News & Comment

The 2.7 Å structure of the tetanus neurotoxin receptor binding fragment H_C reveals a jelly-roll domain and a β-trefoil domain. H_C retains the unique transport properties of the holotoxin and is capable of eliciting a protective immunological response against the full length holotoxin.

A combination of equilibrium amide exchange and kinetic folding data show that the essential features of the complex topology of the N-terminal domain of a thermophilic phosphoglycerate kinase are established on a millisecond or faster timescale, before the rate-limiting step in the folding pathway commences.

The structure of a conserved hairpin loop involved in peptidyl–tRNA recognition by SOS ribosomal subunits has been solved by NMR. The loop is closed by a novel G–C base pair and presents guanine residues for RNA recognition.

Amaranthus caudatus agglutinin contains a novel arrangement of four β-trefoil domains. The sugar-binding site provides specificity for the carcinoma-associated T-antigen disaccharide even when ‘masked’ by other sugars.

NK-lysin is the first representative of a family of sequence related proteins — saposins, surfactant-associated protein B, pore forming amoeba proteins, and domains of acid sphingomyelinase, acyloxyacylhydrolase and plant aspartic proteinases — for which a structure has been determined.

Staurosporine exhibits nanomolar IC₅₀ values against a wide range of protein kinases. The structure of a CDK2 strauroporine complex explains the tight binding of this inhibitor, and suggests features to be exploited in the design of specific inhibitors of CDKs.

Spermadhesins, 12,000–14,000 M_r mammalian proteins, include lectins involved in sperm–egg binding and display a single CUB domain architecture. We report the crystal structures of porcine seminal plasma PSP-I/PSP-II, a heterodimer of two glycosylated spermadhesins, and bovine aSFP at 2.4 Å and 1.9 Å resolution respectively.

RhoA, a ubiquitous intracellular GTPase, mediates cytoskeletal responses to extracellular signals. A 2.1 Å resolution crystal structure of the human RhoA–GDP complex shows unique stereochemistry in the switch I region, which results in a novel mode of Mg2+ binding.

The structure of the N-terminal actin binding domain of human f imbrin offers the first view of an F-actin crosslinking protein and is representative of the conserved actin binding domain found in the largest family of crosslinking proteins. This domain is composed of two calponin homology domains and allows for the mapping of residues implicated in F-actin binding.

The structure and dynamics of the first KH domain of FMR1 — the protein responsible for fragile X syndrome — reveal that an exposed loop is highly flexible despite containing a GxxG motif that is well conserved throughout the KH family. We suggest that this region provides a putative binding surface for RNA recognition.

RasGAPs supply a catalytic residue, termed the arginine finger, into the active site of Ras thereby stabilizing the transition state of the GTPase reaction and increasing the reaction rate by more than one thousand-fold, in good agreement with the structure of the RasṁRasGAP complex.

Combined kinetic and cryo-EM analysis of the R197A mutant of GroEL provides insight into the allosteric switching of GroEL, which is at the heart of the chaperonin mechanism.

The solution structure of the Ras-binding domain (RBD) of Ral guanine-nucleotide exchange factor RalGEF was solved by NMR spectroscopy. The overall structure is similar to that of Raf-RBD, another effector of Ras, although the sequence identity is only 13%. 1SN chemical shifts changes in the complex of RalGEF-RBD with Ras indicate an interaction similar to the intermolecular β-sheet observed for the complex between Ras and Raf-RBD.