A structural view of the dissociation of Escherichia coli tryptophanase

A study using the multimeric enzyme tryptophanase as a model and crystal structure analysis suggests a structural view of protein–protein interaction and of the mechanism of dissociation at the molecular level.

Unravelling the shape and structural assembly of the photosynthetic GAPDH–CP12–PRK complex from Arabidopsis thaliana by small-angle X-ray scattering analysis

The structure and the assembly process of the photosynthetic GAPDH–CP12–PRK complex and its single components, i.e. PRK and the GADPH–CP12 complex, from A. thaliana have been investigated by small-angle X-ray scattering.

Sent packing: protein engineering generates a new crystal form of Pseudomonas aeruginosa DsbA1 with increased catalytic surface accessibility

The crystal structure of a P. aeruginosa DsbA1 variant is more suitable for fragment-based lead discovery efforts to identify inhibitors of this antimicrobial drug target. In the reported structures the active site of the protein can simultaneously bind multiple ligands introduced in the crystallization solution or via soaking.

X-ray-induced catalytic active-site reduction of a multicopper oxidase: structural insights into the proton-relay mechanism and O₂-reduction states

12 crystallographic structures of T. thermophilus HB27 multicopper oxidase in holo, apo and Hg-bound forms and with different absorbed X-ray doses are reported, revealing the first structural evidence for the proton-relay mechanism in the X-ray-induced reduction of O₂ to 2H₂O at the trinuclear copper cluster of the enzyme. Different O₂-reduction states and a total depletion of T2Cu at radiation doses higher than 0.2 MGy were also observed.

Small-angle scattering determination of the shape and localization of human cytochrome P450 embedded in a phospholipid nanodisc environment

A combined ab initio and rigid-body approach has been developed for small-angle scattering analysis. This provides a previously inaccessible insight into the low-resolution structure of the human cytochrome P450 CYP3A4 when embedded in nanodiscs mimicking a native membrane.

An enzyme captured in two conformational states: crystal structure of S-adenosyl-L-homocysteine hydrolase from Bradyrhizobium elkanii

S-Adenosyl-L-homocysteine hydrolase from a nitrogen-fixing bacterium was crystallized as a biologically relevant homotetramer composed of subunits in different conformational states. While three of them are in the Ado product-bound closed conformation, the fourth is empty and open.

Structure–function relationships in Gan42B, an intracellular GH42 β-galactosidase from Geobacillus stearothermophilus

The crystal structure of the GH42 β-galactosidase Gan42B from G. stearothermophilus has been determined in its wild-type form (2.45 Å resolution) and its nucleophile catalytic mutant (E323A; 2.50 Å resolution). These structures show that the Gan42B protein is a homotrimer in which the three active sites are formed at the interfaces between each pair of monomers that build it, all facing a cone-shaped internal cavity.

Crystal structure and kinetic studies of a tetrameric type II β-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae

The kinetic characterization and the crystal structure of the recombinant type II β-CA from V. cholerae determined to a resolution of 1.9 Å with a closed active-site configuration are reported.

Octameric structure of Staphylococcus aureus enolase in complex with phosphoenolpyruvate

Non-ligand-bound and PEP-bound structures of S. aureus enolase (Sa_enolase) were solved, and catalytic loop 1 in the PEP-bound structure was found to show both `open' and `closed' conformations. Structural and biochemical results indicate that octamerization is required for substrate binding and catalysis by Sa_enolase.

Sequence-dependent structural changes in a self-assembling DNA oligonucleotide

The X-ray crystal structure of a self-assembling DNA 14-mer containing a tertiary-structural mimic of tandem G–A base pairs is reported.

Structural characterization of a mitochondrial 3-keto­acyl-CoA (T1)-like thiolase from Mycobacterium smegmatis

The crystal structures of a T1-like thiolase from M. smegmatis in three apo forms and one liganded form reveal an asymmetric tetrameric organization and a novel substrate-specificity pocket.

Atomic resolution crystal structure of Sapp2p, a secreted aspartic protease from Candida parapsilosis

The crystal structure of the secreted aspartic protease Sapp2p from C. parapsilosis at an atomic resolution of 0.825 Å, the highest resolution aspartic protease structure deposited in the PDB to date, is reported.

The first crystal structure of the peptidase domain of the U32 peptidase family

The first crystal structure of a U32 peptidase domain shows a TIM barrel-type architecture with an extended β7–β8 connection. There are no discernible motifs that are suitable for catalysing peptide-bond hydrolysis.

Serial crystallographic analysis of protein isomorphous replacement data from a mixture of native and derivative microcrystals

Serial crystallography enables the extraction/purification of single-phase subsets from a mixture of multiphase diffraction snapshots.

Native sulfur/chlorine SAD phasing for serial femtosecond crystallography

Sulfur SAD phasing facilitates the structure determination of diverse native proteins using femtosecond X-rays from free-electron lasers via serial femtosecond crystallography.

Structural insights into the synthesis of FMN in prokaryotic organisms

The FAD synthetase from C. ammoniagenes (CaFADS) is a bifunctional enzyme that folds into two almost independent modules. Binding of ligands to its individually expressed C-terminal riboflavin kinase (RFK) module triggers important structural changes. Their evaluation provides structural insights into the conformational changes that take place during the RFK catalytic cycle of CaFADS.