forthcoming articles

The values of anisotropic atomic displacement parameters (ADP) that correspond to concerted motions can be obtained from refined TLS matrices analytically or numerically. A difference between the ADP obtained using these two methods can be used to assess results of TLS refinement.

A new algorithm, MR-REX, has been developed to perform a molecular-replacement search through replica-exchange Monte Carlo simulations. The algorithm enables cooperative rotation and translation searches and simultaneous clash and occupancy optimization, and improves the success rate of molecular replacement on low-accuracy structure models.

The structure of monohaem flavocytochrome c sulfide dehydrogenase co-purified and co-crystallized with the copper-binding protein CopC was solved and refined to 2.6 Å resolution.

Structures of orthorhombic crystals of lysozyme at pH 4.5 show that the binding of phosphate ion produces long-range conformational changes and that low humidity produces a displacement of the fifth α-helix towards the active-site cavity. The interaction of some anions must be considered when analysing experiments with lysozyme at acidic pH values.

To improve the sensitivity of hydrogen detection using neutrons, high-pressure freezing of a relatively larger protein single crystal and the proton polarization of a protein poly crystalline state were demonstrated as preliminary experiments.

Small-angle neutron scattering (SANS) provides structural information on biological macromolecules in solution, perfectly complementary to those obtained by other structural biology techniques, including crystallography, nuclear magnetic resonance (NMR) and electron microscopy (EM). Compared to its sister technique SAXS (small angle X-ray scattering), SANS allows to obtain specific and individual information on subunits within important heterogeneous biological assemblies such as multi-protein or protein-RNA/DNA complexes as well as solubilized membrane proteins.

Three industrially relevant glucoamylase structures have been determined, revealing how the starch-binding module can adopt different orientations relative to the catalytic domain.

A large domain swap encompassing half of the molecule is observed in the crystal structure of the C-terminal domain of human doublecortin. Combined with ultracentrifugation data, the domain swap suggests a mechanism by which doublecortin may cooperatively bind and bundle microtubule fibres.

Recent work applying neutron and X-ray scattering to elucidate molecular mechanisms of volatile anesthetics is reviewed

Using the unique ability of small angle neutron scattering to resolve a hydrogen rich surfactant from a deuterated membrane protein, we reveal the results of removing free surfactant from the equilibrium.

A procedure for optimizing the sharpening of a map based on maximizing the level of detail and connectivity of the map has been developed and applied to 361 pairs of deposited cryo-EM maps and associated models.

Models of crystal structures determined by neutron diffraction deposited in the Protein Data Bank to date were analysed. Lessons learned from this data-mining effort are summarized and suggestions for improvements to the deposition and validation of neutron models are outlined.

An automated data-processing pipeline for protein microcrystals is presented. The processing of multiple small-wedge data sets was made dramatically easier by this pipeline.

Significant improvements to the sample-location, characterization and data-collection algorithms on the autonomous ESRF beamline MASSIF-1 are described. The workflows now include dynamic beam-diameter adjustment and multi-position and multi-crystal data collections.

Microfocus X-ray data collection from 18 non-overlapping regions of a single protein crystal revealed unit-cell non-isomorphism and subtle protein dynamics across the crystal specimen.

The high-resolution crystal structure of a Z. variegatus flavin-dependent monooxygenase is reported at 1.6 Å resolution together with kinetic studies of structure-based protein variants in order to investigate significant differences in enzyme activity between isoforms.

The interaction between the integral membrane protein zinc metalloprotease ZMPSTE24 and the natural product broad-specificity zinc metalloprotease peptidic inhibitor phosphoramidon has been characterized functionally and structurally. The functional results demonstrate the sensitivity of ZMPSTE24 to phosphoramidon in a manner consistent with competitive inhibition, as in soluble zinc metalloproteases, and that the overall mode of binding of phosphoramidon to ZMPSTE24 and soluble zinc metalloproteases, especially gluzincins, is conserved.

Mismatch conformations are dynamic and vary depending on the environment, including restraints imposed by DNA-binding proteins such as apurinic/apyrimidic endonuclease 1 (APE1), a key DNA-repair enzyme. Here, both key insights revealed by X-ray crystallography of APE1 bound to mismatch-containing substrates and the specific challenges associated with elucidating base-pairing properties based on implied protonation states and X-ray crystallographic data alone are highlighted.

The structure of tryptophan indole-lyase with a bound inhibitor, oxindolyl-L-alanine, was determined. The structure provides new insights into the reaction mechanism of the enzyme.

The densities of aqueous solutions of eight common cryoprotectants were measured at T = 77 K and were used to determine electron densities at T = 77 K and thermal contractions on cooling from room temperature. The results provide a quantitative basis for choosing cryoprotectants to optimize outcomes in cryocrystallography, cryo-SAXS, cryogenic temperature X-ray imaging and vitrification-based biological cryopreservation.

A method is presented to simultaneously resolve the crystal symmetry and indexing ambiguity from sparse data sets.

Analysing two sequence-related bacterial glycoside hydrolase family 92 mannosidases with distinct functions, a structural basis for their varied specificities is revealed.

High-resolution crystal structures of closed and open conformations of Mycobacterium smegmatis MabA are reported.

The capabilities of the IMAGINE neutron protein diffractometer at the Oak Ridge National Laboratory High Flux Isotope Reactor and highlights of the first five years of the scientific program are reviewed.