High-resolution structure of a retroviral protease folded as a monomer

The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs.

A thermal stability assay can help to estimate the crystallization likelihood of biological samples

A large-scale study indicates a correlation between thermal stability, as measured using a simplified Thermofluor assay, and crystallization likelihood.

Crystallographic analysis of human hemoglobin elucidates the structural basis of the potent and dual antisickling activity of pyridyl derivatives of vanillin

Pyridyl derivatives of vanillin increase the fraction of the more soluble oxygenated sickle hemoglobin and/or directly increase the solubility of deoxygenated sickle hemoglobin. Crystallographic analysis reveals the structural basis of the potent and dual antisickling activity of these derivatives.

The active conformation of human glucokinase is not altered by allosteric activators

Glucokinase (GK) catalyses the formation of glucose 6-­phosphate from glucose and ATP. Here, the first structures of a GK–glucose complex without activator, of GK–glucose–AMP-PNP and of GK–glucose–AMP-PNP with a bound activator are reported.

PAN-modular structure of microneme protein SML-2 from the parasite Sarcocystis muris at 1.95 Å resolution and its complex with 1-thio-β-D-galactose

The PAN-modular structure of the parasite Sarcocystis murismicroneme protein SML-­2 and of the complex with 1-thio-β-D-galactose SML-­2 was determined by SAD-sulfur phasing. The crystallographic analysis reveals a dimeric lectin structure and the structural basis of the protein's stability in the intestinal tract of intermediate and final hosts, and suggests a role for SML-2 during host-cell invasion.

Structures of Burkholderia thailandensis nucleoside kinase: implications for the catalytic mechanism and nucleoside selectivity

Crystal structures of B. thailandensis nucleoside kinase in complex with various ligands are reported.

Polarizable atomic multipole X-ray refinement: weighting schemes for macromolecular diffraction

The limitations of weighting between the sum of chemical and data-based targets in macromolecular crystallographic refinement based on comparing the gradients or Hessian diagonal terms of the two potential functions are demonstrated, especially in the context of a maximum-likelihood target that is inherently weighted by the model and data errors

Apparent instability of crystallographic refinement in the presence of disordered model fragments and upon insufficiently restrained model geometry

Possible causes of the instability of crystallographic refinement are discussed and a criterion of model convergence is proposed.

A suite of Switch I and Switch II mutant structures from the G-protein domain of FeoB

Five structures of NFeoB mutant proteins from S. thermophilus have been determined and reveal how GTP binding induces domain rearrangements in the protein.

Construct optimization for studying protein complexes: obtaining diffraction-quality crystals of the pseudosymmetric PSPC1–NONO heterodimer

A challenging case of crystallization of a human nuclear protein complex consisting of two very similar proteins is described. We highlight the considerations to be made in construct design to obtain diffraction-quality crystals of multi-domain, multi-subunit proteins.

Human Suv3 protein reveals unique features among SF2 helicases

Crystal structures of the human mitochondrial helicase hSuv3 in complex with AMPPNP and with a short strand of RNA are presented.