Neutron diffraction experiment with the Y116S variant of transthyretin using iBIX at J-PARC: application of a new integration method

A large single crystal of the Y116S variant of transthyretin was grown and neutron diffraction data were collected to 1.9 Å resolution using the IBARAKI biological crystal diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC).

Lattice-translocation defects in specific crystals of the catalytic head domain of influenza neuraminidase

Crystallization of the tetramer of the head domain of influenza neuraminidase (NA) may result in a specific crystal with space group C222₁ and unit-cell parameters a ≃ 120, b ≃ 143, c ≃ 120 Å. The molecular packing of NA tetramers in this crystal intrinsically causes pathological imperfections, lattice-translocation defects, which complicate the structure determination.

Insulin polymorphism induced by two polyphenols: new crystal forms and advances in macromolecular powder diffraction

The polymorphism of human insulin upon the binding of p-coumaric acid or resveratrol and pH variation is reported.

Crystal structures of peanut lectin in the presence of synthetic β-N- and β-S-galactosides disclose evidence for the recognition of different glycomimetic ligands

Crystal structures of peanut lectin are reported in complex with six novel synthetic hydrolytically stable β-N- and β-S-galactosides, together with binding-affinity studies by isothermal titration calorimetry.

Through-grid wicking enables high-speed cryoEM specimen preparation

Replacing the filter paper used in conventional cryoEM specimen preparation with a glass-fiber filter allows specimens to be prepared by wicking solution through the grid. A new device that uses this approach was constructed, and can freeze high-quality specimens in tens of milliseconds.

Insight into the potential factors influencing the catalytic direction in cellobiose 2-epimerase by crystallization and mutagenesis

An investigation of the structural differences between three newly determined cellobiose 2-epimerases (CEs) and other enzymes in the N-acyl-D-glucosamine 2-epimerase superfamily suggested that it was highly possible that His196 in Spirochaeta thermophila CE was involved in catalyzing isomerization. Rearrangement of the flexible loop during catalysis was significantly involved in the bifunction of this CE and the intermolecular interactions inside the flexible loop greatly influenced the reshaping of the loop and the catalytic direction.

Flipping the substrate preference of Hazara virus ovarian tumour domain protease through structure-based mutagenesis

A structure of the Hazara virus ovarian tumour domain protease (OTU) bound to ubiquitin was elucidated to 2.78 Å resolution. Through structure-guided site-directed mutagenesis, OTUs were engineered to shift the OTU substrate preference from ubiquitin to interferon-stimulated gene product 15.

Structure of a GH51 α-L-arabino­furanosidase from Meripilus giganteus: conserved substrate recognition from bacteria to fungi

The structure of a fungal α-L-arabinofuranosidase has been determined using sulfur SAD data collected in vacuo using beamline I23 at Diamond Light Source. Complexes with L-arabinose, an iminosugar and two covalent inhibitors confirm the identity of the catalytic nucleophile and provide a detailed map of enzyme–substrate interactions that are conserved between bacteria and fungi.

Pre-clustering data sets using cluster4x improves the signal-to-noise ratio of high-throughput crystallography drug-screening analysis

Separating multi-data sets based on C^α differences can help to identify additional hits for drug- and fragment-screening crystallography experiments, expanding the range of crystal systems to which this technique can be applied. This is made available in a graphical user interface.

Quantum refinement with multiple conformations: application to the P-cluster in nitrogenase

The method of quantum refinement has been extended to systems with multiple conformations in the quantum system. It has been used to improve the description of the P-cluster in three different oxidation states in two crystal structures of the enzyme nitrogenase.

A Life among Men, Women and Molecules. Memoirs of an Indian Scientist