Evidence for Conformational Changes upon Copper Binding to Cupriavidus metallidurans CzcE

International audienceCzcE is a periplasmic protein from Cupriavidus metallidurans CH34 that can bind four copper atoms per dimer. We have crystallized the apo form of the protein and determined its structure at 1.85 A ° resolution. Three Cu atoms were localized by soaking apo-CzcE crystals into a CuCl2 solution. We identified His24 as a Cu(II) ligand in each protomer and Asp100 as a key residue for Cu binding at the interface of the dimer. The role of these amino acids was confirmed by site-directed mutagenesis and UV-visible spectroscopy. The fourth Cu atom was not located. The oxidized form of CzcE contains four Cu(II) atoms, while the reduced form contains four Cu(I) atoms. Average coordination spheres of four N or O atoms for Cu(II) and of oneNorOatom and two S atoms for Cu(I) were determined by X-ray absorption spectroscopy. As there is no evidence for preformed metal-binding sites in apo-CzcE, we suggest that different conformational changes occurred upon Cu(II) or Cu(I) binding. These changes were further demonstrated by digestion experiments that gave different proteolysis patterns depending not only on the presence of the metal but also on its speciation. The ability of CzcE to bind copper and to adapt its conformation to different copper oxidation states could be related to a role in copper sensing for this protein

Instrumentation for synchrotron-radiation macromolecular crystallography

International audienceX-ray diffraction is an extremely important tool for structure determination of biological macromolecules, to the extent that currently around 85% of Protein Data Bank entries result from X-ray measurements. Many of these structure determinations use synchrotron radiation for data collection. This article aims to give synchrotron users an overview of the functioning of a synchrotron beamline and how the performance of various instruments combines to allow the collection of diffraction data

Frequency and predictors for chronic thromboembolic pulmonary hypertension after a first unprovoked pulmonary embolism: Results from PADIS studies

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MXCuBE2 : the dawn of MXCuBE Collaboration

MXCuBE2 is the second-generation evolution of the MXCuBE beamline control software, initially developed and used at ESRF – the European Synchrotron. MXCuBE2 extends, in an intuitive graphical user interface (GUI), the functionalities and data collection methods available to users while keeping all previously available features and allowing for the straightforward incorporation of ongoing and future developments. MXCuBE2 introduces an extended abstraction layer that allows easy interfacing of any kind of macromolecular crystallography (MX) hardware component, whether this is a diffractometer, sample changer, detector or optical element. MXCuBE2 also works in strong synergy with the ISPyB Laboratory Information Management System, accessing the list of samples available for a particular experimental session and associating, either from instructions contained in ISPyB or from user input via the MXCuBE2 GUI, different data collection types to them. The development of MXCuBE2 forms the core of a fruitful collaboration which brings together several European synchrotrons and a software development factory and, as such, defines a new paradigm for the development of beamline control platforms for the European MX user community