COVID-19 and cryo-EM

The application of cryo-EM methods to study SARS-CoV-2 proteins provides a convincing demonstration of the power of cryo-EM in the arsenal of structural biology.

Helium's placement in the Periodic Table from a crystal structure viewpoint

The present paper indicates that helium has more in common with the alkaline earths than is often considered. Not only does it share an analogous electron configuration but it also has an analogous crystal structure to that of beryllium and magnesium which is, in contrast, characteristic of the bulk material rather than of isolated atoms.

Making sense of vacancy correlations with single-crystal diffuse scattering data

The results of Roth et al. [IUCrJ (2020). 7, 673–680] provide a clear picture of occupational correlations in half-Heusler compounds.

Bond-length distributions for ions bonded to oxygen: results for the transition metals and qu­antification of the factors underlying bond-length variation in inorganic solids

Bond-length distributions are examined for transition metals bonded to O²⁻. Causal mechanisms underlying bond-length variation in inorganic solids are resolved, and the extent to which these mechanisms individually result in bond-length variation is quantified for transition metals with anomalous bond-length distributions.

The data universe of structural biology

The history of the growth of the Protein Data Bank and the role that the community has played in developing standards and policies are described.

1.8 Å resolution structure of β-galactosidase with a 200 kV CRYO ARM electron microscope

An electron microscope operating at a voltage of 200 kV is shown to be sufficient for determination of protein structures at high resolution using cryo-EM methods. The level of detail in the 1.8 Å map reported by the authors shows visible density bumps for hydrogen atoms and marks an important advance in the establishment of microscopes operating at lower voltages as powerful tools for structure-guided drug design using cryo-EM.

Structure-based screening of binding affinities via small-angle X-ray scattering

A feasibility study on how the binding affinities of protein–ligand interactions are obtained, based on the solution scattering intensities of their respective titration series, is presented. Experimental parameters and their resulting influence on accuracy and precision are analysed.

Crystal structure and magnetism in the S = 1/2 spin dimer compound NaCu₂VP₂O₁₀

The spin dimer magnet NaCu₂VP₂O₁₀ was discovered, and its crystal structure was determined using single-crystal X-ray diffraction and electron diffraction. Maximum magnetic susceptibility was observed at ∼60 K and NaCu₂VP₂O₁₀ became non-magnetic upon further cooling.

Structural definition of polyspecific compensatory ligand recognition by P-glycoprotein

Polyspecific ligand recognition by P-glycoprotein includes compensatory mechanisms in the form of ligand-binding shifts when ligand-interacting residues are challenged by mutagenesis. Point mutations of ligand-interacting phenylalanine residues to alanines resulted in binding shifts of an environmental pollutant, yet its inhibitory function on ATPase activity was preserved.

A simple model for vacancy order and disorder in defective half-Heusler systems

Defective half-Heuslers, X_1−xYZ, with different degrees of short- and long-range vacancy order can be explained using a simple model. In this model, the vacancies avoid being nearest or next-nearest neighbors. The model reproduces previously observed diffuse electron-diffraction data. The findings suggest a method for further improving thermoelectric efficiency of these materials.

Paired refinement under the control of PAIREF

Application of the PAIREF program providing automation of paired refinement is demonstrated on six data sets. The results prove that the inclusion of high-resolution data beyond the conventional criteria can lead to more accurate structure models.

Crystal structure and interaction studies of human DHTKD1 provide insight into a mitochondrial megacomplex in lysine catabolism

Through interaction studies, the crystal structure of human DHTKD1 allows insight into a mitochondrial megacomplex in lysine catabolism. This creates the starting framework for developing DHTKD1 modulators to probe the intricate mitochondrial energy metabolism.

Assessing the JEOL CRYO ARM 300 for high-throughput automated single-particle cryo-EM in a multiuser environment

This paper presents a detailed assessment of the performance of the CRYO ARM 300 electron microscope in a multiuser cryo-EM facility setting. It is shown that the microscope can be used for reliable automated data collection. The strengths and weaknesses of the hardware are discussed.

A self-supervised workflow for particle picking in cryo-EM

A self-supervised workflow uses a 2D class average to progressively train a convolutional neural network for automated particle picking in cryo-EM.

Millisecond time-resolved serial oscillation crystallography of a blue-light photoreceptor at a synchrotron

A method is presented to perform time-resolved X-ray crystallography with a 63 ms time resolution using a fast pixel detector and partial oscillation data sets. This minimizes the number of crystals (<100) required for a complete experiment.

Structural insights into the regulation of SigB activity by RsbV and RsbW

Crystal structures and a SAXS envelope model of the RsbV–RsbW complex reveal that the RsbW tetramer forms a core structure to regulate SigB activity.

Induced DNA bending by unique dimerization of HigA antitoxin

The crystal structures of HigA3 antitoxin and DNA-bound HigA3 allow detailed structural insights into the HigBA toxin–antitoxin system of Mycobacterium tuberculosis. The unique dimerization of HigA3 induces DNA bending.

Evaluation of crystal quality of thin protein crystals based on the dynamical theory of X-ray diffraction

The oscillatory profiles of rocking curves and equal-thickness fringes were observed on nearly perfect protein crystals of ferritin, which matches predictions of dynamical diffraction theory.

Structural basis of self-assembly in the lipid-binding domain of mycobacterial polar growth factor Wag31

The crystal structure of the N-terminal membrane anchoring domain of mycobacterial DivIVA/Wag31 reveals a filament-compatible `dimer-of-dimers' assembly state. The results suggest that, in addition to lipid binding, the N-terminal of Wag31 can participate in self-assembly to form filamentous structures.

Structures of collagen IV globular domains: insight into associated pathologies, folding and network assembly. Corrigendum

Corrigendum to the article by Casino et al. [IUCrJ (2018). 5, 765–779].