Using Phaser and ensembles to improve the performance of SIMBAD

Improvements to the sensitivity of the search for suitable molecular-replacement search models in SIMBAD through the use of Phaser and an ensemble-based model database are reported.

How far are we from automatic crystal structure solution via molecular-replacement techniques?

An automatic pipeline based on molecular-replacement phases is described for the automatic crystal structure solution of protein and DNA/RNA molecules.

Factors influencing estimates of coordinate error for molecular replacement

Improved coordinate error estimates are proposed for the X-ray and NMR models used for maximum-likelihood-based molecular-replacement phasing.

Structural insights into the role of the N-terminus in the activation and function of extracellular serine protease from Staphylococcus epidermidis

Extracellular serine protease (Esp) is a glutamyl endopeptidase from Staphylococcus epidermidis that plays a key role in inhibiting the growth and formation of Staphylococcus aureus biofilms. Here, crystal structures of the Esp zymogen and its N-terminal locked variants are presented, and details are given of the role of the unusually long N-terminus in the activation and function of Esp.

Including crystallographic symmetry in quantum-based refinement: Q|R#2

The C-terminal coiled-coil domain of transient receptor potential channel TRPP3 in space group P321 (PDB entry 4gif) is re-refined with restraints from quantum chemistry using Hartree–Fock theory.

Improved chemistry restraints for crystallographic refinement by integrating the Amber force field into Phenix

The full Amber force field has been integrated into Phenix as an alternative refinement target. With a slight loss in speed, it achieves improved stereochemistry, fewer steric clashes and better hydrogen bonds.

Using cryo-electron microscopy maps for X-ray structure determination of homologues

A hybrid method has been developed to determine crystal structures by utilizing cryo-EM maps of homologous proteins.

Catalytic mechanism and evolutionary characteristics of thioredoxin from Halobacterium salinarum NRC-1

The catalytic mechanism and the evolutionary characteristics of thioredoxin derived from the extreme halophile H. salinarum NRC-1 were elucidated by X-ray crystallographic analysis, circular-dichroism analysis and enzymatic assays.

Refinement of protein structures using a combination of quantum-mechanical calculations with neutron and X-ray crystallographic data. Corrigendum

The article by Caldararu et al. [(2019), Acta Cryst. D75, 368–380] is corrected.