September 2018 issue
Progress in single-particle three-dimensional imaging is discussed, with advances in both data-collection and data-handling techniques described.
Lipid cubic phase supplemented with mercury was used to create a heavy-atom derivative of microcrystals for direct SIRAS phasing using serial millisecond crystallography.
A three-dimensional reconstruction of the Melbournevirus affected by a strong artifact in the center of the particle is presented. Using simulations, the artifact was found to be probably caused by background scattering, while particle size and pulse-energy variation did not affect the quality of the reconstruction. Possible ways to minimize such problems in the future are suggested.
Electron descriptors such as bond order and electron density at the bond critical point are key quantities in establishing the characterization of chemical bonding. This paper analyzes a plethora of quantum chemistry data available in the literature to confirm exponential correlations between these electron descriptors and the interatomic distances for any type of chemical bond. This is particularly relevant for extending the crystal chemistry bond order conservation principle to systems with delocalized electrons.
This work develops an analysis approach that can solve protein structures from data frames whose signals are too weak to be indexed. The approach is demonstrated on a serial microcrystallography data set collected at a storage-ring synchrotron source.
Bioinspired metalloporphyrin-based supramolecular MOFs have been successfully tested for heterogeneous catalytic applications.
Deuteration of ROY at its amine function allowed the circumvention of concomitant polymorphs and produced exclusively the yellow Y polymorph of d1-ROY.
Sample delivery is a major challenge to performing serial crystallography experiments at upcoming high-repetition-rate X-ray free-electron lasers. The feasibility of using gas-driven liquid jets for this purpose at the FLASH facility in Hamburg has been studied.
Thousands of regions missing from existing protein structure models are completed using new methods based on homology.
The crystal structure of chibaite (a natural clathrasil with an MTN-type framework structure) and its structural evolution with decreasing temperature from space-group symmetry to A2/n were investigated with single-crystal X-ray diffraction and Raman spectroscopy.
Co-crystallization with the natural, phosphodiester-linked substrate combined with exhaustive computational analysis reveals how photolyases stabilize and lock the DNA unpaired bubble resulting from cyclobutane pyrimidine dimer binding and subsequent flip-out.
Light control of cell development is revealed by phytochrome structures of Myxobacteria.
Roby–Gould bond orders for intermolecular interactions such as hydrogen bonds, halogen bonds and chalcogen bonds in molecular crystals have been explored. Bond-order values place these interactions on a scale representing their relative strengths, in conjunction with a chemist's notion of bonds.
Experimental and theoretical multipolar charge-density analyses of a unique short Br⋯π interaction in an ebselen derivative have been performed. They establish unequivocally the concomitant existence of the characteristics of σ-hole and π-hole bonding in the same interaction.
The recent claim of structural differences between alanine enantiomers in the solid state is critically discussed.
A response is given to comments by Bürgi & Macchi [IUCrJ (2018), 5, 654–657] about Belo et al. [IUCrJ (2018), 5, 6–12.].