letters to the editor
research papers
With the implementation of a molecular-replacement likelihood target that accounts for translational noncrystallographic symmetry, it became possible to solve the crystal structure of a protein with seven tetrameric assemblies arrayed translationally along the c axis. The new algorithm found 56 protein molecules in reduced symmetry (P1), which was used to resolve space-group ambiguity caused by severe twinning.
research papers
The structure of a peptide–peptoid analogue inhibitor was determined by X-ray crystallography. It is the first structure to reveal the structural basis of the complete proteolytic resistance towards serine proteases by inhibitors containing a peptoid residue at the P1 position.
research papers
Three crystal structures of potassium-dependent plant L-asparaginase were solved in complexes with K+, with Na+ and with both cations. A novel alkali metal-binding loop Val111–Ser118 (the activation loop) changes its conformation upon K+/Na+ exchange, leading to a reconfiguration of three key residues, His117, Arg224 and Glu250 (the catalytic switch), to allow or prevent substrate binding in the active site of the enzyme.
research papers
Two plant cytokinin-specific binding proteins were crystallized in complex with gibberellic acid (GA3), which is an entirely different plant hormone. The crystal structures, determined at high resolution, reveal a highly specific mode of GA3 binding, calling for a revision of the hormone specificity of plant proteins with the PR-10 fold.
research papers
Atomic resolution structures of cytochromes c6 and c6C from Synechococcus sp. PCC 7002 as well as their haem-pocket point mutants are presented. The biophysical and structural properties of these proteins have been characterized with particular focus on the relationship between the structure of the haem-binding pocket and the redox potential.
research papers
An algorithm is proposed for selecting a unique description of macromolecular crystal structures. It is recommended that authors use the procedure before deposition and publication, so that crystal structures are easier to interpret and compare by noncrystallographers.