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Martinez-Salvador S.,University of Zaragoza | Menjon B.,University of Zaragoza | Fornies J.,University of Zaragoza | Martin A.,University of Zaragoza | Uson I.,Institute Of Biologia Molecular Of Barcelona Csic
Angewandte Chemie - International Edition | Year: 2010

Caught in the act: Evidence for the intermediacy of difluorocarbene- platinum species along the acidic degradation of Pt-CF3 bonds was gained by trapping a base-stabilized Pt=CF2 moiety (see scheme). Attack of an N nucleophile (py*) to the highly electrophilic and extremely reactive difluorocarbene carbon atom takes place with C-N bond formation. (Figure Presented) © 2010 Wiley-VCH Verlag GmbH &. Co. KGaA, Weinheim.

Verdaguer N.,Institute Of Biologia Molecular Of Barcelona Csic
Sub-cellular biochemistry | Year: 2013

For about 30 years X-ray crystallography has been by far the most powerful approach for determining virus structures at close to atomic resolutions. Information provided by these studies has deeply and extensively enriched and shaped our vision of the virus world. In turn, the ever increasing complexity and size of the virus structures being investigated have constituted a major driving force for methodological and conceptual developments in X-ray macromolecular crystallography. Landmarks of new virus structures determinations, such as the ones from the first animal viruses or from the first membrane-containing viruses, have often been associated to methodological breakthroughs in X-ray crystallography. In this chapter we present the common ground of proteins and virus crystallography with an emphasis in the peculiarities of virus studies. For example, the solution of the phase problem, a central issue in X-ray diffraction, has benefited enormously from the presence of non-crystallographic symmetry in virus crystals.

Boer D.R.,Barcelona Institute for Research in Biomedicine | Wu L.,Chalmers University of Technology | Lincoln P.,Chalmers University of Technology | Coll M.,Barcelona Institute for Research in Biomedicine | Coll M.,Institute Of Biologia Molecular Of Barcelona Csic
Angewandte Chemie - International Edition | Year: 2014

The crystal structure of the Δ,Δ enantiomer of the binuclear "light-switch" ruthenium complex [μ-(11,11′-bidppz)(1,10- phenanthroline)4 Ru2]4+ bound to the oligonucleotide d(CGTACG) shows that one dppz moiety of the dumbbell-like compound inserts into the DNA stack through the extrusion of an AT base pair. The second dppz moiety recruits a neighboring DNA molecule, and the complex thus cross-links two adjacent duplexes by bridging their major grooves. Pinned together by molecular rivets: The crystal structure of the complex between double-stranded DNA and the binuclear complex [μ-(11,11′-bidppz)(1,10- phenanthroline)4 Ru2]4+ (1, shown in blue; bidppz=bis(dipyridophenazine)), showed that one half of the bidppz ligand inserts into a DNA duplex, and the other half stacks onto the blunt end of a nearby DNA duplex. Two molecules of 1 with the same binding mode effectively cross-link two DNA duplexes. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Brodu V.,French National Center for Scientific Research | Baffet A.D.,French National Center for Scientific Research | Le Droguen P.-M.,French National Center for Scientific Research | Casanova J.,Institute Of Biologia Molecular Of Barcelona Csic | And 2 more authors.
Developmental Cell | Year: 2010

Microtubules (MTs) are essential for many cell features, such as polarity, motility, shape, and vesicle trafficking. Therefore, in a multicellular organism, their organization differs between cell types and during development; however, the control of this process remains elusive. Here, we show that during Drosophila tracheal morphogenesis, MT reorganization is coupled to relocalization of the microtubule organizing centers (MTOC) components from the centrosome to the apical cell domain from where MTs then grow. We reveal that this process is controlled by the trachealess patterning gene in a two-step mechanism. MTOC components are first released from the centrosome by the activity of the MT-severing protein Spastin, and then anchored apically through the transmembrane protein Piopio. We further show that these changes are essential for tracheal development, thus stressing the functional relevance of MT reorganization for morphogenesis. © 2010 Elsevier Inc.

Casanas A.,Institute Of Biologia Molecular Of Barcelona Csic | Casanas A.,ETH Zurich | Querol-Audi J.,Institute Of Biologia Molecular Of Barcelona Csic | Guerra P.,Institute Of Biologia Molecular Of Barcelona Csic | And 6 more authors.
Acta Crystallographica Section D: Biological Crystallography | Year: 2013

The vault particle, with a molecular weight of about 10 14;MDa, is the largest ribonucleoprotein that has been described. The X-ray structure of intact rat vault has been solved at a resolution of 3.5 14;Å [Tanaka et al. (2009), Science, 323, 384-388], showing an overall barrel-shaped architecture organized into two identical moieties, each consisting of 39 copies of the major vault protein (MVP). The model deposited in the PDB includes 39 MVP copies (half a vault) in the crystal asymmetric unit. A 2.1 14;Å resolution structure of the seven N-terminal repeats (R1-7) of MVP has also been determined [Querol-Audí et al. (2009), EMBO J. 28, 3450-3457], revealing important discrepancies with respect to the MVP models for repeats R1 and R2. Here, the re-refinement of the vault structure by incorporating the high-resolution information available for the R1-7 domains, using the deformable elastic network (DEN) approach and maintaining strict 39-fold noncrystallographic symmetry is reported. The new refinement indicates that at the resolution presently available the MVP shell can be described well as only one independent subunit organized with perfect D39 molecular symmetry. This refinement reveals that significant rearrangements occur in the N-terminus of MVP during the closing of the two vault halves and that the 39-fold symmetry breaks in the cap region. These results reflect the highly dynamic nature of the vault structure and represent a necessary step towards a better understanding of the biology and regulation of this particle. © 2013 International Union of Crystallography.

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