Crystals on the cover 2015

Crystals on the cover of Acta Cryst. F.

A comprehensive review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes

A comprehensive and up-to-date review of the lipid cubic phase or in meso method for crystallizing membrane and soluble proteins and complexes is reported. Recent applications of the method for in situ serial crystallography at X-ray free-electron lasers and synchrotrons are described.

Zinc-substituted pseudoazurin solved by S/Zn-SAD phasing

The Cu²⁺ ion of the blue copper protein pseudoazurin from A. faecalis was replaced by a Zn²⁺ ion and the resulting protein was phased by SAD using the anomalous signal of the S and Zn atoms. The Zn²⁺ ion lies closer to the plane of its strong ligand atoms (His40 N^δ1, Cys78 S^γ and His81 N^δ1) and attracts its axial ligand Met86 S^δ closer.

Expression, purification, crystallization and preliminary X-ray crystallographic analysis of the histone-like HU protein from Spiroplasma melliferum KC3

The HU protein from the parasitic mycoplasma S. melliferum KC3 was cloned, overexpressed in E. coli and purified. Crystals of the protein that diffracted to 1.36 Å resolution were obtained for the first time.

Protein purification, crystallization and preliminary X-ray diffraction analysis of L-arabinose isomerase from Lactobacillus fermentum CGMCC2921

L-Arabinose isomerase from L. fermentum CGMCC2921 was heterologously expressed, purified and crystallized, and preliminary X-ray diffraction analysis was successfully carried out.

Structures of Drosophila melanogaster Rab2 and Rab3 bound to GMPPNP

Crystal structures of Rab2 and Rab3 from D. melanogaster in complex with GMPPNP are presented.

Expression and crystallization of a bacterial glycoside hydrolase family 116 β-glucosidase from Thermoanaerobacterium xylanolyticum

A thermostable glycoside hydrolase family 116 β-glucosidase from T. xylanolyticum was expressed in E. coli, purified and crystallized. The crystal diffracted to 3.15 Å resolution with P2₁ symmetry.

Crystallization and preliminary crystallographic studies of a novel noncatalytic carbohydrate-binding module from the Ruminococcus flavefaciens cellulosome

A novel carbohydrate-binding module (CBM-Rf6A) of a modular family 9 glycoside hydrolase from R. flavefaciens was purified and crystallized, and data were collected for the native protein and a selenomethionine derivative to 1.75 and 1.5 Å resolution, respectively. The crystals belonged to orthorhombic and cubic space groups, respectively, and the structure was solved by a single-wavelength anomalous dispersion experiment.

Purification, crystallization and preliminary crystallographic analysis of DR0248, an MNT–HEPN fused protein from Deinococcus radiodurans

DR0248, a MNT–HEPN fused protein from D. radiodurans, was expressed, purified and crystallized in two crystal forms. MAD phases were obtained from zinc identified in the protein by X-ray fluorescence.

Overexpression, purification, crystallization and preliminary X-ray crystallographic analysis of SF173 from Shigella flexneri

This article describes the preliminary crystallographic data of SF173 from Shigella flexneri.

Crystallization and preliminary X-ray analysis of the type IV restriction endonuclease ScoMcrA from Streptomyces coelicolor, which cleaves both Dcm-methylated DNA and phosphoro­thioated DNA

The type IV restriction endonuclease ScoMcrA, which cleaves both Dcm-methylated DNA and phosphorothioated DNA, was crystallized and the crystals diffracted to 3.35 Å resolution. The space group and the unit-cell parameters were determined.

Expression, purification and crystallization of a membrane-associated, catalytically active type I signal peptidase from Staphylococcus aureus

The type I signal peptidase from S. aureus Newman strain was crystallized as a fusion protein with maltose-binding protein. Preliminary X-ray data showed that the crystals diffracted to 2.05 Å resolution.

Three-dimensional structure of a variant `Termamyl-like' Geobacillus stearothermophilus α-amylase at 1.9 Å resolution

The three-dimensional single-crystal X-ray structure of a thermally stable and industrially relevant bacterial α-amylase variant has been determined at 1.9 Å resolution.

Crystallization and preliminary X-ray analysis of the C-terminal fragment of PorM, a subunit of the Porphyromonas gingivalis type IX secretion system

Crystals of the C-terminal part of PorM obtained by limited proteolysis of the purified recombinant protein and grown from PEG solutions were tetragonal (space group P4₃2₁2) and diffracted to 2.85 Å resolution.

Systematic analysis of protein–detergent complexes applying dynamic light scattering to optimize solutions for crystallization trials

Application of in situ dynamic light scattering to solutions of protein–detergent complexes permits characterization of these complexes in samples as small as 2 µl in volume.

Crystallization and preliminary X-ray crystallographic analysis of the CARD domain of apoptosis repressor with CARD (ARC)

The CARD domain of apoptosis repressor with CARD (ARC) was purified and crystallized. Crystals were obtained at 293 K and diffracted to a resolution of 2.1 Å; they belonged to space group P6₁ or P6₅, with unit-cell parameters a = 98.28, b = 98.28, c = 51.86 Å, α = 90, β = 90, γ = 120°.

Structures of the N-acetyltransferase domain of Xylella fastidiosa N-acetyl-L-glutamate synthase/kinase with and without a His tag bound to N-acetyl-L-glutamate

Structures of the catalytic N-acetyltransferase (NAT) domain of the bifunctional N-acetyl-L-glutamate synthase/kinase (NAGS/K) from Xylella fastidiosa bound to N-acetyl-L-glutamate (NAG) with and without an N-terminal His tag have been solved and refined at 1.7 and 1.4 Å resolution, respectively.

Crystallization and preliminary X-ray analysis of the NAD⁺-reducing [NiFe] hydrogenase from Hydrogenophilus thermoluteolus TH-1

An NAD⁺-reducing [NiFe] hydrogenase was purified and crystallized. An X-ray diffraction data set was collected to a resolution of 2.58 Å.

Cleaning protocols for crystallization robots: preventing protease contamination

A protease in the common commercial enzyme cleaner Zymit used for the cleaning of crystallization robots cannot be completely inactivated by EDTA.

Purification, crystallization and preliminary X-ray diffraction analysis of SpaD, a backbone-pilin subunit encoded by the fimbrial spaFED operon in Lactobacillus rhamnosus GG

SpaD, a backbone-pilin fragment from L. rhamnosus GG, was crystallized and X-ray diffraction data were collected to a resolution of 2.0 Å. In-house iodide-derivative data were collected to 2.2 Å resolution for phase determination by the single-wavelength anomalous dispersion method.

Purification, crystallization and preliminary X-ray crystallographic studies of Rv3899c from Mycobacterium tuberculosis

The cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of Rv3899c from M. tuberculosis are described.

Cloning, expression, refolding, purification and preliminary crystallographic analysis of the sensory domain of the Campylobacter chemoreceptor for aspartate A (CcaA)

A periplasmic sensory domain of the C. jejuni chemoreceptor for aspartate A (CcaA) has been purified and crystallized by the hanging-drop vapour-diffusion method. A diffraction data set has been collected to 1.4 Å resolution.

The three-dimensional structure of the cellobio­hydrolase Cel7A from Aspergillus fumigatus at 1.5 Å resolution

The structure of an industrially important thermally stable cellulase, A. fumigatus cellobiohydrolase I, has been solved in apo and product-complex forms at 1.8 and 1.5 Å resolution, respectively.