News & Views

The chemical properties of cytosine present cells with a serious informational ‘disease’, necessitating enzymes with exquisite specificity for deoxyuridine for its prevention and cure.

The structure of a protein–telomere DNA complex from the yeast Saccharamyces cerevisiae suggests a highly conserved mode of telomere recognition.

The crystal structure of the liganded form of a cytochrome c' shows significant structural changes that may be connected with dimer dissociation while NMR studies show how a single electron can cause a large repositioning of a cytochrome P450 substrate.

In a complex RNA, the Tetrahymena ribozyme, folding proceeds by a sequential, hierarchical pathway reminiscent of protein folding pathways.

The first high resolution structures of the kinesin and NCD motor proteins reveal their surprising similarity to myosin but leave open the tantalizing question of what properties determine the directionality of movement along microtubules.

The ATP–Mg²⁺–oxalate ternary complex of Escherichia coli phosphoenolpyruvate carboxykinase shows domain closure on substrate binding, adds a new fold to kinase structures and reveals the first syn conformation of a nucleotide complexed to a protein.

The determination of the three-dimensional structure of the Escherichia coli Lac represser by X-ray crystallography reveals much of the mechanism of action of this historically important molecule.

The solution structure of HIV-1 Nef and mapping of its binding surface for the SH3 domain of a protein tyrosine kinase illustrates how the primate lentiviruses have tapped into host cell activation pathways.

The unusual properties of the Root effect haemoglobins in teleost fish—which allow them to pump O₂ into their swim bladders and eyes against very high pressures—are illuminated in a new fish haemoglobin structure.

The first look at the three-dimensional structure of an essential penicillin binding protein from a human pathogen, and its complex with a β-lactam antibiotic provides hope for the future design of improved antibiotics.

A catalytic transformation of dihydrogen into two protons and two electrons has been discovered with a ruthenium/iron complex. The chemical reactions of complexes between transition metals and dihydrogen give insights into the function of biological hydrogenases.

The first crystal structure of a glycosyl enzyme intermediate provides a detailed look at the mechanism of a glycosidase.

The ligand-binding domain of nuclear receptors appears to contain a common fold that generates a conserved ligand-binding pocket. Their transcriptional activity is induced by ligand through realignment of a Gterminal helix to form a novel interacting surface.

The stuctures of the co-chaperonin GroES and of the GroEL•ATPγS complex raise a host of tantalizing questions and whet the appetite for even more challenging structures, the various GroEL•nucleotide•GroES complexes which facilitate folding.

The crystal structure of a 92,000 M_r fragment of yeast DNA topoisomerase II suggests how the enzyme can facilitate the passage of one segment of duplex DNA through a double-stranded break in another.

Recent NMR structures of bovine immunodeficiency viral TAR RNA–Tat peptide complexes have revealed a new β-hairpin RNA recognition motif. These complexes exhibit intriguing new variations on the recurring themes in nucleic acid recognition.

Rubisco's CO₂ cofactor is involved in divalent -metal binding, activity regulation and probably also in the catalytic chemistry. Recent studies of the CO₂- and metal-binding site in the absence of phosphorylated ligands provide a structural understanding of the unusual activation mechanism.

The difference in amino-acid sequence and inferred molecular mechanisms between the pair of EF-hands in BM-40 and those of other EF-hand proteins force us to reconsider the evolutionary and functional relationships among the members of this diverse family of proteins.

Human aspartylglucosaminidase belongs to the newly recognized structural superfamily of Ntn aminohydrolases, which are characterized by the use of the side chain of the N-terminal amino acid as the nucleophile in catalysis.

The new refinement of GroEL sharpens the boundary between known and unknown regions of the structure, and raises questions about the treatment of ambiguity in structure determination.