Nucleation precursors in protein crystallization

The properties of the mesoscopic protein-rich clusters, within which protein crystal nuclei form, are reviewed. The cluster populations occupy from 10⁻⁷ to 10⁻³ of the solution volume; the cluster radii are of order 100 nm; the clusters exist owing to the formation of transient oligomers that, for some proteins, may be due to conformational flexibility.

A 2.2 Å resolution structure of the USP7 catalytic domain in a new space group elaborates upon structural rearrangements resulting from ubiquitin binding

New crystallization conditions for the catalytic domain of human ubiquitin specific protease 7 (USP7_CD) were found that produced crystals in space group C2 with one molecule in the asymmetric unit which is an advantage over previous crystallization conditions of USP7_CD which produced crystals in space group P2₁ with two molecules in the asymmetric unit. Comparison of the refined structure of USP7_CD in space group C2 with that of P2₁ suggests that conformational rearrangement of blocking loop residues 410–419 must occur in order for ubiquitin to bind and that the catalytic triad and switching loop region are in the same catalytically unproductive conformations as in the P2₁ structure in the absence of ubiquitin.

The 2.2 Å resolution structure of the catalase-peroxidase KatG from Synechococcus elongatus PCC7942

The crystal structure of the catalase-peroxidase KatG from S. elongatus PCC 7942 was determined at 2.2 Å resolution.

Structure of Aurora B–INCENP in complex with barasertib reveals a potential transinhibitory mechanism

Two structures of Aurora B kinase bound to the specific inhibitor barasertib and to a nonhydrolyzable nucleotide provide evidences for a potential transinhibitory mechanism.

Structure of human farnesyl pyrophosphate synthase in complex with an amino­pyridine bis­phosphonate and two molecules of inorganic phosphate

A co-crystal structure of human farnesyl pyrophosphate synthase in complex with an aminopyridine bisphosphonate, YS0470, and two molecules of inorganic phosphate has been determined. The identity of the phosphate ligands was confirmed by anomalous diffraction data.

A range of C∊3–C∊4 interdomain angles in IgE Fc accommodate binding to its receptor CD23

The structure of a new crystal form of IgE-Fc in complex with its B-cell receptor CD23 has been determined. The structure reveals that there is conformational variability at the interface in both IgE-Fc and CD23.

Crystallization and preliminary X-ray diffraction analysis of the amidase domain of allophanate hydrolase from Pseudomonas sp. strain ADP

The amidase domain of the allophanate hydrolase AtzF from Pseudomonas sp. strain ADP has been crystallized and preliminary X-ray diffraction data have been collected.

Cloning, expression, purification, crystallization and X-ray crystallographic analysis of β-keto­thiolase B from Ralstonia eutropha H16

β-Ketothiolase B from R. eutropha, an enzyme involved in polyhydroxyalkanoate synthesis, has been crystallized and X-ray diffraction data have been collected from the crystal and analyzed.

Purification, crystallization and preliminary crystallographic analysis of the catalytic core of cysta­thionine β-synthase from Saccharomyces cerevisiae

The purification, crystallization and preliminary crystallographic analysis of the catalytic core of cystathionine β-synthase (CBS) from Saccharomyces cerevisiae is reported.

Crystallization of the N-terminal regulatory domain of the enhancer-binding protein FleQ from Stenotrophomonas maltophilia

Native and SeMet-labelled FleQ domains of S. maltophilia were crystallized and diffracted to resolutions of 2.08 and 2.58 Å, respectively.

Expression, purification, crystallization and preliminary X-ray diffraction analysis of the pectin methylesterase from the sugar cane weevil Sphenophorus levis

Pectin methylesterase from S. levis was produced, purified and crystallized. This is the first report of an X-ray diffraction study of a recombinant pectinase of animal origin.

Crystallization and preliminary X-ray study of TsiV3 from Vibrio cholerae

Immunity protein TsiV3 from Vibrio cholera has been expressed, purified and crystallized. The crystal belonged to space group P2₁2₁2₁, with unit-cell parameters a = 73.3, b = 78.12, c = 106.18 Å and diffract to 2.55 Å resolution.

Crystallization and preliminary X-ray crystallographic analysis of a putative nonribosomal peptide synthase AmbB from Pseudomonas aeruginosa

A truncated form of AmbB from Pseudomonas aeruginosa that contains a phosphopantetheine binding (PB) domain and a condensation domain has been crystallized and diffraction data were collected to 2.45 Å resolution.

Expression, purification and preliminary crystallographic studies of the C-terminal SH3 domain of human Tks4

The C-terminal Src homology 3 domain of human Tks4 (residues 853–911) was expressed, purified and crystallized, and X-ray diffraction data were collected to 2.3 Å resolution.

Tetartohedral twinning in IDI-2 from Thermus thermophilus: crystallization under anaerobic conditions

Crystals of T. thermophilus IDI-2 obtained under anaerobic conditions (<5 p.p.m. O₂) will be useful in understanding the active-site conformation of the reduced flavin cofactor.

Crystallization and preliminary X-ray analysis of the catalytic domains of Paenibacillus sp. strain FPU-7 cell-surface-expressed chitinase ChiW

The crystallization and preliminary X-ray diffraction analysis of the catalytic domains of cell-surface-expressed chitinase ChiW from Paenibacillus sp. strain FPU-7 are reported.

Purification, crystallization and preliminary X-ray diffraction analysis of the kinase domain of human tousled-like kinase 2

The C-terminal kinase domain of TLK2 (a human tousled-like kinase) has been cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4₁22 and cubic P2₁3.

Crystallization and preliminary X-ray diffraction analysis of the interleukin-3 alpha receptor bound to the Fab fragment of antibody CSL362

The soluble extracellular fragment of the interleukin-3 alpha receptor (IL3Rα) was complexed with the Fab fragment of antibody CSL362 and crystals of the IL3Rα–CSL362 complex were obtained. These crystals belonged to the monoclinic P2₁ space group and diffracted to 2.8 Å resolution at the Australian Synchrotron.

Refolding, crystallization and preliminary X-ray crystallographic studies of the β-barrel domain of BamA, a membrane protein essential for outer membrane protein biogenesis

BamA is a central component of the β-barrel Assembly Machinery complex, and the transmembrane domain of BamA from E. coli is refolded and crystallized at 2.6 Å resolution.

Crystallization and preliminary X-ray diffraction analysis of the diterpene cyclo­octatin synthase (CYC) from Streptomyces sp. LZ35

The expression, purification, crystallization and preliminary crystallographic characterization of the diterpene cyclooctatin synthase (CYC) from Streptomyces sp. LZ35 are reported.

Crystallization and preliminary X-ray analysis of a novel haemagglutinin component of the toxin complex of serotype C Clostridium botulinum

The 33 kDa haemagglutinin subcomponent of the botulinum toxin complex of the unique strain of serotype C Clostridium botulinum was crystallized and X-ray diffraction data were collected to 2.2 Å resolution.

Crystallization and preliminary X-ray diffraction analysis of the Fab portion of the Alzheimer's disease immunotherapy candidate bapineuzumab complexed with amyloid-β

In order to understand the molecular basis of action of the Alzheimer's disease passive immunotherapy candidate bapineuzumab, the Fab fragment of this antibody was crystallized in complexes with Aβ peptides. The best crystals diffracted to a resolution of 2.0 Å (Aβ residues 1–8) and 2.2 Å (Aβ residues 1–28).

Combining secondary-structure and protein solvent-accessibility predictions in me­thionine substitution for anomalous dispersion

A combination of secondary-structure and solvent-accessibility predictions for methionine substitution is a useful method in SAD and MAD phasing