Celebrating biological crystallography: Acta D twenty years on

Editorial.

Placement of molecules in (not out of) the cell

The importance of presenting macromolecular structures in unified, standard ways is discussed.

A novel crystal form of pyrrolysyl-tRNA synthetase reveals the pre- and post-amino­acyl-tRNA synthesis conformational states of the adenylate and amino­acyl moieties and an asparagine residue in the catalytic site

Structural snapshots of the pre- and post-aminoacyl-tRNA synthesis stages have been captured by X-ray crystallography of a novel crystal form of pyrrolysyl-tRNA synthetase.

Structure and activity of the Streptococcus pyogenes family GH1 6-phospho-β-glucosidase SPy1599

The S. pyogenes ORF SPy1599, classified into CAZy family GH1, has been shown to display 6-phospho-β-glucosidase activity through a series of kinetics studies on aryl glycosides. The three-dimensional structure has been solved at 2.5 Å resolution from both twinned and untwinned crystal forms.

Structure of Gentlyase, the neutral metalloprotease of Paenibacillus polymyxa

The crystal structure of the metalloprotease Gentlyase is described and compared with the structures of other related thermolysin-like proteases.

Structures of aminophenol dioxygenase in complex with intermediate, product and inhibitor

Crystal structures of 2-amino­phenol 1,6-dioxygenase, an enzyme that represents a minor group of extradiol dioxygenases and that catalyses the ring opening of 2-aminophenol, in complex with the lactone intermediate (4Z,6Z)-3-iminooxepin-2(3H)-one and the product 2-aminomuconic 6-semialdehyde and in complex with the suicide inhibitor 4-nitrocatechol are reported.

The structure of the de­acetylase domain of Escherichia coli PgaB, an enzyme required for biofilm formation: a circularly permuted member of the carbohydrate esterase 4 family

Biofilm is an extracellular matrix created by many microorganisms, and a major problem in clinical and technical settings. The crystal structure reported here helps elucidate the synthesis of the major component of biofilm produced by Y. pestis and E. coli, and may assist in the development of agents to block it.

Structures of an active-site mutant of a plant 1,3-β-glucanase in complex with oligosaccharide products of hydrolysis

Two crystal structures of a plant endo-1,3-β-glucanase representing glycoside hydrolase family GH17 in complexes with products of laminarahexose hydrolysis reveal the protein–saccharide interactions at five key binding subsites for the first time. A trisaccharide is bound at subsites −3, −2 and −1 of the nonreducing end (glycon portion) in both structures, and in one structure an extra tetrasaccharide is bound at subsites +1 to +4 of the reducing end (aglycon portion).

The structure of a novel glucuronoyl esterase from Myceliophthora thermophila gives new insights into its role as a potential biocatalyst

The crystal structures of an M. thermophila glucuronoyl esterase (StGE2) and of its S213A mutant in the unliganded form and in complex with methyl 4-O-methyl-β-D-glucopyranuronate determined at 1.55, 1.90 and 2.35 Å resolution, respectively, are presented for the first time, disclosing the role of StGE2 as a potential biocatalyst.

Polarization-resolved second-harmonic generation microscopy as a method to visualize protein-crystal domains

Polarization-resolved second-harmonic generation microscopy is applied to the identification of multiple crystalline domains within protein-crystal samples.

High-resolution structures of AidH complexes provide insights into a novel catalytic mechanism for N-acyl homoserine lactonase

Crystal structures of the AHL-lactonase AidH in complex with substrate and product are reported at high resolution and a catalytic mechanism is proposed for the metal-independent AHL-lactonase.

Structure of a C-terminal AHNAK peptide in a 1:2:2 complex with S100A10 and an acetylated N-terminal peptide of annexin A2

Structure of a 20-amino-acid peptide of AHNAK bound asymmetrically to the AnxA2–S100A10A heterotetramer (1:2:2 symmetry) provides insights into the atomic level interactions that govern this membrane-repair scaffolding complex.

Structure and ligand-binding properties of the biogenic amine-binding protein from the saliva of a blood-feeding insect vector of Trypanosoma cruzi

Biogenic amine-binding proteins mediate the anti-inflammatory and antihemostatic activities of blood-feeding insect saliva. The structure of the amine-binding protein from R. prolixus reveals the interaction of biogenic amine ligands with the protein.

Structural characterization of Spinacia oleracea trypsin inhibitor III (SOTI-III)

The crystal structure of SOTI-III in complex with bovine pancreatic trypsin has been solved to 1.7 Å resolution.

The crystal structure analysis of the relative binding of cisplatin and carboplatin in a mixture with histidine in a protein studied at 100 and 300 K with repeated X-ray irradiation

The anticancer agents cisplatin and carboplatin bind to a free histidine in a protein. This crystal structure study at data-collection temperatures of 100 and 300 K examines their relative binding affinities to a histidine side chain and the effect of a high radiation dose on the stability of the subsequent protein–Pt adducts. Cisplatin binding is visible and carboplatin binding is not, indicating stronger binding of cisplatin.

Adenosine kinase from Schistosoma mansoni: structural basis for the differential incorporation of nucleoside analogues

The structural basis for differential nucleoside-analogue incorporation by S. mansoni and human adenosine kinase is revealed.

Selective X-ray-induced NO photodissociation in haemoglobin crystals: evidence from a Raman-assisted crystallographic study

NO photodissociation in a tetrameric haemoglobin has been detected via Raman microscopy on protein single crystals during X-ray diffraction data collection at different radiation doses.