Carbohydrate structure hits the groove

An introduction to the Acta Cryst. F special issue on glycoproteins and protein–carbohydrate complexes in which the contents, the current state of the field and the future of glycan structural biology are briefly discussed.

A perspective on structural and mechanistic aspects of protein O-fu­cosylation

Protein O-fucosyltransferases 1 and 2 perform the same post-transcriptional modification albeit on different substrates. Correct folding of the substrates is essential for protein recognition, and the crystal structures of these proteins have shown the mechanism of how these two proteins are highly specific.

Spin ballet for sweet encounters: saturation-transfer difference NMR and X-ray crystallography complement each other in the elucidation of protein–glycan interactions

Proton-based saturation-transfer difference NMR (STD-NMR) is a technique that has proven to be particularly useful in the elucidation of protein–glycan interactions. This article explains the method for non-NMR spectroscopists and uses a number of crystal structures of viral capsid proteins in complex with respective glycan receptors to compare findings from crystallography and STD-NMR side by side, highlighting the complementary nature of the approaches.

Making glycoproteins a little bit sweeter with PDB-REDO

The results and challenges of carbohydrate handling in the current PDB-REDO databank are discussed.

Conformations of the type-1 lacto-N-biose I unit in protein complex structures

Lacto-N-biose I units in the PDB were investigated. Instances and conformational features of the disaccharide in proteins and enzymes in the PDB from various organisms are reviewed.

Crystal structure of highly glycosylated human leukocyte elastase in complex with an S2′ site binding inhibitor

A novel binding mode of a small-molecule inhibitor of human leukocyte elastase is revealed by its co-crystal structure with the enzyme. In the structure, a comparatively large part of the N-glycan chains attached to the enzyme are visible.

Structure of a Talaromyces pinophilus GH62 arabino­furanosidase in complex with AraDNJ at 1.25 Å resolution

The three-dimensional structure of a fungal arabinofuranosidase from CAZY family GH62 has been solved at 1.25 Å resolution in complex with the bespoke arabinofuranosidase inhibitor AraDNJ, shedding light on the activity of this catalyst in the enzymatic deconstruction of arabinoxylans.

Structural studies of the unusual metal-ion site of the GH124 endoglucanase from Ruminiclostridium thermocellum

The CAZY family GH124 endoglucanase from Ruminiclostridium thermocellum contains an unusual metal-ion site featuring a covalently modified `2-oxohistidine' residue. Atomic resolution (∼1 Å) three-dimensional analyses, in conjunction with ITC and mass spectrometry, show that this metal site can accommodate a diverse array of transition metals, all of which confer a stabilizing effect on the enzyme.

Crystal structure of the effector-binding domain of Synechococcus elongatus CmpR in complex with ribulose 1,5-bis­phosphate

The structure of the effector-binding domain of CmpR in complex with the co-activator ribulose 1,5-bisphosphate is reported, revealing a novel ligand-binding pattern for the LysR-type transcriptional regulator family.

Structure of the GH9 glucosidase/glucosaminidase from Vibrio cholerae

The structure of a Vibrio cholerae `exo'-glycosidase from CAZy family GH9 has been solved at 3.17 Å resolution. Preliminary activity assays show that the enzyme is active towards both chitosan-derived oligosaccharides and β-glucosides.