Editorial

Notes for Authors

On the application of one-wavelength anomalous scattering. IV. The absolute configuration of the anomalous scatterers

It is shown that from a Fourier map calculated using anomalous intensity differences the absolute configuration of the anomalous scatterers, and hence of the complete structure, may be determined.

MAD phasing: Bayesian estimates of F_A

A Bayesian approach is applied to the calculation of Patterson functions and cross-Fourier maps in the analysis of multi-wavelength anomalous-diffraction (MAD) data.

MAD phasing: treatment of dispersive differences as isomorphous replacement information

A framework analogous to that used for the analysis of data in the method of isomorphous replacement is applied to the analysis of multi-wavelength anomalous-diffraction (MAD) data.

Cross-validation tests of time-averaged molecular dynamics refinements for determination of protein structures by X-ray crystallography

Using crystallographic cross-validation it is shown that time-averaged ensembles of protein structures overfit data unless individual B values are retained on atoms throughout the refinement. Ensembles refined with B values yield genuinely low R values as well as valuable information about conformational substates not present in a single refined structure.

Crystallization and preliminary crystallographic data for the azurin mutant End-121 from Pseudomonas aeruginosa

Preliminary crystallographic data are reported on the azurin mutant where residues Met121 to Lys128 have been deleted.

Structure of chicken skeletal muscle troponin C at 1.78 Å resolution

1.78 Å resolution refinement of chicken skeletal muscle troponin C reveals a bound sulfate ion and five side chains with two discrete conformations.

Structure of the recombinant Paramecium tetraurelia calmodulin at 1.68 Å resolution

Highest resolution CaM structure from rPCaM reveals that all central helix hydrogen bonds are intact, the D-E linker C=O groups are girdled by water molecules and the mini β-sheets in both domains are extended by water bridges.

Crystallization of two monoclonal Fab fragments of similar amino-acid sequence bound to the same area of horse cytochrome c and interacting by potentially distinct mechanisms

The preparation of Fab fragments of two monoclonal antibodies specific for the same site on horse cytochrome c is described. In addition, the conditions for crystallization of Fab-cytochrome c complexes are presented along with the results of preliminary X-ray diffraction studies.

Isomorphous binding of mercury-substituted thiosaccharides to pertussis toxin crystals yields crystallographic phases

The affinity of pertussis toxin for sialic acid has been used to design a thiosaccharide with a covalently bound Hg atom suitable for use as a heavy-atom isomorphous derivative.

Crystal structure of chloromuconate cycloisomerase from Alcaligenes eutrophus JMP134 (pJP4) at 3 Å resolution

The structure of chloromuconate cycloisomerase. a chloride-eliminating enzyme, was determined at 3 Å resolution and compared with that of the homologous muconate cycloisomerase to reveal the reasons for the altered substrate specificity. Differences were found in polarity, accessibility and hydrogen-bonding potential.

Comparison of two crystal structures of TGF-β2: the accuracy of refined protein structures

Two independently determined crystal structures of TGF-β2 have been compared and the results are used to evaluate several error assessment methods including a new local error estimation method using Cruickshank's formula.

X-ray analysis of metal-substituted human carbonic anhydrase II derivatives

The natural zinc ion in carbonic anhydrase II was replaced with various other metals. Tetrahedral coordination was observed only for the active metals zinc and cobalt, and higher coordination for the inactive metals.

Wild-type and E106Q mutant carbonic anhydrase complexed with acetate

Wild-type carbonic anhydrase II and mutant ElO6Q were found to bind acetate differently. In the mutant acetate is coordinated to the zinc ion but not in the wild-type enzyme.

Crystallization and preliminary X-ray diffraction studies of the bacteriophage Qβ

Crystals of bacteriophage Qβ have been obtained by the vapour-diffusion technique. The crystal space group is C222₁ with the unit-cell parameters a = 478, b = 296, c = 477 Å, α = β = γ = 90°.

Crystallization and preliminary X-ray studies on the mannose-specific lectin from Amaryllis bulbs

Monoclinic crystals of a 14 kDa mannose-specific protein from Amaryllis bulbs were obtained by the hanging-drop method and diffract to 2.25 Å resolution.

Crystallization of nucleic acids and proteins: a practical approach edited by A. Ducroix and R. Giegé

Restructuring of the IUCr editorial office