Some lessons from COVID: science and communication

Biomedical challenges such as the present COVID-19 pandemic require both good science and excellent communication between scientists and the general public. This underscores the importance of presenting our science in innovative ways that make it accessible to all.

Cryo-EM structure of a thermophilic encapsulin offers clues to its functions

Wiryaman & Toor [IUCrJ (2021). 8, 342–350] report the cryo-EM structure of a Thermotoga maritima encapsulin, a nanocompartment that encapsulates a ferritin-like protein cargo. The 2 Å resolution structure offers insights into the active role of this thermostable encapsulin in regulating iron homeostasis to reduce oxidative stress.

Structural biology in the time of COVID-19: perspectives on methods and milestones

The one-year anniversary of the declaration of the outbreak of SARS-CoV-2 as a pandemic, combined with the 50th anniversary of the PDB, provides a unique occasion to observe the role played by structural methods in the fight against COVID-19. A revealing portrait of the many contributions of the structural biology community is presented.

Cryo-EM structure of a thermostable bacterial nanocompartment

A 2.0 Å resolution cryo-EM structure of a thermostable bacterial nanocompartment is reported, with the high-resolution structure allowing the visualization of key details and new proposed biological functions.

Supramolecular structures of Ni^II and Cu^II with the sterically demanding Schiff base dyes driven by cooperative action of preagostic and other non-covalent interactions

This work shows the importance of counterintuitive ultra long distances, intramolecular preagostic attractive C—H⋯Ni/Cu and C—H⋯O, C—H⋯H—C contacts and a bunch of other extremely strong non-classic mainly London dispersion driven intermolecular interactions involving C—H bonds: C—H⋯X (X = H—C, N, O, π) in the crystal structures of the Ni^II and Cu^II based complexes fabricated from the sterically crowding cyclo­hexyl-containing Schiff base dyes. Photophysical properties of the reported complexes are also discussed.

Structural and functional analysis of the Klebsiella pneumoniae MazEF toxin–antitoxin system

The first crystal structure of a type II toxin–antitoxin complex structure of Klebsiella pneumoniae at 2.3 Å resolution is presented. Mutational experiments and cell-growth assays confirm Arg28 and Thr51 as critical residues for MazF ribonuclease activity.

Structural insights into protein folding, stability and activity using in vivo perdeuteration of hen egg-white lysozyme

Perdeuteration and in vitro refolding of hen egg-white lysozyme impact protein thermal stability and activity. Deuteration appears to primarily affect enzymatic function through changes in protein dynamics, while refolding contributes to a small decrease in protein thermal stability.

Synchrotron total-scattering data applicable to dual-space structural analysis

Synchrotron X-ray scattering data with high Q resolution, Q range and dynamic range are collected using the OHGI detector system, and excellent correspondence is achieved in structural refinements of the data in reciprocal and direct space.

Rapid response to emerging biomedical challenges and threats

When biomedical crises strike, structural biologists worldwide respond by determining the structures of relevant proteins and their complexes, resulting in an avalanche of data that can be overwhelming without a resource designed to classify, annotate and validate them. An advanced information system is necessary to extract and infer knowledge from a deluge of uncurated and disjointed data and publications.

Enhancing deep-learning training for phase identification in powder X-ray diffractograms

A framework is described for the efficient and realistic simulation of X-ray diffraction scans to train machine- or deep-learning models like convolutional neural networks for the automatic phase-identification task in multiphase compounds.

Structural plasticity of the selectivity filter in a nonselective ion channel

The X-ray structure of a nonselective sodium potassium ion channel reveals structural asymmetry in the selectivity filter of an integral membrane protein responsible for ion permeation. NMR studies showed the dynamical nature of the protein structure in the membrane, and molecular dynamics suggest different degrees of conformational plasticity are required for conducting potassium and sodium.

Capturing structural changes of the S₁ to S₂ transition of photosystem II using time-resolved serial femtosecond crystallography

A method for determining the sample flow rate and concomitant light condition in time-resolved serial femtosecond crystallography is developed to analyze the intermediate-state structures of photosystem II.

Structural evolution in thermoelectric zinc antimonide thin films studied by in situ X-ray scattering techniques

Phase evolution was monitored during annealing of as-deposited amorphous zinc antimonide thin films using in situ X-ray diffraction and in situ X-ray total scattering coupled with electrical resistivity measurements.

Impact of the neutron-depolarization effect on polarized neutron scattering in ferromagnets

A model is proposed to describe the depolarization of a neutron beam traversing a ferromagnetic sample, provide the procedure for data correction and give guidelines to choose the optimum sample thickness. It is experimentally verified for a small-angle neutron-scattering geometry with samples of the nanocristalline soft-magnet Vitroperm (Fe₇₃Si₁₆B₇Nb₃Cu₁).

Reduction of dislocations in α-Ga₂O₃ epilayers grown by halide vapor-phase epitaxy on a conical frustum-patterned sapphire substrate

Low dislocation density of α-Ga₂O₃ grown on conical frustum-patterned sapphire substrate (CF-PSS) has been studied. The threading dislocation propagation path of α-Ga₂O₃ on CF-PSS was observed.

Unveiling the self-association and desolvation in crystal nucleation

The importance of self-association and desolvation in the process of crystal nucleation is emphasized; the rearrangement of supramolecular structures also has a non-negligible effect on the nucleation kinetics.