Computational modelling as a tool in structural science

This editorial gives a brief discussion of the current status and role of computational modelling as a technique in structural science.

Electrons receive individual treatment with electron-event representation

Electron-event representation saves the spatial and temporal coordinates of every electron with ultimate accuracy. Through maximum signal extraction, it will improve the performance of electron cryo-microscopy.

The crystallography of Pluto

Maynard-Casely and co-workers [IUCrJ (2020). 7, 844–851.] investigate two of Pluto's most abundant minerals with neutron diffraction. The new results will be key to understanding the geology of our distant neighbour and represent a significant advance in the emerging field of small-molecule geology.

Gold Standard for macromolecular crystallography diffraction data

A large portion of the research community concerned with high data-rate macromolecular crystallography has agreed to an updated specification of data and metadata for diffraction images to be produced at light sources to facilitate the processing of data sets and to enable data archiving according to FAIR principles. Here, the resulting standard is presented.

Sensitive imaging of intact microvessels in vivo with synchrotron radiation

In this article, move contrast X-ray imaging (MCXI) based on high-brightness synchrotron radiation is developed. Experiments with live rodents demonstrate the practicability of the MCXI method for sensitive and intact imaging of microvessels in vivo.

Spin-density studies of the multiferroic metal-organic compound [NH₂(CH₃)₂][Fe^IIIFe^II(HCOO)₆]

Polarized neutron diffraction on the flipping-ratio technique has been used to determine the spin-density map for the multiferroic compound [NH₂(CH₃)₂][Fe^IIIFe^II(HCOO)₆]. The proposed models give an alternative explanation for the origin of the multiferroic behaviour of this compound.

Crystal structures of SARS-CoV-2 ADP-ribose phosphatase: from the apo form to ligand complexes

High-resolution crystal structures of the ADP-ribose phosphatase domain (ADRP; also known as the macrodomain) from SARS-CoV-2 with multiple ligands illustrate how the protein undergoes conformational changes to adapt to the ligand in the manner observed for homologues from other viruses.

The susceptibility of di­sulfide bonds towards radiation damage may be explained by S⋯O interactions

Irradiation of proteins with intense X-ray radiation generates specific structural and chemical alterations, such as metal-ion reduction, reduction of disulfide bonds and decarboxylation reactions. An analysis of a set of disulfide bonds in known structures suggests that the most susceptible disulfide bonds feature a carbonyl O atom positioned along the extension of the S—S bond vector, forming a stabilizing S⋯O interaction, which upon irradiation leads to polarization of the disulfide bond and its eventual reduction.

The structure of a potassium-selective ion channel reveals a hydrophobic gate regulating ion permeation

The atomic resolution structure of a potassium-selective ion channel reveals a hydrophobic gate that regulates ion permeation.

Re-examining the crystal structure behaviour of nitrogen and methane

In an effort to better understand Plutonian glaciology, the thermal expansion of solid methane and nitrogen have been determined using neutron powder diffraction. Additional results include a resolution of the long-standing dispute over the α-nitrogen crystal structure, and observations of β-nitrogen texture change with temperature.

Protein–lipid architecture of a cholinergic postsynaptic membrane

Cryo-EM reconstruction of the native Torpedo membrane reveals that cholesterol segregates preferentially around nicotinic acetyl­choline receptors, interacting robustly with specific transmembrane sites and creating a network of bridging microdomains. The microdomains may promote cooperativity between neighbouring receptors, leading to an enhanced postsynaptic response.

Electron-event representation data enable efficient cryoEM file storage with full preservation of spatial and temporal resolution

Electron-event representation is a new data format for cryoEM that preserves the full temporal and spatial resolution of movies from direct detector device cameras.

Machine learning deciphers structural features of RNA duplexes measured with solution X-ray scattering

A supervised machine learning approach is applied to integrate molecular dynamics simulations with solution X-ray scattering of double-stranded ribonucleic acid (dsRNA) structures with a focus on extracting critical structural information hidden in the wide-angle regime.

Deep learning enables the atomic structure determination of the Fanconi Anemia core complex from cryoEM

This paper describes a method for determining an atomic model of a protein complex using moderate-resolution cryoEM data and distance predictions from deep learning.

Neutron sub-micrometre tomography from scattering data

Neutron-scattering data are passed into a phase-recovered computed-tomography algorithm, producing real-space reconstructions of periodic samples. The spatial resolution of the reconstructions is much smaller than what is achievable using other forms of neutron computed tomography.

Anaerobic fixed-target serial crystallography

An effective and simple-to-implement approach for anaerobic room-temperature data collection is described and demonstrated by application to dioxygen utilizing enzymes.

Charge density waves and degenerate modes in exfoliated monolayer 2H-TaS₂

Using temperature-dependent Raman scattering, it is demonstrated for the first time that charge density waves can exist in exfoliated monolayer 2H-TaS₂ with a phase transition temperature much higher than that in the bulk.

On the accuracy and precision of X-ray and neutron diffraction results as a function of resolution and the electron density model

The aspherical models (MM, TAAM, HAR) give far more accurate and precise single-crystal X-ray results than IAM, sometimes identical to results from neutron diffraction and at low resolution. Hence, aspherical approaches open new routes for improving all of the existing structural information collected over the last century.

Structural insights into the histidine-containing phospho­transfer protein and receiver domain of sensor histidine kinase suggest a complex model in the two-component regulatory system in Pseudomonas aeruginosa

Two crystal structures of the histidine-containing phospho­transfer protein (HptB) and the receiver domain of the hybrid sensor histidine kinase PA1611 (PA1611REC) in the two-component regulatory system of Pseudomonas aeruginosa have been determined. With the modeled structure of the PA1611REC/HptB complex, the interactions and phospho­ryl group transfer between HptB and PA1611REC are elucidated.