxidized and O2is generated. Here, we have studied the transition between the low spin (LS) and high spin (HS) configurations of S2using EPR spectroscopy, quantum chemical calculations using Density Functional Theory (DFT), and time-resolved UV-visible absorption spectroscopy. The EPR experiments show that the equilibrium between S2LSand S2HSis pH dependent, with a pKa ≈ 8.3 (n ≈ 4) for the native Mn4CaO5and pKa ≈ 7.5 (n ≈ 1) for Mn4SrO5. The DFT results suggest that exchanging Ca with Sr modifies the electronic structure of several titratable groups within the active site, including groups that are not direct ligands to Ca/Sr, e.g., W1/W2, Asp61, His332 and His337. This is consistent with the complex modification of the pKaupon the Ca/Sr exchange. EPR also showed that NH3addition reversed the effect of high pH, NH3-S2LSbeing present at all pH values studied. Absorption spectroscopy indicates that NH3is no longer bound in the S3TyrZstate, consistent with EPR data showing minor or no NH3-induced modification of S3and S0. In both Ca-PSII and Sr-PSII, S2HSwas capable of advancing to S3at low temperature (198 K). This is an experimental demonstration that the S2LSis formed first and advances to S3via the S2HSstate without detectable intermediates. We discuss the nature of the changes occurring in the S2LSto S2HStransition which allow the S2HSto S3transition to occur below 200 K. This work also provides a protocol for generating S3in concentrated samples without the need for saturating flashes.
    Mots-clés : B3S, DFT, EPR, Mn(4)CaO(5) cluster, Oxygen evolution, Photosystem II, PS2, Spin state.

  • M. Byrdin, C. Duan, D. Bourgeois, et K. Brettel, « A Long-Lived Triplet State Is the Entrance Gateway to Oxidative Photochemistry in Green Fluorescent Proteins », Journal of the American Chemical Society, vol. 140, nᵒ 8, p. 2897-2905, févr. 2018.
    Résumé : Though ubiquitously used as selective fluorescence markers in cellular biology, fluorescent proteins (FPs) still have not disclosed all of their surprising properties. One important issue, notably for single-molecule applications, is the nature of the triplet state, suggested to be the starting point for many possible photochemical reactions leading to phenomena such as blinking or bleaching. Here, we applied transient absorption spectroscopy to characterize dark states in the prototypical enhanced green fluorescent protein (EGFP) of hydrozoan origin and, for comparison, in IrisFP, a representative phototransformable FP of anthozoan origin. We identified a long-lived (approximately 5 ms) dark state that is formed with a quantum yield of approximately 1% and has pronounced absorption throughout the visible-NIR range (peak at around 900 nm). Detection of phosphorescence emission with identical kinetics and excitation spectrum allowed unambiguous identification of this state as the first excited triplet state of the deprotonated chromophore. This triplet state was further characterized by determining its phosphorescence emission spectrum, the temperature dependence of its decay kinetics and its reactivity toward oxygen and electron acceptors and donors. It is suggested that it is this triplet state that lies at the origin of oxidative photochemistry in green FPs, leading to phenomena such as so-called "oxidative redding", "primed photoconversion", or, in a manner similar to that previously observed for organic dyes, redox induced blinking control with the reducing and oxidizing system ("ROXS").
    Mots-clés : B3S, LPB.

  • T. Candelli, D. Challal, J. - B. Briand, J. Boulay, O. Porrua, J. Colin, et D. Libri, « High-resolution transcription maps reveal the widespread impact of roadblock termination in yeast », The EMBO journal, janv. 2018.
    Résumé : Transcription termination delimits transcription units but also plays important roles in limiting pervasive transcription. We have previously shown that transcription termination occurs when elongating RNA polymerase II (RNAPII) collides with the DNA-bound general transcription factor Reb1. We demonstrate here that many different DNA-binding proteins can induce termination by a similar roadblock (RB) mechanism. We generated high-resolution transcription maps by the direct detection of RNAPII upon nuclear depletion of two essential RB factors or when the canonical termination pathways for coding and non-coding RNAs are defective. We show that RB termination occurs genomewide and functions independently of (and redundantly with) the main transcription termination pathways. We provide evidence that transcriptional readthrough at canonical terminators is a significant source of pervasive transcription, which is controlled to a large extent by RB termination. Finally, we demonstrate the occurrence of RB termination around centromeres and tRNA genes, which we suggest shields these regions from RNAPII to preserve their functional integrity.
    Mots-clés : BDG, DBG, pervasive transcription, Rap1, roadblock termination, TENOR, transcription readthrough, transcription termination mechanism.

  • N. Canu, P. Belin, R. Thai, I. Correia, O. Lequin, J. Seguin, M. Moutiez, et M. Gondry, « Incorporation of Non-canonical Amino Acids into 2,5-Diketopiperazines by Cyclodipeptide Synthases », Angewandte Chemie (International Ed. in English), vol. 57, nᵒ 12, p. 3118-3122, mars 2018.
    Résumé : The manipulation of natural product biosynthetic pathways is a powerful means of expanding the chemical diversity of bioactive molecules. 2,5-diketopiperazines (2,5-DKPs) have been widely developed by medicinal chemists, but their biological production is yet to be exploited. We introduce an in vivo method for incorporating non-canonical amino acids (ncAAs) into 2,5-DKPs using cyclodipeptide synthases (CDPSs), the enzymes responsible for scaffold assembly in many 2,5-DKP biosynthetic pathways. CDPSs use aminoacyl-tRNAs as substrates. We exploited the natural ability of aminoacyl-tRNA synthetases to load ncAAs onto tRNAs. We found 26 ncAAs to be usable as substrates by CDPSs, leading to the enzymatic production of approximately 200 non-canonical cyclodipeptides. CDPSs constitute an efficient enzymatic tool for the synthesis of highly diverse 2,5-DKPs. Such diversity could be further expanded, for example, by using various cyclodipeptide-tailoring enzymes found in 2,5-DKP biosynthetic pathways.
    Mots-clés : biocatalysis, BIOSYN, biosynthesis, Cyclodipeptide synthases, cyclodipeptides, Diketopiperazines, MICROBIO, Natural product engineering, Non-canonical amino acid.

  • M. Cardoso Dos Santos, J. Goetz, H. Bartenlian, K. - L. Wong, L. J. Charbonnière, et N. Hildebrandt, « Autofluorescence-Free Live-Cell Imaging Using Terbium Nanoparticles », Bioconjugate Chemistry, févr. 2018.

  • D. Carmona-Gutierrez, M. A. Bauer, A. Zimmermann, A. Aguilera, N. Austriaco, K. Ayscough, R. Balzan, S. Bar-Nun, A. Barrientos, P. Belenky, M. Blondel, R. J. Braun, M. Breitenbach, W. C. Burhans, S. Buettner, D. Cavalieri, M. Chang, K. F. Cooper, M. Côrte-Real, V. Costa, C. Cullin, I. Dawes, J. Dengjel, M. B. Dickman, T. Eisenberg, B. Fahrenkrog, N. Fasel, K. - U. Froehlich, A. Gargouri, S. Giannattasio, P. Goffrini, C. W. Gourlay, C. M. Grant, M. T. Greenwood, N. Guaragnella, T. Heger, J. Heinisch, E. Herker, J. M. Herrmann, S. Hofer, A. Jiménez-Ruiz, H. Jungwirth, K. Kainz, D. P. Kontoyiannis, P. Ludovico, S. Manon, E. Martegani, C. Mazzoni, L. A. Megeney, C. Meisinger, J. Nielsen, T. Nystroem, H. D. Osiewacz, T. F. Outeiro, H. - O. Park, T. Pendl, D. Petranovic, S. Picot, P. Polčic, T. Powers, M. Ramsdale, M. Rinnerthaler, P. Rockenfeller, C. Ruckenstuhl, R. Schaffrath, M. Segovia, F. F. Severin, A. Sharon, S. J. Sigrist, C. Sommer-Ruck, M. J. Sousa, J. M. Thevelein, K. Thevissen, V. Titorenko, M. B. Toledano, M. Tuite, F. - N. Voegtle, B. Westermann, J. Winderickx, S. Wissing, S. Woelfl, Z. J. Zhang, R. Y. Zhao, B. Zhou, L. Galluzzi, G. Kroemer, et F. Madeo, « Guidelines and recommendations on yeast cell death nomenclature », Microbial Cell, vol. 5, nᵒ 1, p. 4-31, janv. 2018.

  • R. Catchpole, A. Gorlas, J. Oberto, et P. Forterre, « A series of new E. coli-Thermococcus shuttle vectors compatible with previously existing vectors », Extremophiles: Life Under Extreme Conditions, mars 2018.
    Résumé : Hyperthermophilic microorganisms are an important asset in the toolkits of biotechnologists, biochemists and evolutionary biologists. The anaerobic archaeon, Thermococcus kodakarensis, has become one of the most useful hyperthermophilic model species, not least due to its natural competence and genetic tractability. Despite this, the range of genetic tools available for T. kodakarensis remains limited. Using sequencing and phylogenetic analyses, we determined that the rolling-circle replication origin of the cryptic mini-plasmid pTP2 from T. prieurii is suitable for plasmid replication in T. kodakarensis. Based on this replication origin, we present a novel series of replicative E. coli-T. kodakarensis shuttle vectors. These shuttle vectors have been constructed with three different selectable markers, allowing selection in a range of T. kodakarensis backgrounds. Moreover, these pTP2-derived plasmids are compatible with the single-existing E. coli-T. kodakarensis shuttle vector, pLC70. We show that both pTP2-derived and pLC70-derived plasmids replicate faithfully while cohabitating in T. kodakarensis cells. These plasmids open the door for new areas of research in plasmid segregation, DNA replication and gene expression.
    Mots-clés : Archaea, ARCHEE, Cloning, Gene cloning and expression, Genetics of extremophiles, Hyperthermophiles, MICROBIO, Molecular biology, Molecular biology of archaea.

  • F. Celli, A. Petitalot, C. Samson, F. - X. Theillet, et S. Zinn-Justin, « 1 H,13C and15N backbone resonance assignment of the lamin C-terminal region specific to prelamin A », Biomolecular NMR assignments, mars 2018.
    Résumé : Lamins are the main components of the nucleoskeleton. They form a protein meshwork that underlies the inner nuclear membrane. Mutations in the LMNA gene coding for A-type lamins (lamins A and C) cause a large panel of human diseases, referred to as laminopathies. These diseases include muscular dystrophies, lipodystrophies and premature aging diseases. Lamin A exhibits a C-terminal region that is different from lamin C and is post-translationally modified. It is produced as prelamin A and it is then farnesylated, cleaved, carboxymethylated and cleaved again in order to become mature lamin A. In patients with the severe Hutchinson-Gilford progeria syndrome, a specific single point mutation in LMNA leads to an aberrant splicing of the LMNA gene preventing the post-translational processing of prelamin A. This leads to the accumulation of a permanently farnesylated lamin A mutant lacking 50 amino acids named progerin. We here report the NMR1H,15N,13CO,13Cα and13Cβ chemical shift assignment of the C-terminal region that is specific to prelamin A, from amino acid 567 to amino acid 664. We also report the NMR1H,15N,13CO,13Cα and13Cβ chemical shift assignment of the C-terminal region of the progerin variant, from amino acid 567 to amino acid 614. Analysis of these chemical shift data confirms that both prelamin A and progerin C-terminal domains are largely disordered and identifies a common partially populated α-helix from amino acid 576 to amino acid 585. This helix is well conserved from fishes to mammals.
    Mots-clés : B3S, INTGEN, Intrinsically disordered protein, NMR spectroscopy, Nuclear envelope, Nucleoskeleton.

  • H. - J. Chang, P. Mayonove, A. Zavala, A. De Visch, P. Minard, M. Cohen-Gonsaud, et J. Bonnet, « A Modular Receptor Platform To Expand the Sensing Repertoire of Bacteria », ACS synthetic biology, vol. 7, nᵒ 1, p. 166-175, janv. 2018.
    Résumé : Engineered bacteria promise to revolutionize diagnostics and therapeutics, yet many applications are precluded by the limited number of detectable signals. Here we present a general framework to engineer synthetic receptors enabling bacterial cells to respond to novel ligands. These receptors are activated via ligand-induced dimerization of a single-domain antibody fused to monomeric DNA-binding domains (split-DBDs). Using E. coli as a model system, we engineer both transmembrane and cytosolic receptors using a VHH for ligand detection and demonstrate the scalability of our platform by using the DBDs of two different transcriptional regulators. We provide a method to optimize receptor behavior by finely tuning protein expression levels and optimizing interdomain linker regions. Finally, we show that these receptors can be connected to downstream synthetic gene circuits for further signal processing. The general nature of the split-DBD principle and the versatility of antibody-based detection should support the deployment of these receptors into various hosts to detect ligands for which no receptor is found in nature.
    Mots-clés : B3S, MIP.

  • F. Coll, J. Phelan, G. A. Hill-Cawthorne, M. B. Nair, K. Mallard, S. Ali, A. M. Abdallah, S. Alghamdi, M. Alsomali, A. O. Ahmed, S. Portelli, Y. Oppong, A. Alves, T. B. Bessa, S. Campino, M. Caws, A. Chatterjee, A. C. Crampin, K. Dheda, N. Furnham, J. R. Glynn, L. Grandjean, D. Minh Ha, R. Hasan, Z. Hasan, M. L. Hibberd, M. Joloba, E. C. Jones-López, T. Matsumoto, A. Miranda, D. J. Moore, N. Mocillo, S. Panaiotov, J. Parkhill, C. Penha, J. Perdigão, I. Portugal, Z. Rchiad, J. Robledo, P. Sheen, N. T. Shesha, F. A. Sirgel, C. Sola, E. Oliveira Sousa, E. M. Streicher, P. V. Helden, M. Viveiros, R. M. Warren, R. McNerney, A. Pain, et T. G. Clark, « Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis », Nature Genetics, janv. 2018.

  • M. Crüsemann, R. Reher, I. Schamari, A. O. Brachmann, T. Ohbayashi, M. Kuschak, D. Malfacini, A. Seidinger, M. Pinto-Carbó, R. Richarz, T. Reuter, S. Kehraus, A. Hallab, M. Attwood, H. B. Schiöth, P. Mergaert, Y. Kikuchi, T. F. Schäberle, E. Kostenis, D. Wenzel, C. E. Müller, J. Piel, A. Carlier, L. Eberl, et G. M. König, « Heterologous Expression, Biosynthetic Studies, and Ecological Function of the Selective Gq-Signaling Inhibitor FR900359 », Angewandte Chemie (International Ed. in English), vol. 57, nᵒ 3, p. 836-840, janv. 2018.
    Résumé : The cyclic depsipeptide FR900359 (FR), isolated from the tropical plant Ardisia crenata, is a strong and selective inhibitor of Gq proteins, making it an indispensable pharmacological tool to study Gq-related processes, as well as a promising drug candidate. Gq inhibition is a novel mode of action for defense chemicals and crucial for the ecological function of FR, as shown by in vivo experiments in mice, its affinity to insect Gq proteins, and insect toxicity studies. The uncultured endosymbiont of A. crenata was sequenced, revealing the FR nonribosomal peptide synthetase (frs) gene cluster. We here provide a detailed model of FR biosynthesis, supported by in vitro enzymatic and bioinformatic studies, and the novel analogue AC-1, which demonstrates the flexibility of the FR starter condensation domains. Finally, expression of the frs genes in E. coli led to heterologous FR production in a cultivable, bacterial host for the first time.
    Mots-clés : biosynthesis, FR900359, G proteins, G proteins, Heterologous expression, MICROBIO, natural products, PBI.

  • V. Da Cunha, M. Gaia, A. Nasir, et P. Forterre, « Asgard archaea do not close the debate about the universal tree of life topology », PLOS Genetics, vol. 14, nᵒ 3, p. e1007215, mars 2018.

  • C. Dard-Dascot, D. Naquin, Y. d'Aubenton-Carafa, K. Alix, C. Thermes, et E. van Dijk, « Systematic comparison of small RNA library preparation protocols for next-generation sequencing », BMC genomics, vol. 19, nᵒ 1, p. 118, 2018.
    Résumé : BACKGROUND: Next-generation sequencing technologies have revolutionized the study of small RNAs (sRNAs) on a genome-wide scale. However, classical sRNA library preparation methods introduce serious bias, mainly during adapter ligation steps. Several types of sRNA including plant microRNAs (miRNA), piwi-interacting RNAs (piRNA) in insects, nematodes and mammals, and small interfering RNAs (siRNA) in insects and plants contain a 2'-O-methyl (2'-OMe) modification at their 3' terminal nucleotide. This inhibits 3' adapter ligation and makes library preparation particularly challenging. To reduce bias, the NEBNext kit (New England Biolabs) uses polyethylene glycol (PEG), the NEXTflex V2 kit (BIOO Scientific) uses both randomised adapters and PEG, and the novel SMARTer (Clontech) and CATS (Diagenode) kits avoid ligation altogether. Here we compared these methods with Illumina's classical TruSeq protocol regarding the detection of normal and 2' OMe RNAs. In addition, we modified the TruSeq and NEXTflex protocols to identify conditions that improve performance. RESULTS: Among the five kits tested with their respective standard protocols, the SMARTer and CATS kits had the lowest levels of bias but also had a strong formation of side products, and as a result performed relatively poorly with biological samples; NEXTflex detected the largest numbers of different miRNAs. The use of a novel type of randomised adapters called MidRand-Like (MRL) adapters and PEG improved the detection of 2' OMe RNAs both in the TruSeq as well as in the NEXTflex protocol. CONCLUSIONS: While it is commonly accepted that biases in sRNA library preparation protocols are mainly due to adapter ligation steps, the ligation-free protocols were not the best performing methods. Our modified versions of the TruSeq and NEXTflex protocols provide an improved tool for the study of 2' OMe RNAs.
    Mots-clés : 2’-O-methyl RNA, ANGE, Bias, CHERDIR, DBG, Library preparation, Next-generation sequencing, NGS, PF, Small RNA.

  • M. David, C. Lebrun, T. Duguet, F. Talmont, R. Beech, S. Orlowski, F. André, R. K. Prichard, et A. Lespine, « Structural model, functional modulation by ivermectin and tissue localization of Haemonchus contortus P-glycoprotein-13 », International Journal for Parasitology. Drugs and Drug Resistance, vol. 8, nᵒ 1, p. 145-157, avr. 2018.
    Résumé : Haemonchus contortus, one of the most economically important parasites of small ruminants, has become resistant to the anthelmintic ivermectin. Deciphering the role of P-glycoproteins in ivermectin resistance is desirable for understanding and overcoming this resistance. In the model nematode, Caenorhabditis elegans, P-glycoprotein-13 is expressed in the amphids, important neuronal structures for ivermectin activity. We have focused on its ortholog in the parasite, Hco-Pgp-13. A 3D model of Hco-Pgp-13, presenting an open inward-facing conformation, has been constructed by homology with the Cel-Pgp-1 crystal structure. In silico docking calculations predicted high affinity binding of ivermectin and actinomycin D to the inner chamber of the protein. Following in vitro expression, we showed that ivermectin and actinomycin D modulated Hco-Pgp-13 ATPase activity with high affinity. Finally, we found in vivo Hco-Pgp-13 localization in epithelial, pharyngeal and neuronal tissues. Taken together, these data suggest a role for Hco-Pgp-13 in ivermectin transport, which could contribute to anthelmintic resistance.
    Mots-clés : ABC transporters, B3S, Haemonchus contortus, Homology modeling, Ivermectin, LPSM, LSOD, Nematode, P-glycoprotein.

  • A. De Muyt, A. Pyatnitskaya, J. Andréani, L. Ranjha, C. Ramus, R. Laureau, A. Fernandez-Vega, D. Holoch, E. Girard, J. Govin, R. Margueron, Y. Couté, P. Cejka, R. Guérois, et V. Borde, « A meiotic XPF–ERCC1-like complex recognizes joint molecule recombination intermediates to promote crossover formation », Genes & Development, vol. 32, nᵒ 3-4, p. 283-296, févr. 2018.

  • Y. Dessaux et D. Faure, « Niche Construction and Exploitation by Agrobacterium: How to Survive and Face Competition in Soil and Plant Habitats », Berlin, Heidelberg: Springer Berlin Heidelberg, 2018.

  • G. M. Dias, A. Bidault, P. Le Chevalier, G. Choquet, C. Der Sarkissian, L. Orlando, C. Medigue, V. Barbe, S. Mangenot, C. C. Thompson, F. L. Thompson, A. Jacq, V. Pichereau, et C. Paillard, « Vibrio tapetis Displays an Original Type IV Secretion System in Strains Pathogenic for Bivalve Molluscs », Frontiers in Microbiology, vol. 9, p. 227, 2018.
    Résumé : The Brown Ring Disease (BRD) caused high mortality rates since 1986 in the Manila clamVenerupis philippinarumintroduced and cultured in Western Europe from the 1970s. The causative agent of BRD is a Gram-Negative bacterium,Vibrio tapetis, which is also pathogenic to fish. Here we report the first assembly of the complete genome ofV. tapetisCECT4600T, together with the genome sequences of 16 additional strains isolated across a broad host and geographic range. Our extensive genome dataset allowed us to describe the pathogen pan- and core genomes and to identify putative virulence factors. TheV. tapetiscore genome consists of 3,352 genes, including multiple potential virulence factors represented by haemolysins, transcriptional regulators, Type I restriction modification system, GGDEF domain proteins, several conjugative plasmids, and a Type IV secretion system. Future research on the coevolutionary arms race betweenV. tapetisvirulence factors and host resistance mechanisms will improve our understanding of how pathogenicity develops in this emerging pathogen.
    Mots-clés : BDG, comparative genomics, core genome, pangenome, pathogenicity, SRRB, T4SS, Venerupis philippinarum, Vibrio tapetis.

  • A. Doerflinger, N. N. Quang, E. Gravel, G. Pinna, M. Vandamme, F. Ducongé, et E. Doris, « Biotin-functionalized targeted polydiacetylene micelles », Chemical Communications, 2018.

  • D. Drubay, D. Gautheret, et S. Michiels, « A benchmark study of scoring methods for non-coding mutations », Bioinformatics (Oxford, England), janv. 2018.
    Résumé : Motivation: Detailed knowledge of coding sequences has led to different candidate models for pathogenic variant prioritization. Several deleteriousness scores have been proposed for the non-coding part of the genome, but no large-scale comparison has been realized to date to assess their performance. Results: We compared the leading scoring tools (CADD, FATHMM-MKL, Funseq2 and GWAVA) and some recent competitors (DANN, SNP and SOM scores) for their ability to discriminate assumed pathogenic variants from assumed benign variants (using the ClinVar, COSMIC and 1000 genomes project databases). Using the ClinVar benchmark, CADD was the best tool for detecting the pathogenic variants that are mainly located in protein coding gene regions. Using the COSMIC benchmark, FATHMM-MKL, GWAVA and SOMliver outperformed the other tools for pathogenic variants that are typically located in lincRNAs, pseudogenes, and other parts of the non-coding genome. However, all tools had low precision, which could potentially be improved by future non-coding genome feature discoveries. These results may have been influenced by the presence of potential benign variants in the COSMIC database. The development of a gold standard as consistent as ClinVar for these regions will be necessary to confirm our tool ranking. Availability and Implementation: The Snakemake, C ++ and R codes are freely available from and supported on Linux. Contact: Supplementary information: Supplementary results are available at Bioinformatics online.
    Mots-clés : DBG, SSFA.

  • G. Dubeaux, J. Neveu, E. Zelazny, et G. Vert, « Metal Sensing by the IRT1 Transporter-Receptor Orchestrates Its Own Degradation and Plant Metal Nutrition », Molecular Cell, vol. 69, nᵒ 6, p. 953-964.e5, mars 2018.
    Résumé : Plant roots forage the soil for iron, the concentration of which can be dramatically lower than those needed for growth. Soil iron uptake uses the broad metal spectrum IRT1 transporter that also transports zinc, manganese, cobalt, and cadmium. Sophisticated iron-dependent transcriptional regulatory mechanisms allow plants to tightly control the abundance of IRT1, ensuring optimal absorption of iron. Here, we uncover that IRT1 acts as a transporter and receptor (transceptor), directly sensing excess of its non-iron metal substrates in the cytoplasm, to regulate its own degradation. Direct metal binding to a histidine-rich stretch in IRT1 triggers its phosphorylation by the CIPK23 kinase and facilitates the subsequent recruitment of the IDF1 E3 ligase. CIPK23-driven phosphorylation and IDF1-mediated lysine-63 polyubiquitination are jointly required for efficient endosomal sorting and vacuolar degradation of IRT1. Thus, IRT1 directly senses elevated non-iron metal concentrations and integrates multiple substrate-dependent regulations to optimize iron uptake and protect plants from highly reactive metals.
    Mots-clés : Arabidopsis, BIOCELL, degradation, metal homeostasis, phosphorylation, plant, receptor, sensing, transceptor, transporter, UBINET, ubiquitin.

  • A. Durand, M. - L. Bourbon, A. - S. Steunou, B. Khalfaoui-Hassani, C. Legrand, A. Guitton, C. Astier, et S. Ouchane, « Biogenesis of the bacterial cbb3 cytochrome c oxidase: Active subcomplexes support a sequential assembly model », The Journal of Biological Chemistry, vol. 293, nᵒ 3, p. 808-818, janv. 2018.
    Résumé : The cbb3 oxidase has a high affinity for oxygen and is required for growth of bacteria, including pathogens, in oxygen-limited environments. However, the assembly of this oxidase is poorly understood. Most cbb3 are composed of four subunits: the catalytic CcoN subunit, the two cytochrome c subunits (CcoO and CcoP) involved in electron transfer, and the small CcoQ subunit with an unclear function. Here, we address the role of these four subunits in cbb3 biogenesis in the purple bacterium Rubrivivax gelatinosus Analyses of membrane proteins from different mutants revealed the presence of active CcoNQO and CcoNO subcomplexes and also showed that the CcoP subunit is not essential for their assembly. However, CcoP was required for the oxygen reduction activity in the absence of CcoQ. We also found that CcoQ is dispensable for forming an active CcoNOP subcomplex in membranes. CcoNOP exhibited oxygen reductase activity, indicating that the cofactors (hemes b and copper for CcoN and cytochromes c for CcoO and CcoP) were present within the subunits. Finally, we discovered the presence of a CcoNQ subcomplex and showed that CcoN is the required anchor for the assembly of the full CcoNQOP complex. On the basis of these findings, we propose a sequential assembly model in which the CcoQ subunit is required for the early maturation step: CcoQ first associates with CcoN before the CcoNQ-CcoO interaction. CcoP associates to CcoNQO subcomplex in the late maturation step, and once the CcoNQOP complex is fully formed, CcoQ is released for degradation by the FtsH protease. This model could be conserved in other bacteria, including the pathogenic bacteria lacking the assembly factor CcoH as in R. gelatinosus.
    Mots-clés : BACADA, bacteria, cbb3 cytochrome c oxidase biogenesis, cytochrome oxidase, Membrane protein, MICROBIO.

  • Z. Edoo, L. Iannazzo, F. Compain, I. Li de la Sierra Gallay, H. van Tilbeurgh, M. Fonvielle, F. Bouchet, E. Le Run, J. - L. Mainardi, M. Arthur, M. Ethève-Quelquejeu, et J. - E. Hugonnet, « Synthesis of avibactam derivatives and activity on β-lactamases and peptidoglycan biosynthesis enzymes of mycobacteria », Chemistry - A European Journal, mars 2018.

  • M. El Ghachi, N. Howe, C. - Y. Huang, V. Olieric, R. Warshamanage, T. Touzé, D. Weichert, P. J. Stansfeld, M. Wang, F. Kerff, et M. Caffrey, « Crystal structure of undecaprenyl-pyrophosphate phosphatase and its role in peptidoglycan biosynthesis », Nature Communications, vol. 9, nᵒ 1, 2018.

  • M. J. Fer, L. L. Corre, N. Pietrancosta, N. Evrard-Todeschi, S. Olatunji, A. Bouhss, S. Calvet-Vitale, et C. Gravier-Pelletier, « Bacterial Transferase MraY, a Source of Inspiration towards New Antibiotics », Current Medicinal Chemistry, vol. 25, mars 2018.

  • L. Galvan, L. Francelle, M. - C. Gaillard, L. de Longprez, M. - A. Carrillo-de Sauvage, G. Liot, K. Cambon, L. Stimmer, S. Luccantoni, J. Flament, J. Valette, M. de Chaldée, G. Auregan, M. Guillermier, C. Joséphine, F. Petit, C. Jan, M. Jarrige, N. Dufour, G. Bonvento, S. Humbert, F. Saudou, P. Hantraye, K. Merienne, A. - P. Bemelmans, A. L. Perrier, N. Déglon, et E. Brouillet, « The striatal kinase DCLK3 produces neuroprotection against mutant huntingtin », Brain, mars 2018.

  • F. Giordano, « Non-vesicular lipid trafficking at the endoplasmic reticulum–mitochondria interface », Biochemical Society Transactions, p. BST20160185, mars 2018.

  • M. Gondry, I. B. Jacques, R. Thai, M. Babin, N. Canu, J. Seguin, P. Belin, J. - L. Pernodet, et M. Moutiez, « A Comprehensive Overview of the Cyclodipeptide Synthase Family Enriched with the Characterization of 32 New Enzymes », Frontiers in Microbiology, vol. 9, p. 46, 2018.
    Résumé : Cyclodipeptide synthases (CDPSs) use as substrates two amino acids activated as aminoacyl-tRNAs to synthesize cyclodipeptides in secondary metabolites biosynthetic pathways. Since the first description of a CDPS in 2002, the number of putative CDPSs in databases has increased exponentially, reaching around 800 in June 2017. They are likely to be involved in numerous biosynthetic pathways but the diversity of their products is still under-explored. Here, we describe the activity of 32 new CDPSs, bringing the number of experimentally characterized CDPSs to about 100. We detect 16 new cyclodipeptides, one of which containing an arginine which has never been observed previously. This brings to 75 the number of cyclodipeptides formed by CDPSs out of the possible 210 natural ones. We also identify several consensus sequences related to the synthesis of a specific cyclodipeptide, improving the predictive model of CDPS specificity. The improved prediction method enables to propose the main product synthesized for about 80% of the CDPS sequences available in databases and opens the way for the deciphering of CDPS-dependent pathways. Analysis of phylum distribution and predicted activity for all CDPSs identified in databases shows that the experimentally characterized set is representative of the whole family. Our work also demonstrates that some cyclodipeptides, precursors of diketopiperazines with interesting pharmacological properties and previously described as being synthesized by fungal non-ribosomal peptide synthetases, can also be produced by CDPSs in bacteria.
    Mots-clés : ACTINO, activity prediction, BIOSYN, Biosynthetic Pathways, cyclodipeptide MS/MS, cyclodipeptide synthase, diketopiperazine, MICROBIO, Secondary metabolites, tRNA-dependent enzymes.

  • B. Gourion et B. Alunni, « Strain-Specific Symbiotic Genes: A New Level of Control in the Intracellular Accommodation of Rhizobia Within Legume Nodule Cells », Molecular plant-microbe interactions: MPMI, vol. 31, nᵒ 3, p. 287-288, mars 2018.
    Résumé : This is a short commentary on the article by Wang et al. published in MPMI Vol. 31, No. 2, pages 240-248.
    Mots-clés : MICROBIO, PBI.

  • Y. Ishino, M. Krupovic, et P. Forterre, « History of CRISPR-Cas from Encounter with a Mysterious Repeated Sequence to Genome Editing Technology », Journal of Bacteriology, vol. 200, nᵒ 7, avr. 2018.
    Résumé : Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems are well-known acquired immunity systems that are widespread in archaea and bacteria. The RNA-guided nucleases from CRISPR-Cas systems are currently regarded as the most reliable tools for genome editing and engineering. The first hint of their existence came in 1987, when an unusual repetitive DNA sequence, which subsequently was defined as a CRISPR, was discovered in theEscherichia coligenome during an analysis of genes involved in phosphate metabolism. Similar sequence patterns were then reported in a range of other bacteria as well as in halophilic archaea, suggesting an important role for such evolutionarily conserved clusters of repeated sequences. A critical step toward functional characterization of the CRISPR-Cas systems was the recognition of a link between CRISPRs and the associated Cas proteins, which were initially hypothesized to be involved in DNA repair in hyperthermophilic archaea. Comparative genomics, structural biology, and advanced biochemistry could then work hand in hand, not only culminating in the explosion of genome editing tools based on CRISPR-Cas9 and other class II CRISPR-Cas systems but also providing insights into the origin and evolution of this system from mobile genetic elements denoted casposons. To celebrate the 30th anniversary of the discovery of CRISPR, this minireview briefly discusses the fascinating history of CRISPR-Cas systems, from the original observation of an enigmatic sequence inE. colito genome editing in humans.
    Mots-clés : archaea, ARCHEE, casposon, genome editing, MICROBIO, repeated sequence.

  • S. M. Kapetanaki, M. J. Burton, J. Basran, C. Uragami, P. C. E. Moody, J. S. Mitcheson, R. Schmid, N. W. Davies, P. Dorlet, M. H. Vos, N. M. Storey, et E. Raven, « A mechanism for CO regulation of ion channels », Nature Communications, vol. 9, nᵒ 1, p. 907, 2018.
    Résumé : Despite being highly toxic, carbon monoxide (CO) is also an essential intracellular signalling molecule. The mechanisms of CO-dependent cell signalling are poorly defined, but are likely to involve interactions with heme proteins. One such role for CO is in ion channel regulation. Here, we examine the interaction of CO with KATP channels. We find that CO activates KATP channels and that heme binding to a CXXHX16H motif on the SUR2A receptor is required for the CO-dependent increase in channel activity. Spectroscopic and kinetic data were used to quantify the interaction of CO with the ferrous heme-SUR2A complex. The results are significant because they directly connect CO-dependent regulation to a heme-binding event on the channel. We use this information to present molecular-level insight into the dynamic processes that control the interactions of CO with a heme-regulated channel protein, and we present a structural framework for understanding the complex interplay between heme and CO in ion channel regulation.
    Mots-clés : B3S, LSOD.

  • F. Khoder-Agha, J. M. Dias, M. Comisso, et M. Mirande, « Characterization of association of human mitochondrial lysyl-tRNA synthetase with HIV-1 Pol and tRNA3Lys », BMC biochemistry, vol. 19, nᵒ 1, p. 2, mars 2018.
    Résumé : BACKGROUND: An important step in human immunodeficiency virus type 1 (HIV-1) replication is the packaging of tRNA3Lysfrom the host cell, which plays the role of primer RNA in the process of initiation of reverse transcription. The viral GagPol polyprotein precursor, and the human mitochondrial lysyl-tRNA synthetase (mLysRS) from the host cell, have been proposed to be involved in the packaging process. More specifically, the catalytic domain of mLysRS is supposed to interact with the transframe (TF or p6*) and integrase (IN) domains of the Pol region of the GagPol polyprotein. RESULTS: In this work, we report a quantitative characterization of the protein:protein interactions between mLysRS and its viral partners, the Pol polyprotein, and the isolated integrase and transframe domains of Pol. A dissociation constant of 1.3 ± 0.2 nM was determined for the Pol:mLysRS interaction, which exemplifies the robustness of this association. The protease and reverse transcriptase domains of GagPol are dispensable in this association, but the TF and IN domains have to be connected by a linker polypeptide to recapitulate a high affinity partner for mLysRS. The binding of the viral proteins to mLysRS does not dramatically enhance the binding affinity of mLysRS for tRNA3Lys. CONCLUSIONS: These data support the conclusion that the complex formed between GagPol, mLysRS and tRNA3Lys, which involves direct interactions between the IN and TF domains of Pol with mLysRS, is more robust than suggested by the previous models supposed to be involved in the packaging of tRNA3Lysinto HIV-1 particles.
    Mots-clés : BDG, Binding affinity, HIV-1, Integrase, MARS, Mitochondrial lysyl-tRNA synthetase, Transframe (TF or p6*), tRNA3 Lys packaging.

  • L. Laboureur, V. Guérineau, S. Auxilien, S. Yoshizawa, et D. Touboul, « Profiling of modified nucleosides from ribonucleic acid digestion by supercritical fluid chromatography coupled to high resolution mass spectrometry », Journal of Chromatography. A, vol. 1537, p. 118-127, févr. 2018.
    Résumé : A method based on supercritical fluid chromatography coupled to high resolution mass spectrometry for the profiling of canonical and modified nucleosides was optimized, and compared to classical reverse-phase liquid chromatography in terms of separation, number of detected modified nucleosides and sensitivity. Limits of detection and quantification were measured using statistical method and quantifications of twelve nucleosides of a tRNA digest from E. coli are in good agreement with previously reported data. Results highlight the complementarity of both separation techniques to cover the largest view of nucleoside modifications for forthcoming epigenetic studies.
    Mots-clés : DBG, Epigenetic, High resolution mass spectrometry, Nucleoside, RNA, RNASTR, Supercritical fluid chromatography.

  • F. Lallemand, A. Petitalot, S. Vacher, L. de Koning, K. Taouis, B. S. Lopez, S. Zinn-Justin, N. Dalla-Venezia, W. Chemlali, A. Schnitzler, R. Lidereau, I. Bieche, et S. M. Caputo, « Involvement of the FOXO6 transcriptional factor in breast carcinogenesis », Oncotarget, vol. 9, nᵒ 7, p. 7464-7475, janv. 2018.
    Résumé : In mammals, FOXO transcriptional factors form a family of four members (FOXO1, 3, 4, and 6) involved in the modulation proliferation, apoptosis, and carcinogenesis. The role of the FOXO family in breast cancer remains poorly elucidated. According to the cellular context and the stage of the disease, FOXOs can have opposite effects on carcinogenesis. To study the role of FOXOs in breast carcinogenesis in more detail, we examined their expression in normal tissues, breast cell lines, and a large series of breast tumours of human origin. We found a very low physiological level ofFOXO6expression in normal adult tissues and high levels of expression in foetal brain.FOXOgene expressions fluctuate specifically in breast cancer cells compared to normal cells, suggesting that these genes may have different roles in breast carcinogenesis. For the first time, we have shown that, among the variousFOXOgenes, onlyFOXO6was frequently highly overexpressed in breast cell lines and tumours. We also found that inhibition of the endogenous expression of FOXO6 by a specific siRNA inhibited the growth of the human breast cell lines MDA-MB-468 and HCC-38. FACS and Western blot analysis showed that inhibition of endogenous expression of FOXO6 induced accumulation of cells in G0/G1 phase of the cell cycle, but not apoptosis. These results tend to demonstrate that the overexpression of the humanFOXO6gene that we highlighted in the breast tumors stimulates breast carcinogenesis by activating breast cancer cell proliferation.
    Mots-clés : B3S, cervical squamous cell carcinoma, endometrial adenocarcinoma, gynecological cancers, INTGEN, prognosis, uc.189.

  • L. Latino et C. Pourcel, « Recovery and Characterization of Bacteria Resisting Infection by Lytic Bacteriophage », Methods in Molecular Biology (Clifton, N.J.), vol. 1693, p. 85-98, 2018.
    Résumé : Bacteria and bacteriophages coexist and coevolve, bacteriophages being obligatory predators exerting an evolutionary pressure on their prey. Mechanisms in action vary depending on the bacterial genomic content and on the regulation of the bacteriophage cycle. To assess the multiplicity of bacterial genes involved in resistance as well as the changes in the bacteriophage interactions with the bacteria, it is necessary to isolate and investigate large numbers of independent resistant variants. Here we describe protocols that have been applied to the study of Pseudomonas aeruginosa and four of its virulent bacteriophages belonging to the Podoviridae and Myoviridae bacteriophage families. Mutations are identified using whole genome sequencing of resistant variants. Phenotypic analyses are performed to describe the changes conferred by the mutations.
    Mots-clés : Bacterial phenotype, Bacteriophages, Complementation, Genome sequencing, LGBMB, MICROBIO.

  • L. Lecoq, S. Wang, T. Wiegand, S. Bressanelli, M. Nassal, B. H. Meier, et A. Böckmann, « Localizing conformational hinges by NMR: where do HBV core proteins adapt for capsid assembly? », ChemPhysChem, mars 2018.

  • L. Lecoq, S. Wang, T. Wiegand, S. Bressanelli, M. Nassal, B. H. Meier, et A. Böckmann, « Solid-state [13C-15N] NMR resonance assignment of hepatitis B virus core protein », Biomolecular NMR assignments, vol. 12, nᵒ 1, p. 205-214, avr. 2018.
    Résumé : Each year, nearly 900,000 deaths are due to serious liver diseases caused by chronic hepatitis B virus infection. The viral particle is composed of an outer envelope and an inner icosahedral nucleocapsid formed by multiple dimers of a ~ 20 kDa self-assembling core protein (Cp). Here we report the solid-state 13C and 15N resonance assignments of the assembly domain, Cp149, of the core protein in its capsid form. A secondary chemical shift analysis of the 140 visible residues suggests an overall alpha-helical three-dimensional fold matching that derived for Cp149 from the X-ray crystallography of the capsid, and from solution-state NMR of the Cp149 dimer. Interestingly, however, at three distinct regions the chemical shifts in solution differ significantly between core proteins in the capsid state versus in the dimer state, strongly suggesting the respective residues to be involved in capsid assembly.
    Mots-clés : AMIG, Assignments, B3S, Core protein, Hepatitis B virus, IMAPP, Nucleocapsid, Solid-state NMR.

  • V. S. Lioy, A. Cournac, M. Marbouty, S. Duigou, J. Mozziconacci, O. Espéli, F. Boccard, et R. Koszul, « Multiscale Structuring of the E. coli Chromosome by Nucleoid-Associated and Condensin Proteins », Cell, vol. 172, nᵒ 4, p. 771-783.e18, févr. 2018.
    Résumé : As in eukaryotes, bacterial genomes are not randomly folded. Bacterial genetic information is generally carried on a circular chromosome with a single origin of replication from which two replication forks proceed bidirectionally toward the opposite terminus region. Here, we investigate the higher-order architecture of the Escherichia coli genome, showing its partition into two structurally distinct entities by a complex and intertwined network of contacts: the replication terminus (ter) region and the rest of the chromosome. Outside of ter, the condensin MukBEF and the ubiquitous nucleoid-associated protein (NAP) HU promote DNA contacts in the megabase range. Within ter, the MatP protein prevents MukBEF activity, and contacts are restricted to ∼280 kb, creating a domain with distinct structural properties. We also show how other NAPs contribute to nucleoid organization, such as H-NS, which restricts short-range interactions. Combined, these results reveal the contributions of major evolutionarily conserved proteins in a bacterial chromosome organization.
    Mots-clés : bacteria, BDG, chromatin, genome organization, Hi-C, HU, MatP, OCB, SMC.

  • H. Liu, Y. Zhang, Z. Liu, J. Liu, Y. Hauck, J. Liu, H. Dong, J. Liu, X. Zhao, B. Lu, Y. Jiang, G. Vergnaud, C. Pourcel, et K. Wan, « Associations between Mycobacterium tuberculosis Beijing genotype and drug resistance to four first-line drugs: a survey in China », Frontiers of Medicine, vol. 12, nᵒ 1, p. 92-97, 2018.

  • W. Liu, T. Rochat, C. Toffano-Nioche, T. N. Le Lam, P. Bouloc, et C. Morvan, « Assessment ofBona FidesRNAs inStaphylococcus aureus », Frontiers in Microbiology, vol. 9, p. 228, 2018.
    Résumé : Bacterial regulatory RNAs have been extensively studied for over a decade, and are progressively being integrated into the complex genetic regulatory network. Transcriptomic arrays, recent deep-sequencing data and bioinformatics suggest that bacterial genomes produce hundreds of regulatory RNAs. However, while some have been authenticated, the existence of the others varies according to strains and growth conditions, and their detection fluctuates with the methodologies used for data acquisition and interpretation. For example, several small RNA (sRNA) candidates are now known to be parts of UTR transcripts. Accurate annotation of regulatory RNAs is a complex task essential for molecular and functional studies. We definedbona fidesRNAs as those that (i) likely act intransand (ii) are not expressed from the opposite strand of a coding gene. Using published data and our own RNA-seq data, we reviewed hundreds ofStaphylococcus aureusputative regulatory RNAs using the DETR'PROK computational pipeline and visual inspection of expression data, addressing the question of which transcriptional signals correspond to sRNAs. We conclude that the model strain HG003, a NCTC8325 derivative commonly used forS. aureusgenetic regulation studies, has only about 50bona fidesRNAs, indicating that these RNAs are less numerous than commonly stated. Among them, about half are associated to theS. aureussp. core genome and a quarter are possibly expressed in otherStaphylococci. We hypothesize on their features and regulation using bioinformatic approaches.
    Mots-clés : BDG, bona fide sRNA, gene regulation, RNA-seq, SRRB, SSFA, Staphylococcus aureus HG003, transcription factors.

  • M. J. Llansola-Portoles, K. Redeckas, S. Streckaité, C. Ilioaia, A. A. Pascal, A. Telfer, M. Vengris, L. Valkunas, et B. Robert, « Lycopene crystalloids exhibit singlet exciton fission in tomatoes », Physical Chemistry Chemical Physics, vol. 20, nᵒ 13, p. 8640-8646, 2018.

  • A. Maikova, J. Peltier, P. Boudry, E. Hajnsdorf, N. Kint, M. Monot, I. Poquet, I. Martin-Verstraete, B. Dupuy, et O. Soutourina, « Discovery of new type I toxin–antitoxin systems adjacent to CRISPR arrays in Clostridium difficile », Nucleic Acids Research, févr. 2018.

  • W. Majeran, J. - P. Le Caer, L. Ponnala, T. Meinnel, et C. Giglione, « Targeted profiling of A. thaliana sub-proteomes illuminates new co- and post-translationally N-terminal Myristoylated proteins », The Plant Cell, p. tpc.00523.2017, févr. 2018.

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