Protein di­sulfide bond generation in Escherichia coli DsbB–DsbA

The crystal structure of the DsbB–DsbA–ubiquinone ternary complex has revealed a mechanism of protein disulfide bond generation in Escherichia coli.

Ultrahigh-resolution crystallography and related electron density and electrostatic properties in proteins

Ultrahigh-resolution protein diffraction data allow valence electron density modelling and calculations of experimental electrostatic properties. Protein–ligand interaction energy may therefore be estimated.

Key steps in the structure-based optimization of the hepatitis C virus NS3/4A protease inhibitor SCH503034

Crystal structures of protease/inhibitor complexes guided optimization of the buried nonpolar surface area thereby maximizing hydrophobic binding. The resulting potent tripeptide inhibitor is in clinical trials.

Structural studies on Helicobacter pylori ATP-dependent protease, FtsH

The crystal structures of the Helicobacter pylori FtsH ATPase domain in the nucleotide-free state and complexed with ADP have been determined.

Structure of six-transmembrane cation channels revealed by single-particle analysis from electron microscopic images

Single-particle analysis is a computer-aided method for determining protein structure using projection images obtained by electron microscopy. Recently reconstructed 6-TM-type cation channels demonstrate the structural similarities and divergence of the family.

Protein structures by spallation neutron crystallography

The capabilities of the Protein Crystallography Station at Los Alamos Neutron Science Center for determining protein structures by spallation neutron crystallography are illustrated, and the methodological and technological advances that are emerging from the Macromolecular Neutron Crystallography consortium are described.

Solution structures of RseA and its complex with RseB

Conformational changes of RseA and RseB were observed by circular dichroism and small-angle X-ray scattering upon the formation of their complex.

An optimal exposure strategy for cryoprotected virus crystals with lattice constants greater than 1000 Å

Many supramolecular complexes form crystals that have lattice constants of the order of 1000 Å. An optimized method for data collection and processing is described.

Fragment approaches in structure-based drug discovery

Fragment-based methods are successfully generating novel and selective drug-like inhibitors of protein targets, with a number of groups reporting compounds entering clinical trials. This paper summarizes the key features of the approach as one of the tools in structure-guided drug discovery.

Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode

A very compact X-ray generator, 4.3 times more brilliant than can be attained by a conventional rotating-anticathode X-ray generator, has been developed using a U-shaped rotating anticathode and a high-flux electron gun with focusing bending magnet.

High-resolution X-ray microdiffraction analysis of natural teeth

In situ microzone X-ray diffraction analysis of natural teeth is presented. From our experiment, layer orientation and continuous crystal variations in teeth could be conveniently studied using fast online measurements by high-resolution X-ray microdiffraction equipment.

Interaction of HIV-1 aspartic protease with its inhibitor, by molecular dynamics and ab initio fragment molecular orbital method

Molecular dynamics and the ab initio fragment molecular orbital method were applied to investigate the interaction of HIV-1 aspartic protease with its inhibitor. The interaction energy of the inhibitor at the active sites of aspartic acid obtained by the ab initio fragment molecular orbital method was as great as 50 kcal mol⁻¹, coinciding with a tetrahedral transition state.

Trimeric structure and conformational equilibrium of M-ficolin fibrinogen-like domain

The crystal structure and ligand-binding study of M-ficolin provides an insight into its discrimination mechanism between self and non-self.

A degradation signal recognition in prokaryotes

Substrates tagged with ssrA are recognized and degraded by a subset of the Clp family, ATP-dependent proteases in prokaryotes. This paper describes the mechanism of intracellular breakdown of ssrA-tagged substrates by ClpXP and its adaptor protein, SspB.

Deduced catalytic mechanism of D-amino acid amidase from Ochrobactrum anthropi SV3

The catalytic mechanism of D-amino acid amidase from Ochrobactrum anthropi SV3 has been deduced.

Novel dimer structure of a membrane-bound protease with a catalytic Ser–Lys dyad and its linkage to stomatin

The crystal structure of the K138A mutant of the 1510-N protease specific for p-stomatin was determined at 2.3 Å resolution. The structure shows a novel dimer form, and the kinked L2 loop indicates that Lys138 would probably have an important effect on the conformation of L2.

Performance of an electron gun for a high-brightness X-ray generator

The development of an electron gun for a high-brightness X-ray generator whose target brilliance is 60 kW mm⁻² is reported.

Crystal twinning of human MD-2 recognizing endotoxin cores of lipopolysaccharide

Twinned crystals of humaan MD-2 are transformed into single crystals with cryoprotectant optimization.

Crystallization of the Atg12–Atg5 conjugate bound to Atg16 by the free-interface diffusion method

The Atg12–Atg5 conjugate was prepared by in vivo reconstitution and was crystallized with Atg16 using the free-interface diffusion method.

Protein crystallization in a 100 nl solution with new stirring equipment

To investigate quantitatively the effects of stirring on protein crystallization, a new stirring system which can agitate a protein solution, ∼100 nl, by providing Hagen–Poiseuille flow has been successfully developed.

Structural insights into the similar modes of Nrf2 transcription factor recognition by the cytoplasmic repressor Keap1

The structure of mouse Keap1-DC complexed with the DLG motif peptide of Nrf2 transcription factor was determined at 1.9 Å resolution. The structure showed that the peptide binds to Keap1-DC at the bottom region of the β-propeller domain.

Hydrogen bonds of DsrD protein revealed by neutron crystallography

Hydrogen bonds of DNA-binding protein DsrD have been determined by neutron diffraction. In terms of proton donors and acceptors, DsrD protein shows striking differences from other proteins.

Development of an X-ray HARP–FEA detector system for high-throughput protein crystallography

A new detector system for protein crystallography based on an X-ray HARP–FEA is presented.

Mutagenesis of the crystal contact of acidic fibroblast growth factor

Several mutations at Glu81 located on the crystal contact of human acidic fibroblast growth factor were studied in an effort to improve crystal growth. Mutation to Ser and Thr resulted in crystallization of a rather bulky form of the wild type, whereas mutation to Val prohibited crystallization. These results suggest that crystal growth may be controlled by designing a new interface by protein engineering.

Mail-in data collection at SPring-8 protein crystallography beamlines

A mail-in data collection system at SPring-8, which is a web application with automated beamline operation, has been developed.

X-ray beam stabilization at BL-17A, the protein microcrystallography beamline of the Photon Factory

BL-17A is a new structural biology beamline at the Photon Factory, dedicated to protein crystallography of microcrystals. Here the X-ray beam stabilization techniques used at BL-17A are described.

Implementation of remote monitoring and diffraction evaluation systems at the Photon Factory macromolecular crystallography beamlines

At the Photon Factory macromolecular crystallography beamlines, two new functions, remote monitoring and diffraction image evaluation, have been developed and installed on the beamline controlling system STARS (simple transmission and retrieval system).

High-throughput operation of sample-exchange robots with double tongs at the Photon Factory beamlines

Sample-exchange robots with a double-tongs system that could exchange samples within 10 s have been developed.

X-ray crystallographic and biochemical characterizations of a mutant photosystem II complex from Thermosynechococcus vulcanus with the psbTc gene inactivated by an insertion mutation

The characterization of a PsbTc-truncated mutant photosystem II complex is described.

Complex of human neutrophil elastase with 1/2SLPI

The 1/2SLPI and HNE complex structure was solved at 1.7 Å resolution and compared with the interaction mechanism of elafin.

Crystallization and evaluation of hen egg-white lysozyme crystals for protein pH titration in the crystalline state

Hen egg-white lysozyme was crystallized over a wide pH range (2.5–8.0) and the quality of the crystals was characterized. Crystallization phase diagrams at pH 2.5, 6.0 and 7.5 were determined

Effect of amino acids and amino acid derivatives on crystallization of hemoglobin and ribonuclease A

The effect of the addition of amino acids and amino acid derivatives on the crystallization of hemoglobin and ribonuclease A has been evaluated. The results showed that certain types of additives expand the concentration conditions in which crystals are formed.

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