Structure and mechanism of a type III secretion protease, NleC

The crystal structure of NleC is reported at 1.55 Å resolution. In conjunction with biochemical analyses, the structure reveals that NleC is a member of the zincin zinc protease family and that the configuration of the NleC active site resembles that of the metzincin clan of metallopeptidases.

Exploiting large non-isomorphous differences for phase determination of a G-segment invertase–DNA complex

An accumulation of severely non-isomorphous native data sets using the swelling-and-shrinking method or during search for the isomorphous replacement solutions can be beneficial for phase improvement and perhaps for structure refinement.

Diamonds in the rough: a strong case for the inclusion of weak-intensity X-ray diffraction data

Here, new evidence is provided to show that the inclusion of weak-intensity, high-resolution X-ray diffraction data helps to improve the quality of experimental phases by imposing proper constraints on electron-density models during noncrystallographic symmetry averaging.

Exploiting subtle structural differences in heavy-atom derivatives for experimental phasing

Small differences between heavy-atom derivatives can be exploited to improve the experimental phasing by treating each derivative as an independent SAD data set and combining these data sets with circular permutable pairs of SIR data sets. The basis for this generally applicable approach is that the effective resolution of isomorphous signals between highly isomorphous derivatives is often much higher than the effective resolution of the anomalous signals of individual derivative data sets.